This document presents an experimental analysis of surface roughness when using abrasive magnetic particles on EN8 steel. Nine experiments were conducted using Taguchi's design of experiments method to determine the optimal levels of four factors (current, grit size, iron percentage, and speed). The order of significance for the factors was found to be current > grit size > iron percentage > speed. Across all experiments, surface roughness improved by 33.5-60.5% compared to the initial roughness, with higher currents, finer grit sizes, higher iron percentages, and faster speeds generally producing better surface finishes.
Framing an Appropriate Research Question 6b9b26d93da94caf993c038d9efcdedb.pdf
Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle Using Taguchi Design Method
1. IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 10, 2015 | ISSN (online): 2321-0613
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Experimental Analysis on Surface Roughness of Abrasive Magnetic
Particle using Taguchi Design Method
B. Suresh Babu1 Dr. P. Suresh Babu2
1
Associate Professor 2
Principal & Professor
1,2
Department of Mechanical Engineering
1
Sri Vasavi Institute of Engineering and Technology, Nandhamur, Krishna Dist -52163 A.P 2
Challapathi
Institute of Engineering and Technology Guntur, Andhra Pradesh India
Abstract— Here, we study about, influence of various
machining parameters like current, grit size %iron, and speed.
In the present study, experiments are conducted on En8 steel
material with four factors and five levels by using abrasive
magnetic particle and try to find out optimum surface
roughness. By using taguchi method. Of orthogonal array
conventional number of experiments is reduced to nine by
choosing four factors and three level of experiments and
proved the result is same. This paper attemptsto introduce
how Taguchi parameter design could be used in identifying
the significant processing parameters and optimizing the
surface roughness abrasive magnetic particle of operations.
In this study, it was observed that, the order of significance of
the main variables is as A3 > B1 > C1 > D3
Key words: current (A), grit size (B), %iron(C), speed (D),.
abrasive magnetic particle, Taguchi parameter design
I. INTRODUCTION
Extrude Hone Corporation, USA, originally developed the
AFM process in 1966. Since then, a few empirical studies [1–
5] have been carried out and also research work regarding
process mechanisms, modeling of surface generation and
process monitoring of AFM was conducted by Williams and
Rajurkar [6] during the late 1980s. Their work [7] was mainly
related to online monitoring of AFM with acoustic emission
and stochastic modeling of the process.
Shinmura et al [8] have studied basic principle of the
MAF process and concluded that the stock removal and
surface finish value (Ra) increase as the magnetic abrasive
particle diameter “D” increases. Ra value of the final surface
finish increases as the abrasive grain diameter “d” increases.
In order to achieve smooth surface and remove surface
damage, the ferromagnetic particle diameter must be chosen
as a compromise of material removal rate and resulting
surface finish. Small diameter abrasive grains produce good
surface finish.
Kremen et al. [9,10] have proposed a model for
material removal in MAF.
Kim et al. [11,12] have also modeled and simulated
the MAF process and concluded that the magnetic flux
density in the air-gap is affected greatly by the length of the
air-gap; magnetic flux density increases as the air-gap length
decreases. They have also found that simulation results for
surface finish agree better with the experimental data for the
low magnetic flux density than they do for high magnetic flux
density.
II. MAGNETIC ABRASIVE FINISHING
Magnetic abrasive finishing (MAF) process is the one in
which material is removed in such a way that surface
finishing and debarring are performed simultaneously with
the applied magnetic field in the finishing zone.
The technology for super finishing needs ultra
clean machining of advanced engineering materials such as
silicon nitride, silicon carbide, and aluminum oxide which
are used in high- technology industries and are difficult to
finish by conventional grinding and polishing techniques
with high accuracy, and minimal surface defects, such as
micro cracks. Therefore, magnetic abrasive finishing (MAF)
process has been recently developed for efficient and
precision finishing of internal and flat surfaces. This process
can produce surface finish of the order of few nanometers.
A. Formation of Magnetic Abrasive Brush:
A forming mechanism of a magnetic abrasive brush can be
clarified from observations made on in various abrasive
volumes; mass of abrasive was varied from 0.1 to 1.0g by 0.1
g. Fig.1.10shows typical cases of 0.1, 0.2 and 0.6 g. The
characteristics of the observed brush are as follows:
– At an abrasive small volume, the diameter of each bundle
is in the order of a few hundred micrometer that are
separated from each other.
– With an increase of volume, the bundles get closer to
other and the diameter of the bundles increase to several
hundred micrometer, corresponding to several abrades.
– At large abrasive volume, the maximum diameter of a
bundle does not increase but the number of bundles of
several diameter increase
III. EXPERIMENTAL SET UP[13].
A. Requirements of Set Up
Fundamental requirements of the experimental set-up are:
1) Magnetization Unit
2) Electromagnet
3) Motion Control Unit.
