Effect of annealing temperature on microstructure and superelastic properties of Ti-Au-Cr-Zr alloy

Abstract

Effect of annealing temperature on microstructure and superelasticity of Ti-4Au-5Cr-8Zr (mol%) was investigated. Only β phase was observed in the specimen annealed at 1173 K, whereas the precipitation of Ti3Au, Zr33Ti40Au27 (Laves phase) and α phase occurred in the specimens annealed below 1073 K. Superelasticity was clearly observed in the specimens annealed at 1073K and 1173 K, though it was absent in the specimens annealed at 873K and 973 K. The maximum superelastic recovery strain was increased by the precipitation of Ti3Au in the specimen annealed at 1073 K. This is due to the increase in the critical stress for slip by the precipitation strengthening effect of Ti3Au.