中熵共晶CrCoNiNb0.4合金层状组织的热稳定性

对CrCoNiNb_0.4中熵共晶合金层片状组织的热稳定性进行了研究。结果表明:CrCoNiNb_0.4合金共晶层状组织在1023 K及以下温度可以保持较长时间的热稳定性;随热处理时间从24 h增加至168 h,CrCoNiNb_0.4合金共晶片层厚度从约0.19 μm增加至约0.39 μm,且片层间隙析出相逐渐增多,同时伴随着边界断裂,边缘球化等层状失效形式的发生,在析出强化相以及层状组织失效的共同作用下,CrCoNiNb_0.4合金共晶组织硬度值随热处理时间呈先增大后减小的趋势。

Lamellar structure thermal stability of inmedium-entropy eutectic CrCoNiNb0.4 alloy

Thermal stability of lamellar structure in CrCoNiNb_0.4 medium-entropy eutectic alloy was characterized and examined. The results show that the lamellar structures in CrCoNiNb_0.4 medium-entropy alloy are stable when the heat treatment temperature is blower than 1023 K. While the heat treatment time increase from 24 h to 168 h, the lamellar spacing of lamellar structures in CrCoNiNb_0.4 eutectic alloy increases from about 0.19 μm to about 0.39 μm, and more and more precipitation phases are detected in the lamellar spacing, meanwhile, boundary splitting and edge spheroidization can be found in CrCoNiNb_0.4 eutectic alloy. The hardness of CrCoNiNb0.4 eutectic alloy shows a tendency of increase first and decrease later with the increase of heat treatment time under the synergy effect of precipitation strength and lamellar structure failure.