4) Work Piece Fixture.
1) Magnetization Unit
Basic purpose of magnetization unit is to generate the
required magnetic field to assist the finishing process. Main
parts of magnetization unit are –
– D.C. Power supply
– Electromagnet
2) Electromagnet
To energize the electromagnet a constant voltage/current
D.C. regulated power supply of output voltage 220 V and
output current from 0 to 1A was used. By controlling the
induced current from D.C. power supply the generated
magnetic field can be controlled. In order to get the required
current and voltage RPS(Regulated Power Supply) is used.
2. Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method
(IJSRD/Vol. 3/Issue 10/2015/079)
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By using the RPS we can get a voltage of 220V and we can
vary the current between 0-2A.
By using the electromagnet we can vary the
intensity of the magnetic field. The electromagnet mainly
consists of a iron core at the center and copper wire is wound
around the core. The intensity of the magnetic field is directly
proportional to the number of windings or the applied electric
current. To protect the copper winding from damage varnish
coating is applied around the winding. It also helps in
insulating the copper wire.
3) Motion Control Unit
The workpiece is firmly fixed in the chuck of the lathe
machine. The speed of the workpiece is maintained with the
help of the motor that is provided in the lathe machine. The
experimentation is carried out at a constant speed i.e.,
355rpm.
4) Fixture And Work Piece
The material chosen is Mild Steel(EN-8). The work piece was
made in cylindrical shape. The diameter of the work pieces
are 35mm. The work piece is hold firmly in the chuck of the
lathe machine.
5) Specifications of lathe machine:
Power of the Motor : 2.2 H.P
No.of Spindle Speeds : 9
Hole through Spindle : 38mm
Length of bed : 1800mm
Height of centres : 510mm
Admit between centres : 1000mm
Swing Over bed : 360mm
B. Experimental Procedure
The parameters that are kept constant during the
experimentation are:
Parameter Value
Size of the iron particles 40#
Finishing Time 15 min.
The variable parameters and their ranges are:
Parameter Value
Mesh size of the abrasive particles 18# - 60#
Current(amp) 0.1A – 0.5A
Percent composition of iron in
MAP’s
60% - 90%
Abrasive Powder Used SiC
Speed
355, 535 and 835
rpm
Conversion grit sizes into measurements in inches and
microns.
GRI
T
INCH
ES
MICR
ONS
SIZ
E(#)
AVE
RAG
E
MAXI
MUM
MINI
MUM
AVE
RAG
E
MAXI
MUM
MINI
MUM
20 0.037 0.053 0.026 940 1346 660
30 0.022 0.032 0.014 559 813 356
46 0.014 0.022
0.009
5
356 559 241
60 0.01 0.016
0.006
5
254 406 165
The following are the procedural steps during MAF process.
1) Work pieces were initially ground by cylindrical grinder
to give most same initial surface roughness value.
Cylindrical grinding is done at following conditions:
Speed = 1440 rpm
Feed = 13.33 mm/min
2) After the grinding process, the work pieces were
manually cleaned by acetone to remove the foreign
particles. Initial surface roughness values were
measured by using Tally surf analyzer with least count
of 0.001µm
3) To conduct the surface finish experiments, the work
piece was mounted on the lathe. The work piece was
made parallel to the electromagnet using a dial indicator
(least count-0.01mm) to maintain proper gap between
them. The work piece was made parallel in both X and
Y direction. The position of work piece in XY plane was
kept in such a way that the center of the electromagnet
coincide with the center of the work piece.
4) Working gap between electromagnet and work piece
was maintained by a filler gauge and this gap was filled
with the MAP. The amount of MAP depends on the
working gap. Percent by weight method was used to
calculate the amount of MAP in the working gap
5) The current to the electromagnet was supplied and got it
energized and abrasive powder fill between the
electromagnet and work piece making FMAB. By
giving rotation to the magnet, this FMAB performs the
actual finishing operation.
6) After completing the finishing operation, work piece
was again cleaned manually using acetone and final
surface roughness value was measured.
