SlideShare a Scribd company logo
1 of 12
Download to read offline
2011 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies.
              2011 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies.




International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies

                                  http://www.TuEngr.com, http://go.to/Research




  Prediction of Weld Pool Geometry in Pulsed Current Micro
  Plasma Arc Welding of SS304L Stainless Steel Sheets
                                  a*                           b                            b
  Kondapalli Siva Prasad , Ch. Srinivasa Rao , D. Nageswara Rao

  a
      Department of Mechanical Engineering, Anil Neerukonda Institute of Technology & Sciences, INDIA
  b
      Department of Mechanical Engineering, Andhra University, INDIA


  ARTICLEINFO                          A B S T RA C T
  Article history:                             Pulsed Micro Plasma Arc Welding (MPAW) is a metal
  Received 21 March 2011
  Received in revised form             joining technique widely used in manufacturing of thin sheet
  27 May 2011                          components due to its inherent properties. The weld quality and
  Accepted 13 June 2011                productivity are controlled by the process parameters. The paper
  Available online
  14 June 2011                         discuses about development of mathematical models for weld
  Keywords:                            pool geometry of stainless steel 304L sheets. Design of
  Pulsed Current MPAW,                 experiments based on full factorial design is employed for the
  SS304L,                              development of a mathematical model correlating the important
  ANOVA,                               controlled pulsed MPAW process parameters like peak current,
  Bead Geometry
                                       background current, pulse and pulse width with front width, back
                                       width, front height and back height. The developed mode has
                                       been checked for adequacy based on ANOVA analysis. Weld
                                       bead parameters obtained by the models are found to confirm
                                       actual values with high accuracy. Using these models effect of
                                       pulsed MPAW process parameters on weld pool geometry are
                                       studied.

                                         2011 International Transaction Journal of Engineering, Management, &
                                       Applied Sciences & Technologies.                 Some Rights Reserved.



  1. Introduction  
         The plasma welding process was introduced to the welding industry in 1964 as a method
  of bringing better control to the arc welding process in lower current ranges (Modern
  Application News, 1999 ). Today, plasma retains the original advantages it brought to the

  *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
  kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
  & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.                            325
  Online Available at http://TuEngr.com/V02/325-336.pdf
industry by providing an advanced level of control and accuracy to produce high quality
welds in both miniature and pre precision applications and to provide long electrode life for
high production requirements at all levels of amperage. Plasma welding is equally suited to
manual and automatic applications. It is used in a variety of joining operations ranging from
welding of miniature components to seam welding to high volume production welding and
many others.

    The welding optimization literature frequently reveals correlation among responses.
(D.K.Zhang et.al,2010) studied the influence of welding current, arc voltage, welding speed,
wire feed rate and magnitude of ion gas flow on front melting width, back melting width and
weld reinforcement of Alternating Current Plasma Arc Welding process of LF6 Aluminum
alloy of thickness 3mm using Artificial Neural Network- Back Propagation algorithm.
(Sheng-Chai Chi et. al ,2001) developed an intelligent decision support system for Plasma
Arc Welding of stainless steel plates of thickness range from 3 to 9 mm based on fuzzy Radial
Basis Function (RBF) neural network by performing experiments using Taguchi method. (Y.
F. Hsiao et. Al,2008) studied the optimal parameters process of plasma arc welding of SS316
of thickness 4mm by Taguchi method with Grey relational analysis is studied. Torch stand-
off, welding current, welding speed and plasma gas flow rate (Argon) were chosen as input
variables and welding groove root penetration, welding groove width, front-side undercut
were measured as output parameters. (K.Siva et.al, 2008) used central composite rotatable full
factorial design matrix and conducted experiments in optimization of weld bead geometry in
Plasma arc hardfaced austenitic stainless steel plates using Genetic Algorithm.
(A.K.Lakshminarayan et.al, 2008) predicted the Dilution of Plasma Transferred Arc
Hardfacing of Stellite on Carbon Steel using Response Surface Methodology (RSM). (V
Balasubramanian et.al, 2009) used Response Surface Methodology to predict and optimize the
percentage of dilution of iron-based hardfaced surface produced by the Plasma transferred arc
welding process.

    From the earlier works, it has been observed that much work is not reported so far to
investigate the effect of pulsed current MPAW process parameters on stainless steel weld
characteristics; and developing the related mathematical models to predict the same especially
for welding of thin stainless steel sheets. Hence an attempt was made to correlate important
pulsed MPAW process parameters to bead geometry of thin AISI 304L stainless steel welds


    326         K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
by developing mathematical models. The models developed will be very useful to predict the
weld pool geometry parameters for desired bead geometry. A statistically designed
experiment based on full factorial design has employed for the development of mathematical
models (Montgomery DC ,2005).




                              Figure 1: Typical weld pool geometry.


2. Experimental procedure 
     Austenitic stainless steel sheets of type AISI 304L 100×50×0.25 mm are welded
autogenously with square butt joint without edge preparation. To evaluate the quality of
MPAW welds, measurements of the front width, back width, front height and back height of
the weld pool are considered. Figure 1 indicates the typical weld pool geometry. Table 1
indicates the chemical composition of AISI 304L stainless steel sheet. Experiments are
conducted using the Pulsed Micro Plasma Arc Welding (MPAW) process with pulse DCEN.
Industrial pure and commercial grade argon gases are used for shielding and back purging,
respectively. Automatic voltage control available in the welding equipment is used. Fixture
variation effects are not considered as the same setup has been used throughout the
experiment. Some of the welding process parameters are fixed based on earlier work and also
from the trial run so as to obtain full penetration weld. Trial runs are conducted to find the
limits of each controllable process parameter so as to obtain full penetration weld, free from
any visible defects. Because of computational ease and enhanced interpretability of the
models, parameters are converted to coded form for developing mathematical models
(Giridharan PK et.al, 2007). The upper limit of a factor is coded as +1 and the lower limit as
*Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
& Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.          327
Online Available at http://TuEngr.com/V02/325-336.pdf
−1. Table 2 represents the levels determined for process variables with their levels, units and
notations for the pulsed MPAW process. Table 3 represents the fixed pulsed MPAW process
parameters and their values.

         Table 1: Chemical composition of austenitic stainless steel (AISI 304L) sheet.
Elements      Chromium       Silicon        Nickel        Carbon       Manganese     Iron

% by            18.2%           0.5%          8.5%          0.015%        1.6%         Balance
weight


                              Table 2: Input variables and their levels
                                                                     Levels
                 SI No       Input Factor     Units          -1         +1
                 1           Peak Current     Amps           6.5        7.5
                 2           Back Current     Amps           3.5        4.5
                 3           Pulse            No’s /Sec      30         50
                 4           Pulse width      %              40         60


              Table 3: Fixed pulsed MPAW process parameters and their values.

                     Power source                    Secheron Micro Plasma Arc Machine
                                                         (Model: PLASMAFIX 50E)
               Polarity                                   DCEN
               Mode of operation                          Pulse mode
               Electrode                                  2% thoriated tungsten electrode
               Electrode Diameter                         1mm
               Plasma gas                                 Argon & Hydrogen
               Plasma gas flow rate                       6 Lpm
               Shielding gas                              Argon
               Shielding gas flow rate                    0.4 Lpm
               Purging gas                                Argon
               Purging gas flow rate                      0.4 Lpm
               Copper Nozzle diameter                     1mm
               Nozzle to plate distance                   1mm
               Welding speed                              260mm/min
               Torch Position                             Vertical
               Operation type                             Automatic

    From the Design of Experiments and due to wide range of input process parameters, the
present work is limited to use four factors, two levels, full factorial design matrix in order to
simplify the present problem. Table 4 shows the measured values of output response by
taking an average value of three samples of 16 sets of coded conditions used in the form of
design matrix. The 16 experiments have been formulated as per 24 (two levels and four
factors) factorial design.

    328          K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
3. Recording the Responses 
     Three samples are cut from the welded specimens at an interval of 25mm and mounted in
Bakelite powder, polished and etched with Oxalic acid as per ASTM E3 and ASTM E340.
Weld pool geometries are measured using Metallurgical Microscope make Dewinter
Technologie, Model No. DMI-CROWN-II. Figure 2 represents the Photomacrographs of a
typical weld specimen showing the bead profile at 100X magnification.




                     Figure 2: Photomacrographs of a typical weld specimen.

            Table 4: Welding parameters and responses for the full factorial design.
   Exp      Peak         Back        Pulse    Pulse    Front        Back        Front       Back
   No      Current      Current       (P)     Width    Width        Width       Height      Height
            (PC)         (BC)                 (PW)
           Amperes      Amperes      No’s       %      Microns      Microns     Microns     Microns
   1         7.5          3.5         30       60      1579.22      1499.50     63.209      57.775
   2         6.5          4.5         30       60      1486.59      1361.64     59.137      49.443
   3         7.5          4.5         50       60      1383.04      1301.22     53.953      48.422
   4         6.5          3.5         50       40      1539.88      1480.60     54.191      49.422
   5         7.5          4.5         30       60      1582.92      1506.41     76.886      71.209
   6         7.5          3.5         50       40      1404.63      1283.25     71.247      65.947
   7         6.5          3.5         30       60      1477.09      1393.14     60.583      54.737
   8         6.5          3.5         50       60      1451.98      1372.69     61.896      54.251
   9         6.5          3.5         30       40      1530.30      1453.96     57.514      52.538
   10        6.5          4.5         50       60      1382.42      1305.11     63.619      58.265
   11        7.5          3.5         50       60      1392.70      1337.14     59.083      54.855
   12        6.5          4.5         30       40      1543.53      1466.85     42.855      36.559
   13        7.5          3.5         30       40      1581.70      1537.70     48.824      42.514
   14        7.5          4.5         50       40      1503.05      1436.88     64.101      59.595
   15        7.5          4.5         30       40      1547.92      1474.37     52.275      46.553
   16        6.5          4.5         50       40      1486.94      1408.72     65.613      58.092


4. Development of Mathematical Models 
     A low-order polynomial is employed for developing the mathematical model for
predicting weld pool geometry. Equation (1) represents a typical mathematical model, in
which the response is well modeled by a linear function of the independent variables.


*Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
& Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.            329
Online Available at http://TuEngr.com/V02/325-336.pdf
Table 5: ANOVA test results.
   ANOVA for Front Width
   Source                  DF       Seq SS     Adj SS       Adj MS                F
   Main Effects             4        25659      25659        6415                1.40
   2-Way Interactions       6        23462      23462        3910                0.85
   3-Way Interactions       4        23142      23142        5785                1.26
   Residual Error           1         4575       4575        4575
   Total                   15        76837
   R2 Value =94.05
   ANOVA for Back Width
   Source                  DF       Seq SS     Adj SS       Adj MS                F
   Main Effects             4        35868      35868        8967                2.47
   2-Way Interactions       6        38078      38078        6346                1.75
   3-Way Interactions       4        19057       9057        4764                1.31
   Residual Error           1         3633       3633        3633
   Total                   15        96636
   R2 Value = 96.24
   ANOVA for Front Height
   Source                  DF        Seq SS    Adj SS       Adj MS                F
   Main Effects             4        499.22    499.22       124.80               2.48
   2-Way Interactions       6        335.64    335.64        55.94               1.11
   3-Way Interactions       4        157.23    157.23        39.31               0.78
   Residual Error           1         50.23     50.23        50.23
   Total                   15       1042.32
   R2 Value = 95.18
   ANOVA for Back Height
   Source                  DF        Seq SS    Adj SS       Adj MS                F
   Main Effects             4        487.77     487.77      121.94               4.31
   2-Way Interactions       6        336.44     336.44       56.07               1.98
   3-Way Interactions       4        233.81     233.81       58.45               2.06
   Residual Error           1         28.32       32         28.32
   Total                   15       1086.34
   R2 value = 97.39
               Where SS =Sum of Squares, MS=Mean Square, F=Fishers ratio


    Y = β + β1 x1 + β2 x2 + …._ βx xx + ∈                                               (1)


    The regression coefficients were calculated using MINITAB14 software and Equations
(2), (3), (4), and (5) represent the developed mathematical models with welding parameters in
coded form.


Front Width =1492.12+(38.45*X1)-(6.42*X2)+(7.07*X3)+(5.85*X4) +(26.12*X1*X2)
+(9.6*X1*X3)+(24.67*X1*X4)+(2.1*X2*X3)+(4.17*X2*X4)-(7.86*X3*X4)+
(16.27*X1*X2*X3)+(28.66*X1*X2*X4)-(10.35*X1*X3*X4)-(15.91*X2*X3*X4)                     (2)

    330         K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
Back Width =1413.7+(46.21*X1)-(5.53*X2)-(1.79*X3)+(8.53*X4)-(34.34*X1*X2)
+(15.69*X2*X3)+(27.73*X1*X4)+(9.46*X2*X3)-(1.52*X2*X4)-(9.7*X3*X4)+
(10.7*X1*X2*X3)+(28.4*X1*X2*X4)-(10.32*X1*X3*X4)-(12.8*X2*X3*X4)                                     (3)


Front Height = 59.687-(1.253*X1)-(0.756*X2)+(3.032*X3)-(4.457*X4)
+(1.146*X1*X2)+(3.509*X1*X3)-(1.707*X1*X4)-(1.891*X2*X3)+(0.676*X2*X4)
-(0.639*X3*X4)+(0.937*X1*X2*X3)-(0.304*X1*X2*X4)+(0.529*X1*X3*X4)+
(2.929*X2*X3*X4)                                                                                     (4)


Back Height = 53.761-(1.212*X1)-(0.513*X2)+(2.845*X3)-(4.545*X4)
+(0.637*X1*X2)+(3.731*X1*X3)-(1.436*X1*X4)-(1.886*X2*X3)+(0.671*X2*X4)
-(0.795*X3*X4)+(0.571*X1*X2*X3)-(0.195*X1*X2*X4)+(1.25*X1*X3*X4)
+(3.562*X2*X3*X4)                                                                                    (5)


                Table 6: Comparison of actual and predicted values of responses.
              Front Width              Back Width              Front Height            Back Height
 Run
          Actual     Predicted     Actual     Predicted    Actual    Predicted     Actual   Predicted
 Order
   1      1579.22     1562.31      1499.5     1484.43      63.209     61.4371      57.775    56.4446
   2      1486.59     1469.68     1361.64     1346.57      59.137     57.3651      49.443    48.1126
   3      1383.04     1399.94     1301.22     1316.28      53.953     55.7249      48.422    49.7524
   4      1539.88     1556.79      1480.6     1495.67      54.191     55.9629      49.422    50.7524
   5      1582.92     1566.01     1506.41     1491.34      76.886     75.1141      71.209    69.8786
   6      1404.63     1421.54     1283.25     1298.32      71.247     73.0189      65.947    67.2774
   7      1477.09     1460.18     1393.14     1378.07      60.583     58.8111      54.737    53.4066
   8      1451.98     1435.07     1372.69     1357.62      61.896     60.1241      54.251    52.9206
   9       1530.3     1513.39     1453.96     1438.89      57.514     55.7421      52.538    51.2076
  10      1382.42     1365.51     1305.11     1290.04      63.619     61.8471      58.265    56.9346
  11       1392.7     1409.60     1337.14     1352.21      59.083     60.8549      54.855    56.1854
  12      1543.53     1560.44     1466.85     1481.92      42.855     44.6269      36.559    37.8894
  13       1581.7     1564.79      1537.7     1522.63      48.824     47.0521      42.514    41.1836
  14      1503.05     1519.95     1436.88     1451.95      64.101     65.8729      59.595    60.9254
  15      1547.92     1564.83     1474.37     1489.44      52.275     54.0469      46.553    47.8834
  16      1486.94     1503.85     1408.72     1423.79      65.613     67.3849      58.092    59.4224


5. Checking the Adequacy of the Mathematical Models  
     The adequacy of the developed models is tested using Analysis of Variance (ANOVA)
technique. As per this technique, if the calculated value of Fratio of the developed model is less

*Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
& Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.            331
Online Available at http://TuEngr.com/V02/325-336.pdf
than the standard Fratio (from F-table) value at a desired level of confidence (say 99%), then
the model is said to be adequate within the confidence limit. ANOVA test results of all the
responses are presented in Table 5.


    The ANOVA table (Table 5) reveals that all the calculated F values are less than standard
table F value; hence developed mathematical models are adequate.


6. Results & Discussion 
    Table 6 represents the predicted values of weld pool geometry. Figures 3, 4, 5, and 6
represents the scatter plots of weld bead parameters, indicating that the actual and predicted
values of Weld pool geometry parameters are very close to each other.


                          Scatter plot of Fr ont Width                                        Scatter plot of Fr ont H eight
                1600                                                              80

                1550
                                                                                  70
                1500
      A ctual




                                                                        A ctual




                                                                                  60
                1450

                                                                                  50
                1400

                1350                                                              40
                   1350    1400     1450      1500       1550   1600                40           50            60          70        80
                                      P r edicted                                                         P r edicted


     Figure 3: Scatter plot of Front Width                             Figure 5: Scatter plot of Front Height


                          Scatter plot of Back Width                                          Scatter plot of Back H eight
                1550
                                                                                  70
                1500                                                              65

                1450                                                              60
                                                                        A ctual
      A ctual




                                                                                  55
                1400
                                                                                  50
                1350
                                                                                  45
                1300                                                              40

                1250                                                              35
                   1250   1300    1350 1400 1450          1500 1550                 35   40      45    50     55    60     65   70   75
                                      Predicted                                                          P r edicted


     Figure 4: Scatter plot of Back Width                              Figure 6: Scatter plot of Back Height

    Figures 7, 8, 9, 10, 11, 12, 13, and 14 represent the main and interaction effects of
different pulsed MPAW process parameters on the weld pool geometry. From Figures 7, 8, 9,
and 10, it is understood from the results that peak current & pulse had more significant effect
on weld pool geometry compared to back current and pulse width.



    332                    K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
M ain Effects P lot ( data means) for FRO NT WIDT H                                M ain Effects P lot (data means) for BA C K WIDT H
                                            PEAK CURRENT        BACK CURRENT                                                PEAK CURRENT         BACK CURRENT
                                1525                                                                           1460
   M ean of FRO NT WIDT H




                                                                                  M ean of BA C K WIDT H
                                                                                                               1440
                                1500
                                                                                                               1420
                                1475                                                                           1400
                                                                                                               1380
                                1450
                                        -1                 1   -1         1                                              -1                1    -1          1
                                               PULSE            PULSE WIDTH                                                    PULSE             PULSE WIDTH
                                1525                                                                           1460
                                                                                                               1440
                                1500
                                                                                                               1420
                                1475                                                                           1400
                                                                                                               1380
                                1450
                                        -1                 1   -1         1                                              -1                1    -1          1



                                 Figure 7: Main effects for Front Width. Figure 8: Main effects for Back Width.




