Multicomponent high-entropy Cantor alloys

Multicomponent high-entropy Cantor alloys are single-phase and near-single-phase face-centred cubic alloys, occupying an enormous region of multicomponent phase space. They were discovered by Cantor and co-workers in the late 1970s/early 1980s, but have not been studied intensively until the last decade or so. This review describes: the extensive range and complexity of multicomponent phase space, including the prevalence of single (or relatively few) phases and the paucity of intrinsically new multicomponent compounds; the thermodynamics of multicomponent single-phase materials such as the Cantor alloys, and the extent to which they are stabilised by a high configurational entropy; the multiplicity and complexity of local atomic configurations and associated lattice strains in multicomponent single-phase high-entropy materials such as the Cantor alloys; the effect of multiple atomic configurations and lattice strains on the rate of atomic diffusion and on the creation and motion of dislocations; and the resulting excellent mechanical properties, equal to and sometimes exceeding the very best high strength steels, nickel superalloys and hard ceramics, with enormous potential for future further enhancement and optimisation.