Suresh Kumar | Thapar University, Patiala (original) (raw)

Papers by Suresh Kumar

Th e interest in natural mineral reinforced composite materials is rapidly growing both in terms ... more Th e interest in natural mineral reinforced composite materials is rapidly growing both in
terms of their industrial applications and material research as minerals are renewable, cheap,
completely or partially recyclable, and bio-degradable. In the present studies, LM13 alloy
matrix composite reinforced with rutile particles is fabricated by stir casting process. Th e
sliding wear tests were performed at diff erent temperatures against an EN32 steel disc at
diff erent pressures. Th e continuous increase in wear rate was observed with the increase in
temperature from 50-200°C and thereaft er the wear rate decreases sharply up-to 250°C. Th e
formation of anti-wear protective tribo-oxide layers on the contact surface in the temperature
range from 200-250°C considerably reduces the wear. Energy dispersive X-ray spectroscopy
(EDX) analysis of the wear tracks and wear debris in the temperature range 50-200°C have
shown no traces of tribo-oxides, so higher wear rate was observed. Th e eff ect of temperature
and contact pressure on the worn surface and wear debris was thoroughly investigated for
the morphology (scuffi ng, layer blistering and delamination), composition and structure of
tribo-layers using scanning electron microscopy (SEM).

The present investigation aims to find the combined effect of coarse and fine size particle reinf... more The present investigation aims to find the
combined effect of coarse and fine size particle reinforcement
of zircon sand in aluminum alloy LM13 on the wear
behavior. The composites are fabricated by varying the
reinforcement of fine and coarse size zircon sand particles
and compared with the single size reinforcement. Coarse
and fine particle zircon sand of 106–125 and 20–32-lm
size, respectively, are used in this study. The wear test was
carried out on pin-on-disc machine. Microhardness measurement
was done for developed composites. Wear track
and debris are analyzed by SEM to study the wear mechanism.
Line profile and EDS analysis is also done to validate
the microstructural results. Study reveals that a
combination of 3 % fine and 12 % coarse particle reinforced
composite exhibits better wear resistance while 3 %
coarse and 12 % fine particle reinforcement decreases the
wear resistance. It is also observed that zircon sand particles
provide effective nucleation site for the eutectic silicon.
Microstructural examination shows globular and
finely distributed eutectic silicon in the vicinity of the
reinforced particles.

The tribological behaviour of samples of LM13 alloy matrix reinforced with 15 wt. % Zircon sand a... more The tribological behaviour of samples of LM13 alloy matrix reinforced with 15 wt. % Zircon sand also
15wt.% and Zirfloor particles in low and high range of loads (1kg and 5kg) was determined using a pin-on-disc wear and
friction monitor at a constant velocity of 1.6 m/s. Zircon sand and Zirfloor sand (particles size 5-32m) are reinforced in
the LM13 alloy by stir casting method. Optical microscopy show uniform distribution of particles and reveal better
bonding in the case of zircon particles reinforced composite compared to that in zirfloor particles reinforced composite.
It is observed that the zircon particle reinforced composite shows relatively better wear resistance property compared to
zirfloor-reinforced composite.

In the present work, a detailed study of ceramic reinforcement of different size ranges in the ma... more In the present work, a detailed study of ceramic
reinforcement of different size ranges in the matrix of
LM13 alloy on the friction and wear behavior has been
carried out. For this purpose, LM13/Zr composite containing
10 wt% zircon sand particles of different size ranges
using stir casting process has been developed. Zircon
sand particles were incorporated in two ways: firstly as
single size reinforcement and secondly dual size reinforcement.
Durability of the composites was tested by
finding the wear rate of the composite against the steel disk
by pin-on-disk method. Addition of zircon sand particles in
the LM13 alloy improves the hardness of the composite as
well as wear resistance. Wear rate of the developed composites
was tested under different test conditions by varying
the applied load and ambient temperatures. Wear rate
of the composite changes significantly at different ambient
temperatures. SEM analysis of the worn surfaces was done
to know the operative wear mechanism.

The present investigation aims to evaluate the wear behavior of aluminum (LM13) alloy composites ... more The present investigation aims to evaluate the wear behavior of aluminum (LM13) alloy composites reinforced with garnet particles. The liquid metallurgy technique was used to fabricate the composites. The reinforcement content was 10wt.% and 15wt.% garnet particles. A pin-on disc wear testing machine was used to evaluate the wear loss of composites. The results reveal that the wear loss of composites was less than that of the aluminum (LM13) alloy, but increased with increase of reinforcement in load and sliding distance. It was found that the wear resistance increases with increase in garnet content and decreases with the reinforced particle size. The nature of wear has been explained using scanning electron microscopy (SEM) analysis of the worn surfaces and debris.

