CHAPTER 1
INTRODUCTION
1.1 TYPES OF MANUFACTURING:
There are two types of manufacturing process that has been widely used in the
industries
1.) Metal forming process
2.) Metal removal process
1.2 METAL FORMING PROCESS:
Forming, metal forming, is the metalworking process of fashioning metal parts and
objects through mechanical deformation; the work piece is reshaped without adding
or removing material, and its mass remains unchanged.
1.3 TYPES OF METAL FORMING PROCESS:
1.) Roll forming.
2.) Extrusion.
3.) Press braking.
4.) Stamping.
5.) Forging.
6.) Casting.
1.4 POWDER METALLURGY:
Powder metallurgy is a metal-forming process performed by heatingcompacted
metal powders to just below their melting points.
FIG 1.1 Powder Metallurgy
1
1.5 METAL REMOVAL PROCESS:
This is a type of manufacturing process in which the final product is obtained
by removing excess metal from the stock. The perfect example of a
machining process is generating a cylindrical surface from a metal stock with the
help of a lathe.
1.6 TYPES OF METAL REMOVING PROCESS:
1.) Turning
2.) Drilling
3.) Milling
4.) Shaping
5.) Planning
6.) Boring
7.) Broaching
8.) Sawing
FIG 1.2 TYPES OF METAL REMOVING PROCESS
2
1.7 POWDER METALLURGY:
It is a term covering a wide range of ways in which materials or components are
obtained from metal powders. This process can avoid, or greatly reduce, the need to
use metal removal processes, thereby drastically reducing yield losses in
manufacture and often resulting in lower costs.
1.7.1 PRINCIPLE:
Powder metallurgy is a highly evolved method of manufacturing reliable net shaped
components by blending elemental or pre-alloyed powders together, compacting
this blend in die, and sintering or heating the pressed part in controlled furnace
atmosphere.
FIG 1.3 FLOW CHART
1.7.2 ADVANTAGES:
1.) It Minimizes machining by producing parts at, or close to, final dimensions.
2.) It Minimizes scrap losses by typically using more than 97% of the starting raw
material in the finished part.
3.) It Permits a wide variety of alloy systems.
4.) It Produces good surface finish.
3
1.8 METAL MATRIX COMPOSITES:
A metal matrix composite is composite material with at least two constituent parts,
one being a metal necessarily, the other material may be a different metal or another
material, such as a ceramic or organic compound. When at least three materials are
present, it is called a hybrid composite. A METAL MATRIX COMPOSITE is
complementary to a cermet.
MATRIX:
The matrix is the monolithic material into which the reinforcement is embedded, and
is completely continuous. This means that there is a path through the matrix to any
point in the material, unlike two materials sandwiched together.
REINFORCEMENT:
The reinforcement material is embedded into a matrix. The reinforcement does not
always serve a purely structural task (reinforcing the compound), but is also used to
change physical properties such as wear resistance, friction coefficient, or thermal
conductivity. The reinforcement can be either continuous or discontinuous.
MANUFACTURING METHODS:
1.) Solid state methods
2.) Liquid state methods
3.) Semi-solid state methods
4.) Vapor deposition
5.) In-situ fabrication technique
4
1.9 COMPACTING:
First of all, this technology requires an absolutely pure environment. No atmospheric
intrusion is allowed. Perform the compacting or pressing operation in a vacuum or
with an oxidization-inhibiting gas. Next, the atomization stage has done its work;
the powder is currently piled in a finely ground mass. It may even have been mixed
with a lubricant or some other process additive, and now the powder metal is on its
way to the compaction stage. A rigid toolset, a die, or some other form-pressing
mechanism finally presses the powder until it assumes the desired shape
1.9.1 TYPES OF POWDER COMPACTION:
1.) Single-action compaction
2.) Opposed Double-action compaction
3.) Double action with floating die
4.) Double action with drawl die
FIG 1.4 DIE COMPACTION PROCESS
5
1.10 UNIVERSAL TESTING MACHINE:
Compaction can be carried out using a universal testing machine.
FIG 1.5 UNIVERSAL TESTING MACHINE
A Universal testing machine (UTM) is used to test the mechanical properties
(tension, compression etc.) of a given test specimen by exerting tensile, compressive
or transverse stresses. The machine has been named so because of the wide range of
tests it can perform over different kind of materials. Different tests like peel test,
flexural test, tension test, bend test, friction test, spring test etc. can be performed
with the help of UTM.
6
COMPONENTS OF UTM:
1. LOAD FRAME
The load frame of a universal testing machine can be made either by single support
or by double support. The load Frame consists of a table (where the specimen is
placed for the compression test), upper crosshead, and lower crosshead.
2. UPPER CROSSHEAD AND LOWER CROSSHEAD
The upper crosshead is used to clamp one end of the test specimen. The lower
crosshead in the load frame is the movable crosshead whose screws can be loosened
for height adjustment and tightened. Both the crossheads have a tapered slot at the
center. This slot has a pair of racked jaws that is intended to grip and hold the tensile
test specimen.
3. ELONGATION SCALE
The relative movement of the lower and upper table is measured by an elongation
scale which is provided along with the loading unit.
4. HYDRAULIC POWER UNIT
This unit consists of an oil pump that provides non-pulsating oil flow into the main
cylinder of the load unit. This flow helps in the smooth application of load on the
specimen. The oil pump in a hydraulic power unit is run by an electric motor and
sump.
5. LOAD MEASURING UNIT:
This unit has a pendulum dynamometer unit that has a small cylinder with a piston
which moves with the non-pulsating oil flow. The pendulum is connected to the
piston by pivot lever. The pivot lever deflects based on the load applied to the
specimen. This deflection is converted to the load pointer and displays as the load
on the dial. The range of load application can be adjusted by means of a knob in the
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load measuring unit (0-100 kN; 0-250 kN; 0-500 kN and 0-1000 kN). The accuracy
of measuring unit controls the overall accuracy of the machine.
6. CONTROL DEVICES
The control devices can be electric or hydraulic. Electric control devices make use
of switches to move the crossheads and switch on/off the unit.
FUNCTIONS OF UNIVERSAL TESTING MACHINE:
The main functions of UTM are to test the mechanical properties of materials. The
standard tests performed by UTM are:
1. Tensile Test
2. Compression Test
3. Adhesion Tests
4. Pull-Out Tests
5. Bending Test
6. Hysteresis Test
1.11 DIE AND PUNCHING TOOL:
DIE:
A die is a specialized machine tool used in manufacturing industries to cut
and/or form material to a desired shape or profile. Stamping dies are used with
a press, as opposed to drawing dies (used in the manufacture of wire) and casting
dies (used in molding) which are not. Like molds, dies are generally customized to
the item they are used to create.
COMPONENTS OF A DIE:
Stamping dies have several components. They are as follows:
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1.) Die sets and plates
2.) Die shoes
3.) Bushings and guide pins
4.) Heel plates and heel blocks
5.) Die pads
TYPES OF A DIE:
According to the use in the operation of sheet metal, die are of six types. These are:

Simple Die

Combination Die

Compound Die

Progressive Die

Transfer Die

Multiple Die
MATERIALS OF DIE:
To make a die, so many materials are needed to be present. These contain so many
steels of different kinds and the material of non-metallic and the casting of nonferrous and ferrous.
CARBON STEEL:
Manganese 0.20 to 0.45, Carbon 0.90 to 1.15, Sulphur 0.025, Phosphorus 0.025 and
Silicon 0.16 are present in this Carbon steel.
CARBON BLOCK STEEL:
Carbon Block Steel contains manganese 0.50 to 0.70, carbon 0.55 to 0.65, chromium
0.60 to 1.10 and nickel 1.25 to 1.75.
TUNGSTEN OIL HARDENING STEEL:
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This Tungsten Oil Hardening Steel contains manganese 0.25, tungsten 1.75 and
carbon 1.20.
HIGH-ALLOY OIL-HARDENING STEEL:
This High-Alloy Oil-Hardening Steel is the non-deforming in nature. It contains
about chromium 12.00, carbons 2.15 and manganese 0.35. Other elements,
Tungsten, Nickel, and Vanadium can add to this steel.
MANGANESE AIR HARDENING STEEL:
This Manganese Air Hardening Steel contains manganese 2.5, carbon 0.90,
molybdenum 1.00, chromium 1.5 and silicon 0.30.
CHROMIUM AIR HARDENING STEEL:
This Chromium Air Hardening Steel contains chromium 5.00, carbon 1.00,
manganese 0.50, molybdenum 1.00, silicon 0.25, and sometimes vanadium 0.50 can
be added.
HIGH ALLOY AIR-HARDENING STEELS:
This High Alloy Air-Hardening steel is as same as the High-Alloy Oil-Hardening
Steel. It contains chromium 12.00. The carbon varies between 1.00 to 2.15,
molybdenum 0.80, silicon 0.35, manganese 0.35 and sometimes vanadium 0.50 can
be added too.
1.12 SINTERING:
Sintering is the process of compacting and forming a solid mass of material by
heat or pressure without melting it to the point of liquefaction. Sintering happens
naturally in mineral deposits or as part of a manufacturing process used
with metals, ceramics, plastics, and other materials. The atoms in the materials
diffuse across the boundaries of the particles, fusing the particles together and
creating one solid piece. Because the sintering temperature does not have to reach
the melting point of the material, sintering is often chosen as the shaping process for
materials with extremely high melting points such as tungsten and molybdenum.
The study of sintering in metallurgy powder-related processes is known as powder
metallurgy.
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TYPES OF SINTERING:








General sintering.
Ceramic sintering.
Sintering of metallic powders.
Plastics sintering.
Liquid phase sintering.
Electric current assisted sintering.
Pressure less sintering.
Microwave sintering.
FIG 1.6 SINTERED MOLECULES
1.13 HARDNESS:
Hardness is the ability of a material to resist deformation, which is determined by a
standard test where the surface resistance to indentation is measured. The most
commonly used hardness tests are defined by the shape or type of indent, the size,
and the amount of load applied.
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Hardness correlates approximately with ultimate tensile strength in metals.
Hardness conversion numbers for commonly used material types can be found in
ASTM Specification E140.
TYPES OF HARDNESS:
Materials behave differently under different types of loading. For example, a metal that
can take a huge one-time impact extremely well may not act the same during continuous
loading.
Hardness testing must be carried out for each case so that a well-informed choice can be
made for the application.
The three types of hardness are scratch, rebound, and indentation hardness. Measuring
each type of hardness requires a different set of tools. Also, the same material will have
different hardness values for each of the above-mentionedtypes.
1.) INDENTATION HARDNESS:
This hardness type refers to the resistance to permanent deformation when subjecting a
material to a continuous load. It is what engineers and metallurgists usually refer to when
they talk about hardness. Measuring its value is of primary interest as continuous loading
is the most common form of loading metals are subjected to.
2.) SCRATCH HARDNESS:
This type of hardness refers to a material’s ability to resist scratches on the surface.
Scratches are narrow continuous indentations in the upper layer due to contact with a
sharp, harder material.
3.) REBOUND OR DYNAMIC HARDNESS
Rebound hardness has more to do with elastic hardness than plastic hardness. The
material absorbs the energy on impact and returns it to the indenter.
TYPES OF HARDNESS TESTING MACHINES:



Rockwell Hardness Testing Machines.
Micro Vickers Hardness Testing Machines.
Brinell Hardness Testing Machines.
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


Brinell Image Analysis System (B.I.A.S.)
Digital Portable Hardness Testers.
Universal Hardness Testers.
1.) ROCKWELL HARDNESS:
The Rockwell hardness test method consists of indenting the test material with a
diamond cone or hardened steel ball indenter. The indenter is forced into the test
material under a preliminary minor load 𝐹0 usually 10 kgf. When equilibrium has
been reached, an indicating device, which follows the movements of the indenter
and so responds to changes in depth of penetration of the indenter is set to a datum
position. While the preliminary minor load is still applied an additional major load
is applied with resulting increase in penetration. When equilibrium has again been
reach, the additional major load is removed but the preliminary minor load is still
maintained. Removal of the additional major load allows a partial recovery, so
reducing the depth of penetration. The permanent increase in depth of penetration,
resulting from the application and removal of the additional major load is used to
calculate the Rockwell hardness number.
There are several considerations for Rockwell hardness test
- Require clean and well positioned indenter and anvil
- The test sample should be clean, dry, smooth and oxide-free surface
- The surface should be flat and perpendicular to the indenter 3
- Low reading of hardness value might be expected in cylindrical surfaces
- Specimen thickness should be 10 times higher than the depth of the indenter
- The spacing between the indentations should be 3 to 5 times of the indentation
diameter
- Loading speed should be standardized.
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FIG 1.7 ROCKWELL HARDNESS
2.) BRINELL HARDNESS TEST:
The Brinell hardness test method consists of indenting the test material with a 10
mm diameter hardened steel or carbide ball subjected to a load of 3000 kg. For softer
materials the load can be reduced to 1500 kg or 500 kg to avoid excessive
indentation. The full load is normally applied for 10 to 15 seconds in the case of iron
and steel and for at least 30 seconds in the case of other metals. The diameter of the
indentation left in the test material is measured with a low powered microscope. The
Brinell harness number is calculated by dividing the load applied by the surface area
of the indentation. When the indentor is retracted two diameters of the impression,
d1 and d2, are measured using a microscope with a calibrated graticule.
FIG 1.8 BRINELL HARDNESS
The diameter of the impression is the average of two readings at right angles and the
use of a Brinell hardness number table can simplify the determination of the Brinell
hardness. A well-structured Brinell hardness number reveals the test conditions, and
looks like this, "75 HB 10/500/30" which means that a Brinell Hardness of 75 was
obtained using a 10mm diameter hardened steel with a 500-kilogram load applied
for a period of 30 seconds. On tests of extremely hard metals a tungsten carbide ball
is substituted for the steel ball. Compared to the other
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hardness test methods, the Brinell ball makes the deepest and widest indentation, so
the test averages the hardness over a wider amount of material, which will more
accurately account for multiple grain structures and any irregularities in the
uniformity of the material. This method is the best for achieving the bulk or macrohardness of a material, particularly those materials with heterogeneous structures.
3.) VICKER’S HARDNESS TEST:
The Vickers hardness test method consists of indenting the test material with a
diamond indenter, in the form of a right pyramid with a square base and an angle of
136 degrees between opposite faces subjected to a load of 1 to 100 kgf. The full load
is normally applied for 10 to 15 seconds. The two diagonals of the indentation left
in the surface of the material after removal of the load are measured using a
microscope and their average calculated. The area of the sloping surface of the
indentation is calculated. The Vickers hardness is the quotient obtained by dividing
the kgf load by the square mm area of indentation.
FIG 1.9 VICKERS HARDNESS
When the mean diagonal of the indentation has been determined the Vickers
hardness may be calculated from the formula, but is more convenient to use
conversion tables. The Vickers hardness should be reported like 800 HV/10, which
means a Vickers hardness of 800, was obtained using a 10 kgf force. Several
different loading settings give practically identical hardness numbers on uniform
material, which is much better than the arbitrary changing of 5 scale with the other
hardness testing methods. The advantages of the Vickers hardness test are that
extremely accurate readings can be taken, and just one type of indenter is used for
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all types of metals and surface treatments. Although thoroughly adaptable and very
precise for testing the softest and hardest of materials, under varying loads, the
Vickers machine is a floor standing unit that is more expensive than the Brinell or
Rockwell machines.
FIG 1.10 VICKERS HARDNESS MACHINE
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1.14 COMPRESSION TEST:
Compression testing is used to determine how a product or material reacts when it
is compressed, squashed, crushed or flattened by measuring fundamental parameters
that determine the specimen behavior under a compressive load.
These fundamental parameters include the elastic limit, which for "Hookean"
materials is approximately equal to the proportional limit, and also known as yield
point or yield strength, Young's Modulus (these, although mostly associated with
tensile testing, may have compressive analogs) and compressive strength.
Compression testing can be undertaken as part of the design process, in the
production environment or in the quality control laboratory, and can be used to:



Assess the strength of components e.g. automotive and aeronautical control
switches, compression springs, bellows, keypads, package seals, PET
containers, PVC / ABS pipes, solenoids, etc.
Characterize the compressive properties of materials e.g. foam, metal, PET,
and other plastics and rubber
Assess the performance of products e.g. the expression force of a syringe or
the load-displacement characteristics of a tennis ball
TYPES OF COMPRESSION TESTING INCLUDE:
 Flexure/Bend
 Spring Testing
 Top-load/Crush
PURPOSE OF COMPRESSION TEST:
The data produced in a compression test can be used in many ways including:

To determine batch quality
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



To determine consistency in manufacture
To aid in the design process
To reduce material costs and achieve lean manufacturing goals
To ensure compliance with international and industry standards
FIG 1.11 COMPRESSION TESTING MACHINE
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1.15 WEAR TEST:
Wear test is carried out to predict the wear performance and to investigate the wear
mechanism.
TWO SPECIFIC REASONS ARE AS FOLLOWS:
1.) From a material point of view, the test is performed to evaluate the wear property
of a material so as to determine whether the material is adequate for a specific wear
application.
2.) From a surface engineering point of view, wear test is carried out to evaluate the
potential of using a certain surface engineering technology to reduce wear for a
specific application, and to investigate the effect of treatment conditions
(processing parameters) on the wear performance, so that optimized surface
treatment conditions can be realized.
TEST METHODS:
The review finishes by listing and describing the test methods that are most likely
to be a reasonable match to the industrial need established by the survey of
industrial wear problems. The tests are:
• Fluid jet erosion testing
• Gas blast erosion test
• Three body abrasion testing
• ASTM B611, wet slurry steel wheel
• ASTM G65, dry sand rubber wheel
• ASTM G105, wet sand rubber wheel
• Ball cratering
• Scratch testing
• Pin-on-disc sliding wear
• Reciprocating sliding wear
• Fretting wear
• Thrust washer sliding wear
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TYPES OF WEAR:
TABLE 1.1 TYPES OF WEAR
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1.16 Optical Micro Scope
The optical microscope, often referred to as the “light optical microscope,” is a
type of microscope that uses visible light and a system of lenses to magnify images
of small samples. Optical microscopes are the oldest design of microscope and
were possibly designed in their present compound form in the 17th century. Basic
optical microscopes can be very simple, although there are many complex designs
that aim to improve resolution and sample contrast. Historically, optical
microscopes were easy to develop and are popular because they use visible light,
so samples may be directly observed by the eye.
Optical microscopes have a ubiquitous presence in modern society. Virtually
everyone has used one at some point in their life, if only to dissect a frog in school
or observe the life hidden in a drop of pond water. They are used in laboratories
and health clinics around the world. They have been developed into powerful
measurement and observational tools with applications in geology, medicine, and
manufacturing, to name a few areas. In the last few years, new types of optical
microscopes have emerged. These microscopes enable researchers to visualize
submicron structures, determine their surface profiles, and observe selected cross
sections of transparent materials without cutting the sample into thin slices. In
biology, fluorescence imaging has become increasingly important because
biological activity can be traced by the fluorescence of markers associated with
particular atomic or molecular species as they move through a cell. Application of
microscopy principles in other fields, such as optical storage on compact disks, has
also become important.
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CHAPTER 2
LITERATURE SURVEY
Venkatesh R and Vaddi Seshagiri Rao (2000) studied wear and corrosion
resistances and Vickers hardness on copper-based metal matrix composites with
alumina and graphite. This study has concluded that with the assistance of
Thermogravimetric analysis the material stability of the composite mixtures
were ascertained. The sample peak values were read with the help of FTIR
analysis. The corrosion resistance of the composite with the maximum alumina
reinforcement in nano scale exhibited better wear resistance. The presence of
graphite certainly provides lubricating effect. There are only subtle changes in
the wear resistance, since the material compaction required more compaction
pressure. Had the distribution of reinforcements been even, the net wear
characteristics would have been meticulous. The uneven surface occupation of
the reinforcements could not yield a structural pattern in the outcome. The
compacting pressure, sintering temperature and the mixing of the composite
powders using a ball mill have a definite implication in enhancing the wear
resistance
H.Yang et al. (2010) studied the effect of the ratio of graphite/pitch coke on the
mechanical and tribological properties of copper–carbon composites. Addition
of pitch coke in the matrix can much improve the interfacial bonding strength
between carbon particles and phenolic resin (binder). The bending strength and
micro- hardness of the copper–carbon composites increased with increase in the
content of pitch coke and reached a maximum. The friction coefficient of
copper– carbon composites increased significantly with increasing the content
of pitch coke .The wear rate of composites initially decreased as the content of
pitch coke increased and obtained a minimum and then ascended.
K. Rajkumar and S. Aravindan (2009) studied microwave sintering of
copper– graphite composites. Coarser microstructure with larger porosity is
obtained by this conventional sintering process which decreases the strength,
wear resistance as well. In microwave sintering, heat is generated internally
within the material and the sample becomes the source of heat. The direct
22
delivery of energy to the material through the molecular interaction, results in
