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IJIRST –International Journal for Innovative Research in Science & Technology| Volume 3 | Issue 01 | June 2016 ISSN (online): 2349-6010
All rights reserved by www.ijirst.org 101
Tribological Investigations on Al-Al3Ti In-situ
Metal Matrix Composite
Veeresha G
Assistant Professor
Department of Mechanical Engineering
New Horizon College of Engineering, Bangalore-560103, Karnataka, India
Abstract
In the present study, an attempt has been made to prepare and characterize Al-Al3Ti metal matrix composites with varying
percentage of in-situ Al3Ti (3, 5 and 7%). The composites were prepared by the reaction commercial purity aluminum 99.7%
and K2TiF6 salt at a reaction temperature of 800 °C. The prepared samples were characterized by optical microscopy. The wear
tests were conducted on all the prepared samples by varying parameters like wt. % of Al3Ti particles, normal pressures, sliding
speeds. Mechanical properties were assessed using computerized universal testing machine, Brinell hardness tester, Surface
roughness tester and micro hardness tester. The worn surfaces were examined by optical microscopy after wear test.Al-3Ti, Al-
5Ti and Al-7Ti alloys were prepared and effect of Ti content on hardness, tensile strength, volumetric wear rate and surface
roughness were examined. Experimental alloys were fabricated by salt route method. Volumetric wear rate of the reinforced Al-
3Ti, Al-5Ti and Al-7Ti alloys at room temperature were measured. The present results suggest that the wear resistance of Al-
Al3Ti composites increases with increase in percentage of Al3Ti particles compared to pure aluminum. In addition, the
improvement in mechanical properties of the composite was observed in Al-5Ti composite when compared to Al-3Ti and Al-7Ti
and to the pure Al. Better tribological properties of these alloys can be achieved at Al-5Ti.
Keywords: Al-Al3Ti, Intermetallic compounds, Hardness, Tensile strength, Volumetric wear rate, sliding speed, Surface
roughness, frictional force
_______________________________________________________________________________________________________
I. INTRODUCTION
For structural application of moving components, the tribological properties (friction and wear) are considered to be one of the
major factors controlling the performance. In recent years, lightweight metal matrix composites (MMC) have received wider
attention for their technological application, such as automotive parts etc. This paper reports the tribological behavior of Al based
composites reinforced with in situ TixAly and Al2O3 particles. The wear experiments were performed on a newly designed
fretting tribometer to evaluate the role of intermetallic particulates on the wear performance of in situ composites against bearing
steel under the ambient conditions of temperature (22–25 °C) and humidity (50–55% RH). Based on the topographical
observation of the worn surfaces the plausible wear mechanisms are discussed. An important result is that Al-based composites
with 20 vol% reinforcement exhibit an extremely low coefficient of friction of 0.2 under unlubricated conditions. Also, around
five times lower wear volume is measured with 20 vol% composites when compared to unreinforced Al.
During past two decades, requirements for specific property material for advanced aerospace and automobile application have
escalated since conventional alloy systems are not suitable there. Attempts to enhance the performance characteristics of
monolithic materials by reinforcement with high strength/ high stiffness second phase are therefore required. By selecting the
appropriate reinforced constituents of a material that is volume fraction, shape and size. It is possible to design alloys with
enhanced strength and stiffness. Polymers, ceramics or metals such as aluminum, magnesium, titanium, copper and nickel alloys
serve as matrix materials with whiskers (SiC), monofilaments (SiC, B, W), fiber (SiC, Al2O3, graphite) and particulate (SiC,
Al2O3, Al3Ti) acting as reinforcement. These reinforcements normally strengthen the matrix as they are stronger than the matrix
alloys. Due to the presence of hard particles these metal matrix composites (MMCs) are currently being considered as promising
tribological materials with applications in the aerospace, aircrafts and in a particular automotive industries. The high strength to
weight ratio and wear resistance of aluminum MMCs makes the substitution of steel engine parts such as pistons, liners, clutches,
pulleys rockers and pivots by MMCs parts in automobiles. This results in improved engine efficiency a reduction in noise and
friction.
Aluminum based particulate reinforced metal matrix composites have emerged as an important class of high performance
materials for use in aerospace, automobile, chemical and transportation industries because of their improved strength, high
elastic modulus and increased wear resistance over conventional base alloys. Recently, in situ techniques have been developed to
fabricate aluminum-based metal matrix composites [1-4], which can lead to better adhesion at the interface and hence better
mechanical properties. Owing to low density, low melting point, high specific strength and thermal conductivity of aluminum, a
wide variety of ceramic particulates such as SiC, B4C, Al2O3, TiC and graphite have been reinforced into it.
Among these particulates, Al3Ti has emerged as an outstanding reinforcement. This is due to the fact that Al3Ti is stiff, hard
and more importantly, does not react with aluminum to form any reaction product at the interface between the reinforcement and
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 102
matrix. There are a few routes to synthesis Al–Al3Ti composites, but in-situ approach is particularly suitable. Apart from the Al3-
Ti exothermic nature with Al, its clean interface resulting from absence of oxidation during the creation of reinforcement offers
its potential as a wear resistant composite. Its strong bonding with the Al matrix has been verified to be the control factor that
affects the wear improvement of the composite. In situ composites are multiphase materials where the reinforcing phase is
synthesized within the matrix during composite fabrication.
Titanium Aluminide, which belongs to the refractory transition metal Aluminde, is well known for its stiffness and hardness.
Furthermore it has good toughness and a high melting point and a good corrosion resistance. The Al3Ti additions greatly
increases the stiffness, hardness and wear resistance and decrease the coefficient of thermal expansion while reducing the
electrical and thermal conductivity much less than the addition of the most other ceramic reinforcement. Furthermore Al3Ti is a
nucleating agent for aluminum, which of significance for the grain refining of Al. Therefore recently Al3Ti reinforced Al matrix
composite have been studied.