                    M ain Effects P lot ( data means) for FRO NT H EIGH T                                  M ain Effects P lot ( data means) for BA C K H EIGH T

                                       PEAK CURRENT            BACK CURRENT                                             PEAK CURRENT            BACK CURRENT
                                64                                                                             58
     M ean of FRO NT H EIGH T




                                                                                    M ean of BA C K H EIGH T


                                62                                                                             56
                                60                                                                             54
                                58                                                                             52
                                56                                                                             50
                                       -1              1       -1         1                                            -1              1        -1          1
                                              PULSE             PULSE WIDTH                                                   PULSE              PULSE WIDTH
                                64                                                                             58
                                62                                                                             56
                                60                                                                             54
                                58                                                                             52
                                56                                                                             50
                                       -1              1       -1         1                                            -1              1        -1          1



                                Figure 9: Main effects for Front Height. Figure 10: Main effects for Back Height.


                          As the peak current and number of pulses increases, heat input also increases, which
leads to higher penetration and hence wider front and back widths. As the widths become
wider the slopes become smaller, thereby decreasing the front and back heights. As the pulse
with increases the weld pool geometry parameters decreases because of lower cooling rate of
weld metal.


                          Back current is helpful in maintain the continuous arc, however increasing the back
current decrease the weld pool geometry parameters because of large variation in pulse/sec.




*Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
& Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.                                                                             333
Online Available at http://TuEngr.com/V02/325-336.pdf
Inter action P lot (data means) for FRO NT WIDT H                                       Inter action P lot ( data means) for BA C K WIDT H
                   -1    1        -1       1        -1     1                                              -1    1       -1       1        -1     1
                                                                   1550                                                                                  1500
                                                                              PEAK                                                                                 PEAK
                                                                   1500   CURRENT                                                                               CURRENT
   PEAK CURRENT                                                                -1         PEAK CURRENT                                                   1400        -1
                                                                   1450
                                                                                1                                                                                     1
                                                                   1550      BACK                                                                        1500
                                                                                                                                                                   BACK
                                                                   1500   CURRENT                                                                               CURRENT
              BACK CURRENT                                                        -1                 BACK CURRENT                                        1400
                                                                                                                                                                        -1
                                                                   1450
                                                                                   1                                                                                     1
                                                                                                                                                         1500
                                                                   1550   PULSE                                                                                 PULSE
                                                                   1500      -1                                                                                    -1
                                   PULSE                                      1                                          PULSE                           1400
                                                                   1450                                                                                            1




                                                   PULSE WIDTH                                                                           PULSE WIDTH




  Figure 11: Main effects for Back Height.                                             Figure 12: Interaction effect for Front Width.



    Inter action P lot (data means) for FRO NT H EIGH T                                     Inter action P lot ( data means) for BA C K H EIGH T
                    -1       1     -1          1      -1       1                                           -1       1    -1          1      -1       1

                                                                              PEAK                                                                                 PEAK
                                                                     65                                                                                    60
                                                                          CURRENT                                                                               CURRENT
   PEAK CURRENT                                                      60        -1         PEAK CURRENT                                                     55        -1
                                                                     55         1                                                                          50         1
                                                                             BACK                                                                                  BACK
                                                                     65                                                                                    60
                                                                          CURRENT                                                                               CURRENT
                  BACK CURRENT                                       60                                  BACK CURRENT                                      55
                                                                                  -1                                                                                    -1
                                                                     55            1                                                                       50            1
                                                                          PULSE                                                                                 PULSE
                                                                     65                                                                                    60
                                                                             -1                                                                                    -1
                                       PULSE                         60                                                      PULSE                         55
                                                                              1                                                                                    1
                                                                     55                                                                                    50



                                                    PULSE WIDTH                                                                           PULSE WIDTH




Figure 13: Interaction effect for Front Height. Figure 14: Interaction effect for Back Height.


     From Figures 11 and 12, it is understood that the interaction effect on Front Width and
Back Width are almost same i.e. the combined effect peak current and back current decrease
in Front Width and Back Width, the combined effect of Peak Current and pulse increase the
Front and Back Width and the combined effect of peak current and pulse width decrease in
Front and Back Width.


     From Figures 13 and 14 it is understood that the interaction effect on Front Width and
Back Width are almost same i.e. the combined effect peak current and back current decrease
in Front Width and Back Width, the combined effect of Peak Current and pulse decrease the
Front and Back Width and the combined effect of peak current and pulse width increase in
Front and Back Width.


     Finally from Figures 11 to 14, it is understood that peak current and number of pulses has
more significant effect on weld pool geometry parameters over other weld parameters.

     334                         K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
7. Conclusion 
     From the developed mathematical models predicted values of weld pool geometry
parameters were computed and found to be very close to actual values. Front Width & Back
Width increases with Peak Current & Pulse, where as it decreases with Back Current and
Pulse Width. Front Height and Back Height decreases with Peak Current, Back Current, Pulse
and Pulse Width. The present study is limited to four process parameters namely peak
current, back current, pulse and pulse width for predicting the weld pool geometry. One may
consider other factors like welding speed, nozzle stand of distance, plasma and shielding gas
flow rates and more levels for improving the statistical mathematical model.


8. Acknowledgements 
     We express our sincere thanks to Shri. R.Gopla Krishnan, Director, M/s Metallic Bellows
(I) Pvt Ltd, Chennai, INDIA and management of MVGR Engineering College, Vizianagaram,
INDIA for their support to carry out experimentation. A very special thank you is due to
Associate Professor Dr. Bovornchok Poopat for insightful comments, helping clarify and
improve the manuscript.


9. References 
Lakshinarayana.A.K, Balasubramanian.V, Varahamoorthy.R and Babu.S. (2008). Predicted
       the Dilution of Plasma Transferred Arc Hardfacing of Stellite on Carbon Steel using
       Response Surface Methodology, Metals and Materials International, Vol.14, No.6,
       pp.779-789.

Balasubramanian.V, Lakshminarayanan.A.K, Varahamoorthy.R and Babu.S. (2009).
       Application of Response Surface Methodolody to Prediction of Dilution in Plasma
       Transferred Arc Hardfacing of Stainless Steel on Carbon Steel, Science Direct,
       Volume 16, Issue 1, pp.44-53.

Giridharan P.K, Murugan N. (2007). Effect of pulsed gas tungsten arc welding process
       parameters on pitting corrosion resistance of type 304L stainless steel welds, Corros
       J,63(5),pp.433–441.

Hsiao.Y.F, Tarng.Y.S and Huang.W.J. (2008). Optimization of Plasma Arc Welding
       Parameters by Using the Taguchi Method with the Grey Relational Analysis, Journal
       of Materials and Manufacturing Processes, 23, pp.51–58.

Montgomery DC, Design and analysis of experiments, 6th Ed. Wiley, New York, 2005.

*Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses:
kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management,
& Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642.          335
Online Available at http://TuEngr.com/V02/325-336.pdf
Plasma Welding: more accurate, better control at lower currents, Modern Application News,
      December 1999.

Siva.K, Muragan.N, Logesh.R. (2008). Optimization of weld bead geometry in Plasma
       transferred arc hardfacing austenitic stainless steel plates using genetic algorithm, Int J
       Adv Manuf Technol, Volume 41,Numbers 1-2, pp.24-30.

Sheng-Chai Chi, LI-Chang Hsu. (2001). A fuzzy Radial Basis Function Neural Network for
      Predicting Multiple Quality characteristics of Plasma Arc Welding, IEEE,0-7803-
      7078-3/01,pp.2807 -2812.

Zhang. D.K. and Niu.J.T. (2010). Application of Artificial Neural Network modeling to
       Plasma Arc Welding of Aluminum alloys, Journal of Advanced Metallurgical
       Sciences, Vol.13, No.1,pp.194-200.


           K.Siva Prasad is an Assistant Professor of Department of Mechanical Engineering at Anil Neerukonda
           Institute of Technology & Sciences, Visakhapatnam, India. He received his Bachelors degree from Osmania
           University, India and Master Degree from JNTU, Hyderabad, India. He is also a part time scholar at Andhra
           University. He is a member of various professional bodies like ISTE, FPSI, ISHRAE etc. His area of research
           is micro welding processes.

           Dr.Ch.Srinivasa Rao is an Associate Professor in the Mechanical Engineering Department at Andhra
           University, Visakhapatnam, India. He obtained his PhD degree from Andhra University, Visakhapatnam,
           India. He has published his research papers in various International Journals and conferences proceedings.
           He is a member of various professional bodies like ISTE, IE etc. His area of interest is manufacturing
           sciences, rapid prototyping and robotics.

           Dr.D.Nageswara Rao is a Professor in the Mechanical Engineering Department at Andhra University,
           Visakhapatnam, India. He obtained his PhD degree from Indian Institute of Technology Delhi, India. He is
           the coordinator for Centre for Nanotechnology at Andhra University. He has successfully completed various
           projects sponsored by DST, UGC, AICTE, NRB etc. His area of research is manufacturing sciences and
           nanotechnology.

Peer Review: This article has been internationally peer-reviewed and accepted for publication
               according to the guidelines given at the journal’s website.




