What is a composite material?

Composite material is a new type of material which combines different material components by using advanced material preparation technology. Generally defined composite materials must meet the following conditions:

(1) Composite materials must be man-made and designed and manufactured by people according to their needs;

(2) Composite materials must be composed of two or more material components with different chemical and physical properties according to the designed form, proportion and distribution, and there are obvious interfaces between the components;

(3) It has structural designability and can be used for the structural design of composite materials;

(4) The composite material not only maintains the advantages of the performance of each component material, but also obtains the comprehensive performance that can not be achieved by a single component material through the complementarity and correlation of the performance of each component. ?

The matrix materials of composite materials can be divided into two categories: metal and nonmetal. Commonly used metal substrates are aluminum, magnesium, copper, titanium and their alloys. Non-metallic matrix mainly includes synthetic resin, rubber, ceramics, graphite, carbon and so on. The reinforcing materials mainly include glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whisker and metal.

Extended data

The forming methods of composite materials vary with the matrix materials. There are many molding methods of resin-based composites, such as hand-paste molding, spray molding, fiber winding molding, compression molding, pultrusion molding, RTM molding, autoclave molding, diaphragm molding, migration molding, reactive injection molding, flexible film expansion molding, stamping molding and so on.

The forming methods of metal matrix composites are divided into solid phase forming method and liquid phase forming method. The former is formed by applying pressure below the melting point of the matrix, including diffusion welding, powder metallurgy, hot rolling, hot stretching, hot isostatic pressing and explosive welding. The latter is to melt the matrix and fill it into reinforced materials, including traditional casting, vacuum suction casting, vacuum back pressure casting, extrusion casting and spray casting. The molding methods of ceramic matrix composites mainly include solid state sintering, chemical vapor infiltration molding, chemical vapor deposition molding and so on.