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TRIBOLOGICAL AND MECHANICAL BEHAVIOUR OF
HYBRID METAL MATRIX COMPOSITE
CHAPTER 1
INTRODUCTION
Composite materials (also called composition materials or shortened to
composites) are materials made from two or more constituent materials with
significantly different physical or chemical properties, that when combined,
produce a material with characteristics different from the individual components.
The individual components remain separate and distinct within the finished
structure. A typical composite material is a system of materials composing of two
or more materials (mixed and bonded) on a macroscopic scale. For example,
concrete is made up of cement, sand, stones, and water. f the composition occurs
on a microscopic scale (molecular level), the new material is then called an alloy
for metals or a polymer for plastics.
!enerally, a composite material is composed of reinforcement (fibers,
particles, fla"es and fillers) embedded in a matrix (polymers, metals or ceramics).
The matrix holds the reinforcement to form the desired shape while the
reinforcement improves the overall mechanical properties of the matrix. #hen
designed properly, the new combined material exhibits better strength than would
each individual material.
n general, fibers are the principle load carrying members, while the
surrounding matrix "eeps them in the desired location and orientation, acts as a
load transfer medium between them and protects them from environmental
damages due to elevated temperature and humidity.
$roperties of composites are strongly influenced by the properties of their
constituent materials, their type, their distribution and the interaction between
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them. %i"e conventional materials, composites are not homogeneous and isotropic.
Composites are generally completely elastic up to failure exhibit no yield point or a
region of plasticity. Composites that forms heterogeneous structures which meet
the re&uirements of specific design and function, imbued with desired properties
which limit the scope for classification. 'owever, this lapse is made up for, by the
fact new types of composites are being innovated all the time, each with their own
specific purpose li"e the filled, fla"e, particulate and laminar composites. n
matrixbased structural composites, the matrix serves two paramount purposes vi.,
binding the reinforcement phases in place and deforming to distribute the stresses
among the constituent reinforcement materials under an applied force.
1.1 COMMON CATEGORIES OF COMPOSITE MATERIALS
*ased on the form of reinforcement, common composite materials can be
classified as follows+
Figure 1.1 Ran!" #i$er %&'!r( #i$er) rein#!r*e *!"+!&i(e&
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Figure 1., Par(i*u-a(e *!"+!&i(e
Figure 1. F-a/e *!"+!&i(e&
Figure 1.0 Fi--er *!"+!&i(e&
1., BENEFITS OF COMPOSITES
#hen composites are selected over traditional materials such as metal alloys
or woods, it is usually because of one or more of the following+
1.,.1 C!&(
$rototypes
-ass production
$art consolidation
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-aintenance
%ong term durability
$roduction time
-aturity of technology
1.,., eig'(
%ight weight
#eight distribution
1.,. S(reng(' an &(i##ne&&
'igh strengthtoweight ratio
irectional strength and/or stiffness
1.,.0 Di"en&i!n
%arge parts
0pecial geometry
1.,.2 Sur#a*e +r!+er(ie& Corrosion resistance
#eather resistance
Tailored surface finish
1.,.3 T'er"a- +r!+er(ie&
%ow thermal conductivity
%ow coefficient of thermal expansion
1.,.4 E-e*(ri* +r!+er(5
'igh dielectric strength
1onmagnetic
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2adar transparency.
1. CLASSFICATION OF COMPOSITE MATERIALS
The composite materials are classified as follows
3. -etal matrix composites
4. $olymer matrix composites
5. Ceramic matrix composites
1..1 Me(a- "a(ri6
-etal matrix composites, at present though generating a wide interest in
research fraternity, are not as widely in use as their plastic counterparts. 'igh
strength, fracture toughness and stiffness are offered by metal matrices than thoseoffered by their polymer counterparts. They can withstand elevated temperature in
corrosive environment than polymer composites. -ost metals and alloys could be
used as matrices and they re&uire reinforcement materials which need to be stable
over a range of temperature and nonreactive too. 'owever the guiding aspect for
the choice depends essentially on the on the matrix material. %ight metals form the
matrix for temperature application and the reinforcements in addition to the
aforementioned reasons are characteried by high modulus
-ost metals and alloys ma"e good matrices. 'owever, practically, the
choices for low temperature applications are not many. 6nly light metals are
responsive, with their low density proving an advantage. Titanium, Aluminium and
magnesium are the popular matrix metals currently in vogue, which are
particularly useful for aircraft applications. f metallic matrix materials have to
offer high strength, they re&uire high modulus reinforcements.
The strengthtoweight ratios of resulting composites can be higher than
most alloys. The melting point, physical and mechanical properties of the
composite at various temperatures determine the service temperature of
composites.
