Composite material is a new material that people use advanced material preparation technology to optimize and combine different material components. Generally defined composite materials shall meet the following conditions:
1. The composite material must be artificial and designed and manufactured by people according to their needs;
2. The composite material must be composed of two or more material components with different chemical and physical properties in the designed form, proportion and distribution, with obvious interface between each component;
3. It has structural designability and can be used for composite structure design;
4. Composite materials not only maintain the advantages of the properties of each component, but also obtain the comprehensive properties that can not be achieved by a single component material through the complementation and correlation of the properties of each component.
The matrix materials of composite materials are divided into metal and nonmetal. Aluminum, magnesium, copper, titanium and their alloys are commonly used as metal substrates. Non-metallic matrix mainly includes synthetic resin, rubber, ceramic, graphite, carbon, etc. Reinforcing materials mainly include glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whisker, metal.