Potential and prospects of some intermetallic compounds for structural applications

Abstract

In this paper the potential and prospects of some intermetallic compounds for structural applications are discussed, with an emphasis on two specific aspects which seem to be of prime importance for future research and development activities. First, the benefits associated with the development of multiphase intermetallics are stressed and a novel approach for creating the two phase γ–γ′ type microstructure in different alloy systems is described. Second, the problem of stability of the constituent phases in these multiphase materials is considered. The superiority of nickel base γ–γ′ superalloys over the single phase γ′ is demonstrated by comparison of their creep behaviour, and advantages of multiphase alloys are also briefly reviewed with reference to other alloy systems. The discussion is frequently illustrated by reference to recent results obtained by the present authors for various alloy systems based on Ni3Al, iron, niobium, Ti3Al+X (X=Nb, V, or Mo), and NiAl.MST/1547