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-ost metals, ceramics and compounds can be used with matrices of low
melting point alloys. The choice of reinforcements becomes more stunted with
increase in the melting temperature of matrix materials.
The development ob7ectives for light metal composite material are,
ncrease in yield strength and tensile strength at room temperature and above
while maintaining the minimum ductility or rather toughness.
ncrease in creep resistance at higher temperature compared to that of
Conventional alloys.
ncrease in fatigue strength, especially at higher temperature.
mprovement of thermal shoc" resistance.
ncrease in young8s modulus.
2eduction of thermal elongation.
2einforcement of metal matrix composite have a manifold demand profile
which is determined by production and processing and by the matrix system of the
composite material ,the following demands are generally applicable +
%ow density
-echanical compatibility
Chemical compatibility
Thermal stability
'igh young8s modulus.
!ood process ability
9conomic efficiency
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CHAPTER ,
LITERATURE REVIE
7.7. C'a8-a e( a-.9 :1;. -etalmatrix composites (--Cs) are engineered
combinations of two or more materials (one of which is a metal) where tailored
properties are achieved by systematic combinations of different constituents.
Conventional monolithic materials have limitations in respect to achievable
combinations of strength, stiffness and density. 9ngineered --Cs consisting of
continuous or discontinuous fibres, whis"ers, or particles in a metal achieve
combinations of very high specific strength and specific modulus. Furthermore,systematic design and synthesis procedures allow uni&ue combinations of
engineering properties in composites li"e high elevated temperature strength,
fatigue strength, damping property, electrical and thermal conductivities, friction
coefficient, wear resistance and expansion coefficient.
T.. C-5ne an P.
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I.A. I$ra'i" e( a-.9:0;. The modem composites are non e&uilibrium
combinations of metals and ceramics, where there are fewer thermodynamic
restrictions on the relative volume percentages, shapes and sie of ceramic phases.
S. Ra5 :2;. Composite materials are attractive since they offer the possibility
of attaining property combinations which are not obtained in monolithic materials
and which can result in a number of significant service benefits. These could
include increased strength, decreased weight, higher service temperature, improved
wear resistance, higher elastic modulus, controlled coefficients of thermal
expansion and improved fatigue properties.
S.V. Pra&a an R. A&('ana e( a-.9 :3;.The &uest for improved performance
has resulted in a number of developments in the area of --C fabrication
technology .These includes both the preparation of the reinforcing phases and the
development of fabrication techni&ues. A number of composite fabrication
techni&ues have been developed that can be placed into four broad categories.
These are powder metallurgical techni&ues, li&uid metallurgy. The li&uid
metallurgy techni&ues include unidirectional solidifications to produce
directionally aligned --Cs, suspension of reinforcement in melts followed by
solidification, compo casting, s&ueee casting, spray casting, and pressure
infiltration. The li&uid metallurgy techni&ues are the least expensive of all, and the
multistep diffusion bonding techni&ues may be the most expensive.
B.P. 7ri&'nan e( a-.9 :4;.!raphite is a soft grayishblac" greasy substance.
The word graphite comes from a !ree" word meaning :to write8. The lead in our
writing pencils is graphite mixed with clay. !raphite is also "nown as blac" lead or
plumb ago. !raphite is also crystallied carbon. The carbon atoms of graphite form
a crystal pattern that differs from that of the carbon atoms in diamond. n graphite,
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the carbon atoms are arranged in flat planes of hexagonal rings stac"ed on one
another. This free electron accounts for the electrical conductivity of graphite. The
lac" of carboncarbon bonding between ad7acent planes enables them to slide over
each other ma"ing graphite soft, slippery and useful as a lubricant. The presence of
free electrons ma"es graphite a good conductor of electricity and it is used to ma"e
electrodes.
S. Bi&8a& e( a-.9:=;.!raphite has the following properties. (i) !raphite is a
soft, slippery, grayishblac" substance. t has a metallic luster and is opa&ue to
light. (ii)0pecific gravity of graphite is 4.5. (iii)!raphite is a good conductor of
heat and electricity. (iv)Although graphite is a very stable allotrope of carbon but at
a very high temperature it can be transformed into artificial diamond.
(v)Chemically, graphite is slightly more reactive than diamond.
S.Ven/a(e&' e( a-.9:>;. 0ubse&uently several aluminum companies further
refined and modified the process which is currently employed to manufacture a
variety of aluminum metal matrix composites on commercial scale and also which
is used to manufacturing the automobile parts.
7.Sara?ana/u"ar e( a-.9 :1@;. many optimiation techni&ues and design of
experiment techni&ues are used to find the best combinations composite
parameters by this techni&ue the &uality of metal matrix composites are increased.
n this wor" taguchi techni&ue through %; orthogonal array is used to find the best
combinations of metal matrix composites.