    336          K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao

More Related Content

What's hot

Relevance vector machine based prediction of mrrand sr for electro chemical m...
Relevance vector machine based prediction of mrrand sr for electro chemical m...Relevance vector machine based prediction of mrrand sr for electro chemical m...
Relevance vector machine based prediction of mrrand sr for electro chemical m...iaemedu
 
Modelling and prediction of surface roughness
Modelling and prediction of surface roughnessModelling and prediction of surface roughness
Modelling and prediction of surface roughnessIAEME Publication
 
Ijartes v2-i2-003
Ijartes v2-i2-003Ijartes v2-i2-003
Ijartes v2-i2-003IJARTES
 
Parametric optimization for cutting speed – a statistical regression modeling...
Parametric optimization for cutting speed – a statistical regression modeling...Parametric optimization for cutting speed – a statistical regression modeling...
Parametric optimization for cutting speed – a statistical regression modeling...IAEME Publication
 
Optimization of the Process Parameters of Wire Cut EDM - A Review
Optimization of the Process Parameters of Wire Cut EDM - A ReviewOptimization of the Process Parameters of Wire Cut EDM - A Review
Optimization of the Process Parameters of Wire Cut EDM - A ReviewIJSRD
 
Optimization of edm process parameters using taguchi method a review
Optimization of edm process parameters using taguchi method  a reviewOptimization of edm process parameters using taguchi method  a review
Optimization of edm process parameters using taguchi method a revieweSAT Journals
 
Implimentation of Taguchi method on CNC EDM and CNC WEDM
Implimentation of Taguchi method on CNC EDM and CNC WEDMImplimentation of Taguchi method on CNC EDM and CNC WEDM
Implimentation of Taguchi method on CNC EDM and CNC WEDMkiranhg
 
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...Dr. Amarjeet Singh
 
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...IJMER
 
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...IRJET Journal
 
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi Method
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi MethodOptimization of WEDM Process Parameters on Titanium Alloy Using Taguchi Method
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi MethodIJMER
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)ijceronline
 
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...IRJET Journal
 
Anaysis of Material Removal Rate of AISI 304 SS In EDM Process
Anaysis of Material Removal Rate of AISI 304 SS In EDM ProcessAnaysis of Material Removal Rate of AISI 304 SS In EDM Process
Anaysis of Material Removal Rate of AISI 304 SS In EDM Processijsrd.com
 
A Literature Review on Effect of Machining Parameters in Wire - EDM
A Literature Review on Effect of Machining Parameters in Wire - EDMA Literature Review on Effect of Machining Parameters in Wire - EDM
A Literature Review on Effect of Machining Parameters in Wire - EDMijsrd.com
 
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...ijceronline
 
IRJET- Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...
IRJET-  	  Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...IRJET-  	  Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...
IRJET- Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...IRJET Journal
 

What's hot (19)

Relevance vector machine based prediction of mrrand sr for electro chemical m...
Relevance vector machine based prediction of mrrand sr for electro chemical m...Relevance vector machine based prediction of mrrand sr for electro chemical m...
Relevance vector machine based prediction of mrrand sr for electro chemical m...
 
Modelling and prediction of surface roughness
Modelling and prediction of surface roughnessModelling and prediction of surface roughness
Modelling and prediction of surface roughness
 
Ijartes v2-i2-003
Ijartes v2-i2-003Ijartes v2-i2-003
Ijartes v2-i2-003
 
Parametric optimization for cutting speed – a statistical regression modeling...
Parametric optimization for cutting speed – a statistical regression modeling...Parametric optimization for cutting speed – a statistical regression modeling...
Parametric optimization for cutting speed – a statistical regression modeling...
 
Optimization of the Process Parameters of Wire Cut EDM - A Review
Optimization of the Process Parameters of Wire Cut EDM - A ReviewOptimization of the Process Parameters of Wire Cut EDM - A Review
Optimization of the Process Parameters of Wire Cut EDM - A Review
 
Optimization of edm process parameters using taguchi method a review
Optimization of edm process parameters using taguchi method  a reviewOptimization of edm process parameters using taguchi method  a review
Optimization of edm process parameters using taguchi method a review
 
Implimentation of Taguchi method on CNC EDM and CNC WEDM
Implimentation of Taguchi method on CNC EDM and CNC WEDMImplimentation of Taguchi method on CNC EDM and CNC WEDM
Implimentation of Taguchi method on CNC EDM and CNC WEDM
 
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...
Wire EDM Parameters for Surface Roughness in Straight Gear Manufacturing: An ...
 
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...
Multiple Optimization of Wire EDM Machining Parameters Using Grey Based Taguc...
 
30120140507009 2
30120140507009 230120140507009 2
30120140507009 2
 
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...
Finite Element Analysis of MEMS based Piezoresistive Diamond Thin Film Cantil...
 
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi Method
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi MethodOptimization of WEDM Process Parameters on Titanium Alloy Using Taguchi Method
Optimization of WEDM Process Parameters on Titanium Alloy Using Taguchi Method
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)
 
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...
IRJET-Optimization of Process Parameter in Hardfacing by Shield Metal Arc Wel...
 
Anaysis of Material Removal Rate of AISI 304 SS In EDM Process
Anaysis of Material Removal Rate of AISI 304 SS In EDM ProcessAnaysis of Material Removal Rate of AISI 304 SS In EDM Process
Anaysis of Material Removal Rate of AISI 304 SS In EDM Process
 
A Literature Review on Effect of Machining Parameters in Wire - EDM
A Literature Review on Effect of Machining Parameters in Wire - EDMA Literature Review on Effect of Machining Parameters in Wire - EDM
A Literature Review on Effect of Machining Parameters in Wire - EDM
 
Lk2419191924
Lk2419191924Lk2419191924
Lk2419191924
 
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...
Multi-Response Optimization of WEDM Process Parameters of Monel 400 using Int...
 
IRJET- Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...
IRJET-  	  Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...IRJET-  	  Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...
IRJET- Parametric Optimization of Tig Welding on SS 304 and MS using Tagu...
 

Viewers also liked

Viewers also liked (9)

Mig welding(edit)
Mig welding(edit)Mig welding(edit)
Mig welding(edit)
 
16March2012
16March201216March2012
16March2012
 
Experimental and Finite Element Analysis of Single-V Groove Butt Weld on Weld...
Experimental and Finite Element Analysis of Single-V Groove Butt Weld on Weld...Experimental and Finite Element Analysis of Single-V Groove Butt Weld on Weld...
Experimental and Finite Element Analysis of Single-V Groove Butt Weld on Weld...
 
gmaw mig welding
gmaw  mig weldinggmaw  mig welding
gmaw mig welding
 
Distortion in welding
Distortion in weldingDistortion in welding
Distortion in welding
 
Tig welding
Tig weldingTig welding
Tig welding
 
Arc Welding Processes 2 1
Arc Welding Processes 2 1Arc Welding Processes 2 1
Arc Welding Processes 2 1
 
arc welding
arc weldingarc welding
arc welding
 
Welding ppt
Welding pptWelding ppt
Welding ppt
 

Similar to Prediction of Weld Pool Geometry in Pulsed Current Micro Plasma Arc Welding of SS304L Stainless Steel Sheets

IJSRED-V2I5P28
IJSRED-V2I5P28IJSRED-V2I5P28
IJSRED-V2I5P28IJSRED
 
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...IRJET Journal
 
A review on Parametric Optimization of Submerged arc welding process
A review on Parametric Optimization of Submerged arc welding processA review on Parametric Optimization of Submerged arc welding process
A review on Parametric Optimization of Submerged arc welding processIJSRD
 
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...dbpublications
 
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...IJCI JOURNAL
 
Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...drboon
 
Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...drboon
 
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...ijiert bestjournal
 
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...ijsrd.com
 
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...iosrjce
 
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...IJERA Editor
 

Similar to Prediction of Weld Pool Geometry in Pulsed Current Micro Plasma Arc Welding of SS304L Stainless Steel Sheets (20)

OPTIMIZATION OF WELD BEAD GEOMETRICAL PARAMETERS FOR BEAD ON PLATE SUBMERGED ...
OPTIMIZATION OF WELD BEAD GEOMETRICAL PARAMETERS FOR BEAD ON PLATE SUBMERGED ...OPTIMIZATION OF WELD BEAD GEOMETRICAL PARAMETERS FOR BEAD ON PLATE SUBMERGED ...
OPTIMIZATION OF WELD BEAD GEOMETRICAL PARAMETERS FOR BEAD ON PLATE SUBMERGED ...
 
IJSRED-V2I5P28
IJSRED-V2I5P28IJSRED-V2I5P28
IJSRED-V2I5P28
 
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...
IRJET- Analysis of Process Parameters of Plasma ARC Cutting using Design of E...
 
Ijebea14 225
Ijebea14 225Ijebea14 225
Ijebea14 225
 
A review on Parametric Optimization of Submerged arc welding process
A review on Parametric Optimization of Submerged arc welding processA review on Parametric Optimization of Submerged arc welding process
A review on Parametric Optimization of Submerged arc welding process
 
Km3419041910
Km3419041910Km3419041910
Km3419041910
 
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...
Effect Of Wire Edm Process Parameters On Surface Roughness Of Aisi-4140 (Carb...
 
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...
REAL TIME ERROR DETECTION IN METAL ARC WELDING PROCESS USING ARTIFICIAL NEURA...
 
Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...
 
Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...Establishing empirical relations to predict grain size and hardness of pulsed...
Establishing empirical relations to predict grain size and hardness of pulsed...
 
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...
ELECTRO CHEMICAL MACHINING AND ELECTRICAL DISCHARGE MACHINING PROCESSES MICRO...
 
IJRRA-02-04-26
IJRRA-02-04-26IJRRA-02-04-26
IJRRA-02-04-26
 
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...
Parametric Optimization on MIG Welded EN8 Material Joints by using Taguchi Me...
 
Effect of Process Parameters on MRR for HCHCr in WEDM using RSM methodology
Effect of Process Parameters on MRR for HCHCr in WEDM using RSM methodologyEffect of Process Parameters on MRR for HCHCr in WEDM using RSM methodology
Effect of Process Parameters on MRR for HCHCr in WEDM using RSM methodology
 
J021053057
J021053057J021053057
J021053057
 
C012641821
C012641821C012641821
C012641821
 
C012641821
C012641821C012641821
C012641821
 
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...
 
