2. First approach

Few chemical elements are used in their pure, solid form. Carbon, in its diamond or graphite form, is the exception. Most functional materials are complex, and can be broadly classified into two main families: alloys and composites. For a precise classification, please refer to the "Choice and use of materials" section . An alloy, in the broadest sense of the term, is made up of several chemical elements that mix intimately on an atomic scale to create new properties. Today, we know how to synthesize all kinds of alloys for various applications. A composite is a successful "assembly" of two materials, generally immiscible, each providing a particular functionality....