Aluminum composite foams are the commercially used materials for different engineering applicatio... more Aluminum composite foams are the commercially used materials for different engineering applications because of their unique combination of properties such as high energy absorption, very low density, blast amelioration, flame resistance, and sound absorption. In the present work various types of polyhedron structure of particulate reinforced composite foams were developed by stir casting process at different temperatures. The work describes the effect of casting temperature on the development of different shapes of polyhedron structure. The associated mechanism for the formation of such structure is also described. The results show that casting temperature had little effect on the polyhedron structure of particulate reinforced composite foams in the temperature range from 850 ᵒC to 875 ᵒC

The present article describes in detail the wear behavior of rutile-reinforced LM13 alloy composi... more The present article describes in detail the wear behavior of rutile-reinforced LM13 alloy
composite at elevated temperatures. Rutile particles in different amounts were reinforced
into LM13 alloy by stir casting route. The microhardness measured at different areas
indicates good interfacial bonding. Wear tests were conducted for composites containing
rutile particles in 10wt.% and 15wt.% with variation in particle size (50-75μm and 106-
125μm). The presence of ceramic particle in the matrix improves the hardness, wear
resistance, thermal stability as well as durability of the materials. The wear of composite
at 200 ºC presented entirely different wear behavior mode than that at 250 ºC. The wear
rate of fine size reinforced composite at 200 ºC at higher load was substantially lower
than that of coarse size reinforced composite. A transition from mild-to-severe wear at
higher load was observed above 150 ºC. The morphology of wear track and debris
indicate that nucleation of cracks around the void on the interface of the particles is the
main cause of surface damage.

In the present paper, well known piston alloy (LM13) reinforced with ZrSiO4 particles was develop... more In the present paper, well known piston alloy (LM13) reinforced with ZrSiO4 particles was developed and
studied as wear resistant material. The particle reinforced aluminum metal matrix (PAMC) was developed by stir casting
route. Composite was developed by reinforcing 10 wt. % of ZrSiO4 particles into LM13 alloy. Wear behavior of LM13
alloy reinforced with ZrSiO4 particles have been carried out with different applied load. Micrographs of worn surfaces
after wear test were examined by scanning electron microscope. These micrographs indicate the presence of the adhesive
and abrasive wear mechanism, and transition from mild to severe wear at higher load.

Aluminium alloy matrix composites have found its wide applications in the manufacturing of the va... more Aluminium alloy matrix composites have found its wide
applications in the manufacturing of the various components
such as piston, brakes, piston liners and engine where tribological
properties are a predominant process. Aluminium alloy reinforced
with 5wt.% and 10wt.% of rutile concentration was prepared by
liquid metallurgy route. Wear tests were performed at different
loads varying from 9.8N to 49N at constant sliding velocity of
1.6m/sec. Materials possessing high wear resistance under dry
sliding conditions are associated with a formation of stable
tribo-layer on the wearing surface. In this work, a systematic
experimental study was performed to analyse the effect of contact
pressure on the formation of the tribo oxide layers during sliding.
The shape and size of the wear debris clearly demonstrated that
how the particles were fractured and comminuted, losing their
role as load supporters.

The basic aim of the present investigation is to study the role of particle size for high-tempera... more The basic aim of the present investigation is to study the role of particle size for high-temperature
application of ZrSiO4-reinforced aluminum-based LM13 alloy composite as a bearing
material. Composites containing 15 wt pct ZrSiO4 particles of two different size ranges (20 to 32
and 106 to 125 lm) in different proportion were prepared by the stir casting route. The
microhardness measured at different areas indicates good interfacial bonding. Transition in the
wear mode for all composites occurs after temperature 423 K (150 C). The overall wear
properties of DPS-2 composite containing 12 pct fine and 3 pct coarse particles are better at all
temperatures for both low and high loads

In the present investigations, LM13 aluminium alloy reinforced with 15 and 20wt.% rutile mineral ... more In the present investigations, LM13 aluminium alloy reinforced with 15 and 20wt.% rutile mineral of fine (50–75 mm) and
coarse (106–125 mm) size range was prepared through stir casting technique. The microhardness on different phase of
the composite was measured to check the interfacial bonding of particles with the base material. The wear properties of
the samples were studied using pin-on-disc tribometer at high load (49 N) with variation in temperatures from 50C to
300C. Wear results indicated that the composites containing fine size reinforced particles showed around two times
higher wear resistance over a wide range of temperature than the composite-containing coarse particles. A transition in
wear mode from mild to severe was observed above 200C. Wear track and wear debris were analysed to understand
the nature of wear.

Pyrochlore-structured materials are very important materials due to their structural and conducti... more Pyrochlore-structured materials are very important
materials due to their structural and conducting properties.
These properties can be further modified by changing
processing conditions. In the present study, pyrochlore
(Y2Ti2O7) is synthesized using high-energy ball milling.
During various stages of ball milling, the ball-milled powder
is taken for investigating the structural and thermal properties.
The replacement of Ti2O3 by TiO2 in nominal composition
leads to lower ball milling duration to form Y2Ti2O7.
Differential thermal analysis showed the single exothermic
peak below 800 °C, which indicates formation of disordered
pyrochlore phase. The as prepared powders (40-h ball milled)
were compacted and heat treated at 1,450 °C for 12 h. The
conductivity of sintered sample is found to be one order
higher than earlier reported pure Y2Ti2O7 pyrochlore.