Most process employed in the synthesis of MMCs involve the incorporation of ceramic particles into the matrices via solid
state (diffusion bonding, powder metallurgy, co extrusion, plasma spray, chemical and physical vapour deposition) and liquid
state (squeeze casting) fabrication techniques. In these processes preexisting ceramic particles incorporated into the aluminum
matrices. The major draw backs in these process involves the difficulties encountered in incorporating the fine ceramic
enforcements into the matrices, agglomeration and poor wetting between particles and matrices.
To overcome this problem and to increase the bonding strength between the particles and the matrix, the exothermic reaction
process is good way to produce in situ ceramic particulates in the fabrication of Al based, Ti based, Ni based and other type
based MMCs. Some commercial examples of in situ processing routes are lanxide’s DIMOX and PRIMEX, Martin Marientta’s
XD synthesis, self-propagating high temperature synthesis, mechanical alloying, reactive gas injection, and reactive infiltration.
One of the major drawback of these in situ composite is highly porous nature of the products.
A new technology has been developed for the preparation of Al-Al3Ti in situ composites. In this process K2TiF6and KBF4 salts
are mixed in molten Al. An exothermic reaction takes place to produce a dispassion of Al3Ti particles. This is a single step and
cheap casting process. This is a practical method for making wear structural parts. Hence the present study is taken up for
preparing Al- Al3Ti in situ composites with varying percentage of Al3Ti particle.
II. LITERATURE REVIEW
As compared to most other aluminum -rich intermetallic phases, Al3Ti is very attractive because it has higher melting point
(1460ºc) and relatively low density (3.91 g/cm3).The presence of Al3Ti particles can increase the creep strength of the alloy
significantly (In Al-Al3Ti).By considering load sharing effect Al3Ti, an analysis based on continuum mechanics approach has
been conducted. The threshold stress for creep in these composites was found to increase with increasing Al-Al3Ti composite.
The presence of Al3Ti phase is very effective in increasing the stiffness of Al alloys. Alloy with fine two- phase Al-Al3Ti
structure and significant Al3Ti content have been successfully produced by MA process. The young’s modulus of Al3Ti phase
has been determined to be 176GPa.The mechanical Alloying (MA) Al-Al3Ti alloys are characterized by very fine grain size and
the presence of large volume fraction of fine dispersions of Al3Ti, Al4C3, and Al2O3 particles. The size range of both the Al3Ti
particles and the Al grains are 100-500 nm. According to the characteristics of the microstructure , MA Al-Ti alloy may be
considered as a fine Al-Al3Ti two phase composite , in which the Al matrix further strengthened by the fine dispersoids of
carbide and oxide. The fine carbide and oxide particles are mainly responsible for the fine grain structure as well as
microstructural stability of the Aluminum matrix. The Al-Al3Ti composites have been shown to exhibit attractive combinations
of low density (2.8g/cm3), high modulus, elevated temperature strength, thermal stability, and corrosion resistance. The young’s
modulus of Al-Al3Ti composites was shown to increase to increase linearly with the content of Al3Ti, that the increment is 1.1GP
for every 1 volume % addition A The Al-Al3Ti composites exhibit good elevated temperature strength 115-155MPa, at 698K.A
series of Al-Al3Ti composites of various Al3Ti content were prepared from Al and Titanium powders of commercial purity by
mechanical Alloying (MA) [1].
Al3Ti intermetallic compounds were known as ductile materials with low toughness that causes some restriction in many
applications. Since 1980, in order to increase the usage of these compounds and obtain tougher materials, they were used as
reinforcements in metal matrix composites. During the last few decades, most researches have focused on ceramic reinforced
aluminum metal matrix composites (MMCs). But there were some limitations in the fabrication process. These limitations
include large differences between the coefficient of thermal expansions (CTE) of Al matrix and the ceramic reinforcements, and
also high brittleness of ceramics. Intermetallic compounds which have low density and high modulus were a convenient choice
when compared to ceramics. Since Al intermetallic compounds such as Al3Tihave highly close CTE compared with Al and
lower brittleness compared to the ceramics, they can be a better choice than ceramics to overcome the mentioned obstacles.
These prominent properties caused intermetallic compounds and mainly in this study, Al3Ti proves to be an attractive
reinforcement for Al base metal matrix composites. Al3Ti with the density of 3.3 g/cm3, high melting mechanical properties.
Al3Ti particles that form through in situ method are bonded strongly to the Al matrix due to the thermodynamic equilibrium.
This strong bond is due to the good compatibility of a-Al having FCC crystal structure and tetragonal Al3Ti. Due to the high
melting temperature of Al3Ti, the most appropriate fabrication methods are powder metallurgy, such as hot pressing (HP), hot
extrusion, and hot isostatic pressing (HIP) at temperatures close to the melting point of Al (660°C). These in situ generated
particles increase the strength and modulus of the composite, which would significantly improve its wear resistance [2].
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 103
Kuruvilla et.al have fabricated the in-situ particulate reinforced aluminum composite by hot pressing and reacting sintering Ti
, Al and B powders. They reported that Al3Ti particulates with a size of about 1µm were formed in-situ in the aluminum matrix.
In addition, there also existed some irregularly shaped Al3Ti particles (about 1 vol. %) with a size of several tens of micrometers
in the in-situ composites, it is expected that a reduction in the particles would have an influence on properties of the composites,
it is expected that a reduction in the particle size of the reinforcement would lead to improvements in strength, assuming all
others things (shape, chemistry and distribution) are equal [3].
Carpenter et.al used molten salt (K2TiF6 and KBF4) reactive casting process to produce a dispersion of TiB2 particles in
Aluminum matrix. They found out three distinct size distributions of particulates (or rods): (a) coarse, with diameters (or length)
5-10µm. (b) fine, 1-2µm in size and (c) minute, about 10nm diameters. The coarse particles are composed of Al3Ti and finer
particles appeared to be randomly oriented and homogeneously distributed in the matrix. They have reinforced aluminum based
metal matrix composites (MMCs), the automotive industries has identified a number of application for these materials [4].
