Surface texturing is a means for enhancing tribological properties of mechanical components. Shot peening control is a cold working method accomplished by pelting the surface of a metal part with round metallic shot thrown at relatively high velocity. Each shot acts as tiny peening hammer, Causing the surface to yield in plastic deformation & leaving a small concave depression on the surface of the metal. The material on which the work carried out was pump shaft. The pump shaft is used as a En-8 Material. The experimental work deals with shot peening of the surface of the pump shaft material for the study of surface roughness, surface hardness and the tribological properties as compared with heat treatment process of pump shaft. The shot peening was carried out by altering the peening pressures and the shot sizes. The changes in pressure and shot size have changes on the surface roughness, surface hardness and tribological properties of the surface.

1. International Journal of Research in Advanced Technology - IJORAT
Vol. 2, Issue 1, JANUARY 2016
All Rights Reserved © 2016 IJORAT 1
DESIGN A TRIBOLOGICAL BEHAVIOUR OF
PUMP SHAFT USING SHOT PEENING
PROCESS
Mr.R.KARTHIKEYAN.1
, Mr.S.SHEIK SULAIMAN 2
, Mr. K.KRISHNAMOORTHY 3
Assistant Professor/Mechanical Engineering, Francis Xavier Engineering College, Tirunelveli, India1
Assistant Professor/Mechanical Engineering, Francis Xavier Engineering College, Tirunelveli, India2
Assistant Professor/Mechanical Engineering, Francis Xavier Engineering College, Tirunelveli, India3
Abstract: Surface texturing is a means for enhancing tribological properties of mechanical components. Shot peening
control is a cold working method accomplished by pelting the surface of a metal part with round metallic shot thrown at
relatively high velocity. Each shot acts as tiny peening hammer, Causing the surface to yield in plastic deformation &
leaving a small concave depression on the surface of the metal. The material on which the work carried out was pump
shaft. The pump shaft is used as a En-8 Material. The experimental work deals with shot peening of the surface of the
pump shaft material for the study of surface roughness, surface hardness and the tribological properties as compared
with heat treatment process of pump shaft. The shot peening was carried out by altering the peening pressures and the
shot sizes. The changes in pressure and shot size have changes on the surface roughness, surface hardness and
tribological properties of the surface.
Key words: Shot Peening, Surface Texturing, Intensity, Heat Treatment
I. INTRODUCTION
Surface texturing is a means for enhancing
tribological properties of mechanical components is well
known for many years. Perhaps the most familiar and earliest
commercial application of surface texturing is that of cylinder
liner honing. Today surfaces of modern magnetic storage
devices are commonly textured and surface texturing is also
considered as a means for overcoming adhesion and stiction in
MEMS devices. For mechanical seals a 30% reduction in
friction, reduced leakage, and 2-10X increase in breakdown
load is created with the help of surface texturing. Similar
friction reductions claimed for automotive piston rings, planar
thrust bearings, and some tools are also a main application of
surface texturing.
The term surface texture refers to the fine
irregularities (peaks and valleys) produced on a surface by the
forming process. By convention, the texture comprises of two
components; roughness and waviness. Roughness consist of
finer irregularities characteristics of the process itself, such as
the grit spacing of the grinding wheel or the feed of the single
point cutting tool. Waviness consists of more widely spaced
irregularities that are often produced by the vibration in the
machining process. Usually, the terms surface texture and
roughness are used interchangeably, because roughness is
specified and measured much more often than waviness. The
surface topography includes these surface texture components
as well as any other irregularities, such as error of any form.
Fundamental research work on various forms and
shapes of surface texturing for tribological applications is
carried out by several research groups worldwide and various
texturing techniques are employed in these studies including
machining, ion beam texturing, etching techniques, shot
peening and laser texturing.
