Löbel Martin, Lindner Thomas, Pippig Robert, Lampke Thomas
Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Chemnitz University of Technology, D-09107 Chemnitz, Germany.
Entropy (Basel). 2019 Jun 12;21(6):582. doi: 10.3390/e21060582.
In this study, the wear behaviour of a powder metallurgically produced AlCoCrFeNiTi high-entropy alloy (HEAs) is investigated at elevated temperatures. Spark plasma sintering (SPS) of inert gas atomised feedstock enables the production of dense bulk material. The microstructure evolution and phase formation are analysed. The high cooling rate in the atomisation process results in spherical powder with a microstructure comprising two finely distributed body-centred cubic phases. An additional phase with a complex crystal structure precipitates during SPS processing, while no coarsening of microstructural features occurs. The wear resistance under reciprocating wear conditions increases at elevated temperatures due to the formation of a protective oxide layer under atmospherical conditions. Additionally, the coefficient of friction (COF) slightly decreases with increasing temperature. SPS processing is suitable for the production of HEA bulk material. An increase in the wear resistance at elevated temperature enables high temperature applications of the HEA system AlCoCrFeNiTi.
在本研究中，对粉末冶金法制备的AlCoCrFeNiTi高熵合金（HEAs）在高温下的磨损行为进行了研究。对惰性气体雾化原料进行放电等离子烧结（SPS）可制备出致密的块状材料。分析了微观结构演变和相形成情况。雾化过程中的高冷却速率导致形成具有由两个精细分布的体心立方相组成的微观结构的球形粉末。在SPS加工过程中会析出一种具有复杂晶体结构的附加相，而微观结构特征未出现粗化现象。在往复磨损条件下，由于在大气条件下形成了保护性氧化层，高温下的耐磨性增加。此外，摩擦系数（COF）随温度升高略有降低。SPS加工适用于制备HEA块状材料。高温下耐磨性的提高使得HEA体系AlCoCrFeNiTi能够应用于高温领域。
