The as-cast AlxCrTaTi refractory medium entropy alloys with good room- temperature mechanical properties and high-temperature oxidation resistance

Refractory medium entropy alloys (RMEAs) usually show good mechanical properties at high temperature. Unfortunately, their very poor room-temperature plasticity and high-temperature oxidation resistance still greatly limit their practical application. In this work, the room-temperature mechanical properties and high-temperature oxidation resistance of AlxCrTaTi RMEAs (x = 0, 0.15, 0.25, 0.35) are systematically studied. It is found that the AlxCrTaTi RMEAs exhibit very high yield strength of about 1700 MPa and plasticity of above 10%. For Al-bearing RMEAs, a composite oxide layer containing Al2O3 is formed on the alloy surface. Under the synergistic effect with the CrTaO4 oxide layer in the middle layer, Al0.25CrTaTi alloy possesses good oxidation resistance at 1000 celcius for 100 h with the oxidation weight gain of only 7.3 mg/cm2. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study systematically investigates the room-temperature mechanical properties and high-temperature oxidation resistance of AlxCrTaTi RMEAs. The results show that AlxCrTaTi RMEAs possess high yield strength and plasticity, and the Al0.25CrTaTi alloy exhibits good oxidation resistance at high temperature.