II. SHOT PEENING
Shot peening is a cold working method accomplished
by pelting the surface of a metal part with round metallic shot
thrown at relatively high velocity. Each shot acts as tiny
peening hammer, causing the surface to yield in plastic
deformation & leaving a small concave depression on the
surface of the metal. The depressions created by shot peening
have stress characteristics similar to a flat bar being bent. In
the case of a flat bar, the concave side of the bar is in
compression and the convex side in tension. The stress profile
in the bar goes from maximum compressive stresses on the
concave surface, to zero stresses at centre, then to maximum
tensile stress on the convex surface. In case of shot peening,
maximum compressive stresses are at the surface, due to the
deformation of the surface as opposed to bending. The stresses
go to zero at the transition zone between the surface material,
which has yielded to plastic deformation and the material
below, which has not below the transition zone the material is
in tension.
It is well known that cracks will not initiate nor
propagate in a compressively stressed zone. Because nearly all
fatigue and stress corrosion failures originate at or near the
surface of a part, compressive stresses induced by shot
peening provide significant increases in part life. The
magnitude of residual compressive stress produced by shot
peening is at least as great as half the tensile strength of the
material being peened. In most modes of long term failure the
common denominator is tensile stress. These stresses can

2. International Journal of Research in Advanced Technology - IJORAT
Vol. 2, Issue 1, JANUARY 2016
All Rights Reserved © 2016 IJORAT 2
result from externally applied loads or be residual stresses
from manufacturing processes such as welding, grinding or
machining. Tensile stresses attempt to stretch or pull the
surface apart and may eventually lead to crack initiation.
Compressive stress squeezes the surface grain boundaries
together and will significantly delay the initiation of fatigue
cracking. Because crack growth is slowed significantly in a
compressive layer, increasing the depth of this layer increases
crack resistance. Shot peening is the most economical and
practical method of ensuring surface residual compressive
stresses.
Shot peening is used on gear parts, cams & cam
shafts, cluster springs, connecting rods, crank shafts, gear
wheels, leaf & suspension springs, rock drills, and turbine
blades. It is also used in foundaries for sand removal,
descaling and surface finishing of castings such as engine
blocks and heads.
2.1.METHODS OF SHOT PEENING
The most popular method of shot peening are air
blast systems and centrifugal blast wheels.
2.1.1. Air Blast System
In air blast systems, media is introduced by various
methods into the path of high pressure air and accelerated
through a nozzle directed at the part to be peened. This system
is suitable for lower production applications where maximum
flexibility is needed. These systems are very flexible in that
the shot can be delivered horizontally through a rubber hose
and nozzle assembly. This enables uses in finishing operations
of steel frames and weldments thereby replacing hand tools.
Because of this, an air blasting machine for a production line
is expensive compared to the centrifugal wheel blasting
machine.
2.1.2.Centrifugal Blast System
The centrifugal blast wheel consists of a high speed
paddle wheel. Shot media is introduced in the centre of the
spinning wheel & propelled by the centrifugal force by the
spinning paddles towards the part by adjusting the media
entrance location effectively timing the media entrance
location effectively timing the release of the media.
Centrifugal wheel blasting is the more common blasting
technique as well as the most economical and environmentally
friendly method. The turbine delivers abrasive shot by
centrifugal force in a specific and controlled direction, speed
and quantity. Function of the turbine is similar to that of a fan
or centrifugal pump. Shot blasting machines may use one or a
multitude of turbines positioned in such a way that the
abrasive blast pattern covers the entire surface of the material
to be shot cleaned. The shape and size of the parts determine
the number of turbines used in a machine. Power of the
turbine motor is based on degree of cleaning needed and
throughout speed of the material.
2.2.CONTROLLED SHOT PEENING
Controlled short peening is the general method used
to describe the controlling of shot peening can be done in
many methods
a) Interactive shot peening control
b) Passive shot peening control
2.2.1.Interactive shot peening control
The Interactive controlling of shot peening is done
with the help of CNC shot peening machines. This will
control the almen intensity, shot diameter, peening pressure,
shot velocity etc. The LVDT will measure the deformation on
the almen strip on every interval & the intensity is being
produced on the CNC shot peening machine.
2.2.2.Passive shot peening control
The intensity of the shot stream is directly
proportional to the particles kinetic energy. When a particle
impacts the surface of a material, some of that kinetic energy
is absorbed and used to cold work the surface and put the
materials surface into compression.