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CHAPTER
PROBLEM IDENTIFICATION
From the literature survey we have identified the problem that nic"el and
cobalt has less oxidation resistance. 0o, this material is not used in aerospace.
9arlier composites ma"e corrode li"e metals, the combination of corrosion
and fatigue crac"ing is a significant problem for aluminum commercial fuselage
structure. -agnesium has less atmospheric corrosion resistance. 1ic"el, Cobalt,
-agnesium and *oron and others are cost wise high. Cost of a material is a big problem.
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CHAPTER 0
METHODOLOGY
0election of matrix and reinforcement
(AA =>=3 ? Fly ash ? !raphite)
To prepare the various specimens using
0tir casting route
-easuring dimensions and $reparation of
ndividual specimens
Testing on -echanical and Tribological properties
of the various specimens
Conducting -icrostructural analysis for the
@arious specimens
To obtain the results and conclusions
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CHAPTER 2
MATERIALS AND METHODSS
2.1 MATRIX
The matrix is the monolithic material into which the reinforcement is
eembedded, and is completely continuous. This means that there is a path through
the matrix to any point in the material, unli"e two materials sandwiched together.
n a composite material, the matrix material serves the following functions+
3. 'olds the fibers together.
4. $rotects the fibers from environment.
5. 9nhances transverse properties of a laminate.
. mproves impact and fracture resistance of a component.
B. 'elps to avoid propagation of crac" growth through the fibers by
providing alternate failure path along the interface between the fibers
and the matrix.
=. Carry inner laminar shear.
2., MATRIX MATERIAL
2.,.1 A-u"iniu"
Aluminium is the matrix and reinforcement is usually nonmetallic and
ceramic materials. $roperties of A-Cs can be tailored by varying the nature of
constituents and their volume fraction. The ma7or advantage of A-Cs compared to
unreinforcement materials are as follows.
!reater strength
mproved stiffness
2educed density
mproved high temperature properties
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Controlled thermal expansion coefficient
Thermal/ heat management
9nhanced and tailored electrical performance.
mproved abrasion and wear resistance.
mproved damping properties
2.,., Pr!+er(ie& !# A-u"iniu" 3@31
Typical properties of aluminium alloy =>=3 include+
-edium to high strength
!ood toughness
!ood surface finish
9xcellent corrosion resistance to atmospheric conditions
!ood corrosion resistance to sea water
Can be anodied
!ood weldability and braability
!ood wor"ability
#idely available
Ta$-e 2.1 C'e"i*a- C!"+!&i(i!n !# A-u"iniu" A--!5
E-e"en( eig'(
Al ;.
Cu >.3B
-g >.
Dn >.4B
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2.,. A++-i*a(i!n&
Typical applications for aluminium alloy =>=3 include+
Aircraft and aerospace components
-arine fittings
Transport
*icycle frames
Camera lenses
rive shafts
9lectrical fittings and connectors
*ra"e components
@alves
Couplings2. REINFORCEMENT
The reinforcement material is embedded into the matrix the reinforcement does
not always serve a purely structural tas" (reinforcing the compound), but is also
used to change physical properties such as wear resistance, friction coefficient, or
thermal conductivity. 2einforcement materials are,
• Fly ash and !raphite
2.0 FLY ASH
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Fly ash is one of the residues generated in combustion, and comprises the
fine particles that rise with the flue gases. Ash which does not rise is termed
bottom ash. Fly ash is generally captured by electrostatic precipitators or other
particle filtration e&uipments before the flue gases reach the chimneys of coalfired
power plants, and together with bottom ash removed from the bottom of the
furnace is in this case 7ointly "nown as coal ash.
The preference to use fly ash as a filler or reinforcement in metal and
polymer matrices is that fly ash is a byproduct of coal combustion, available in
very large &uantities (>million tons per year) at very low costs since much of this
is currently land filled. The high electrical resistivity, low thermal conductivity and
low density of flyash may be helpful for ma"ing a light weight insulating
composites.
Ta$-e 2., C'e"i*a- C!"+!&i(i!n !# F-5 A&'
Component *ituminous 0ub bituminous %ignite
0i64 (E) 4>=> >=> 3BB
Al465 (E) B5B 4>5> 4>4BFe465 (E) 3>> 3> 3B
Ca6 (E) 334 B5> 3B>
Fly ash as a filler in Al casting reduces cost, decreases density and increase
hardness, stiffness, wear and abrasion resistance. t also improves the
machinability, damping capacity, coefficient of friction etc. which are needed in
various industries li"e automotive etc. n the fly ash increases hardness alsoincreases. Toxic constituents depend upon the specific coal bed ma"eup, but may
include one or more of the following elements or substances in &uantities from
trace amounts to several percent+ arsenic, beryllium, boron, cadmium, chromium,
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chromium @, cobalt, lead, manganese, mercury, molybdenum, selenium,
strontium, thallium, and vanadium, along with dioxins and $A' compounds.
