钛合金表面激光熔覆AlCoCrFeMoVTi高熵合金涂层的摩擦磨损和高温抗氧化性能

DI Yingnan,LIU Hongxi*,CHEN Lin,ZHANG Xiaowei,LIU Jingzhou,LIN Jianquan

摘要:

为提高钛合金的摩擦磨损和高温抗氧化性能，采用激光熔覆技术在Ti6AI4V钛合金（TC4）表面制备了近等原子比的AlCoCrFeMoVTi高熵合金（HEA）涂层。借助X射线衍射（XRD）、扫描电镜（SEM）、能谱仪（EDS）等分析了涂层的物相组成和显微组织；运用HDX-1000维氏硬度仪测试了熔覆层显微硬度；通过UMT-3摩擦磨损试验机和GSL-1400X 型管式电阻炉分别测试了HEA涂层的摩擦磨损性能和高温抗氧化性能。结果表明，HEA涂层主要由面心立方（FCC）、体心立方（BCC）二元共晶相组成；HEA涂层最高显微硬度为1099 HV0.2，是基体TC4的3.29倍；涂层摩擦系数为0.31，磨损体积为1.79×10-4 mm3，分别为基体的59.62%和12.01%；在800℃恒温下氧化50 h后，HEA涂层的氧化增重为1.49 mg，仅为基体的16.37%。激光熔覆高熵合金AlCoCrFeMoVTi涂层能显著改善Ti6Al4V钛合金的摩擦磨损和高温抗氧化性能。

Abstract:

In order to improve the friction and wear behavior and high-temperature oxidation resistance of titanium alloy, AlCoCrFeMoVTi high-entropy alloy (HEA) were designed and AlCoCrFeMoVTi HEA coatings were prepared by laser cladding technique on Ti6AI4V titanium alloy (TC4) surface. The phase composition and microstructure of AlCoCrFeMoVTi HEA coating were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The microhardness of coatings was measured by HDX-1000 Vickers hardness tester. The wear resistance and high-temperature oxidation resistance of the coating were tested by UMT-3 friction tester and GSL-1400X tubular resistance furnace. The results show that the AlCoCrFeMoVTi HEA coating is mainly composed of face centered cubic (FCC) structures and body centered cubic (BCC) structures binary eutectic phase. The maximum microhardness of the coating was 1099 HV0.2, which was 3.29 times that of TC4 titanium alloy substrate. The friction coefficient of the coating was 0.31, and the wear volume was 1.79×10-4 mm3, respectively 59.62% and 12.01% of the matrix. After oxidation at 800℃ for 50 h, the oxidation weight of the coating was 1.49 mg, which was only 16.37% of the matrix. Laser cladding AlCoCrFeMoVTi HEA coating can significantly improve the friction and wear behavior and high-temperature oxidation resistance of Ti6Al4V titanium alloy.