III. EXPERIMENTAL DETAILS
Material preparation:
First of all Al-3wt%Ti, Al-5Ti and Al-7wt%Ti composites were prepared by reaction of halide salt such as K2TiF6 with molten
Al in the resistance furnace. The process parameters such as reaction temperature of 800C and reaction time 60min were used in
the present study. Initially commercial purity aluminium (99.7%) was heated to 8000C in the resistance furnace. Once the
required temperature was attained, the pre heated halide salts were added to the melt. The reaction between molten Al and the
halide salts is generally vigorous and highly exothermic. Melt was stirred for 60min with zirconium coated steel rods to mix the
halide salts with commercial purity aluminium (CPAl). After the completion of reaction, the spent salt was decanted from the
surface of molten alloy and the melts were poured into the cylindrical graphite mould to prepare master alloys.
Resistance Furnace
Specifications:
Power Rating - 6KW Supply 3 phase, 440V Max. Temperature 1300°C Capacity – 5KG
Microstructure studies:
The castings (25 mm ф and 100 mm length) were sectioned at a height of 25 mm from the bottom. A specimen of 5 mm height
was cut from the section, which was left after 25 mm from the bottom surface of the casting. One surface of the specimen was
initially polished using belt grinder and then a series of waterproof emery papers with increasing fineness to remove any of the
scratches present. Final polishing was carried out on a disc polisher using 400 – mesh alumina powder until the mirror finishes
and scratch free surface was obtained. Polished samples were cleaned with soap solution and distilled water and then the
polished specimens were taken for optical microscopy.
Experimental Procedure:
Physical tests have been conducted on Al-3Ti, Al-5Ti, and Al-7Ti materials like Hardness, Tensile and surface roughness to
understand the material properties.
Hardness Test:
The hardness test was conducted on brinell hardness tester. All Brinell tests use a carbide ball indenter. The test procedure is first
the indenter is pressed into the sample by an accurately controlled test force. The force is maintained for a specific dwell time,
normally 10 - 15 seconds. After the dwell time is complete, the indenter is removed leaving a round indent in the sample. The
size of the indent is determined optically by measuring two diagonals of the round indent using either a portable microscope or
one that is integrated with the load application device. The Brinell hardness number is a function of the test force divided by the
curved surface area of the indent. The indentation is considered to be spherical with a radius equal to half the diameter of the
ball. The average of the two diagonals is used in the following formula to calculate the Brinell hardness.
Fig. 3.1: Schematic diagram of the hardness test
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 104
Table - 3.1
Brinell Hardness Number
Sl. No Specimen BHN(Kg/mm2)
1 Al-3Ti 68.33
2 Al-5Ti 73.33
3 Al-7Ti 70
Tensile Test:
The tensile test was conducted on the Universal Testing Machine(UTM). The test specimen overall length is 12mm.The D/L
ratio is 1:8 i.e mean diameter is 8mm and gage length is 64mm.
The test procedure is first to measure the mean diameter and nominal length. After that insert the specimen in the UTM and
attach the extensometer. Selected a load range for UTM that will accommodate the maximum anticipated load during the test.
Applied the load slowly, obtaining simultaneous readings of load from the UTM and elongation from the extensometer. When
the extensometer nears its range, removed. Then continue monitoring the elongation of the specimen until fracture occurs.
Attempt to obtain the load at fracture. After failure, fit the broken valves together and measure the final “gage” length, and the
smallest diameter.
Fig. 3.2: Typical tensile specimen, showing a reduced gage section and enlarged shoulders.
For Al-3Ti,
Before breaking, Mean diameter= 8.073 mm
Gage length= 64.5
After breaking, Mean diameter= 8 mm
Gage length= 66 mm
Peak load= 6.025 KN
Displacement at Fmax= 11.090 mm
Breaking load= 1.520 KN
Maximum Displacement = 11.250 mm
Area= 51.170 mm2
Ultimate stress= 0.118 KN/mm2
Elongation= 2.326%
Reduction in area= 1.727%
For Al-5Ti,
Before breaking, Mean diameter= 8.01 mm
Gage length= 61.9 mm
After breaking, Mean diameter= 7.7 mm
Gage length =65 mm
Peak load= 5.503 KN
Displacement at Fmax= 7.780 mm
Breaking load= 0.215 KN
Maximum displacement= 7.990 mm
Area= 50.412 mm2
Ultimate stress= 0.109 KN/mm2
Elongation= 5.008%
Reduction in area= 7.591%
For AL-7Ti,
Before breaking, Mean diameter= 8.046 mm
Gage length= 62.8 mm
After breaking, Mean diameter= 7.9 mm
Gage length= 66.3 mm
Peak load= 4.568 KN
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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Displacement at Fmax= 8.900 mm
Breaking load= 0.915 KN
Maximum displacement= 8.940 mm
Area= 50.790 mm2
Ultimate stress= 0.090 KN/mm2
Elongation= 5.573%
Reduction in area= 3.452%
Wear Test:
Wear tests were conducted on pin on disc machine. The disc was made up of low carbon alloy steel (diameter 210mm) with
hardness value about HRc 65. Five variables noted during the experiments were normal load, frictional force on the specimen,
weight loss of the specimen due to wear, rotational speed and wearing time. Wear loss of the specimen was calculated by
weighing the specimen before and after the each experimental on electronic analytical balance.
All the wear tests were carried out at room temperature without any lubrication. Twelve experiments were conducted under
operational conditions of two loads and two speeds. The process was repeated and compared the estimated values. Variables
considered:
Following wear test variables were selected.
Sliding distance = 3000 m
Sliding speed = 1 m/s, 3 m/s
Load= 1 Kg, 3 Kg
Estimation of speed and time for the experimental sliding speed:
D- Diameter of wear track= 90 mm
d- Diameter of wear pin= 10 mm
v- Sliding speed (m/s)
N- Rotational speed of wear disc (rpm)
V= π ×D×N/1000×60
N= v×1000×60/π×D
= 1×1000×60/π×90
= 212 rpm
N= 3×1000×60/ π ×90
= 636 rpm
For present investigation sliding distance, s= 3,000 m is considered.