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...
Process Parameter Optimization of WEDM for AISI M2 & AISI H13 by Anova & Anal...
 
E0353044047
E0353044047E0353044047
E0353044047
 

More from drboon

11(7) 2020 ITJEMAST's published research articles
11(7) 2020 ITJEMAST's published research articles11(7) 2020 ITJEMAST's published research articles
11(7) 2020 ITJEMAST's published research articlesdrboon
 
11(6) 2020 ITJEMAST Research Articles
11(6) 2020 ITJEMAST Research Articles11(6) 2020 ITJEMAST Research Articles
11(6) 2020 ITJEMAST Research Articlesdrboon
 
11(5) 2020 ITJEMAST Research Papers
11(5) 2020 ITJEMAST Research Papers 11(5) 2020 ITJEMAST Research Papers
11(5) 2020 ITJEMAST Research Papers drboon
 
11(4) 2020 ITJEMAST Multidisciplinary Research Articles
11(4) 2020 ITJEMAST Multidisciplinary Research Articles11(4) 2020 ITJEMAST Multidisciplinary Research Articles
11(4) 2020 ITJEMAST Multidisciplinary Research Articlesdrboon
 
11(3) 2020 ITJEMAST Multidisciplinary Research Articles
11(3) 2020 ITJEMAST Multidisciplinary Research Articles 11(3) 2020 ITJEMAST Multidisciplinary Research Articles
11(3) 2020 ITJEMAST Multidisciplinary Research Articles drboon
 
11(1)2020 ITJEMAST RESEARCH ARTICLES
11(1)2020 ITJEMAST RESEARCH ARTICLES11(1)2020 ITJEMAST RESEARCH ARTICLES
11(1)2020 ITJEMAST RESEARCH ARTICLESdrboon
 
11(2)2020 International Transaction Journal of Engineering, Management, & Ap...
11(2)2020  International Transaction Journal of Engineering, Management, & Ap...11(2)2020  International Transaction Journal of Engineering, Management, & Ap...
11(2)2020 International Transaction Journal of Engineering, Management, & Ap...drboon
 
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...drboon
 
The Streets in a Livable City
The Streets in a Livable CityThe Streets in a Livable City
The Streets in a Livable Citydrboon
 
Impact of Building Envelope Modification on Energy Performance of High-Rise A...
Impact of Building Envelope Modification on Energy Performance of High-Rise A...Impact of Building Envelope Modification on Energy Performance of High-Rise A...
Impact of Building Envelope Modification on Energy Performance of High-Rise A...drboon
 
Enhancement of Space Environment Via Healing Garden
Enhancement of Space Environment Via Healing GardenEnhancement of Space Environment Via Healing Garden
Enhancement of Space Environment Via Healing Gardendrboon
 
Design of Quadruped Walking Robot with Spherical Shell
Design of Quadruped Walking Robot with Spherical ShellDesign of Quadruped Walking Robot with Spherical Shell
Design of Quadruped Walking Robot with Spherical Shelldrboon
 
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...drboon
 
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...drboon
 
Effect of Oryzalin on Growth of Anthurium andraeanum In Vitro
Effect of Oryzalin on Growth of Anthurium andraeanum In VitroEffect of Oryzalin on Growth of Anthurium andraeanum In Vitro
Effect of Oryzalin on Growth of Anthurium andraeanum In Vitrodrboon
 
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...drboon
 
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...drboon
 
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...drboon
 
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...drboon
 
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...drboon
 

More from drboon (20)

11(7) 2020 ITJEMAST's published research articles
11(7) 2020 ITJEMAST's published research articles11(7) 2020 ITJEMAST's published research articles
11(7) 2020 ITJEMAST's published research articles
 
11(6) 2020 ITJEMAST Research Articles
11(6) 2020 ITJEMAST Research Articles11(6) 2020 ITJEMAST Research Articles
11(6) 2020 ITJEMAST Research Articles
 
11(5) 2020 ITJEMAST Research Papers
11(5) 2020 ITJEMAST Research Papers 11(5) 2020 ITJEMAST Research Papers
11(5) 2020 ITJEMAST Research Papers
 
11(4) 2020 ITJEMAST Multidisciplinary Research Articles
11(4) 2020 ITJEMAST Multidisciplinary Research Articles11(4) 2020 ITJEMAST Multidisciplinary Research Articles
11(4) 2020 ITJEMAST Multidisciplinary Research Articles
 
11(3) 2020 ITJEMAST Multidisciplinary Research Articles
11(3) 2020 ITJEMAST Multidisciplinary Research Articles 11(3) 2020 ITJEMAST Multidisciplinary Research Articles
11(3) 2020 ITJEMAST Multidisciplinary Research Articles
 
11(1)2020 ITJEMAST RESEARCH ARTICLES
11(1)2020 ITJEMAST RESEARCH ARTICLES11(1)2020 ITJEMAST RESEARCH ARTICLES
11(1)2020 ITJEMAST RESEARCH ARTICLES
 
11(2)2020 International Transaction Journal of Engineering, Management, & Ap...
11(2)2020  International Transaction Journal of Engineering, Management, & Ap...11(2)2020  International Transaction Journal of Engineering, Management, & Ap...
11(2)2020 International Transaction Journal of Engineering, Management, & Ap...
 
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...
V8(3) 2017:: International Transaction Journal of Engineering, Management, & ...
 
The Streets in a Livable City
The Streets in a Livable CityThe Streets in a Livable City
The Streets in a Livable City
 
Impact of Building Envelope Modification on Energy Performance of High-Rise A...
Impact of Building Envelope Modification on Energy Performance of High-Rise A...Impact of Building Envelope Modification on Energy Performance of High-Rise A...
Impact of Building Envelope Modification on Energy Performance of High-Rise A...
 
Enhancement of Space Environment Via Healing Garden
Enhancement of Space Environment Via Healing GardenEnhancement of Space Environment Via Healing Garden
Enhancement of Space Environment Via Healing Garden
 
Design of Quadruped Walking Robot with Spherical Shell
Design of Quadruped Walking Robot with Spherical ShellDesign of Quadruped Walking Robot with Spherical Shell
Design of Quadruped Walking Robot with Spherical Shell
 
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...
Motion Analysis of Pitch Rotation Mechanism for Posture Control of Butterfly-...
 
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...
Analysis of Roll Rotation Mechanism of a Butterfly for Development of a Small...
 
Effect of Oryzalin on Growth of Anthurium andraeanum In Vitro
Effect of Oryzalin on Growth of Anthurium andraeanum In VitroEffect of Oryzalin on Growth of Anthurium andraeanum In Vitro
Effect of Oryzalin on Growth of Anthurium andraeanum In Vitro
 
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...
Role of 2,4-D on Callus Induction and Shoot Formation to Increase Number of S...
 
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...
 
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(2): Latest Research from International Transaction Journal of Engin...
 
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...
ITJEMAST5(1): Latest Research from International Transaction Journal of Engin...
 
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...
Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosy...
 

Recently uploaded

Call Girls Pune Just Call 9907093804 Top Class Call Girl Service Available
Call Girls Pune Just Call 9907093804 Top Class Call Girl Service AvailableCall Girls Pune Just Call 9907093804 Top Class Call Girl Service Available
Call Girls Pune Just Call 9907093804 Top Class Call Girl Service AvailableDipal Arora
 
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...lizamodels9
 
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779Best VIP Call Girls Noida Sector 40 Call Me: 8448380779
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779Delhi Call girls
 
BEST ✨ Call Girls In Indirapuram Ghaziabad ✔️ 9871031762 ✔️ Escorts Service...
BEST ✨ Call Girls In  Indirapuram Ghaziabad  ✔️ 9871031762 ✔️ Escorts Service...BEST ✨ Call Girls In  Indirapuram Ghaziabad  ✔️ 9871031762 ✔️ Escorts Service...
BEST ✨ Call Girls In Indirapuram Ghaziabad ✔️ 9871031762 ✔️ Escorts Service...noida100girls
 
Progress Report - Oracle Database Analyst Summit
Progress  Report - Oracle Database Analyst SummitProgress  Report - Oracle Database Analyst Summit
Progress Report - Oracle Database Analyst SummitHolger Mueller
 
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...Dave Litwiller
 
Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni
 
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewas
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service DewasVip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewas
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewasmakika9823
 
Grateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfGrateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfPaul Menig
 
Insurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageInsurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageMatteo Carbone
 
The Coffee Bean & Tea Leaf(CBTL), Business strategy case study
The Coffee Bean & Tea Leaf(CBTL), Business strategy case studyThe Coffee Bean & Tea Leaf(CBTL), Business strategy case study
The Coffee Bean & Tea Leaf(CBTL), Business strategy case studyEthan lee
 
Pharma Works Profile of Karan Communications
Pharma Works Profile of Karan CommunicationsPharma Works Profile of Karan Communications
Pharma Works Profile of Karan Communicationskarancommunications
 
Call Girls in Gomti Nagar - 7388211116 - With room Service
Call Girls in Gomti Nagar - 7388211116  - With room ServiceCall Girls in Gomti Nagar - 7388211116  - With room Service
Call Girls in Gomti Nagar - 7388211116 - With room Servicediscovermytutordmt
 
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdf
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdfCatalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdf
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdfOrient Homes
 
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...Lviv Startup Club
 
DEPED Work From Home WORKWEEK-PLAN.docx
DEPED Work From Home  WORKWEEK-PLAN.docxDEPED Work From Home  WORKWEEK-PLAN.docx
DEPED Work From Home WORKWEEK-PLAN.docxRodelinaLaud
 
Cash Payment 9602870969 Escort Service in Udaipur Call Girls
Cash Payment 9602870969 Escort Service in Udaipur Call GirlsCash Payment 9602870969 Escort Service in Udaipur Call Girls
Cash Payment 9602870969 Escort Service in Udaipur Call GirlsApsara Of India
 
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999Tina Ji
 

Recently uploaded (20)

Call Girls Pune Just Call 9907093804 Top Class Call Girl Service Available
Call Girls Pune Just Call 9907093804 Top Class Call Girl Service AvailableCall Girls Pune Just Call 9907093804 Top Class Call Girl Service Available
Call Girls Pune Just Call 9907093804 Top Class Call Girl Service Available
 
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...
Call Girls In DLf Gurgaon ➥99902@11544 ( Best price)100% Genuine Escort In 24...
 
