Transcript BAHAN TERMAJU & KOMPOSIT (EBB 324/4)

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Course Code
Course Title
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EBB 337
Advanced Materials
and Composites
Course Unit
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3
Type of Course :
Core
Name of academics :
Dr. Mariatti Jaafar
Dr. Ahmad Azmin Mohamed
Dr. Zuhailawati Hussin
(6) Contribution of Assessment: 70% final examination
& 30% course work (15% Test and 15% Assignment/PBL)
Course Objectives/Course Outcomes (CO)
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1. To classify different types of advanced composite
materials
2. To select and justify a suitable advanced composite
materials for specific applications
3. To propose a suitable fabrication technique of
advanced composite materials for specific applications
4. To apply suitable theory to estimate the properties of
the advanced composite materials
EBB 337 (Advanced Materials &
Composites)
Topic Contents
Introduction to composite materials
(Definition and classification of composite materials,
natural composites, the benefit of composites)
Introduction to composite materials
(Types of matrix (natural and synthetic), types of
reinforcement (natural and synthetic), factors which
determine properties)
Reinforcement-matrix interface
(Wettability, Interfacial bonding, methods to measure
bond strength)
Polymer matrix composites
(Introduction,
types
of
polymer
matrices
(thermoplastics, thermoset & rubber), processing of
PMC- Hand lay-up, spray-up moulding methods
(match die moulding, bag moulding method, vacuum
bagging, pressure bagging, RTM), pultrusion,
filament winding)
Polymer matrix composites
(Some commercial PMCs- epoxy and polyester matrix
composites, PEEK matrix composites, rubber matrix
composites, etc.)
References
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R.F. Gibson, Principles of Composite Materials
Mechanics, McGraw Hill, Inc, 1994.
F.L. Matthews, R.D. Rawlings, Composite Materials;
Engineering & Science, Chapman & Hall, 1994.
R.P Sheldon, Composite Polymeric Materials, Applied
Science Publisher, 1982
S. C. Sharma, Composite Materials, Narosa
Publishing House, 2000
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Test 1 – 16 Jan. 2009 (Friday)
Short Assignment (not more than 5 pages;2 in a
group)- due date 9 Jan. 2009
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Find an article from Journal on the following titles;
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1) Nanoparticles filled Polymer matrix composites for food packaging
applications
2) Nanoparticles filled Polymer matrix composites for electronic
packaging applications
3) Natural fiber reinforced Polymer matrix composites for
construction or automotive applications
4) Synthetic fiber reinforced Polymer matrix composites for
aerospace applications
5) Particulate filler filled Polymer matrix composites for medical
applications
Short Assignment
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Summarize the followings;
Materials used (what is the matrix,
reinforcement/filler, etc)
 Processing involved (hand lay-up, vacuum technique,
injection molding, etc.)
 Properties of composites measured, relate the
properties of composites compared to monolithic
materials
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Composites vs. monolithic materials
What is Composites?
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Combination of 2 or more materials
Each of the materials must exist more than 5%
Presence of interphase
The properties shown by the composite
materials are differed from the initial materials
Can be produced by various processing
techniques
Composite materials- a new emerging class of materials to overcome a current
limits of monolithic of conventional materials
Constituents of composite materials
1. Matrix phase
Continuous phase, the primary phase.
It holds the dispersed phase and shares a load with it.
2. Dispersed (reinforcing) phase
The second phase (or phases) is imbedded in the matrix in a
continuous/discontinuous form.
Dispersed phase is usually stronger than the matrix, therefore it is sometimes
called reinforcing phase.
3. Interface
Zone across which matrix and reinforcing phases interact (chemical, physical,
mechanical)
Matrix: Function
however the distribution of loads depends on the interfacial bondings
Reinforcement: Function
Reinforcement: Function depends
on matrix
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Metal matrix: to increase the hardness and
creep resistance at high temp.