Fly ash material solidifies while suspended in the exhaust gases and is
collected by electrostatic precipitators or filter bags.
Figure 2.1 F-5 a&' P!8er
0ince the particles solidify rapidly while suspended in the exhaust gases,
flyash particles are generally spherical in shape and range in sie from >.B m
to5>> m.
2.0.1 C-a&& F #-5 a&'
The burning of harder, older anthracite and bituminous coal typically
produces Class F fly ash. This fly ash is poolanic in nature, and contains less
than 4>E lime (Ca6). $ossessing poolanic properties, the glassy silica and
alumina of Class F fly ash re&uires a cementing agent, such as $ortland cement,
&uic"lime, or hydrated lime, with the presence of water in order to react and
produce cementitious compounds.
2.0., C-a&& C #-5 a&'
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Fly ash produced from the burning of younger lignite or subbituminous coal,
in addition to having poolanic properties, also has some selfcementing
properties. n the presence of water, Class C fly ash will harden and gain strength
over time. Class C fly ash generally contains more than 4>E lime (Ca6).
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mechanical treatment and the beta form reverts to the alpha form when it is heated
above 35>> IC.
Figure 2., S*anning (unne-ing "i*r!&*!+e i"age !# gra+'i(e &ur#a*e a(!"&
Figure 2. Gra+'i(e& uni( *e--
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Figure 2.0 Ani"a(e ?ie8 !# ('e uni( *e-- in ('ree -a5er& !#
gra+'ene
Figure 2.2 Ba--an&(i*/ "!e- !# gra+'i(e %(8! gra+'ene -a5er&)
Figure 2.3 Sie ?ie8 !# -a5er &(a*/ing
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Figure 2.4 P-ane ?ie8 !# -a5er &(a*/ing
2.2., Pr!+er(ie&
The acoustic and thermal properties of graphite are highly anisotropic,
since phonons propagate &uic"ly along the tightlybound planes, but are slower to
travel from one plane to another.!raphite can conduct electricity due to the
vast electron delocaliation within the carbon layers (a phenomenon
called aromaticity). These valence electrons are free to move, so are able to
conduct electricity. 'owever, the electricity is primarily conducted within the planeof the layers. The conductive properties of powdered graphite allowed its use as a
semiconductor substitute in early carbon microphones.
!raphite and graphite powder are valued in industrial applications for their
selflubricating and dry lubricating properties. There is a common belief that
graphiteJs lubricating properties are solely due to the loose interlamellar
coupling between sheets in the structure. 'owever, it has been shown that in
a vacuum environment (such as in technologies for use in space), graphite is a
verypoor lubricant. This observation led to the hypothesis that the lubrication is
due to the presence of fluids between the layers, such as air and water, which are
naturally adsorbed from the environment. This hypothesis has been refuted by
20
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studies showing that air and water are not absorbed. 2ecent studies suggest that an
effect called superlubricity can also account for graphiteJs lubricating properties.
The use of graphite is limited by its tendency to facilitate pitting corrosion in
some stainless steel, and to promote galvanic corrosion between dissimilar metals
(due to its electrical conductivity). t is also corrosive to aluminium in the presence
of moisture. For this reason, the >>K35>> IC then it is
isotropic turbostratic, and is used in blood contacting devices li"e mechanical heart
valves and is called (pyrolytic carbon), and is not diamagnetic. $yrolytic graphite,
and pyrolytic carbon are often confused but are very different materials.
1atural and crystalline graphites are not often used in pure form as structural
materials, due to their shearplanes, brittleness and inconsistent mechanical
properties.
Ta$-e 2. Pr!+er(ie& !# Gra+'i(e
0.16 $26$92TL C6--92CA% !2A$'T9
3 *ul" ensity (g/cm5) 3.53.;B
4 $orosity (E) >.GB5
21
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5 -odulus of 9lasticity (!$a) 3B
Compressive strength (-$a) 4>4>>
B Coefficient of Thermal 9xpansion(3>= IC) 3.4.4
= Thermal conductivity (#/m.M) 4BG>
G 9lectrical resistivity (N.m) Bx3>=5>x3>=
2.2. U&e& !# Gra+'i(e
1atural graphite is mostly consumed for refractories, batteries, steelma"ing,
expanded graphite, bra"e linings, foundry facings and lubricants.!raphene, whichoccurs naturally in graphite, has uni&ue physical properties and might be one of the
strongest substances "nownO however, the process of separating it from graphite
will re&uire some technological development before it is economically feasible to
use it in industrial processes.