S= πDNT
Where T= time in minutes
T= s/π×D×N
= 3,000/π×90×212
= 50 min
T= 3,000/ π ×90×636
= 17 min
Estimation of Experimental Results
Specimen Load
(Kg)
Normal Pressure
(MPa)
Sliding
spee(m/s)
Frictional force
(N)
Weight
loss(Kg)
Volume
loss(m3)
Volumetrc wearrate
(m3/m)
1
Al-3Ti
1 0.1248 1 9.9 0.0000313 1.16E-8 3.864E-12
2 1 0.1248 3 9.7 0.00001861 3.703E-7 1.234E-10
3 3 0.3747 1 13.8 0.00005752 2.13E-8 7.101E-12
4 3 0.3747 3 3.8 0.00029601 1.096E-7 3.65E-11
5
Al-5Ti
1 0.1248 1 5.5 0.00002927 1.084E-8 3.615E-12
6 1 0.1248 3 5.8 0.00001794 6.644E-9 2.225E-12
7 3 0.3747 1 11.5 0.00005883 2.28E-8 7.26E-12
8 3 0.3747 3 17 0.00003381 1.25E-8 4.174E-12
9
Al-7Ti
1 0.1248 1 5.2 0.00002897 1.073E-8 3.57E-12
10 1 0.1248 3 10.3 0.00002273 8.418E-9 2.806E-12
11 3 0.3747 1 12 0.0000664 2.459E-8 8.197E-12
12 3 0.3747 3 14.8 0.00003729 1.381E-8 4.603E-12
For Al-3Ti,
(1) Volume loss= Weight loss/Density
= 0.0000313/2700
= 1.16E-8 m3
Volumetric wear rate = Volume loss/Sliding distance
= 1.16E-8/3,000
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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= 3.864E-12 m3/m
(2) Volume loss= Weight loss/Density
= 0.0000186/2700
= 3.703E-7 m3
Volumetric wear rate = Volume loss/Sliding distance
= 3.703E-7/3,000
= 1.234E-10 m3/m
(3) Volume loss= Weight loss/Density
= 0.00005752/2700
= 2.13E-8 m3
Volumetric wear rate = Volume loss/Sliding distance
= 2.13E-8/3,000
= 7.1012E-12 m3/m
(4) Volume loss= Weight loss/Density
= 0.0000296/2700
= 1.0966E-7 m3
Volumetric wear rate= Volume loss/Sliding distance
= 1.0966E-7/3,000
=3.65E-11 m3/m
For Al-5Ti,
(1) Volume loss= Weight loss/Density
= 0.00002927/2700
= 1.084E-8 m3
Volumetric wear rate = Volume loss/Sliding distance
= 1.084E-8/3,000
= 3.613E-12 m3/m
(2) Volume loss= Weight loss/Density
= 0.00001794/2700
= 6.644E-9 m3
Volumetric wear rate= Volume loss/Sliding distance
=6.644E-9/3,000
=2.214E-12 m3/m
(3) Volume loss= Weight loss/Density
= 0.00005883/2700
= 2.178E-8 m3
Volumetric wear rate = Volume loss/Sliding distance
=2.178E-8/3,000
= 7.26E-12 m3/m
(4) Volume loss= Weight loss/Density
= 0.00003381/2700
= 1.252E-8 m3
Volumetric wear rate= Volume loss/Sliding distance
= 1.252E-8/3,000
= 4.174E-12 m3/m
For Al-7Ti,
Volume loss= Weight loss/Density
= 0.00002897/2700
= 1.0729E-8 m3
Volumetric wear rate = Volume loss/Sliding distance
= 1.0729E-8/3,000
= 3.576E-12 m3/m
(2) Volume loss= Weight loss/Density
= 0.00002273/270
= 8.418E-9 m3
Volumetric wear rate= Volume loss/Sliding distance
=8.418E-9/3,000
=2.806E-12 m3/m
(3) Volume loss= Weight loss/Density
= 0.0000664/2700
= 2.459E-8 m3
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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Volumetric wear rate = Volume loss/Sliding distance
=2.459E-8/3,000
= 8.197E-12 m3/m
(4) Volume loss= Weight loss/Density
= 0.00003729/2700
= 1.381E-8 m3
Volumetric wear rate= Volume loss/Sliding distance
= 1.381E-8/3,000
= 4.603E-12 m3/m
Surface Roughness Test:
The surface roughness test was conducted on the SJ-201P surface roughness tester. Set up the SJ-201P (attaching/detaching the
drive unit/detector, and cable connection, etc.) according to the feature of the work piece to be measured. Select either the AC
adapter or built-in battery as the power supply. Modify the measurement conditions as necessary. Calibration is a means of
adjusting the detector gain so that the SJ-201P can yield correct measurements. This can be easily performed by measuring a
supplied precision roughness specimen. Measure the roughness specimen and display the result. Measurement results can be
saved, printed, outputted as SPC data, and communicated with a personal computer via RS-232C interface.
After measurement, store the SJ-201P safely by detaching the drive/detector unit, etc. Recharge the built-in battery as
required.
Surface Roughness (Ra)
Sl. No Specimen Load(Kg) Sliding speed(m/s) Perpendicular to Ra(µm)
1
Al-3Ti
1 1 2.713
2 1 3 4.33
3 3 1 3.33
4 3 3 3.146
5
Al-5Ti
1 1 1.96
6 1 3 2.17
7 3 1 3.553
8 3 3 2.67
9
Al-7Ti
1 1 2.163
10 1 3 2.41
11 3 1 2.37
12 3 3 1.173
VPN Test:
The VPN test was conducted on the micro Vickers hardness tester after the wear test. The test procedure is first press the START
key on the scales section then add the test load, the (LOADING) lights up. After completing the exertion of the first test load, the
delay time (DWELL) LED lights up, at this time, the T on the LED screen will according to the number of time elapsed counter
clockwisely. When the delayed time arrives, then test load is unloaded, and the unloading test load (UNLOADED) LED lights
up. Before LED is extinguished, it is not allowed to turn the indenter to measure the changeover handle, else it will affect the
precision (or accuracy) measured for indentation. Turn the changeover handle clock wisely, and make the 40 X objective lens in
the front part of the main body. Then is measured, the diagonal length from the micrometer eyepiece. Before measurement, first
turn clock wisely the drum wheel on the right side of micrometer eyepiece, so as to make the two calibrated lines observed in the
eyepiece moving mutually closely. When the edges of two calibrated lines draw closely (overlapped), the right penetrating gap
gradually diminishes, once the two calibrated lines are in a threshold state of no light gap, then press the ‘CL’ key to clear to zero
at display of D1. First turn the left side drum wheel and make the calibration line to one corner of the indentation. Next, turn the
right side drum wheel, then the two calibration lines are separated, and make the right side calibration line align to the diagonal
of the indentation correctly, press at once the button at the lower part of the micrometer eyepiece and input. It will display D1 on
the display screen. When the right side drum wheel rotates, figures after D1 on the LED screen flare, it means that the result has
not yet been input. After the result has been input, there will be no more flare, and the cursor turns to D2. According to the
method as mentioned above, measure and determine the length of another diagonal again. At this time, the HV hardness value on
the LCD screen will be displayed automatically.