SPEED=355 RPM
Initial Roughness value=1.685 Abrasive powder=SiC Ra-Surface Roughness
GRI
T
60 46 30 20
Current(Amps
)
%iro
n
Ra
%improvemen
t
Ra
%improvemen
t
Ra
%improvemen
t
Ra
%improvemen
t
90
1.29
2
39.3 1.3 38.5 1.32 36.5 1.33 35.5
80 1.3 38.5
1.31
4
37.1 1.31 37.5 1.34 34.5
0.1 70 1.31 37.5
1.32
6
36.5 1.33 35.5 1.35 33.5
60 1.32 36.5
1.34
2
34.3
1.34
8
33.7
1.35
7
32.5
4. Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method
(IJSRD/Vol. 3/Issue 10/2015/079)
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0.1 70 1.18 50.5 1.19 49.5 1.23 45.5 1.25 43.5
60 1.19 49.5 1.22 46.5 1.24 44.5 1.26 42.5
90 1.12 56.5 1.13 55.5 1.15 53.5 1.18 50.5
80 1.14 54.5 1.15 53.5 1.17 51.5 1.2 48.5
0.2 70 1.15 53.5 1.17 51.5 1.18 50.5 1.21 47.5
60 1.17 51.5 1.19 49.5 1.2 48.5 1.22 46.5
90 1.09 59.5 1.11 57.5 1.12 56.5 1.14 54.5
80 1.11 57.5 1.13 55.5 1.14 54.5 1.16 52.5
0.3 70 1.12 56.5 1.15 53.5 1.15 53.5 1.17 51.5
60 1.14 54.5 1.17 51.5 1.17 51.5 1.19 49.5
90 1.07 61.5 1.08 60.5 1.1 58.5 1.1 58.5
80 1.08 60.5 1.1 58.5 1.12 56.5 1.12 56.5
0.4 70 1.09 59.5 1.12 56.5 1.13 55.5 1.14 54.5
60 1.11 57.5 1.14 54.5 1.15 53.5 1.16 52.5
90 1.05 63.5 1.06 62.5 1.08 60.5 1.09 59.5
80 1.06 62.5 1.07 61.5 1.09 59.5 1.1 58.5
0.5 70 1.07 61.5 1.08 60.5 1.1 58.5 1.12 56.5
60 1.09 59.5 1.1 58.5 1.13 55.5 1.14 54.5
Table 3: Effect of % composition of iron powder, Grit Size and current on surface roughness of EN-8 during MAF process
when speed is 835 rpm
IV. TAGUCHI’S DESIGN OF EXPERIMENTS
An objective function with constraint is formulated to solve
the optimal cutting parameters using
Taguchi’s Design of Experiments. The optimization
of process and product parameters considerably improvesthe
quality characteristics. A large number of experiments are
required to be conducted when the number ofparameters and
levels increases.
In order to reduce the number of experiments to be
conducted for the same number of parameters and
levels, the Taguchi’s Design of Experiment employs a
specially designed orthogonal array to study the
entireparameter levels with a conduct of lesser number of
experiments. The minimum number of experiments to
beconducted is calculated as,
Minimum number of experiments = [(L – 1) x P] + 1
= [(3-1) × 4]+1 =9≈L9
where,
L – Number of levels of fin parameters and
P – Number of fin parameters
S/N RATIO LOWER THE BETER =-10LOG1/n Σn i=1 yi2
Where, n = number of measurements Ina trial/row,
yi = the ith measured value in a run/row.
By applying Taguchi’s technique one can
significantly reduce the time required for experimental
investigation, as it is effective in investigating the effects of
multiple factors on performance as well as to study the
influence of individual factors to determine which factor has
more influence and which has less (Lin, 2001). Taguchi
method is a powerful tool for the design of high quality
systems. Taguchi method is efficient method for designing
process that operates consistently and optimally over a
variety of conditions. To determine the best design it requires
the use of a strategically designed experiment. Taguchi
approach to design of experiments in easy to adopt and apply
for users with limited knowledge of statistics, hence gained
wide popularity in the engineering and scientific community.
The desired cutting parameters are determined based on
experience or by hand book where cutting parameters are
reflected. Steps of Taguchi method are as follows:
1) Identification of main function, side effects and failure
mode.
2) Identification of noise factor, testing condition and
quality characteristics.
3) Identification of the main function to be optimized.
4) Identification the control factor and their levels.
5) Selection of orthogonal array and matrix experiment.
6) Conducting the matrix experiment.
7) Analyzing the data, prediction of the optimum level and
performance.
8) Performing the verification experiment and planning
Table1 shows all Taguchi design parameters and
levels.
One of the most important considerable attributes of Taguchi
parameter design was S/N ratio. It was differ at different p-
laces
1 2 3
A CURRENT amp 0.1 0.3 0.5
B. GRIT SIZE 60 30 20
C%iron 90 70 60
D SPEED rpm 355 535 835
Table 4
A. Select Orthogonal Array
Literature survey and discuss with some industrial person, we
considered four factors and three levels in ourstudy. As per
above parameters we select L9 orthogonal array (OA) in the
Taguchi parameter design. The layout of L9 orthogonal array
is shown in Table-2.
s.