3.Amorphous !raphite is used in +
-etallurgy
$encil $roduction
2efractories Coatings
%ubricants
$aint $roduction
4.Crystalline !raphite is used in+
*atteries %ubricants
!rinding #heels $owder -etallurgy.
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2.3 EAR STUDY AND EAR BEHAVIOUR
#ear is erosion or sideways displacement of material from its HderivativeH
and original position on a solid surface performed by the action of another surface.
#ear is related to interactions between surfaces and more specifically the removal
and deformation of material on a surface as a result of mechanical action of the
opposite surface. The definition of wear may include loss of dimension from
plastic deformation if it is originated at the interface between two sliding surfaces.
'owever, plastic deformation such as yield stress is excluded from the wear
definition if it doesnJt incorporates a relative sliding motion and contact against
another surface despite the possibility for material removal, because it then lac"s
the relative sliding action of another surface. mpact wear is in reality a short
sliding motion where two solid bodies interact at an exceptional short time interval.
$reviously due to the fast execution, the contact found in impact wear was referred
to as an impulse contact by the nomenclature. mpulse can be described as a
mathematical model of a synthesied average on the energy transport between two
travelling solids in opposite converging contact.
2.3.1 T5+e& !# 8ear "e*'ani&"
The study of the processes of wear is part of the discipline of tribology. The
complex nature of wear has delayed its investigations and resulted in isolated
studies towards specific wear mechanisms or processes.0ome commonly referred
to wear mechanisms (or processes) include+
3. Adhesive wear
4. Abrasive wear
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5. 0urface fatigue
. Fretting wear
B. 9rosive wear
CHAPTER 3
EXPERIMENTEL PROCEDURE
3.1 IMPACT TEST
The Charpy impact test, also "nown as the Charpy @notch test, is a
standardied high strainrate test which determines the amount of energy absorbed
by a material during fracture. This absorbed energy is a measure of a givenmaterialJs notch toughness and acts as a tool to study temperaturedependent
ductilebrittle transition. t is widely applied in industry, since it is easy to prepare
and conduct and results can be obtained &uic"ly and cheaply. A disadvantage is
that some results are only comparative.
The apparatus consists of a pendulum of "nown mass and length that is
dropped from a "nown height to impact a notched specimen of material. The
energy transferred to the material can be inferred by comparing the difference in
the height of the hammer before and after the fracture (energy absorbed by the
fracture event).
The notch in the sample affects the results of the impact test thus it is
necessary for the notch to be of regular dimensions and geometry. The sie of the
sample can also affect results, since the dimensions determine whether or not the
material is in plane strain. This difference can greatly affect conclusions made.
The H0tandard methods for 1otched *ar mpact Testing of -etallic
-aterialsH can be found in A0T- where all the aspects of the test and e&uipment
used are described in detail.
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According to A0T- A5G>, the standard specimen sie for Charpy
impact testing is 3> mm P 3>mm P BBmm. 0ubsie specimen sies are+ 3> mm P
G.B mm P BBmm, 3> mm P =.G mm P BB mm, 3> mm P B mm P BB mm, 3> mm P
5.5 mm P BB mm, 3> mm P 4.B mm P BB mm. etails of specimens as per A0T-
A5G> (0tandard Test -ethod and efinitions for -echanical Testing of 0teel
$roducts).
Figure 3.1 I"+a*( Te&( S+e*i"en
3., BRINELL HARDNESS TEST
The *rinell scale characteries the indentation hardness of materials
through the scale of penetration of an indenter, loaded on a material testpiece. t is
one of several definitions of hardness in materials science.
The typical test uses a 3> millimetres (>.5; inch) diametersteel ball as
an indenter with a 5,>>> "gf (4; "1O =,=>> lbf ) force. For softer materials, a
smaller force is usedO for harder materials, a tungsten carbide ball is substituted for
the steel ball. The indentation is measured and hardness calculated as+
25
http://en.wikipedia.org/wiki/ASTMhttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Materials_sciencehttp://en.wikipedia.org/wiki/Diameterhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Kilogram-forcehttp://en.wikipedia.org/wiki/Newton_(unit)http://en.wikipedia.org/wiki/Pound-forcehttp://en.wikipedia.org/wiki/Tungsten_carbidehttp://en.wikipedia.org/wiki/ASTMhttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Materials_sciencehttp://en.wikipedia.org/wiki/Diameterhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Kilogram-forcehttp://en.wikipedia.org/wiki/Newton_(unit)http://en.wikipedia.org/wiki/Pound-forcehttp://en.wikipedia.org/wiki/Tungsten_carbide
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where+
P Q applied force ("gf )
D Q diameter of indenter (mm)
d Q diameter of indentation (mm)
The *'1 can be converted into the ultimate tensile strength (
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3.TENSILE TEST
Tensile testing, also "nown as tension testing,is a fundamental
materials science test in which a sample is sub7ected to a controlled tension until
failure. The results from the test are commonly used to select a material for an
application, for &uality control, and to predict how a material will react under other
types of forces. $roperties that are directly measured via a tensile test are ultimate
tensile strength, maximum elongation and reduction in area.From these
measurements the following properties can also be determined+ LoungJs modulus,
$oissonJs ratio, yield strength, and strainhardening characteristics.