Hardness Value
Sl. No Specimen Load(Kg) Sliding speed(m/s) D1 D2 Distance HV
1
Al-3Ti
1 1 148 191 0.1 0.1570772
2 1 3 104 120 0.1 0.3737331
3 3 1 118 153 0.1 0.2395335
4 3 3 113 154 0.1 0.0374579
5 Al-5Ti 1 1 119 122 0.1 0.3147956
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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6 1 3 89 86 0.1 0.6123244
7 3 1 145 144 0.1 0.2217083
8 3 3 70 80 0.1 0.8126063
9
Al-7Ti
1 1 127 131 0.1 0.2711897
10 1 3 64 54 0.1 1.2634
11 3 1 93 93 0.1 0.5352439
12 3 3 65 51 0.1 1.376137
IV. RESULTS AND DISCUSSION
Wear and physical test have been conducted on the materials Al-3Ti, Al-5Ti and Al-7Ti with varying percentage of Ti from 3 to
7%. Ti is used in Al base alloy. It is well known that by the addition of Ti in the alloy the hardness and wear resistance will
increase. . By knowing this property the physical tests like Hardness, Tensile, surface roughness and wear tests have been carried
out to understand the material behavior.
Microstructure Studies:
The microstructural study starts with the optical microscopy. All the cast samples, after polishing have been studied using image
analyzer to observe the microstructure. The image analyzer photomicrographs of Al-3Ti, Al-5Ti and Al-7Ti alloys are shown in
figs 4.1 and 4.2. It is observed that as the percentage of Ti increases the volume fraction of the Ti increased in the micrographs.
(A)
(B)
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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(C)
Microstructure of different wt% of Ti: (a) Al-3Ti (b) Al-5Ti and (c) Al-7Ti with spot Magnification of 650x.
(A)
(B)
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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(C)
Microstructure of different wt% of Ti: (a) Al-3Ti (b) Al-5Ti and (c) Al-7Ti with spot Magnification of 2000x
(A)
(B)
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
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(C)
(D)
EDX spectrum of (a) Al-3Ti (b) Al-5Ti and (c) Al 5Ti specimens taken on Al3Ti -particles. Hardness Test: Hardness is
resistance of material to plastic deformation caused by indentation. Sometimes hardness refers to resistance of material to
scratching or abrasion. Hardness may be measured from a small sample of material without destroying it. Principle of hardness
test method is forcing an indenter into the sample surface followed by measuring dimensions of the indentation (depth or actual
surface area of the indentation). Hardness is not fundamental property and its value depends on the combination of yield
strength, tensile strength and modulus of elasticity.
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 112
Effect of Ti on hardness: From the fig. 4.4 initially with increase in the volume fraction of the Ti hardness value is increased.
With further increase in the Ti, hardness value is decreased. Ti is a grain refiner. Initially with increase in the grain refines
hardness values is increased. With further increase in more refiner hardness value is decreased because, it may tends towards
brittleness. It is observed that Specimen 2 that is Al-5Ti is having high hardness value compared to the other Specimen and
Specimen 1 having lowest hardness value.
Tensile Test: Tensile strength is defined as a stress, which is measured as force per unit area. For some non-homogeneous
materials (or for assembled components) it can be reported just as a force per unit width. Tensile strengths are rarely used in the
design of ductile members, but they are important in brittle members.
Effect of Ti on tensile test: From the fig. 4.5 with increase in the Ti ductility will decrease. Therefore the ultimate tensile
strength is decreased with increase in the Ti percentage. It is observed that with decrease in the percentage of Titanium the
tensile strength is increased and further increase in the Ti% the tensile strength is decreased.
Wear Test All the composites developed were tested on the pin on disc machine (TR-20, DUCOM). The effect of various
tribological parameters Normal Pressure, Sliding speed and sliding distance was tested on each composite and compared with the
wear behavior.
0 1 2 3 4
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
Bri
ne
ll h
ard
ne
ss n
um
be
r(K
g/m
m2)
Specimen No
Brinell Hardness Test
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
0 2 4
0.090
0.095
0.100
0.105
0.110
0.115
0.120
Ulti
ma
te T
en
sile
str
ess
(KN
/mm
2)
Specimen No
Tensile Test
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 113
1 2 3
0.00E+000
2.00E-011
4.00E-011
6.00E-011
8.00E-011
1.00E-010
1.20E-010
Vo
lum
etr
ic w
ea
r ra
te (
m3/m
)
Specimen Nos.
0.1248 MPa
0.3747 MPaSliding speed - 1 m/s
1 2 3
0.00E+000
2.00E-011
4.00E-011
6.00E-011
8.00E-011
1.00E-010
1.20E-010
Vo
lum
etr
ic w
ea
r ra
te (
m3/m
)
Specimen Nos.
Speed (1m/s)
Speed (3m/s)
Load - 3 KG
Wear Test
1 2 3
0.00E+000
2.00E-011
4.00E-011
6.00E-011
8.00E-011
1.00E-010
1.20E-010
Vo
lum
etr
ic w
ea
r ra
te (
m3/m
)
Specimen Nos.
