Phase transformations in rapidly quenched Al–Cr–Zr alloys during heat treatment

Abstract

Results from studying the effect zirconium has on solid-phase processes in aluminum–chromium alloys are presented. Rapidly quenched alloys are prepared via melt spinning. The quenching rate is ~10⁶ K/s. By means of physicochemical analysis, it is shown that doping Al–Cr alloys with zirconium improves the thermal stability of supersaturated solid solutions and stabilizes their microcrystalline structure; this hinders the coagulation of intermetallic phases and thus improves the hardness of the alloys. It is found that supersaturated solid solutions of Cr and Zr in aluminum undergo stepwise decomposition; the temperature and time parameters of each step are shown in TTT diagrams.