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779Best VIP Call Girls Noida Sector 40 Call Me: 8448380779
Best VIP Call Girls Noida Sector 40 Call Me: 8448380779
 
BEST ✨ Call Girls In Indirapuram Ghaziabad ✔️ 9871031762 ✔️ Escorts Service...
BEST ✨ Call Girls In  Indirapuram Ghaziabad  ✔️ 9871031762 ✔️ Escorts Service...BEST ✨ Call Girls In  Indirapuram Ghaziabad  ✔️ 9871031762 ✔️ Escorts Service...
BEST ✨ Call Girls In Indirapuram Ghaziabad ✔️ 9871031762 ✔️ Escorts Service...
 
Progress Report - Oracle Database Analyst Summit
Progress  Report - Oracle Database Analyst SummitProgress  Report - Oracle Database Analyst Summit
Progress Report - Oracle Database Analyst Summit
 
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...
Enhancing and Restoring Safety & Quality Cultures - Dave Litwiller - May 2024...
 
Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.
 
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewas
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service DewasVip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewas
Vip Dewas Call Girls #9907093804 Contact Number Escorts Service Dewas
 
Grateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfGrateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdf
 
Insurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageInsurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usage
 
The Coffee Bean & Tea Leaf(CBTL), Business strategy case study
The Coffee Bean & Tea Leaf(CBTL), Business strategy case studyThe Coffee Bean & Tea Leaf(CBTL), Business strategy case study
The Coffee Bean & Tea Leaf(CBTL), Business strategy case study
 
Pharma Works Profile of Karan Communications
Pharma Works Profile of Karan CommunicationsPharma Works Profile of Karan Communications
Pharma Works Profile of Karan Communications
 
Best Practices for Implementing an External Recruiting Partnership
Best Practices for Implementing an External Recruiting PartnershipBest Practices for Implementing an External Recruiting Partnership
Best Practices for Implementing an External Recruiting Partnership
 
KestrelPro Flyer Japan IT Week 2024 (English)
KestrelPro Flyer Japan IT Week 2024 (English)KestrelPro Flyer Japan IT Week 2024 (English)
KestrelPro Flyer Japan IT Week 2024 (English)
 
Call Girls in Gomti Nagar - 7388211116 - With room Service
Call Girls in Gomti Nagar - 7388211116  - With room ServiceCall Girls in Gomti Nagar - 7388211116  - With room Service
Call Girls in Gomti Nagar - 7388211116 - With room Service
 
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdf
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdfCatalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdf
Catalogue ONG NƯỚC uPVC - HDPE DE NHAT.pdf
 
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...
Yaroslav Rozhankivskyy: Три складові і три передумови максимальної продуктивн...
 
DEPED Work From Home WORKWEEK-PLAN.docx
DEPED Work From Home  WORKWEEK-PLAN.docxDEPED Work From Home  WORKWEEK-PLAN.docx
DEPED Work From Home WORKWEEK-PLAN.docx
 
Cash Payment 9602870969 Escort Service in Udaipur Call Girls
Cash Payment 9602870969 Escort Service in Udaipur Call GirlsCash Payment 9602870969 Escort Service in Udaipur Call Girls
Cash Payment 9602870969 Escort Service in Udaipur Call Girls
 
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999
Russian Faridabad Call Girls(Badarpur) : ☎ 8168257667, @4999
 

Prediction of Weld Pool Geometry in Pulsed Current Micro Plasma Arc Welding of SS304L Stainless Steel Sheets