volumetric heating. Microwave sintering offers many advantages such as faster
heating rate, lower sintering temperature, enhanced densification, smaller
average grain size and an apparent reduction in activation energy in sintering.
The finer microstructure with relatively smaller and round pores, resulted due to
microwave heating, enhances the performance of the composite.
Wenlin Maa and Jinjun Lu (2010) studied the effect of surface texture on
transfer layer formation and tribological behavior of copper–graphite composite.
Metal matrix composites (MMC) containing graphite particulates usually have
reduced friction under dry sliding, which is closely dependent on the formation
of continuous transfer layer on the sliding surface of counterpart. Friction and
wear tests were conducted under low and high load conditions and various
sliding distances to evaluate the validity of the textures and their effect on the
formation of the transfer layer of Cu/Gr composite.
Simon Dorfman & David Fuksb (1996) studied the stability of copper
segregations on Copper/Carbon Metal-matrix Composite interfaces under
alloying. Stability of interfaces in MMCs is linked to the conditions of the
formation of segregations of the metal alloy at the metal/fiber interface. It is
shown that alloying 11 of the matrix, substituting copper in the interstitial metalmetalloid solid solution, changes the value of the mixing energy and influences
the volume fraction of two dimensional segregations of copper. We expect that
the wettability of carbon fibers by the pure copper matrix may be improved by
the addition of small amounts of zirconium or iron to the matrix.
Onur Guler, Temel Varol 24 Copper-based composites are frequently used in
areas such as contacts, contactors, switches etc. where electrical conductivity and
tribological properties play a critical. In this work, the microstructure, electrical
and wear properties ofsilver plated copper powder matrix and Al2O3 reinforced
composites fabricated by electroless silver plating (ESP) and hot pressing were
investigated. Copper powders with different morphologies fabricated by
mechanical milling (MM) were used as matrix while different Al2O3 contents (0.5
%, 1 %, 2 %, 3 % and 5wt. %) were used as reinforcement materials for the
production of composites. The results showed that the ESP layer on milled copper
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powders for 2h was quite uniform and the Al2O3 distribution was better in these
composites than others. The highest hardness value (∼125 HB) and the lowest
wear rate (1.5E-04mm3 /Nm) were observed in composites including silver plated
copper matrix powders and Al2O3 (3wt. %). Although the electrical conductivity
values decrease with increasing Al2O3 ratio for all composites, the decrease in
electrical conductivity was only up to about 86 %IACS in composites where the
highest hardness value was obtained. Besides, the dominant wear mechanism was
abrasive wear with grooves and scratches while the lowest wear scar width (about
557μm) was observed in these composites.
D. Madhesh, K. Jagatheesan This article focuses on the synthesizing of copper
metal matrix material (CMETAL MATRIX COMPOSITE). Titanium carbide and
groundnut shell ash strengthen the steel. The 70 per cent hybrid mixture with
copper powder, 15 per cent tungsten carbide powder and 15 per cent groundnut
shell ash flavored where copper is mixture content. The composite made using
metallurgical powder technology. The proposed composite studied through study
of microscopy, corrosive analysis and measuring of hardness. Reinforcing the
existing 15% Tungsten Carbide Powder mixture and 15% Groundnut Ash shell,
enhanced hardness and diminished corrosion rate (increased corrosive resistance).
The Scanning Electron Microscopy picture guarantees a clear distribution of
reinforced particles in the matrix content.
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CHAPTER 3
OBJECTIVES
3.1 THE MAIN AIM AND OBJECTIVES OF THIS PROJECT IS
• To Evaluate and analyze the mechanical properties of Cu-METAL MATRIX
COMPOSITEs reinforced with graphite and aluminum Oxide using powder
metallurgy technique.
• To test the following parameters of the METAL MATRIX COMPOSITE:
• Compression strength
• Hardness
• Wear
• Reason for testing the above-mentioned parameters:
• To lower wear rate by using Graphite
• To Improve hardness, compressive strength of METAL MATRIX
COMPOSITE by using SiC.
3.2 METHODOLOGY:
FIG 3.1 METHODOLOGY
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CHAPTER 4
MATERIALS AND MANUFACTURING
4.1 MATERIAL SELECTION:
Copper metal matrix composite is the most promising material for many engineering
applications where the higher temperature resistance and good microstructural
stability is required. The sustainable development of copper metal matrix composite
is based on the use of ceramics as reinforcements. The choice of reinforcement
material is highly influenced by their mechanical properties such as hardness, wear
resistance, cost advantage, availability in market and refractory nature. In the current
scenario, copper and its alloy are gaining popularity due to their high sustainability,
high conductivity and good corrosion resistance. However, the relatively low wear
resistance and high temperature strength restrict the use of copper in many
applications. Recent developments in metal matrix composites have provided new
means to produce high sustainable copper metal matrix composite materials with
high wear resistance and high strength materials. It has been found that the wear
resistance and strength of materials can be improved by adding hard ceramic
particles such as SiC,Al2O3, Graphite and ZrO2 into the metal matrix.
4.1.1 COPPER:
Copper and copper alloy powders have been used in industrial applications for many
years. Probably the best known is the self-lubricating bearing which was the first
major application and still accounts for about 70% of the granular copper powder
used. This application takes advantage of the ability to produce a component with
controlled interconnected and surface-connected porosity. The production of
metallic filters also takes advantage of this ability.
PROPERTIES OF COPPER:
The word copper comes from the Latin word ‘cuprum’, which means ‘ore of
Cyprus’. This is why the chemical symbol for copper is Cu. Copper has many
extremely useful properties, including:


good electrical conductivity
good thermal conductivity & corrosion resistance
It is also:
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








easy to alloy
hygienic
easily joined
ductile
tough
non-magnetic
attractive
recyclable
catalytic
4.1.2 GRAPHITE:
For the production of sintered parts, metal powders are mixed with small quantities
of additives such as waxes and graphite. These powder mixtures are then pressed
under high pressure into so-called green compacts. As part of this process, graphite
ensures reduced wear of the press die and provides internal lubrication within the
powder mixture. As a result, graphite makes maximum compression possible. In the
sintering process, in which the green compacts are heated to slightly below melting
point, the material is then compressed further.
4.1.3 SILICON CARBIDE:
Silicon Carbide has the following properties for which it was selected as one of the
reinforcements in our project.





High Strength.
High hardness and wear resistance.
Low thermal expansion and high thermal conductivity.
Chemically resistant.
Good mechanical properties.
27
4.2 FABRICATION
4.2.1 BLENDING OF POWDERS:
• After confirming the materials to be used we placed an order for the
Copper, Sicand graphite powders.
• There were made 3 samples with 3 different compositions of the base
metal and thereinforcements.
COMPOSITION OF MATERIALS in (%wt.)
15mm - Diameter
25mm – Height
FIG 4.1 COMPOSITION OF SAMPLES
28
1. SAMPLE X
Cu-100, Grp-0, SiC-0. In wt.%
2. SAMPLE NO.1:
Cu-96, Grp-2, SiC-2. In wt.%
3. SAMLE NO.2:
Cu-94, Grp-2, SiC-4. In wt.%
4. SAMPLE NO.3:
Cu-92, Grp-2, SiC-6. In wt.%
4.2.2 COMPACTING:
• The compaction forming of metal powder is a process involving large
deformations, large strain, nonlinear material behavior and friction.
• Consequently, the numerical analysis of such a highly nonlinear process is a
formidable computational problem.
• First the powders were weighed and then filled into the die. Then with the
help of UTM, at 5 ton pressure the compacting was done.
FIG 4.2 COMPACTING
29
4.2.3 SINTERING:
Once all the 4 samples were compacted, they were set up for the sintering process to
follow.
The sintering furnace was set up to 850 degrees Celsius to carry out the process.
It took about 2 hours to attain the desired temperature. Then the samples were taken
in a plate and then placed inside the sintering furnace.
The samples were let to sinter at the temperature of 850 degree Celsius for 8 hours
continuously. After that the Celsius samples were taken out and let to air cool to the
room temperature.
Then with the help of the chisel the scales formed on the surface of the samples were
removed.
FIG 4.3 SINTERING FURNACE
FIG 4.4 SINTERING PROCESS
FIG 4.5 SINTERED SAMPLES
30
CHAPTER 5
RESULT AND DISCUSSION
5.1 HARDNESS TEST:
Hardness is the ability of a material to resist deformation, which is determined by a
standard test where the surface resistance to indentation is measured. The most
commonly used hardness tests are defined by the shape or type of indent, the size
and the amount of load applied.
FIG. 5.1 VICKERS HARDNESS TESTER
We have chosen Vickers Hardness test for our project as it is a widely used test in
the industry.
5.1.1 SPECIFICATIONS AND PARAMETERS:
Machine Name
: Micro Vickers Hardness Tester
Testing load range
:10 grams to 1 Kg Load
Make
: Wilson Wolpert – Germany
Vernier caliper least count
: 0.01 mm
Available Hardness testing Scale
: HV, HRA, HRC, 15N, 30N etc.,
Micro Hardness:




Scale
: Vickers's
Load
: 0.2 Kgf
Dwell time : 10 seconds.
Unit
: H.V.@ 0.2Kgf
31
The samples were taken one by one and their hardness were tested using the Vickers
hardness testing machine and the values were recorded in the following table.
5.1.2 TEST RESULTS:
TABLE 5.1 HARDNESS TEST RESULTS
Sample I.D
Reading-1
Reading-2
Reading-3
Sample X
Cu -100%
Grp -0%,
60.2
59.7
62.5
137.7
135.7
108.1
93.3
83
120.2
114.3
SiC -0%
Sample No:1
Cu -96%
Grp -2%,
SiC -2%
Sample No: 2
Cu -94%
Grp -2%
83.2
SiC -4%
Sample No: 3
Cu -92%
Grp -2%
119
SiC -6%
32
5.1.3 DISCUSSION:
 The average values of the hardness on the zones were calculated to bring the
results conclusive.
 The averages were observed to be 60.8, 127.1, 86.5, 117.8 respectively for
the above mentioned samples.
 It was observed that all the samples at different compositions were having
hardness greater than that of pure copper sample.
 The sample having equal amounts of graphite and SiC were found to have
the most hardness among the other samples. Thus can be applied where
hardness plays a crucial role.
 Other Compositions also exhibit a decent hardness levels.
33
5.2 COMPRESSION TEST:
Compression test is used to determine how a product or material reacts when it is
compressed, squashed, crushed or flattened by measuring fundamental parameters
that determine the specimen behavior under a compressive load.
FIG 5.2 COMPRESSION TEST
5.2.1 SPECIFICATIONS:
MACHINE NAME
: COMPRESSION TESTINGMACHINE
• Testing load range
: Max 5 Tons
• Make
: Associated Scientific Works
• Digital Encoder
make
: Auto Instruments - Kolhapur
• Gear rotation speed
:1.25. 1.5 & 2.5 mm /min
• Software details
: FIE make India
34
SAMPLE X: Cu-100%, Gr0%, SiC-0%
5.2.2
LOAD VS DISPLACEMENT GRAPH:
FIG 5.3 LOAD VS DISPLACEMENT SAMPLE X
The above graph is plotted for Load vs displacement. And various parameters were
determined as follows
1.) Ultimate load = 11020 KN
2.) Max displacement = 13.300 mm
3.) Area = 78.571 sq.mm
4.) Ultimate stress = 140.255 Mpa
5.) Compression strength = Ultimate Load/Area = 11020/78.571 = 140.007N/mm2
35
SAMPLE 1: Cu-96%, Gr2%, SiC-2%
FIG 5.4 LOAD VS DISPLACEMENT-SAMPLE 1
The above graph is plotted for Load vs displacement. And various parameters were
determined as follows
1.) Ultimate load = 9.815 KN
2.) Max displacement = 5.500 mm
3.) Area = 78.571 sq.mm
4.) Ultimate stress = 124.918 Mpa
5.) Compression strength = Ultimate Load/Area = 9815/78.571 = 124.91N/mm2
36
SAMPLE 2: Cu-94%, Gr-2%, SiC-4%
FIG 5.5 LOAD VS DISPLACMENT-SAMPLE 2
The above graph is plotted for Load vs displacement. And various parameters were
determined as follows
1.) Ultimate load = 6.785 kN
2.) Max displacement = 6.900 mm
3.) Area = 78.571 sq.mm
4.) Ultimate stress = 86.355 Mpa
5.) Compression strength = Ultimate Load/Area = 6785/78.51=86.42N/mm2
37
SAMPLE 3: Cu-92%, Gr-2%, SiC-6%
FIG 5.6 LOAD VS DISPLACMENT-SAMPLE 3
The above graph is plotted for Load vs displacement. And various parameters were
determined as follows
1.) Ultimate load = 13.875 kN
2.) Max displacement = 5.700 mm
3.) Area = 78.571 sq.mm
4.) Ultimate stress = 176.591Mpa
5.) Compression strength = Ultimate Load/Area = 13875/78.571= 176.59 N/mm2
38
5.1.1 DISCUSSION:
• Compression test for all the samples were conducted at a maximum load of 5
tons.
• Then graphs were plotted for Load vs Displacement.
• Ultimate load and max displacement values were taken from the graph.
• The compression strength was calculated manually using the formule
Force/Displacement and verified with the mentioned data.
• It is noted that the composite having the highest percentage of SiC holds
greater compression strength than any other tested compositions including
pure copper.
• This verifies that the addition of SiC to this matrix increases the strength and
the applications can be derived based on the requirements.
39
5.3 WEAR TEST:
• Wear test is carried out to predict the wear performance and to investigate
the wear mechanism.
• From a material point of view, the test is performed to evaluate
the wear property of a material so as to determine whether the material is
adequate for a specific wear application.
For wear test to be carried out the sample was reduced to a smaller diameter of 10mm
using turning operation with the help of a conventional lathe.
The wear test for all specimens was conducted under the normal loads of 20 N and
aSliding velocity of 1 m/s.
FIG 5.7 WEAR TEST
40
5.3.1 TEST PARAMETERS:
Wear Test Parameters
Sample
No
Applied Load
(N)
Sliding
Velocity (m /
Sec)
Sliding
Distance
(m)
Sliding Dia
in mm
Rpm
Time in Sec
Time in
Min /
Sec
X
1
2
3
20
20
20
20
1
1
1
1
500
500
500
500
40
40
40
40
478
478
478
478
500
500
500
500
8.332
8.332
8.332
8.332
TABLE 5.3
First the mass of the samples was noted before the wear test.
And once the wear test is completed the samples were again weighed and the
difference in the masses of the samples due to wear was calculated.
5.3.2 WEAR LOSS
TABLE 5.4 WEAR LOSS
Samples
Initial weight g
Final weight g
X
35.655
35.624
0.031
1
17.64
17.574
0.066
2
10.845
10.3664
0.181
3
34.072
34.042
0.03
41
Wear loss in g
5.3.3 SAMPLE X: Cu-100%, Gr-0%, SiC-0%