Speed (1m/s)
Speed (3m/s)
Load - 1 KG
1 2 3
0.00E+000
2.00E-011
4.00E-011
6.00E-011
8.00E-011
1.00E-010
1.20E-010
Vo
lum
etr
ic w
ea
r ra
te (
m3/m
)
Specimen Nos.
0.1248 MPa
0.3747 MPaSliding speed - 3 m/s
Effect of normal pressure on volumetric wear rate for the sliding speeds and loads From fig. 4.6 it is observed that with
increase in volume fraction of Ti volumetric wear rate is decreased. Hence more percentage of Ti is preferable. Hence specimen
Al-3Ti is more volumetric rate as compared to other 2 specimens.
0 1 2 3 4
0.00E+000
1.00E-010
0.0000 0.1248 0.2496 0.3744
0.00E+000
1.00E-010
0 1 2 3 4
0.00E+000
1.00E-010
0.0000 0.1248 0.2496 0.3744
0.00E+000
1.00E-011
2.00E-011
3.00E-011
4.00E-011
5.00E-011
6.00E-011
7.00E-011
8.00E-011
9.00E-011
1.00E-010
1.10E-010
1.20E-010
1.30E-010
1.40E-010
1.50E-010
Vol
umet
ric w
ear
rate
(m
3 /m)
Sliding Speed(m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiLoad - 1 KG
Vol
umet
ric w
ear
rate
(m3 /m
)
Normal Pressure (MPa)
Sp.No.1. Al-3Ti
Sp.No.2. Al-5Ti
Sp.No.3. Al-7Ti
Wear Test
Sliding Speed -1m/s
Vol
umet
ric w
ear
rate
(m
3 /m)
Sliding Speed(m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiLoad - 3 KG
Vol
umet
ric w
ear
rate
(m3 /m
)
Normal pressure (MPa)
Sp.No.1. Al-3Ti
Sp.No.2. Al-5Ti
Sp.No.3. Al-7Ti
Speed - 3 m/s
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 114
Effect of Specimens on Volumetric Wear Rate
From the fig. 4.7 it is observed that, 3Ti values are higher than the other two materials. Ti is ductile material so with decrease in
the volume fraction of the Ti softness is decreased hence the plastic deformation will also decrease. With decrease in the plastic
deformation work hardening does not takes place hence, values of the volumetric wear rate is higher for Al-3Ti than the other
two materials.
0.00000.1248
0.24960.3744
0.00E+0002.00E-0114.00E-0116.00E-0118.00E-0111.00E-0101.20E-0101.40E-010
01
23
0.00000.1248
0.24960.3744
0.00E+0002.00E-0114.00E-0116.00E-0118.00E-0111.00E-0101.20E-0101.40E-010
01
23
0.00000.1248
0.24960.3744
0.00E+0002.00E-0114.00E-0116.00E-0118.00E-0111.00E-0101.20E-0101.40E-010
12
3
Specimen .2. Al-3TiData 1
Data 3
Volu
metr
ic w
ear
rate
(m
3/m
)
Sliding S
peed (m/s)Normal pressure (MPa)
Data 2 Specimen .2. Al-5Ti
Specimen .2. Al-7Ti
Volu
metr
ic w
ear
rate
(m
3/m
)
Sliding S
peed (m/s)Normal Pressure (MPa)
Volu
metr
ic w
ear
rate
(m
3/m
)
Sliding sp
eed (m/s)Normal pressure (MPa)
Wear Test
Effect of normal pressure and sliding speed on volumetric wear rate
From Fig.4.8 Under high sliding speed with increase in the normal pressure volumetric wear rate is decreased. Under high
sliding speed effect of frictional temperature is high.
Therefore volumetric wear rate is high under high sliding speed at low normal pressure. Whereas for the same under high
normal pressure volumetric wear rate is decreased. This may be due to high frictional temperature, at this high frictional
temperature a layer of wearing surface may be melted and this molten layer may be behaved as lubricated film so volumetric
wear rate is decreased. Generally for all specimens under low speed of 1m/s, volumetric wear rate is increased with the normal
pressure. For under high sliding speed of 3m/s the same is decreased with the normal pressure .Under low normal pressure the
volumetric wear rate is increased with the sliding speed as the same is almost decreased with sliding speed under high normal
pressure.
Under low normal pressure with increase in the sliding speed volumetric wear rate is increased. Under low normal pressure very
few asperities are get contact with disc so local stress on the asperities is high. Due to this high local stress, during wearing high
temperature generates. Due to this high temperature softening effect takes place hence volumetric wear rate is increased, where
as under high normal pressure more number of asperities get contact with the disc. Due to more number of asperities local stress
generates on the asperities hence low temperature generates and this temperature may not be sufficient to soften the material also
due to more number of asperities contact more percentage of metal deform plastically so some asperities of work hardening takes
place, therefore volumetric wear rate is decreased.
Under low sliding speed with increase in the normal pressure volumetric wear rate is increased as per the Archard equation,
load is directly proportional the volume loss. Hence with increase in normal pressure volumetric wear rate is increased.
Finally there is no much deviation between Specimens Al-3Ti and Al-7Ti in volumetric wear rate. Due to low volumetric wear
rate in specimen Al-5Ti.Hence Al-5Ti is Preferable.
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 115
0 1 2 3
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Fri
ctio
na
l F
orc
e (
N)
Specimen Nos.
0.1248 MPa
0.3747 Mpa
Wear Test
Sliding Speed - 1 m/s
0 1 2 3
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Fri
ctio
na
l F
orc
e (
N)
Specimen Nos.
0.1248 MPa
0.3747 MPa
Wear Test
Sliding Speed - 3 m/s
0 1 2 3
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
F
rictio
na
l F
orc
e (
N)
Specimen Nos.
Speed (1 m/s)
Speed (3 m/s)
Wear Test
Load - 1 KG
0 1 2 3
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Fri
ctio
na
l F
orc
e (
N)
Specimen Nos.
