AlCoCrFeNi高熵合金的高温摩擦磨损性能  

Tribological Properties of AlCoCrFeNi High Entropy Alloy at Elevated Temperature

作　　者：张爱军[1,2] 韩杰胜 苏博[1] 孟军虎[1] 

机构地区：[1]中国科学院兰州化学物理研究所固体润滑国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《摩擦学学报》2017年第6期776-783,共8页Tribology

摘　　要：AlCoCrFeNi高熵合金因其优异的综合力学性能而有望成为新一代高温结构材料,但对其高温摩擦磨损性能的研究还较为少见.本文中应用放电等离子烧结(SPS)技术制备了AlCoCrFeNi高熵合金,研究了其显微组织和力学性能,系统地考察了其在室温至800℃时的摩擦磨损性能.结果表明:应用SPS技术制备的AlCoCrFeNi高熵合金主要由FCC相、无序BCC相和少量有序BCC相组成;呈网格状分布的FCC相使高熵合金具有良好的塑性和韧性,而呈等轴状分布的BCC相赋予了高熵合金优异的强度;高熵合金室温至800℃时的摩擦系数在0.43~0.51之间,磨损率低于10–5mm3/(N·m).室温至中温阶段主要为磨粒磨损,中温至高温阶段的磨损机制为磨粒磨损、黏着磨损和塑性变形综合作用.高温下高熵合金表面形成了一层主要由为Al2O3和Cr2O3组成的氧化物膜,在一定程度上起到抗磨作用.AlCoCrFeNi high entropy alloy（HEA） is a potential candidate for the next-generation high temperature structural materials because of the excellent properties. However, the tribological properties of the HEA have been rarely reported. In this paper, the AlCoCrFeNi HEA was prepared by spark plasma sintering（SPS）, and the microstructure,mechanical properties and tribological properties from room temperature（RT） to 800 ℃ of the HEA were studied. The SPSed AlCoCrFeNi consisted of a FCC phase, a disordered BCC phase and a little ordered BCC phase. The FCC phase with net-like structure enabled the HEA to have good ductility and fracture toughness, and the BCC phase with nearequiaxed shape made the HEA have excellent strength. The friction coefficients and wear rates of the HEA from RT to800 ℃ were 0.43~0.51 and below 10–5 mm3/（N·m）, respectively. Abrasive wear was the main wear mechanism of the HEA from RT to medium temperatures. From medium temperatures to high temperatures, the main wear mechanism was the combined action of abrasive wear, adhesive wear and plastic deformation. At high temperatures, a oxides layer that mainly consisted of Al2 O3 and Cr2 O3 formed on the HEA surface, and the oxides layer played a key role in improving the wear resistance of the HEA.

关 键 词：高熵合金 AlCoCrFeNi 显微组织 力学性能 摩擦磨损性能 

分 类 号：TG115.5[金属学及工艺—物理冶金]