Evolution of high temperature yield strength of AlCoCrFeNiTi high entropy alloys

Abstract Comparing with the properties of traditional metallic materials, high-entropy alloy has usually exhibited higher yield strength and hardness. Scientists and engineers are very keen to explore the possibilities to use high-entropy alloy in harsh environments with high temperature and pressure. So far, there have been very few reported studies on the yield strength of high-entropy alloys at elevated temperatures. In this study, AlCoCrFeNiTi high-entropy alloy was chosen to investigate its stress-strain relations under high temperature. Three different conditions of AlCoCrFeNiTi were studied (namely, as-cast, homogenized and hot deformed). The high temperature compression tests were conducted by using a Gleeble 3500 machine. AlCoCrFeNiTi material showed a high yield strength (159MPa) under 1100 ˚C with a strain rate of 1s -1 . However, no visible cracks were observed on the surface of specimen after 46.6% of height reduction, which indicated that AlCoCrFeNiTi material possesses high yield strength and good formability.