Seminar on manufacturing of composite materialsPresentation Transcript
Manufacturing of composite
under guidance ofProf. Dr. I. Basak
Raghvendra Kumar Pandey
Composite materials:▪ A microscopic mixture of two or more different materials. One typically being the
continuous phase (matrix), and the other being the discontinuous phase (reinforcement).
▪ Its properties are strongly dependent on the composite structure.
Ceramic fiber composite
Polymer matrix composite
▪ Composites can be very strong and stiff, yet very light in weight, so ratios of strength-to-weight and
stiffness-to-weight are several times greater than steel or aluminium.
▪ Reduces maintenance costs
▪ Reduces or eliminates corrosion
Better fatigue resistance
Less thermal expansion
▪ Enhanced properties via tailor able properties
▪ Reduces cost
Boeing 787 Composite Usage
Types of composites:Fiber
• Ceramics + metals
• For example cemented carbides and other cermet's
• Aluminium or magnesium reinforced by strong, high stiffness fibers
• A ceramic primary phase imbedded with a secondary phase, which usually consists
• Least common composite matrix
• Aluminium oxide and silicon carbide are materials that can be imbedded with fibers
for improved properties, especially in high temperature applications
• Thermosetting resins are the most widely used polymers in PMCs.
• Epoxy and polyester are commonly mixed with fiber reinforcement
Forms the matrix
within which the
secondary phase is
Matrix material function:A.
Provides the bulk form of the part or product
Holds the imbedded phase in place
Shares the load with the secondary phase
Polymer e.g. PEEK, Polyester, polyurethane, Rubber
Metal e.g. Al, Cu, Ti, Ni
Ceramic e.g. cements, glass.
Any of three basic
polymers, metals, or
Referred to as the
imbedded phase or
called the reinforcing
Can be one of the
three basic materials
or an element such as
carbon or boron
Serves to strengthen
Continuous strand mat
Chopped strand mat
Photomicrograph (about 1500X) of cemented carbide with
85% WC and 15% Co
Rule of mixture
▪ For particulate composites, the rule of mixtures predicts the density of the composite as well
as other properties (although other properties may vary depending on how the dispersed
phase is arranged)
▪ Density, r, is given as a fraction, f, as:
rc fm rm f f r f
Note that f m 1 f f
Where the subscripts m and f refer to the matrix and fiber.
For fiber reinforced composites, the rule of mixtures predicts the density of the composite as well as
electrical and thermal conductivity along the direction of the fibers if they are continuous and unidirectional.
Density, r, is given as a fraction, f, as:
rc fm rm f f r f
Note that f m 1 f f
For thermal conductivity:
K c fm K m f f K
For electrical conductivity:
c f m
Thermal and electrical energy can be transferred through the composite at a rate that is proportional to the
volume fraction, f of the conductive material
Bulk of energy transferred through matrix
But , in the fiber (polymer) composite, bulk energy transferred through fibers.
When the fibers are not continuous or unidirectional, the simple rule of mixtures may not apply.
For example, in a metal fiber-polymer matrix composite, electrical conductivity would be low and would depend
on the length of the fibers, the volume fraction of fibers and how often the fibers touch one another.
1) Hand lay up
Low cost tools
Versatile: wide range of
Possibility of trap of air
2) Prepreg forming
orientation of fibers can
needs more customers
limited shelf life
3) Pressure forming
wide range of shapes
high cost of machine
expensive molds (strong
no intricate parts
4) Vacuum bagging
better quality for the cost
cannot be heated up too
breeder clothe has to be
low pressure (760 mm Hg
Die can be easily messed
Mainly thermoset matrix.
6) Spray method: Advantages :
Any materials can be used
Error can be corrected by
No control of fiber
Only one side finished.
7) Sheet moulding:
High productivity thus
low volume fraction.
Only board can be
8) Bulk moulding
Highest volume fraction
for short fiber reinforced
Finish can be applied
Inserts and attachments
High temperature and
Cannot be used for
9) Resin transfer method:
good surface finish on both sides
accurate fiber management is achievable
Ability to build-in fiber volume fraction
loadings up to 65%
Uniformity of thickness and fiber
loading, uniform shrinkage
Inserts may be incorporated into moldings
Tooling costs comparatively low
Uses only low pressure injection
Low volatile emission during processing
Ability to produce near net shape moldings
Process can be automated, resulting in higher
Ability to mould complex structural and hollow
Low resultant voids
Ability to achieve from 0.5mm to 90mm
...And Just what is composite??
Let’s keep It simple
▪ A macroscale material “composed” of multiple non homogenious material
▪ More simpler definition ?? Okay...
▪ Its STRING and GLUE ..!!
▪ Its everywhere...starting from MANGALYAAN to an OPERATION theater in
▪ Why don’t customize the existing design when you have composite ...!!!