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grip assures good alignment. Threaded shoulders and grips also assure good
alignment, but the technician must "now to thread each shoulder into the grip at
least one diameterJs length, otherwise the threads can strip before the specimen
fractures.
n large castings and forgings it is common to add extra material,
which is designed to be removed from the casting so that test specimens can be
made from it. These specimens may not be exact representation of the whole
wor"piece because the grain structure may be different throughout. n smaller
wor"pieces or when critical parts of the casting must be tested, a wor"piece may be
sacrificed to ma"e the test specimens. For wor"pieces that are machined from bar
stoc" , the test specimen can be made from the same piece as the bar stoc".
Figure 3. Ten&i-e Te&( S+e*i"en
A standard specimen is prepared in a round or a s&uare section along
the gauge length, depending on the standard used. *oth ends of the specimens
should have sufficient length and a surface condition such that they are firmly
gripped during testing.
28
http://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Forginghttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Forginghttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Bar_stock
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The test process involves placing the test specimen in the testing
machine and applying tension to it until it fractures. uring the application of
tension, the elongation of the gauge section is recorded against the applied force.
The data is manipulated so that it is not specific to the geometry of the test sample.
The elongation measurement is used to calculate the engineering strain, ε, using the
following e&uation+
where R L is the change in gauge length, L> is the initial gauge length,
and L is the final length. The force measurement is used to calculate the
engineering stress, S, using the following e&uation+
where F is the force and A is the crosssection of the gauge section.
The machine does these calculations as the force increases, so that the data points
can be graphed into a stressstrain curve.
3.0 MICROSTRUCTURE TEST
-icrostructure is defined as the structure of a prepared surface or thin
foil of material as revealed by a microscope above 4BP magnification.The
microstructure of a material (which can be broadly classified into metallic,
polymeric, ceramic and composite) can strongly influence physical properties such
29
http://en.wikipedia.org/wiki/Fracturehttp://en.wikipedia.org/wiki/Elongation_(materials_science)http://en.wikipedia.org/wiki/Deformation_(engineering)http://en.wikipedia.org/wiki/Stress-strain_curvehttp://en.wikipedia.org/wiki/Metallographyhttp://en.wikipedia.org/wiki/Polymerichttp://en.wikipedia.org/wiki/Ceramographyhttp://en.wikipedia.org/wiki/Composite_materialhttp://en.wikipedia.org/wiki/Fracturehttp://en.wikipedia.org/wiki/Elongation_(materials_science)http://en.wikipedia.org/wiki/Deformation_(engineering)http://en.wikipedia.org/wiki/Stress-strain_curvehttp://en.wikipedia.org/wiki/Metallographyhttp://en.wikipedia.org/wiki/Polymerichttp://en.wikipedia.org/wiki/Ceramographyhttp://en.wikipedia.org/wiki/Composite_material
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as strength, toughness, ductility, hardness, corrosion resistance, high/low
temperature behaviour, wear resistance, and so on, which in turn govern the
application of these materials in industrial practice.
3.2 DENSITY TEST
ensity is a ratio expressed by the formula Q# / @ or density e&uals the
weight of material divided by the volume it occupies. A simple example is the
density of water. 9ach cubic foot of water weighs =4. poundsO thus, the density of
water is =4. pounds per cubic foot. n soil testing, density is used to determine the
degree of compaction by comparing the n$lace ensity to the -aximum ensity.
The degree of compaction, expressed as a percent, is then compared to the
specification re&uirement to determine pass or fail. -aximum ensity is a standard
expressed in pounds per cubic foot which is arrived at by applying a standard
compactive effort to a soil mixture under controlled conditions.
ensity measurements are made in different ways depending upon the
physical state of the sample being measured. The volume of a li&uid is commonly
measured in a graduated cylinder. The surface of the li&uid curves upward where it
contacts the cylinder walls. This curved surface is called a meniscus. -easurement
of volume in a graduated cylinder is always made by reading the mar" at the
bottom of the meniscus with the eye positioned at the level of the li&uid surface.
The volume of a solid may be calculated from its dimensions (%x#x'), if the solid
is regular and free of air space. 'owever, if the solid is irregular or contains air
space, its volume must be determined in another way, such as by water
displacement.
