High-Temperature Strength of Ir-Based Refractory Superalloys

Abstract

ABSTRACTIr-based refractory superalloys with an fcc and L12 two-phase structure similar to that in Ni-based superalloys but with considerably higher melting temperatures are proposed. First, the microstructure and strength are shown for several kinds of binary alloys. Then, the effect that the third element and the combination of Ni-Al with an fcc and L12 two-phase structure in binary alloys had on the lattice misfit, microstructure, and strength was investigated. The precipitation-hardening effect in Ir-based alloys was investigated and discussed in terms of precipitate morphology and lattice misfit. The creep properties of Ir-based alloys were also investigated.