A review of Rapid Solidification Studies of Intermetallic Compounds

Abstract

ABSTRACTA review of rapid solidification studies of high temperature ordered intermetallic compounds is presented. Emphasis is on the nickel - and iron - aluminides which are of potential interest as structural materials. The nickel-base aluminides which have been rapidly solidified exhibit changes in grain size, compositional segregation, and degree of long range order (as reflected in APB size and distribution) which markedly affect mechanical properties. Some experiments indicate the formation of a metastable L12 phase in rapidly solidified Fe-(Ni, Mn)-Al-C alloys, while other work observes only a metastable fcc phase in the same composition range. The metastable phases and/or microstructures in both nickel and iron aluminides are destroyed by annealing at temperatures >750K, with subsequent degradation of mechanical properties. Rapid solidification studies of several other intermetallic compounds are briefly noted.