The nature and distribution of hard ceramic particles in composite materials influences the prope... more The nature and distribution of hard ceramic particles in composite materials influences the properties to greater extent. In the present
work, the role of hard ceramic reinforced particles on the tribological behaviour of aluminum metal matrix composites consisting of
single (SRP) and dual reinforced particles (DRP) is studied at different temperatures. Zircon sand and silicon carbide particles of size
20–32 mm were used as reinforcement in commercial grade LM13 piston alloy. Composites of dual reinforced particles in aluminum
matrix (DRP-AMCs) were developed by mixing 15 wt% reinforced particles by two step stir casting technique. The wear behaviour of
DRP-AMCs and SRP-AMCs (single reinforced particles aluminum matrix composite) was investigated using a pin-on-disc method at
high temperatures under dry sliding condition. The microstructural examination of developed composites shows globular and finely
distributed eutectic silicon in the vicinity of the reinforced particles. Metallographic investigation revealed that the wear zone of the SRP
composite consisted of a hardened layer, which is responsible for high wear loss observed in the SRP composite. The results further
indicate a transition in the wear mode that occurs after 150 1C for all composites. Study reveals that the dual reinforcement of particles
enhances the wear resistance as compared to single reinforced particles if mixed in a definite ratio. A combination of 3% zircon sand and
12% silicon carbide particle reinforced composite exhibits better wear resistance as compared to other combinations at all the temperatures for low and high loads both.

Discontinuous reinforced aluminum matrix composites (DAMCs) are widely used in automobiles, milit... more Discontinuous reinforced aluminum matrix composites (DAMCs) are widely used in automobiles,
military and many other engineering areas due to their attractive properties. DAMCs are used in
automobile industries for manufacturing bogies, cars and other structural components. Apart from
this it is also used in components which are subjected to high temperatures. In the present work we
have studied the tribological characteristics of DAMCs containing zircon sand, SiC and Zirfloor as
reinforced ceramic particles in Al alloy. These three types of ceramic particles (particle size 5-32
μm) are reinforced in the Al-12Si alloy (LM13) by liquid metallurgy route (stir casting technique).
Total 15 wt% of the tri reinforced particles (TRP) are added in LM13 alloy to fabricate Al–TRP
composite for tribological application. Wear characteristics of Al–TRP composites have been
investigated under dry sliding conditions. Dry sliding wear tests have been carried out using a pinon-
disc method at 1Kg and 5Kg loads. Sliding distance during the wear test was about 3000 meters
with a constant sliding velocity of 1.6 ms-1. In the study it was observed that wear rate of the
composite increases with increase in amount of load. Microhardness measurement was done for the
developed Al-TRP composite. SEM images of wear track on composite gives better idea of the
wear mechanism. Wear debris collected after the wear test was also examined for deeper
understanding of wear behavior. Study reveals that about equal amount of ZrSiO4, SiC and Zirfloor
reinforced particle in Al-TRP composite exhibits better wear resistance compared to aluminum base
alloy.
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The present study aims to analyze the effect of particle size on nature of microstructural featur... more The present study aims to analyze the effect of particle size on nature of microstructural features
and wear behavior of composite. Stir casting route has been adopted for the fabrication of
aluminium matrix composite using Al-Si LM13 piston alloy. Composites have been developed by
varyig the size of zircon sand particles while keeping the SiC particles of same size.
Microstructural analysis shows that SiC has a pronounced effect on the microstructure and eutectic
silicon refinement. Microstructure evolution is mainly governed by the thermal conductivity
difference between two phase’s i.e. ceramic particle and alloy matrix. The dendritic ripening is also
observed in the composites in microstructural study. EDS analysis reveals the formation of
mechanically mixed layer in the composites enabling better wear properties. Fine size zircon sand
particle reinforced composite exhibits better wear resistance than coarse particle at same weight
percentage of reinforcement. The SiC reinforcement is better as compared to zircon sand particles
for enhancing wear resistance of the composite. Silicon carbide refines the eutectic silicon whereas
zircon sand provides good interfacial bonding. SEM examination of worn surface and wear debris
shows that the various wear mechanism are involved in material removal.

The present investigations are a comparative study of single and dual reinforcement particles on ... more The present investigations are a comparative
study of single and dual reinforcement particles on
microstructural features and wear behavior in LM-13 aluminum–
silicon alloy. Silicon carbide and zircon sand particles
of 20–32 lm are reinforced in the alloy by two-step
stir casting method. Wear study reveals that the dual particle
reinforcement enhances the wear resistance as compared
to single particle reinforcement if mixed in a definite
proportion. Study also indicate that a combination of 15 %
reinforcement of zircon sand and silicon carbide particles
in the ratio of 1:3 into the composite exhibits better wear
resistance as compared to other combination.