The passive control method of determining the
intensity of the process uses strips of spring steel (Almen
strips) with special fixtures to evaluate the energy absorbed
into a surface. When the Almen strips are shot peened on one
side, the strips will bow after they are removed from their
holding fixtures, and the amount of bow or curvature can be
measured using a special gage called an Almen Gage The
amount that the Almen strip bows is known as its arc height,
and is normally measured in 1/1000 of an inch, or in
millimeters. To determine the intensity of a peening process, a
series of arc height readings for different time periods are
recorded and plotted on a curve called a Saturation Curve .
2.3.REVIEW OF SHOT PEENED SURFACE
PROPERTIES
Shot peening is applied to components in order to
induce improvements in their service performance. These
improvements depend, to a large extent, on the properties of
the shot-peened surface. Peening induces four major effects at
the surface of components. The four major surface effects are
• Hardening
• Structural changes
• Compressive residual stress
• Surface dimpling
2.3.1.Hardness
Peening imposes enormous amounts of plastic strain
(rapidly and heterogeneously) on the surface layers of
component material. During peening it is suggested that the
extreme surface hardness will reach its maximum value, even
before full coverage is achieved.
2.3.2.Structural changes
Most metallic engineering components have a
relatively-ductile matrix embedded with a variety of hard,
relatively-brittle, strengthening, phases. Plastic strain on
peening is then concentrated in the matrix. Some 90% of the
energy absorbed from impacting shot particles is converted
into heat energy. The remaining 10% is largely used to
produce a vast increase in the dislocation population. This

3. International Journal of Research in Advanced Technology - IJORAT
Vol. 2, Issue 1, JANUARY 2016
All Rights Reserved © 2016 IJORAT 3
increase is from about 106 to about 1010 (ten billion)
dislocation lines per square millimetre. Such an increase and
such numbers are difficult to visualise.
2.3.3.Induced Compressive Residual Stress
Shot peening induces a characteristic residual stress
profile with extreme surface compressive stress at about 50%
of the as deformed yield strength, increasing with depth to
about 60% of that yield strength before giving way to
balancing tensile stress. Increased peening severity increases
the depth at which the maximum compressive stress occurs.
2.3.4.Surface Dimpling
Shot peening induces a surface texture due to the
superposition of indentations. Individual indentations have a
„favourable‟ profile. That is because the profile is made up of
smooth curves. The stress required to make metal flow
through a 90° angle is infinitely high. It is therefore
impossible for dimples to have sharp-edged ridges. A peened
surface consists of over-lapping dimples, all of which have
smooth-profile ridges.
One considerable advantage of peened surfaces is that they
can induce an element of hydrodynamic lubrication between
moving parts Essentially, oil dragged into the dimples
generates a load-carrying pressure. This, in turn, reduces
surface wear.
III.EXPERIMENTS
3.1 Pump Shaft
Fig 3.1 Pump Shaft
Fig 3.1 is the pump shaft which is a major part whose
function is to transmit input power from the driver to the
impeller/s mounted on the shaft. It is subjected to several
stresses - flexural, shear, torsional, tensile, etc. Of these, the
torsional stress is most significant and is usually used as basis
for sizing the shaft diameter.
The shaft position, horizontally or vertically, defines
whether a pump is considered a horizontal pump, or a vertical
pump.
3.2 Design of Pump Shaft
Dia13*358mm
6 Stages Impeller
Material: En-8
3.3.Comparable Process Details
1.Hardening
2.Shot peening
3.4.Method- I - Heat Treatment
3.4.1.Hardening
Heat uniformly to 830/860°C until heated through.
Quench in oil or water. Can also be induction or flame
hardened.
3.4.2.Tempering
Heat uniformly and thoroughly at the selected
tempering temperatures, between 550°C to 660°C and hold at
heat for one hour per inch of total thickness.
3.4.3.Cylindrical Grinding
The outer diameter has to be just cleaned by the use
of cylindrical grinding machine.