  • 1. 2011 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. 2011 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies http://www.TuEngr.com, http://go.to/Research Prediction of Weld Pool Geometry in Pulsed Current Micro Plasma Arc Welding of SS304L Stainless Steel Sheets a* b b Kondapalli Siva Prasad , Ch. Srinivasa Rao , D. Nageswara Rao a Department of Mechanical Engineering, Anil Neerukonda Institute of Technology & Sciences, INDIA b Department of Mechanical Engineering, Andhra University, INDIA ARTICLEINFO A B S T RA C T Article history: Pulsed Micro Plasma Arc Welding (MPAW) is a metal Received 21 March 2011 Received in revised form joining technique widely used in manufacturing of thin sheet 27 May 2011 components due to its inherent properties. The weld quality and Accepted 13 June 2011 productivity are controlled by the process parameters. The paper Available online 14 June 2011 discuses about development of mathematical models for weld Keywords: pool geometry of stainless steel 304L sheets. Design of Pulsed Current MPAW, experiments based on full factorial design is employed for the SS304L, development of a mathematical model correlating the important ANOVA, controlled pulsed MPAW process parameters like peak current, Bead Geometry background current, pulse and pulse width with front width, back width, front height and back height. The developed mode has been checked for adequacy based on ANOVA analysis. Weld bead parameters obtained by the models are found to confirm actual values with high accuracy. Using these models effect of pulsed MPAW process parameters on weld pool geometry are studied. 2011 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Some Rights Reserved. 1. Introduction   The plasma welding process was introduced to the welding industry in 1964 as a method of bringing better control to the arc welding process in lower current ranges (Modern Application News, 1999 ). Today, plasma retains the original advantages it brought to the *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 325 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 2. industry by providing an advanced level of control and accuracy to produce high quality welds in both miniature and pre precision applications and to provide long electrode life for high production requirements at all levels of amperage. Plasma welding is equally suited to manual and automatic applications. It is used in a variety of joining operations ranging from welding of miniature components to seam welding to high volume production welding and many others. The welding optimization literature frequently reveals correlation among responses. (D.K.Zhang et.al,2010) studied the influence of welding current, arc voltage, welding speed, wire feed rate and magnitude of ion gas flow on front melting width, back melting width and weld reinforcement of Alternating Current Plasma Arc Welding process of LF6 Aluminum alloy of thickness 3mm using Artificial Neural Network- Back Propagation algorithm. (Sheng-Chai Chi et. al ,2001) developed an intelligent decision support system for Plasma Arc Welding of stainless steel plates of thickness range from 3 to 9 mm based on fuzzy Radial Basis Function (RBF) neural network by performing experiments using Taguchi method. (Y. F. Hsiao et. Al,2008) studied the optimal parameters process of plasma arc welding of SS316 of thickness 4mm by Taguchi method with Grey relational analysis is studied. Torch stand- off, welding current, welding speed and plasma gas flow rate (Argon) were chosen as input variables and welding groove root penetration, welding groove width, front-side undercut were measured as output parameters. (K.Siva et.al, 2008) used central composite rotatable full factorial design matrix and conducted experiments in optimization of weld bead geometry in Plasma arc hardfaced austenitic stainless steel plates using Genetic Algorithm. (A.K.Lakshminarayan et.al, 2008) predicted the Dilution of Plasma Transferred Arc Hardfacing of Stellite on Carbon Steel using Response Surface Methodology (RSM). (V Balasubramanian et.al, 2009) used Response Surface Methodology to predict and optimize the percentage of dilution of iron-based hardfaced surface produced by the Plasma transferred arc welding process. From the earlier works, it has been observed that much work is not reported so far to investigate the effect of pulsed current MPAW process parameters on stainless steel weld characteristics; and developing the related mathematical models to predict the same especially for welding of thin stainless steel sheets. Hence an attempt was made to correlate important pulsed MPAW process parameters to bead geometry of thin AISI 304L stainless steel welds 326 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
  • 3. by developing mathematical models. The models developed will be very useful to predict the weld pool geometry parameters for desired bead geometry. A statistically designed experiment based on full factorial design has employed for the development of mathematical models (Montgomery DC ,2005). Figure 1: Typical weld pool geometry. 2. Experimental procedure  Austenitic stainless steel sheets of type AISI 304L 100×50×0.25 mm are welded autogenously with square butt joint without edge preparation. To evaluate the quality of MPAW welds, measurements of the front width, back width, front height and back height of the weld pool are considered. Figure 1 indicates the typical weld pool geometry. Table 1 indicates the chemical composition of AISI 304L stainless steel sheet. Experiments are conducted using the Pulsed Micro Plasma Arc Welding (MPAW) process with pulse DCEN. Industrial pure and commercial grade argon gases are used for shielding and back purging, respectively. Automatic voltage control available in the welding equipment is used. Fixture variation effects are not considered as the same setup has been used throughout the experiment. Some of the welding process parameters are fixed based on earlier work and also from the trial run so as to obtain full penetration weld. Trial runs are conducted to find the limits of each controllable process parameter so as to obtain full penetration weld, free from any visible defects. Because of computational ease and enhanced interpretability of the models, parameters are converted to coded form for developing mathematical models (Giridharan PK et.al, 2007). The upper limit of a factor is coded as +1 and the lower limit as *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 327 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 4. −1. Table 2 represents the levels determined for process variables with their levels, units and notations for the pulsed MPAW process. Table 3 represents the fixed pulsed MPAW process parameters and their values. Table 1: Chemical composition of austenitic stainless steel (AISI 304L) sheet. Elements Chromium Silicon Nickel Carbon Manganese Iron % by 18.2% 0.5% 8.5% 0.015% 1.6% Balance weight Table 2: Input variables and their levels Levels SI No Input Factor Units -1 +1 1 Peak Current Amps 6.5 7.5 2 Back Current Amps 3.5 4.5 3 Pulse No’s /Sec 30 50 4 Pulse width % 40 60 Table 3: Fixed pulsed MPAW process parameters and their values. Power source Secheron Micro Plasma Arc Machine (Model: PLASMAFIX 50E) Polarity DCEN Mode of operation Pulse mode Electrode 2% thoriated tungsten electrode Electrode Diameter 1mm Plasma gas Argon & Hydrogen Plasma gas flow rate 6 Lpm Shielding gas Argon Shielding gas flow rate 0.4 Lpm Purging gas Argon Purging gas flow rate 0.4 Lpm Copper Nozzle diameter 1mm Nozzle to plate distance 1mm Welding speed 260mm/min Torch Position Vertical Operation type Automatic From the Design of Experiments and due to wide range of input process parameters, the present work is limited to use four factors, two levels, full factorial design matrix in order to simplify the present problem. Table 4 shows the measured values of output response by taking an average value of three samples of 16 sets of coded conditions used in the form of design matrix. The 16 experiments have been formulated as per 24 (two levels and four factors) factorial design. 328 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
  • 5. 3. Recording the Responses  Three samples are cut from the welded specimens at an interval of 25mm and mounted in Bakelite powder, polished and etched with Oxalic acid as per ASTM E3 and ASTM E340. Weld pool geometries are measured using Metallurgical Microscope make Dewinter Technologie, Model No. DMI-CROWN-II. Figure 2 represents the Photomacrographs of a typical weld specimen showing the bead profile at 100X magnification. Figure 2: Photomacrographs of a typical weld specimen. Table 4: Welding parameters and responses for the full factorial design. Exp Peak Back Pulse Pulse Front Back Front Back No Current Current (P) Width Width Width Height Height (PC) (BC) (PW) Amperes Amperes No’s % Microns Microns Microns Microns 1 7.5 3.5 30 60 1579.22 1499.50 63.209 57.775 2 6.5 4.5 30 60 1486.59 1361.64 59.137 49.443 3 7.5 4.5 50 60 1383.04 1301.22 53.953 48.422 4 6.5 3.5 50 40 1539.88 1480.60 54.191 49.422 5 7.5 4.5 30 60 1582.92 1506.41 76.886 71.209 6 7.5 3.5 50 40 1404.63 1283.25 71.247 65.947 7 6.5 3.5 30 60 1477.09 1393.14 60.583 54.737 8 6.5 3.5 50 60 1451.98 1372.69 61.896 54.251 9 6.5 3.5 30 40 1530.30 1453.96 57.514 52.538 10 6.5 4.5 50 60 1382.42 1305.11 63.619 58.265 11 7.5 3.5 50 60 1392.70 1337.14 59.083 54.855 12 6.5 4.5 30 40 1543.53 1466.85 42.855 36.559 13 7.5 3.5 30 40 1581.70 1537.70 48.824 42.514 14 7.5 4.5 50 40 1503.05 1436.88 64.101 59.595 15 7.5 4.5 30 40 1547.92 1474.37 52.275 46.553 16 6.5 4.5 50 40 1486.94 1408.72 65.613 58.092 4. Development of Mathematical Models  A low-order polynomial is employed for developing the mathematical model for predicting weld pool geometry. Equation (1) represents a typical mathematical model, in which the response is well modeled by a linear function of the independent variables. *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 329 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 6. Table 5: ANOVA test results. ANOVA for Front Width Source DF Seq SS Adj SS Adj MS F Main Effects 4 25659 25659 6415 1.40 2-Way Interactions 6 23462 23462 3910 0.85 3-Way Interactions 4 23142 23142 5785 1.26 Residual Error 1 4575 4575 4575 Total 15 76837 R2 Value =94.05 ANOVA for Back Width Source DF Seq SS Adj SS Adj MS F Main Effects 4 35868 35868 8967 2.47 2-Way Interactions 6 38078 38078 6346 1.75 3-Way Interactions 4 19057 9057 4764 1.31 Residual Error 1 3633 3633 3633 Total 15 96636 R2 Value = 96.24 ANOVA for Front Height Source DF Seq SS Adj SS Adj MS F Main Effects 4 499.22 499.22 124.80 2.48 2-Way Interactions 6 335.64 335.64 55.94 1.11 3-Way Interactions 4 157.23 157.23 39.31 0.78 Residual Error 1 50.23 50.23 50.23 Total 15 1042.32 R2 Value = 95.18 ANOVA for Back Height Source DF Seq SS Adj SS Adj MS F Main Effects 4 487.77 487.77 121.94 4.31 2-Way Interactions 6 336.44 336.44 56.07 1.98 3-Way Interactions 4 233.81 233.81 58.45 2.06 Residual Error 1 28.32 32 28.32 Total 15 1086.34 R2 value = 97.39 Where SS =Sum of Squares, MS=Mean Square, F=Fishers ratio Y = β + β1 x1 + β2 x2 + …._ βx xx + ∈ (1) The regression coefficients were calculated using MINITAB14 software and Equations (2), (3), (4), and (5) represent the developed mathematical models with welding parameters in coded form. Front Width =1492.12+(38.45*X1)-(6.42*X2)+(7.07*X3)+(5.85*X4) +(26.12*X1*X2) +(9.6*X1*X3)+(24.67*X1*X4)+(2.1*X2*X3)+(4.17*X2*X4)-(7.86*X3*X4)+ (16.27*X1*X2*X3)+(28.66*X1*X2*X4)-(10.35*X1*X3*X4)-(15.91*X2*X3*X4) (2) 330 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