1) Time vs Wear
160
140
120
100
80
WEAR-1(MICRON
METER)
60
40
20
0
0
100
200
300
400
500
600
FIG 5.8 TIME VS WEAR SAMPLE X
2) Time vs Frictional Force
16
14
12
10
8
6
FF -1(N)
4
2
0
0
100
200
300
400
500
600
FIG 5.9 TIME VS FRICTIONAL FORCE SAMPLE X
42
3) Time vs COF
0.8
0.7
0.6
0.5
0.4
0.3
COF-1
0.2
0.1
0
0
100
200
300
400
500
600
FIG 5.10 TIME VS COF SAMPLE X
5.3.4 SAMPLE 1: Cu-96%, Gr-2%, SiC-2%
1) Time vs Wear
300
250
200
150
WEAR
100
50
0
0
100
200
300
400
43
500
600
2) Time vs Frictional Force
18
16
14
12
10
FF
8
6
4
2
0
0
100
200
300
400
500
600
FIG 5.12 TIME VS FRICTIONAL FORCE SAMPLE 1
3) Time vs COF
0.9
0.8
0.7
0.6
0.5
COF
0.4
0.3
0.2
0.1
0
0
100
200
300
400
44
500
600
5.3.5 SAMPLE 2: Cu-94%, Gr-2%, SiC-4%
1) Time vs Wear
250
200
150
WEAR
100
50
0
0
100
200
300
400
500
600
FIG 5.14 TIME VS WEAR SAMPLE 2
2) Time vs Frictional Force
14
12
10
8
FF
6
4
2
0
0
100
200
300
400
500
600
FIG 5.15 TIME VS FRICTIONAL FORCE SAMPLE 2
45
3) Time vs COF
0.7
0.6
0.5
0.4
COF
0.3
0.2
0.1
0
0
100
200
300
400
500
600
FIG 5.16 TIME VS COF SAMPLE 2
5.3.6 SAMPLE 3: Cu-92%, Gr-2%, SiC-6%
1) Time vs Wear
120
100
80
60
WEAR
40
20
0
0
100
200
300
400
500
-20
FIG 5.17 TIME VS WEAR SAMPLE 3
44
600
2) Time vs Frictional Force
14
12
10
8
FF
6
4
2
0
0
100
200
300
400
500
600
FIG 5.18 TIME VS FF SAMPLE 3
3) Time vs COF
0.7
0.6
0.5
0.4
COF
0.3
0.2
0.1
0
0
100
200
300
400
500
FIG 5.19 TIME VS COF SAMPLE 3
45
600
5.3.7 DISCUSSION:
• The samples were subjected to a wear test under 20N for 8 minutes.
•
The samples were weighed before and after the wear test and their masses
were noted.
• It is found that the samples with high SiC content has shown greater wear
resistance.
• Then Graphs were plotted for
1.
Time vs Wear
2.
Time vs Friction force
3.
Time vs Coefficient of friction.
46
5.4 MICROSTRUCTURE:
Sample I.D: X
FIG 5.20 SAMPLE X MICRO STRUCTURE
Sample I.D:1
FIG 5.21 SAMPLE 1 MICRO STRUCTURE
47
Sample I.D :2
FIG 5.22 MICRO STRUCTURE SAMPLE 2
Sample I.D:3
FIG 5.23 MICRO STRUCTURE SAMPLE 3
48
5.4.1 Discussion
• The samples were first placed in a mold and grinded finely on the
upper surface to obtain perfect results.
• After placing in the microscope the images were obtained and
observed.
• It is seen that the most parts contain the copper which is in golden
color.
• The graphite is mixed thoroughly and traces are visible in white
shades above SiC in contrast.
• The SiC is visible in bright dark brown shades at random shapes
indicating its presence.
• There are also some white shades visible on the copper due to
compacting.
49
CHAPTER 6
CONCLUSION
HARDNESS:
• The sample 1 containing equal amounts of graphite and SiC was
observed to have the highest hardness compared to other
compositions.
• All compositions were seen to have a good hardness
levels compared to pure copper.
COMPRESSION:
• It is seen that the sample 3 that contains the highest percentage of
SiC among other compositions has a greater compression
strength.
WEAR TEST:
• It is seen that the sample 3 that contains the highest percentage of
SiC among other compositions has a greater wear resistance. Thus
SiC makes the matrix more resistant to wear.
MICROSTRUCTURE(OPTICAL):
• The microstructure of the 4 samples is observed and studied.
OVERALL CONCLUSION:
• The sample 4 with the composition Cu-92%,SiC-6%,Graphite-2% of has
both higher wear resitance and compression strength.
• The sample 1 holds higher hardness compared to other samples .
• The microstructure of each samples is observed and studied.
50
CHAPTER 7
SCOPE FOR FUTURE
In the future the first thing that the project must be upgraded with is the use of few
more samples with different composition of powders.
So, a further more clear analysis could be done on the chosen reinforcements.
Tests can also be taken by sintering the samples at different temperatures there by
providing a wide range of results.
And also, few more tests can be taken for the samples to determine its success
percentage like,
1.) Electrical conductivity
2.) Thermal conductivity
3.) Macro hardness
4.) Microstructure.
51
CHAPTER 8
REFERENCES
1.) A. Devaraju, P. sivasamy, R. Gopi, A. Muthiah Studies on wear behavior of
silicon carbide and fly ash reinforced copper-based metal matrix composites
2.) Tribological behavior and mechanism of h-BN modified copper metal
matrix composites paired with C/C-SiC.
3.) Pritham Sadhu khan, Rayapati Subbarao. Study of mechanical and
tribological properties of hybrid copper metal matrix composite reinforced with
graphite and SiC
4.) Vishwanath Patil, Sanjeev Janawade Studies on mechanical behavior and
morphology of alumina fibers reinforced with Al4.5% and copper alloy metal
matrixcomposites
5.) Lailesh Kumar, Santosh Kumar Sahoo. Effect of xGnP/MWCNT
reinforcement on mechanical, wear and crystallographic texture of copperbased metal matrix composite.
6.) Qian Zhang, Zonglin Yi. Understanding heterogeneous metal-mediated
interfacial enhancement mechanisms in graphene-embedded copper matrix
composites.
7.) Haibin Zhou, Pingping Yao.Effects of ZrO2 crystal structure on the
tribological properties of coppermetal matrix composites.
52