Speed (1 m/s)
Speed (3 m/s)
Wear Test
Load - 3 KG
Effect of normal pressure on fictional force on sliding speeds and loads
From Fig. 4.9 it observed that with increase in Titanium, the ductility will increase hence the frictional force is increased. In
figure the maximum frictional force is high in specimen Al-5Ti compared to other 2 specimens due ductile property of Titanium.
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
0 1 2 3 4
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
0 1 2 3 4
0
2
4
6
8
10
12
14
16
18
Fric
tiona
l For
ce (N
)
Normal Pressure (MPa)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Sliding speed - 1 m/s
Wear Test
Fric
tiona
l For
ce (N
)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Normal Pressure (MPa)
Sliding speed - 3 m/s
Fric
tiona
l For
ce (N
)
Sliding speed (m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiLoad - 3KG
Fric
tiona
l For
ce (N
)
Sliding speed (m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiLoad - 1 KG
Effect of specimens on frictional force
From fig.4.10 it is observed that, 5Ti values are higher than the other two materials. Ti is ductile material so with increase in the
volume fraction of the Ti softness is increased hence the plastic deformation will also increase. With increase in the plastic
deformation work hardening takes place hence, values of the frictional force is higher for Al-5ti than the other two materials.
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 116
0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
0.00.51.01.52.02.53.0 0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
01
23
0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
01
23
Fri
ctio
nal F
orce
(N
)
Sliding S
peed (m/s)
Normal Pressure (MPa)
Data 1Specimen.1. Al-3Ti
Fri
ctio
nal F
orce
(N
)
Sliding S
peed (m/s)
Normal Pressure (MPa)
Data 2 Specimen.2. Al-5Ti
Fri
ctio
nal F
orce
(N
)
Sliding speed (m
/s)Normal Pressure (MPa)
Data 3Specimen.3. Al-7Ti
Wear Test
Under high sliding speed with increase in the normal pressure frictional force is decreased. Under high sliding speed effect of
frictional temperature is high. Therefore frictional force is high under high sliding speed at low normal pressure. Whereas for the
same under high normal pressure frictional force is decreased.
With increase in contact pressure the percentage at contact area will increase with increase in percentage at contact area
frictional force is increased.
With increase in the sliding speed the residential time between the wearing surface at the pin with the disc is reduced, with
reduction in residential time the growth of micro weld reduces, with reduction in micro weld friction force is reduced. Hence
with increase in sliding speed frictional force is reduced.
With increase in sliding speed the frictional temperature also increases. Hence again the intimate contact between wearing
surfaces increase. So some times with increase in sliding speed frictional force will increase due to more percentage at intimate
contactness due to more plastic deformation of the wearing pin.
Surface Roughness (Perpendicular) Test: Roughness is a measure of the texture of a surface. It is quantified by the vertical
deviations of a real surface from its ideal form. If these deviations are large, the surface is rough; if they are small, the surface is
smooth.
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 117
0 1 2 3
0
1
2
3
4
Sur
face
Rou
ghne
ss(
m)
Specimen Nos.
0.1248MPa
0.3747MPa
Surface Roughness Test
Sliding speed - 3 m/s
0 1 2 3
0
1
2
3
4
Sur
face
Rou
ghne
ss(
m)
Specimen Nos.
Speed (1 m/s)
Speed (3 m/s)
Load - 1 KG
0 1 2 3
0
1
2
3
4
Sur
face
Rou
ghne
ss(
m)
Specimen Nos.
Speed (1 m/s)
Speed (3 m/s)
Load - 3 KG
0 1 2 3
0
1
2
3
4
Sur
face
Rou
gnes
s(m
)
Specimen Nos.
0.1248
0.3747
Sliding Speed - 1 m/s
Effect of normal pressure on surface roughness on sliding speeds and loads
From fig. 4.12 with increase in hardness value surface roughness decreases due to shearing action. Shearing action is due to the
ductile property of Titanium. Under high sliding speed the surface roughness is high, under low normal pressure surface
roughness is high.
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 1 2 3 4
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 1 2 3 4
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Sur
face
Rou
ghne
ss(
m)
Normal Pressure (MPa)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Sliding Speed - 3 m/s
Surface Roughness Test
Sur
face
Rou
ghne
ss(
m)
Sliding speed (m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Load - 1 KG
Sur
face
Rou
ghne
ss(
m)
Sliding speed (m/s)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiLoad -3 KG
Sur
face
Rou
ghne
ss T
est(m
)
Normal Pressure (MPa)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7Ti
Sliding Speed - 1 m/s
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 118
Effect of specimens on surface roughness
From fig. 4.13 it is observed that, 3 Ti values are higher than the other two materials. Ti is ductile material so with decrease in
the volume fraction of the Ti softness is decreased hence the plastic deformation will also decrease. With decrease in the plastic
deformation work hardening does not takes place hence, with decrease in Ti values of the surface roughness is higher than the
other two materials.
0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
0.00.51.01.52.02.53.0 0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
01
23
0.000.050.100.150.200.250.300.350.40
0123456789
1011121314151617
01
23
Fri
ctio
nal F
orce
(N
)
Sliding S
peed (m/s)
Normal Pressure (MPa)
Data 1Specimen.1. Al-3Ti
Fri
ctio
nal F
orce
(N
)
Sliding S
peed (m/s)
Normal Pressure (MPa)
Data 2 Specimen.2. Al-5Ti
Fri
ctio
nal F
orce
(N
)
Sliding speed (m
/s)Normal Pressure (MPa)
Data 3Specimen.3. Al-7Ti
Wear Test
Effect of normal pressure and sliding speed on surface roughness of specimens
From Fig.4.14 Under high sliding speed with increase in the normal pressure surface roughness is decreased. Under high sliding
speed effect of frictional temperature is high.
Therefore volumetric wear rate is high under high sliding speed as low normal pressure. Whereas for the same under high
normal pressure surface roughness is decreased. Under high normal pressure the surface roughness is almost reduced with the
sliding speed. Under high normal pressure the intimate contact between wearing pin surface with the disc is increased. Due to
this increase in more contact area the smoothness is increased hence with under high normal pressure with increase in sliding
speed roughness values is decreased.