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3.2.1 Pr!*eure
3) 6btain clean, dry samples of three different metals. #rite down which
un"nowns you haveO they correspond to the answer "ey.
4) -easure the mass of each metal, using the maximum number of decimal places
allowed by the balance.
5) -easure the volume of each metal separately+
a) Fill a graduated cylinder halfway with sin" water.
b) Tap out any air bubbles.
c) 2ecord initial volume to >.3 ml.
d) Tilt the cylinder gently and slide the metal into it.
t must be submerged.
e) Tap out any air bubbles.
f) 2ecord final volume to >.3 ml.
) #hen finished, carefully pour out the water and metal into your hand. ry the
metal samples and give them to the teacher.
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Figure 3.0 Den&i(5 Te&(
Calculate the density of each metal by the following formula +
Den&i(5 "a&& ?!-u"e.
CHAPTER 4
RESULTS AND DISCUSSIONS
4.1 DENSITY CALCULATION
4.1.1 E6+eri"en(a- Ca-*u-a(i!n
Ma(eria-1
iameter (d) Q 3G.mm
2adius (r) Q .;mm'eight (h) Q 43.=mm
@olume (v) Q r 4h
@ Q B5GB.>=mm5
-ass (m) Q 33.Bg
ensity (U) Q
Q
U Q 4.4>BP3>5 g/mm5
Ma(eria-,+
iameter (d) Q 3G.mm2adius(r) Q .Gmm
'eight (h) Q 44.3mm
@olume (v) Q r 4h
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@ Q B4BB.>Bmm5
-ass (m) Q 33.Bg
ensity (U) Q
Q
U Q 4.4>BP3>5 g/mm5
Ma(eria-+
iameter (d) Q 3=.Bmm2adius(r) Q .4Bmm
'eight (h) Q 43.mm
@olume (v) Q r 4h @ Q ==3.5Gmm5
-ass (m) Q 34.=g
ensity (U) Q
Q
U Q 4.GBP3>5 g/mm5
4.1., T'e!re(i*a- Ca-*u-a(i!n
Ma(eria-1
ensity (U) Q VVWvolume fraction of A=>=3XPWdensity of A=>=3XY ?
VWvolume fraction of fly ashXPWdensity of fly ashXY ?
VWvolume fraction of graphiteXPWdensity of graphiteXYY
Q VW>.;3P4.GX ? W>.>BP3.=X ? W>.>P4.4=XY
Z Q4.=4G"g/mm5
Ma(eria-,+
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ensity (U) Q VVWvolume fraction of A=>=3XPWdensity of A=>=3XY ?
VWvolume fraction of fly ashXPWdensity of fly ashXY ?
VWvolume fraction of graphiteXPWdensity of graphiteXYY
Q VW>.;3P4.GX ? W>.3>P3.=X ? W>.>P4.4=XY
U Q4.G;G"g/mm5
Ma(eria-
ensity (U) Q VVWvolume fraction of A=>=3XPWdensity of A=>=3XY ?
VWvolume fraction of fly ashXPWdensity of fly ashXY ?
VWvolume fraction of graphiteXPWdensity of graphiteXYY
Q VW>.;3P4.GX ? W>.3BP3.=X ? W>.34P4.4=XY
U Q4.;=4"g/mm5
4., TENSILE TEST
!auge length of the rod (%3) Q =>mm
iameter of the rod (3) Q 3=mm
Tensile load for material3 Q 331/mm4
Tensile load for material4 Q 33=1/mm4
Tensile load for material5 Q 331/mm4
4. IOD IMPACT TEST
imension of wor" piece Q GBP3>P3>mm
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Type of notch Q @notch
1otch angle Q B[
epth of notch Q 4mm
istance of notch from one end Q 4mm
epth of the specimen below the notch Q mm
#idth of the specimen Q 3>mm
Cross section area of the notch point Q >m
Ma(eria-1
mpact strength of the specimen Q
Q >.>GB1/mm4
Ma(eria-,
mpact strength of the specimen Q
Q >.>GGB1/mm4
Ma(eria-
mpact strength of the specimen Q
Q >.>=GB1/mm4
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4.0 CHARPY IMPACT TEST
0ie of the specimen Q BB
Type of the notch Q < shaped
Total depth of notch Q Bmm
#idth of notch Q 4mm
2adius of semi circle Q 3mm
istance of notch from one end Q 4G.Bmm
epth of the specimen below the notch Q .Bmm
#idth of the specimen Q 3>mm
Ma(eria-1
mpact strength of the specimen Q
Q >.3BB331m/mm4
Ma(eria- ,
mpact strength of the specimen Q
Q >.35331m/mm4
Ma(eria-
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mpact strength of the specimen Q
Q >.3351m/mm4
4.2 ROC7ELL HARDNESS TEST
Ta$-e 4.1 R!*/8e-- 'arne&& (e&( re&u-(&
-aterial scale %oad "g
Type of
theindenter
Test 3 Test 4 Test 5
2oc"well
hardnessnumber
3 * => 3/\ ball B; B BG B
4 * => 3/\ ball = = =4 =
5 * => 3/\ ball = =B =B =B
Ta$-e 4., Den&i(5 ?a-ue (e&( re&u-(&
SPECIMEN NUMBER COMPOSITION LEVEL DENSITY
g"""
3 Al=>=3?4BEflyash?4>Egraphit
e
4.4>4P3>5
4 Al=>=3?B>Eflyash?>Egraphit
e
4.BG=P3>5
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5 Al=>=3?GBEflyash?=>Egraphit
e
4.GBP3>5
4.3 BRINELL HARDNESS TEST
The resistance to indentation or scratch is termed as hardness. Among
various instruments for measurement of hardness, *rinell8s, 2oc"well8s and
@ic"er8s hardness testers are significant in Figureure .2einforcement and matrix
respectively and v and ' stand for volume fraction and hardness respectively) for
composites helps in approximating the hardness values. Among the variants of
reinforcements, the low aspect ratio particle reinforcements are of much significant
in imparting the hardness of the material in which they are dispersed.
