Refractory high-entropy alloys(HEAs) exhibit remarkable mechanical properties desired for high-temperature applications. However, their oxidation resistance at high temperatures received less attention. Recent work in...Refractory high-entropy alloys(HEAs) exhibit remarkable mechanical properties desired for high-temperature applications. However, their oxidation resistance at high temperatures received less attention. Recent work indicates that MoTaTiCrAl alloy exhibits excellent oxidation resistance,but the effects of Al and Cr remain unclear. In this work, we demonstrate that the addition of Al is unnecessary for preventing oxidation of the MoTaTiCrAl alloy and the removal of Al leads to a more oxidation resistant MoTaTiCr medium entropy alloy. Structural and chemical analyses indicate that the excellent oxidation resistance of MoTaTiCr is mainly associated with the formation of continuous CrTaO4 oxide layer.The results indicate that complex oxides can be adopted as effective candidates for enhancement of oxidation resistance,in addition to typical strategy of forming Al2O3, Cr2O3 or SiO2 barrier layer.展开更多
基金supported by the National Key Research and Development Program of China (2018YFA0703600)the National Science Fund for Distinguished Young Scholars (51825104)+3 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences (QYZDY-SSW-JSC017)the Strategic Priority Research Program of Chinese Academy of Sciences (XDB30000000)the Key Basic and Applied Research Program of Guangdong Province, China (2019B030302010)the National Natural Science Foundation of China (11790291 and 61888102)。
文摘Refractory high-entropy alloys(HEAs) exhibit remarkable mechanical properties desired for high-temperature applications. However, their oxidation resistance at high temperatures received less attention. Recent work indicates that MoTaTiCrAl alloy exhibits excellent oxidation resistance,but the effects of Al and Cr remain unclear. In this work, we demonstrate that the addition of Al is unnecessary for preventing oxidation of the MoTaTiCrAl alloy and the removal of Al leads to a more oxidation resistant MoTaTiCr medium entropy alloy. Structural and chemical analyses indicate that the excellent oxidation resistance of MoTaTiCr is mainly associated with the formation of continuous CrTaO4 oxide layer.The results indicate that complex oxides can be adopted as effective candidates for enhancement of oxidation resistance,in addition to typical strategy of forming Al2O3, Cr2O3 or SiO2 barrier layer.