  • 7. Back Width =1413.7+(46.21*X1)-(5.53*X2)-(1.79*X3)+(8.53*X4)-(34.34*X1*X2) +(15.69*X2*X3)+(27.73*X1*X4)+(9.46*X2*X3)-(1.52*X2*X4)-(9.7*X3*X4)+ (10.7*X1*X2*X3)+(28.4*X1*X2*X4)-(10.32*X1*X3*X4)-(12.8*X2*X3*X4) (3) Front Height = 59.687-(1.253*X1)-(0.756*X2)+(3.032*X3)-(4.457*X4) +(1.146*X1*X2)+(3.509*X1*X3)-(1.707*X1*X4)-(1.891*X2*X3)+(0.676*X2*X4) -(0.639*X3*X4)+(0.937*X1*X2*X3)-(0.304*X1*X2*X4)+(0.529*X1*X3*X4)+ (2.929*X2*X3*X4) (4) Back Height = 53.761-(1.212*X1)-(0.513*X2)+(2.845*X3)-(4.545*X4) +(0.637*X1*X2)+(3.731*X1*X3)-(1.436*X1*X4)-(1.886*X2*X3)+(0.671*X2*X4) -(0.795*X3*X4)+(0.571*X1*X2*X3)-(0.195*X1*X2*X4)+(1.25*X1*X3*X4) +(3.562*X2*X3*X4) (5) Table 6: Comparison of actual and predicted values of responses. Front Width Back Width Front Height Back Height Run Actual Predicted Actual Predicted Actual Predicted Actual Predicted Order 1 1579.22 1562.31 1499.5 1484.43 63.209 61.4371 57.775 56.4446 2 1486.59 1469.68 1361.64 1346.57 59.137 57.3651 49.443 48.1126 3 1383.04 1399.94 1301.22 1316.28 53.953 55.7249 48.422 49.7524 4 1539.88 1556.79 1480.6 1495.67 54.191 55.9629 49.422 50.7524 5 1582.92 1566.01 1506.41 1491.34 76.886 75.1141 71.209 69.8786 6 1404.63 1421.54 1283.25 1298.32 71.247 73.0189 65.947 67.2774 7 1477.09 1460.18 1393.14 1378.07 60.583 58.8111 54.737 53.4066 8 1451.98 1435.07 1372.69 1357.62 61.896 60.1241 54.251 52.9206 9 1530.3 1513.39 1453.96 1438.89 57.514 55.7421 52.538 51.2076 10 1382.42 1365.51 1305.11 1290.04 63.619 61.8471 58.265 56.9346 11 1392.7 1409.60 1337.14 1352.21 59.083 60.8549 54.855 56.1854 12 1543.53 1560.44 1466.85 1481.92 42.855 44.6269 36.559 37.8894 13 1581.7 1564.79 1537.7 1522.63 48.824 47.0521 42.514 41.1836 14 1503.05 1519.95 1436.88 1451.95 64.101 65.8729 59.595 60.9254 15 1547.92 1564.83 1474.37 1489.44 52.275 54.0469 46.553 47.8834 16 1486.94 1503.85 1408.72 1423.79 65.613 67.3849 58.092 59.4224 5. Checking the Adequacy of the Mathematical Models   The adequacy of the developed models is tested using Analysis of Variance (ANOVA) technique. As per this technique, if the calculated value of Fratio of the developed model is less *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 331 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 8. than the standard Fratio (from F-table) value at a desired level of confidence (say 99%), then the model is said to be adequate within the confidence limit. ANOVA test results of all the responses are presented in Table 5. The ANOVA table (Table 5) reveals that all the calculated F values are less than standard table F value; hence developed mathematical models are adequate. 6. Results & Discussion  Table 6 represents the predicted values of weld pool geometry. Figures 3, 4, 5, and 6 represents the scatter plots of weld bead parameters, indicating that the actual and predicted values of Weld pool geometry parameters are very close to each other. Scatter plot of Fr ont Width Scatter plot of Fr ont H eight 1600 80 1550 70 1500 A ctual A ctual 60 1450 50 1400 1350 40 1350 1400 1450 1500 1550 1600 40 50 60 70 80 P r edicted P r edicted Figure 3: Scatter plot of Front Width Figure 5: Scatter plot of Front Height Scatter plot of Back Width Scatter plot of Back H eight 1550 70 1500 65 1450 60 A ctual A ctual 55 1400 50 1350 45 1300 40 1250 35 1250 1300 1350 1400 1450 1500 1550 35 40 45 50 55 60 65 70 75 Predicted P r edicted Figure 4: Scatter plot of Back Width Figure 6: Scatter plot of Back Height Figures 7, 8, 9, 10, 11, 12, 13, and 14 represent the main and interaction effects of different pulsed MPAW process parameters on the weld pool geometry. From Figures 7, 8, 9, and 10, it is understood from the results that peak current & pulse had more significant effect on weld pool geometry compared to back current and pulse width. 332 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
  • 9. M ain Effects P lot ( data means) for FRO NT WIDT H M ain Effects P lot (data means) for BA C K WIDT H PEAK CURRENT BACK CURRENT PEAK CURRENT BACK CURRENT 1525 1460 M ean of FRO NT WIDT H M ean of BA C K WIDT H 1440 1500 1420 1475 1400 1380 1450 -1 1 -1 1 -1 1 -1 1 PULSE PULSE WIDTH PULSE PULSE WIDTH 1525 1460 1440 1500 1420 1475 1400 1380 1450 -1 1 -1 1 -1 1 -1 1 Figure 7: Main effects for Front Width. Figure 8: Main effects for Back Width. M ain Effects P lot ( data means) for FRO NT H EIGH T M ain Effects P lot ( data means) for BA C K H EIGH T PEAK CURRENT BACK CURRENT PEAK CURRENT BACK CURRENT 64 58 M ean of FRO NT H EIGH T M ean of BA C K H EIGH T 62 56 60 54 58 52 56 50 -1 1 -1 1 -1 1 -1 1 PULSE PULSE WIDTH PULSE PULSE WIDTH 64 58 62 56 60 54 58 52 56 50 -1 1 -1 1 -1 1 -1 1 Figure 9: Main effects for Front Height. Figure 10: Main effects for Back Height. As the peak current and number of pulses increases, heat input also increases, which leads to higher penetration and hence wider front and back widths. As the widths become wider the slopes become smaller, thereby decreasing the front and back heights. As the pulse with increases the weld pool geometry parameters decreases because of lower cooling rate of weld metal. Back current is helpful in maintain the continuous arc, however increasing the back current decrease the weld pool geometry parameters because of large variation in pulse/sec. *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 333 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 10. Inter action P lot (data means) for FRO NT WIDT H Inter action P lot ( data means) for BA C K WIDT H -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 1550 1500 PEAK PEAK 1500 CURRENT CURRENT PEAK CURRENT -1 PEAK CURRENT 1400 -1 1450 1 1 1550 BACK 1500 BACK 1500 CURRENT CURRENT BACK CURRENT -1 BACK CURRENT 1400 -1 1450 1 1 1500 1550 PULSE PULSE 1500 -1 -1 PULSE 1 PULSE 1400 1450 1 PULSE WIDTH PULSE WIDTH Figure 11: Main effects for Back Height. Figure 12: Interaction effect for Front Width. Inter action P lot (data means) for FRO NT H EIGH T Inter action P lot ( data means) for BA C K H EIGH T -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 PEAK PEAK 65 60 CURRENT CURRENT PEAK CURRENT 60 -1 PEAK CURRENT 55 -1 55 1 50 1 BACK BACK 65 60 CURRENT CURRENT BACK CURRENT 60 BACK CURRENT 55 -1 -1 55 1 50 1 PULSE PULSE 65 60 -1 -1 PULSE 60 PULSE 55 1 1 55 50 PULSE WIDTH PULSE WIDTH Figure 13: Interaction effect for Front Height. Figure 14: Interaction effect for Back Height. From Figures 11 and 12, it is understood that the interaction effect on Front Width and Back Width are almost same i.e. the combined effect peak current and back current decrease in Front Width and Back Width, the combined effect of Peak Current and pulse increase the Front and Back Width and the combined effect of peak current and pulse width decrease in Front and Back Width. From Figures 13 and 14 it is understood that the interaction effect on Front Width and Back Width are almost same i.e. the combined effect peak current and back current decrease in Front Width and Back Width, the combined effect of Peak Current and pulse decrease the Front and Back Width and the combined effect of peak current and pulse width increase in Front and Back Width. Finally from Figures 11 to 14, it is understood that peak current and number of pulses has more significant effect on weld pool geometry parameters over other weld parameters. 334 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao
  • 11. 7. Conclusion  From the developed mathematical models predicted values of weld pool geometry parameters were computed and found to be very close to actual values. Front Width & Back Width increases with Peak Current & Pulse, where as it decreases with Back Current and Pulse Width. Front Height and Back Height decreases with Peak Current, Back Current, Pulse and Pulse Width. The present study is limited to four process parameters namely peak current, back current, pulse and pulse width for predicting the weld pool geometry. One may consider other factors like welding speed, nozzle stand of distance, plasma and shielding gas flow rates and more levels for improving the statistical mathematical model. 8. Acknowledgements  We express our sincere thanks to Shri. R.Gopla Krishnan, Director, M/s Metallic Bellows (I) Pvt Ltd, Chennai, INDIA and management of MVGR Engineering College, Vizianagaram, INDIA for their support to carry out experimentation. A very special thank you is due to Associate Professor Dr. Bovornchok Poopat for insightful comments, helping clarify and improve the manuscript. 9. References  Lakshinarayana.A.K, Balasubramanian.V, Varahamoorthy.R and Babu.S. (2008). Predicted the Dilution of Plasma Transferred Arc Hardfacing of Stellite on Carbon Steel using Response Surface Methodology, Metals and Materials International, Vol.14, No.6, pp.779-789. Balasubramanian.V, Lakshminarayanan.A.K, Varahamoorthy.R and Babu.S. (2009). Application of Response Surface Methodolody to Prediction of Dilution in Plasma Transferred Arc Hardfacing of Stainless Steel on Carbon Steel, Science Direct, Volume 16, Issue 1, pp.44-53. Giridharan P.K, Murugan N. (2007). Effect of pulsed gas tungsten arc welding process parameters on pitting corrosion resistance of type 304L stainless steel welds, Corros J,63(5),pp.433–441. Hsiao.Y.F, Tarng.Y.S and Huang.W.J. (2008). Optimization of Plasma Arc Welding Parameters by Using the Taguchi Method with the Grey Relational Analysis, Journal of Materials and Manufacturing Processes, 23, pp.51–58. Montgomery DC, Design and analysis of experiments, 6th Ed. Wiley, New York, 2005. *Corresponding author (Kondapalli Siva Prasad). Tel/Fax: +91-9849212391 E-mail addresses: kspanits@gmail.com 2011. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 2 No.3. ISSN 2228-9860. eISSN 1906-9642. 335 Online Available at http://TuEngr.com/V02/325-336.pdf
  • 12. Plasma Welding: more accurate, better control at lower currents, Modern Application News, December 1999. Siva.K, Muragan.N, Logesh.R. (2008). Optimization of weld bead geometry in Plasma transferred arc hardfacing austenitic stainless steel plates using genetic algorithm, Int J Adv Manuf Technol, Volume 41,Numbers 1-2, pp.24-30. Sheng-Chai Chi, LI-Chang Hsu. (2001). A fuzzy Radial Basis Function Neural Network for Predicting Multiple Quality characteristics of Plasma Arc Welding, IEEE,0-7803- 7078-3/01,pp.2807 -2812. Zhang. D.K. and Niu.J.T. (2010). Application of Artificial Neural Network modeling to Plasma Arc Welding of Aluminum alloys, Journal of Advanced Metallurgical Sciences, Vol.13, No.1,pp.194-200. K.Siva Prasad is an Assistant Professor of Department of Mechanical Engineering at Anil Neerukonda Institute of Technology & Sciences, Visakhapatnam, India. He received his Bachelors degree from Osmania University, India and Master Degree from JNTU, Hyderabad, India. He is also a part time scholar at Andhra University. He is a member of various professional bodies like ISTE, FPSI, ISHRAE etc. His area of research is micro welding processes. Dr.Ch.Srinivasa Rao is an Associate Professor in the Mechanical Engineering Department at Andhra University, Visakhapatnam, India. He obtained his PhD degree from Andhra University, Visakhapatnam, India. He has published his research papers in various International Journals and conferences proceedings. He is a member of various professional bodies like ISTE, IE etc. His area of interest is manufacturing sciences, rapid prototyping and robotics. Dr.D.Nageswara Rao is a Professor in the Mechanical Engineering Department at Andhra University, Visakhapatnam, India. He obtained his PhD degree from Indian Institute of Technology Delhi, India. He is the coordinator for Centre for Nanotechnology at Andhra University. He has successfully completed various projects sponsored by DST, UGC, AICTE, NRB etc. His area of research is manufacturing sciences and nanotechnology. Peer Review: This article has been internationally peer-reviewed and accepted for publication according to the guidelines given at the journal’s website. 336 K. Siva Prasad, Ch.Srinivasa Rao, D.Nageswara Rao