Figure 4.1 Harne&& Te&( Ma*'ine
'ardness is probably one of the most used selection factors. The hardness of
materials is often e&uated with wear resistance and durability. This is not a
completely accurate concept but in steels it serves as a measure of abrasion
resistance and strength. There are probably 3>> ways of measuring hardness. n the
early days of metallurgy, heattreated steels were tested for hardness by filing an
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edge. f it did not file, it was hard. -ost presentday hardness tests consist of
pushing a penetrator into the material and measuring the effects. The loading
mechanism varies with the various tests as does the mechanism for measuring the
effect of the indentation.
Ta$-e 4. Brine-- 'arne&& (e&( re&u-(&
SPECIMEN
NUMBER
COMPOSITION LEVEL HARDNESS
%BHN)
3 Al=>=3?4BEflyash?4>Egraphite B;.B5
4 Al=>=3?B>Eflyash?>Egraphite =G.3=
5 Al=>=3?GBEflyash?=>Egraphite G=.3=
4.4 GRAPHICAL REPRESENTATION OF ROC7ELL HARDNESS
TEST
Figure 4., C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& Harne&&%RHN)
4.= GRAPHICAL REPRESENTATION OF DENSITY TEST
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Figure 4. C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& Den&i(5
4.> GRAPHICAL REPRESENTATION OF IMPACT STRENGTH %IOD
TEST)
Figure 4.0 C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& I"+a*(
&(reng(' %I! (e&()
4.1@ GRAPHICAL REPRESENTATION OF IMPACT STRENGTH
%CHARPY TEST)
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Figure 4.2 C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& I"+a*(
&(reng(' %C'ar+5 (e&()
4.11 MICROSTRUCTURAL ANALYSIS TEST RESULTS
Ma(eria- 1
Figure 4.3 O+(i*a- "i*r!&*!+e i"age !# ,2 #-5a&'J,@Gra+'i(e +ar(i*u-a(e
rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n
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Figure 4.4 O+(i*a- "i*r!&*!+e i"age !# ,2 #-5a&'J,@Gra+'i(e +ar(i*u-a(e
rein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n
Ma(eria-,
Figure 4.= O+(i*a- "i*r!&*!+e i"age !# 2@ #-5a&'J0@Gra+'i(e +ar(i*u-a(e
rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n
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Figure 4.> O+(i*a- "i*r!&*!+e i"age !# 2@ #-5a&'J0@Gra+'i(e +ar(i*u-a(erein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n
Ma(eria-
Figure 4.1@ O+(i*a- "i*r!&*!+e i"age !# 42 #-5a&'J3@Gra+'i(e
+ar(i*u-a(e rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n
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Figure 4.11 O+(i*a- "i*r!&*!+e i"age !# 42 #-5a&'J3@Gra+'i(e
+ar(i*u-a(e rein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n
CHAPTER =
CONCLUSION
Thus we found that the aerospace and automotive industry needs a material
in low cost of production with high tensile strength and greatest weight ratio.
Through this literature survey we have gained "nowledge in composite materials
for confirming the pro7ect which will fulfill the need of the aerospace and
automotive industries. #e have ideas in the methodology to complete the pro7ect in
low cost of production with high tensile strength and greatest weight ratio.
n many applications, composite materials play a successive role. 0o, our
pro7ect may useful for the aerospace and automotive industries.
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