Under high sliding speed with increase in the normal pressure the roughness is decreased. Under high sliding speed the micro
growth of weld is reduced due to reduction the residential time between the wearing pin with the disc. Hence under high sliding
speed with increase in normal pressure the roughness values are decreased.
VPN Test: The VPN test was carried out in the micro Vickers hardness tester after the wear test. Hardness is resistance of
material to plastic deformation caused by indentation. Sometimes hardness refers to resistance of material to scratching or
abrasion. Hardness may be measured from a small sample of material without destroying it. Principle of hardness test method is
forcing an indenter into the sample surface followed by measuring dimensions of the indentation (depth or actual surface area of
the indentation).
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 119
0 1 2 3
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Har
dnes
s V
alue
(Kg/
mm
2 )
Specimen Nos.
0.1248 MPa
0.3747 MPa
Sliding Speed - 1m/s
0 1 2 3
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Har
dnes
s V
alue
(Kg/
mm
2 )
Specimen Nos.
0.1248 MPa
0.3747 MPaSliding speed - 3 m/s
0 1 2 3
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Har
dnes
s V
alue
(Kg/
mm
2 )
Specimen Nos.
Speed (1 m/s)
Speed (2 m/s)
Load - 1 KG
0 1 2 3
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
Har
dnes
s V
alue
(Kg/
mm
2 )
Specimen Nos.
Speed (1m/s)
Speed (3m/s)
Load - 3 KG
Hardness Test
Effect of normal pressure on Hardness value for sliding speeds and loads
From fig. 4.15 with increase in hardness fraction of Ti hardness value is increased. Ti is ductile material so with increase in the
volume fraction of the Ti softness is increased hence the plastic deformation will also increase. With increase in the plastic
deformation work hardening takes place hence, values of the hardness for Al-7Ti is higher than the other two materials.
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 1 2 3 4
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 1 2 3 4
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Har
dnes
s V
alue
(Kg/
mm
2 )
Normal Pressure (MPa)
Sp.1. Al-3Ti
Sp.2. Al-5Ti
Sp.3. Al-7TiSliding Speed - 3 m/s
Har
dnes
s V
alue
(Kg/
mm
2 )
Normal Pressure (MPa)
Sp.No.1 Al-3Ti
Sp.No.2 Al-5Ti
Sp.No.3 Al-7Ti
Sliding Speed - 1 m/s
VPN Test
Har
dnes
s V
alue
(Kg/
mm
2 )
Sliding Speed (m/s)
Sp.No.1. Al-3Ti
Sp.No.2. Al-5Ti
Sp.No.3. Al-7Ti
Load -3 KG
Har
dnes
s V
alue
(Kg/
mm
2 )
Sliding Speed (m/s)
Sp.No.1 Al-3Ti
Sp.No.2. Al-5Ti
Sp.No.3. Al-7TiLoad - 1KG
Tribological Investigations on Al-Al3Ti In-situ Metal Matrix Composite (IJIRST/ Volume 3 / Issue 01 / 020)
All rights reserved by www.ijirst.org 120
Effect of specimens on Hardness
From fig.4.16 it is observed that, 7 Ti values are higher than the other two materials. Ti is ductile material so with increase in the
volume fraction of the Ti softness is increased hence the plastic deformation will also increase. With increase in the plastic
deformation work hardening takes place hence, values of the hardness is higher than the other two materials.
0.100.150.200.250.300.350.40
0.00.20.40.60.81.01.21.4
1.01.5
2.02.53.0 0.100.150.200.250.300.350.40
0.00.20.40.60.81.01.21.4
1.01.5
2.02.53.0
0.100.150.200.250.300.350.40
0.00.20.40.60.81.01.21.4
1.01.5
2.02.53.0
Speciman.3.Al-7TiData 3
Har
dnes
s V
alue
(kg/
mm
2 )
Sliding S
peed(m/s)
Normal Pressure(MPa)
Specimen.1.Al-3TiData 1
Har
dnes
s V
alue
(kg/
mm
2 )
Sliding S
peed(m/s)
Normal Pressure(MPa)
Specimen.1. Al-5TiData 2
Har
dnes
s V
alue
(Kg/
mm
2 )
Sliding S
peed(m/s)Normal PressureMPa)
Hardness Test
Effect normal pressure and sliding speed on hardness for specimens
From Fig.4.17 Under high sliding speed with increase in the normal pressure Hardness value is decreased. Under high sliding
speed effect of frictional temperature is high.
Therefore volumetric wear rate is high under high sliding speed as low normal pressure. Whereas for the same under high
normal pressure Hardness value is decreased. This may be due to high frictional temperature, at this high frictional temperature a
layer at wearing surface may be melted and this molten layer may be behaved as lubricated film so Hardness value is decreased.
For the specimen – 1, under low normal pressure of .1248MPa with increase in the sliding speed hardness values are
increased. Under low normal pressure the generation of frictional temperature is usually low hence, with increase in sliding
speed deformation of the worn surface is more so work hardening effect is more. Due to this work hardening the hardness values
are increased. Under high normal pressure with increase in the sliding speed hardness values are decreased. Under high normal
pressure the amount of area of contact is more and generation of frictional temperature is more, due to this frictional temperature
softening effect takes place. Due to this softening effect the worn surface hardness is deceased.
V. CONCLUSION
The present results suggest that the wear resistance of Al-Al3Ti composites increases with increase in percentage of Al3Ti
particles compared to pure aluminum. In addition, the improvement in mechanical properties of the composite was observed in
Al-5Ti specimen when compared to Al-3Ti and Al-7Ti and to the pure Al. Volumetric wear rate of Al-5Ti is less compare to Al-
3Ti and Brinell hardness value also more for Al-5Ti compare Al-3Ti, Al-7Ti. There is almost no variation at properties between
5Ti and 7Ti but there is much variation between 5Ti and 3Ti. Hence 5Ti is better material among 3Ti, 5Ti and 7Ti.
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