Disadvantages Of Composites Essay

Advantages of Compsites
Light weight.
Composites are light in weight, compared to most woods and metals. Their lightness is important in automobiles and aircraft, for example, where less weight means better fuel efficiency (more miles to the gallon). People who design airplanes are greatly concerned with weight, since reducing a craft’s weight reduces the amount of fuel it needs and increases the speeds it can reach. Some modern airplanes are built with more composites than metal including the new Boeing 787, Dreamliner.
High strength.
Composites can be designed to be far stronger than aluminum or steel. Metals are equally strong in all directions. But composites can be engineered and designed to be strong in a specific direction.
Strength

The fabrication process is usually labor intensive and complex, which further increases cost.
Easily damaged
Composites are more brittle than wrought metals and thus are more easily damaged.Cast metals also tend to be brittle.
Complex Repairing
Materials require refrigerated transport and storage and have limited shelf lives. Hot curing is necessary in many cases, requiring special equipment. Curing either hot or cold takes time. The job is not finished when the last rivet has been installed.If rivets have been used and must be removed, this presents problems of removal without causing further damage. Repair at the original cure temperature requires tooling and pressure.
Characterization is also complex.
Frequent debonding failures
Since composites are often constructed of different ply layers into a laminate structure, they can "delaminate" between layers where they are weaker.Delamination and cracks in composites are mostly internal and hence require complicated inspection techniques for detection. Composite to metal joining Metals expand and contract more on variations in temperature as compared to composites. This may cause an imbalance at joinery and may lead to