Composites are made by combining two or more different materials. Most composites have two constituent materials: a matrix (binder) and reinforcing fibre. The reinforcing fibre is usually much stronger and stiffer than the matrix, and gives the composite its good properties. The matrix holds the reinforcing fibre in an orderly pattern. Because the reinforcing fibre is usually discontinuous, the matrix also helps to transfer load among the reinforcements.
What is matrix?
The matrix is the majority of the composite’s volume. Matrices are usually polymers because they are lightweight, inexpensive, and are easy to process and mold. Thermosetting polymers such as epoxies are very attractive as matrices because they don’t readily flow. The matrix is sometimes a metal. Aluminum is commonly used because it is lighter than most other metals of the same volume.
What is reinforcing fibre?
There are 2 types of reinforcing fibre - particulate, and fibrous. A particle has roughly equal dimensions in all directions, though it does not have to be spherical. Gravel, micro-balloons, and resin powder are examples of particulate reinforcements. Fibrous reinforcements (chopped fibres or whiskers) vary in length from a few millimeters to a few centimeters and most fibres are only a few microns in diameter.
Three different ways to make composites
Condition for manufacturing composites
Successfully manufacturing a composite requires the correct combination of temperature, pressure, and curing time. To find the best process for each specific material, several curing processes are tried and the resultant materials tested.
For further information go to Teacher Corner or Student Corner