When monolithic materials fail to meet the required functions, multi-component materials, known as composites, can be designed and implemented. By combining properties of the same kind and/or coupling very different properties within these multi-materials, high levels of performance and complex behavior can be achieved.
Applications are conceivable in all fields where the functional analysis of systems reveals a large number of functions that a single monolithic material cannot fulfil on its own. This is the case, for example, for structural applications requiring a material that is light, tough and refractory, or at the same time an excellent thermal conductor, ductile and with a low coefficient of expansion.
The evolution of these composite materials was initially linked to the development of the aeronautics and aerospace industries, where they are highly appreciated as structural materials for the weight savings they offer compared to conventional metallic materials. Composite materials can also offer excellent thermomechanical properties in erosive and corrosive environments. However, they require special technology and know-how. As a result, new techniques are continually being developed and need to be disseminated throughout the industry.
The many composite materials differ from one another in the following characteristics:
the morphology of elementary constituents: whiskers (single-crystal staple fibres), fibres, lamellae, filaments, particles, etc. ;
their respective nature: organic, metallic, glass, ceramic... ;
the relative arrangement of elementary constituents (aligned, crossed, woven...), which can lead to material heterogeneity with anisotropic properties;
the nature of the overall properties sought (mechanical, magnetic, optical, physico-chemical, etc.).
By definition, a composite material is a multiphase solid in which two or more constituents are combined to give it, on a macroscopic scale and at least in certain directions, an original set of properties that the constituents taken in isolation cannot achieve
.
A composite material is a combination of a reinforcement (elementary component) and a binder (matrix) that ensures cohesion and geometric form.
The properties of the main composite material matrices are shown...