no
A
curr
ent
BG
rit
size
C%i
ron
D
spe
ed
Ra
%improve
ment
S/N
5. Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method
(IJSRD/Vol. 3/Issue 10/2015/079)
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1 0.1 60 90 355
1.2
92
39.3
-
2.22
52
2 0.1 30 70 535
1.2
4
44.5
-
1.86
84
3 0.1 20 60 835
1.2
5
43.5
-
1.93
82
4 0.3 60 70 835
1.1
2
56.5
-
0.98
43
5 0.3 30 60 355
1.3
2
36.5
-
2.41
14
6 0.3 20 90 535
1.2
1
47.5
-
1.65
5
7 0.5 60 60 535 1.1 58.5
-
0.82
57
8 0.5 30 90 835
1.0
8
60.5
-
0.66
84
9 0.5 20 70 355
1.3
1
37.5
-
2.34
54
Table 5: Analysis of raw data from table5
level
A current
amp
B grit
size
C
%iron
D
Speed
1 1.2606 1.1706a 1.194a 1.3073
2 1.2166 1.2133 1.2233 1.775
3 1.1633a 1.2566 1.2233 1.15a
Delta 0.0973 0.086 0.0293 0.1573
Rank 2 3 4 1
Table 6:
a = optimum parameters
predicted mean = A3+B1+C1+D3 – 3*y.1.1633+
1.1706+1.194+1.15- 3*1.2135 =1.0374
Analysis of S/N ratio from table 2
level
A current
amp
B grit
size
C %iron D Speed
1 -2.0106a -1.3457a
-
1.5162a
-2.3273
2 -1.6835 -1.6494 -1.7327 -1.4504
3 -1.2805 -1.9795 -1.7412
-
1.1969a
Delta 0.7301 0.6338 0.2285 1.1304
Rank 2 3 4 1
Table 7:
a = optimum parameters
predicted mean on S/N ratio = A3+B1+C1+D3 – 3*y
= -1.2805-1.3457-1.5162-1.1304-3*1.6615= -0.2833 Db
After raw data were collected, average effect
response values (Table 3) and S/N response ratios (Table
5),respectively, were calculated based on Table 2. The
calculation of average effect response values and S/Nratios
were based on the following procedure. For example, the
average effect for level one of Tool feed was computed using
data from experimental numbers 1-3 of Table 5. The S/N ratio
is calculated in thesame way. The average effects and S/N
ratios for each level of cutting parameters are summarized
andreferred to in the average effects response table and S/N
ratios response table for surface roughness (Ra), as shown in
Tables 6 and 7
Table 1: Above graphs are from raw data of
6. Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method
(IJSRD/Vol. 3/Issue 10/2015/079)
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Table 2: Above graphs are from raw data of
Table 3: Above graphs are from raw data of
7. Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method
(IJSRD/Vol. 3/Issue 10/2015/079)
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The above graphs are based on taguchi design method which
proved same surface finish with minimum number of
experiments.
In each graph x axis is surface roughness (Ra)
series1 means current in the above graph
V. CONCLUSION
In the present paper, MAF setup has been designed and
fabricated. The performance of the setup has also been
studied. MAF process on Mild steel with the use of loosely
bounded MAPs has been carried out. It is concluded
maximum improvement at expt no 8 with 60.5%
improvement from the results and discussion that current and
circumferential speed of workpiece are the parameters which
significantly influence the material removal, change in
surface roughness value(∆Ra),and percent improvement in
surface finish.
It also allows industry to reduce process or
product variability and minimize product defects by using a
relatively small number of experimental runs and costs to
achieve superior-quality products. This research only
demonstrates how to use Taguchi parameter design for
optimizing machining performance with minimum cost. In
this study, the analysis of confirmation experiments has
shown that Taguchi parameter design can successfully verify
the optimum cutting parameters, which are observed that, the
order of significance of the main variables is as A3 > B1 >
C1 > D3: current (A), grit size (B), %iron(C), speed
(D),.value of surface roughness [Mean (= - 1.034 μm) and
S/N ratio (-0.2833 Db.) The other two parameters %iron and
grit size also effects the Ra, slightly to improved surface
finish.
REFERENCES
[1] Traditional Machining Conference, Cincinnati, OH,
December, 1985, pp. 111–120.
[2] L.J. L.J. Rhoades, Abrasive flow machining and its use,
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85-475, Society of Manufacturing Engineers, Dearborn,
MI, USA, 1985, pp. 1–18.
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[4] J. Stackhouse, Deburring by dynaflow, in: SME Paper
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DC, April 1988, pp. 35–43.
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[13]B.suresh babu and DR P.suresh babu from surface
Roughness Improvement of EN8 steel by Magnatic
Abrasive particles 24 th addition ijifr vol 2 aug 15 2015
[14]Data of experiment is obtained from Gudlavalleru
engineering college from B tech project by T . naveena
jyothi