Partially or fully devitrified alloys for mechanical properties

The origins of the mechanical properties of partially or fully devitrified alloys are discussed with particular reference to hardness and wear resistance. Quantitative evidence is presented that nanophase composites, consisting of a dispersion of nanometre-scale crystallites in a glassy matrix, show a novel hardening mechanism based on solute enrichment of the glassy matrix. The importance of microstructural scale is considered, particularly for wear resistance. Focusing on aluminium alloys, the novel nanophase composites and the glassy alloys from which they are derived are compared with conventional high-strength alloys.