ABSTRACT
Composite materials are solids which contain two or more distinct constituent materials or phases, on a scale larger than the atomic. The properties of composite materials depend very much upon structure. Mechanical properties in many composite materials depend on structure in a complex way, however for some structures, the prediction of properties is relatively simple. Anisotropic composites offer superior strength and stiffness in comparison with isotropic ones. Rubber used in catheters, rubber gloves, etc. is usually reinforced with very fine particles of silica to make the rubber stronger and tougher. Unidirectional fibrous composites, when loaded along the fibers, can have strengths and stiffnesses comparable to that of steel, but with much less weight. The presence of voids in porous or cellular solids will reduce the stiffness of the material. Porous layers are used on bone compatible implants to encourage bony ingrowth. Carbon itself has been successfully used as a biomaterial.