3.5.Method – II- Shot Peening
The shot peening was done on air blasting shot
peening equipment which excites the shots with the help of
pressure created by the compressed air. The shot peening
machine have a power of 35 HP. It is a manually operated
machine, consist of a air compression motor, which pumps the
air, a blast cabinet and a nozzle to direct the stream of shots
towards the work piece. . The conditions used for the
experimental set up are given in table . The work is carried
out on low carbon steel specimen. The shot peening was done
on the cross-sectional surface of the En-8 steel specimen
having dimensions of diameter 10mm and length 30mm. The
specimen prepared is of forty in numbers. Eight peening
conditions obtained by varying pressure from 2.5 bars to 4
bars at an increment of 0.5 bars, for two shot sizes S110 &
S230. For each condition five specimens are used for shot
peening.
Factors Values
Nozzle diameter 6 mm
Distance between nozzle
and work piece
152.4 mm
Peening time 5 sec
3.6.Selection of Parameter in Shot Peening Process
3.6.1.Peening Pressure
1. 2.5 Bar
2. 3 Bar
3. 3.5 Bar
4. 4 Bar
3.6.2.Steel Shot Grades
1. S110 – 0.2mm Diameter

4. International Journal of Research in Advanced Technology - IJORAT
Vol. 2, Issue 1, JANUARY 2016
All Rights Reserved © 2016 IJORAT 4
2. S230 – 0.6mm Diameter
3.7.Comparable Testing Parameters
 Surface Roughness
 Micro-Hardness
 Intensity Variation
 Wear
 Frictional Force
 Co-efficient of Friction
IV. RESULTS AND DISCUSSION
4.1. Change in roughness Average
Peening Pressure
(Bar)
Roughness average Ra (µm)
S110 (0.2 mm
Diameter)
S230 (0.6 mm
Diameter)
2.5 4.522 6.272
3 4.644 6.405
3.5 5.487 7.47
4 6.012 7.899
4.2 Change in Micro-Hardness Variation
Peening Pressure
(Bar)
Micro- Hardness (HV)
S110 (0.2 mm
Diameter)
S230 (0.6 mm
Diameter)
2.5 236.1 231.5
3 253 238.5
3.5 264.9 231.7
4 238.2 265.8
4.3. Change in Almen Intensity
0
5
10
15
20
25
30
2.5 3 3.5 4
Pressure (bars)
intensity(A)
S110
S230
V.CONCLUSIONS AND FUTURE WORK
Prepared the En-8 Specimen for comparable analysis
of Heat Treatment and Shot Peening Process.The Shot
Peening has been done and tested in Vickers Hardness. The
following works will be carried out in future.
1. Heat Treatment
2. Cylinderical Grinding
3. Micro-Hardness
4. Wear Test
5. Frictional Force
6. Co-efficient of Friction
ACKNOWLEDGMENT
I am using this opportunity to express my gratitude to
everyone who supported me throughout the project. I am
thankful for their aspiring guidance, invaluably constructive
criticism and friendy advice during the project work. I am
sincerely grateful to them for sharing their truthful and
illuminating views on a number of issues related to the project.
I would also like to thank to all the people who provided me
with the facilities being required and conductive conditions
for my project.
REFRENCES
[1] Peter Bailey & Jack Champaigne; “Factors that
influence Almen strip arc height”; ICSP9.
[2]A.Tange, H.Okada; “Shot peening coverage”.
[3]R. Clausen, J. Stangenberg, “Roughness of shot-
peened surfaces- definition and measurement”; ICSP7
[4]David Kirk; “Interactive shot peening control”; The
Shot Peener.
[5]Bill Barker; “Shot meter: A new tool for evaluating
shot peening intensity”; Progressive technologies.
[6]David Kirk; “Ductility and strength properties of
shot peened surfaces”; The Shot Peener.
[7]Olivier Higounec; “Correlation of shot peening
parameters to surface characteristic”; Metal
Improvement Company. ICSP9.
[8]M.Babic, D.Adamovic, B.Jeremic, S.Mitrovic;
“Tribological effects of shot peening surface
treatment”: ICMEN, October 2008; Greece