Polymer matrix: to improve stiffness, strength
and toughness
Ceramic matrix: to improve toughness
Reinforcement can be in the form of:
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Continuous fiber
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Organic fiber- i.e. Kevlar, polyethylene
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Inorganic fiber- i.e. glass, alumina, carbon
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Natural fiber- i.e. asbestos, jute, silk
Short fiber
whiskers
Particle
Wire
Interface: Function
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To transfer the stress from matrix to
reinforcement
Sometimes surface treatment is carried out to
achieve the required bonding to the matrix
Interfaces & Interphases
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Figure 1.2
Types of matrix (natural and
synthetic)
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Natural
Silica sand, limestone (CaCO3), talc, etc
 Starch, epoxy based on soy bean, chitosan, etc
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Synthetic
Fumed silica, fused silica, glass, etc
 Epoxy, polyester, PP, PE, etc
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Types of reinforcement (natural and
synthetic)
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Natural
Silica sand, limestone (CaCO3), talc, etc
 Natural fibers, wood, etc
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Synthetic
Glass fiber, boron fibers, etc
 Fumed silica, fused silica, glass, etc
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Classifications of composites
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Matrix; PMC, MMC, CMC
Function; electrical & structure
Geometry of reinforcements; fiber composites
& particulate composites
Classification based on Geometry of
reinforcement
Composite
materials
Particulate-
Fibercomposites
Random
orientation
Unidirectional
composites
Twodirectional
Random
Uni
orientation
-directional
Examples of composites
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b)
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Particulate & random
Discontinuous fibers & unidirectional
Discontinuous fibers & random
Continuous fibers & unidirectional
Classification based on Matrices
Composite
materials
Matrices
Polymer Matrix
Composites (PMC)
Thermoset
Metal Matrix
Composites MMC)
Thermoplastic
Rubber
Ceramic Matrix
Composites (CMC)
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Widely used- ease of processing & lightweight
Metal Matrix Composites (MMC)
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Generate wide interest in research
Not as widely use as PMC
Higher strength, stiffness & fracture toughness
Can withstand elevated temperature in corrosive
environment than PMC
Most metal and alloy can be used as matrices
Ceramic Matrix Composites (CMC)
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Able to withstand high temperature (>1649ºC)
& brittle
Used in aeronautics, military, etc
Carbon and glass are common matrix used in
CMC
Natural Composites
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Wood
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Consists of cellulose,
hemiselulose & lignin
Cellulose- the strongest
component, 65%
unidirectional alignment
Lignin behave as
adhesive, tighten the
wood components
Natural Composites
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Bone
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Example; hydroxyapatite reinforced collagen
composites
Pole (Construction Industry)
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Traditional
wood→steel→concrete→pol
ymer composite (made of
layers of glass fabric +
resins)
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Advantages of Polymer
Composites
1) won't rust, or corrode
2)require no preservatives
3) light-weight, lighter than
aluminum, wood, steel or
concrete.
4) the lowest possible total
installed cost
Modern vaulting poles
Here is an example of a vaulting pole made from glass
fibre reinforced polymer (GFRP) composites and
carbon fibre reinforced polymer (CFRP) composites
Benefits of Composites???
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Improved properties (thermal, mechanical,
electrical, etc)
Many end-applications
Properties of composites depend on
Amount of phase
- Amount/proportion (can be expressed in weight
fraction (Wf) or volume fraction (Vf))of
phases strongly influence the properties of
composite materials.
Xc = Xf Vf + Xm (1 - Vf ) - Rule of Mixture
Xc = Properties of composites
Xf = Properties of fiber
Xm= Properties of matrix
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Voids
Free volume
 Gas emission leads to voids in the final
product
 In composites- Voids exist in the matrix,
interface and in between fiber & fiber
 Voids create stress concentration pointsinfluence the properties of the composites
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Geometry of dispersed phase
(particle size, distribution,
orientation)
Shape of dispersed phase (particle- spherical or
irregular, flaky, whiskers, etc)
Particle/fiber size ( fiber- short, long, continuous);
particle (nano or micron size)
Orientation of fiber/particle (unidirection, bidirections, many directions)- influence isotropic dan anisotropic properties
Dictribution of dispersed phase (homogenus/uniform,
inhomogenus)
Examples of different composite
geometrical arrangements
Processing technique and
parameters
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Influence final product, selection of correct raw
materials, void content, etc