Materials technology presentation

MATERIAL TECHNOLOGY

TOPIC

COMPOSITE MATERIALS

GROUP MEMBERS

MUHAMMAD BILAL 142714 MUHAMMAD RAMZAN 142715 CLASS BS MECHANICAL

Definition Importance of composite materials Types of composite Advantages of composite Disadvantages of composite Application of composite

Definition: A composite material can be defined

as a combination of two or more materials that results in better properties than those of the individual components alone. In contrast to metallic alloys, each material retains its separate chemical, physical, and mechanical properties.The main advantages of composite materials are their high strength and stiffness, combined with low density.

Importance of 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 aluminum

Fatigue properties are generally better than for common engineering metals

Toughness is often greater too Composites can be designed that do not corrode

like steel Possible to achieve combinations of properties not

attainable with metals, ceramics, or polymers alone

Types of composite: Natural composite Natural composites exist in both animals and

plants. Wood is a composite – it is made from long cellulose fibres (a polymer) held together by a much weaker substance called lignin. Cellulose is also found in cotton, but without the lignin to bind it together it is much weaker. The two weak substances – lignin and cellulose – together form a much stronger one.

Early composites People have been making composites for

many thousands of years. One early example is mud bricks. Mud can be dried out into a brick shape to give a building material.

Particulate Composites

The particulate composites are designed to produce unusual combinations of properties rather than to improve strength. The particulate composites contain large amounts of coarse particles that do not block slip effectively.

Cast Metal Particulate Composites Aluminum castings containing dispersed SiC

particles for automotive applications, including pistons and connecting rods, represent an important commercial application for particulate composites

Advantages of composite A higher performance for a give weight loads to

fuel saving. Excellent strength-to-weight and stiffness-to-weight ratios can be achieved by composite materials.

Laminate patterns and ply build up in a part can be tailored to give the required. mechanical properties in various directions.

It is easier to achieve smooth aerodynamic profiles for drag reduction.

Production cost is reduce. Composite offer excellent resistance to

corrosion,chemical attack, and outdoor weathering.

Disadvantages of compositeProperties of many important composites are

anisotropic ‑ the properties differ depending on the direction in which they are measured – this may be an advantage or a disadvantage

Many of the polymer‑based composites are subject to attack by chemicals or solvents, just as the polymers themselves are susceptible to attack

Composite materials are generally expensiveManufacturing methods for shaping

composite materials are often slow and costly

Application of composite

Aerospace industry Sporting Goods Industry Automotive Industry Home Appliance IndustrySports and recreation Transportations Constructions