Metastable phase formation in ion-implanted metals

The formation of metastable phases in metals by ion implantation and ion beam mixing is examined for a variety of conditions. The work reviewed shows that ion beams can produce transformations of the metal host to a different crystalline phase, to a compound, to an amorphous phase, or to combinations of such phases. The observed microstructures are discussed in terms of microscopic mechanisms as well as empirical rules currently being developed. (orig.)