激光熔覆MoNbTaVW难熔高熵合金涂层微动磨损性能

Fretting Wear Properties of Laser-cladded MoNbTaVW Refractory High-entropy Alloy Coatings

研究了采用激光熔覆技术制备的MoNbTaVW难熔高熵合金涂层在不同载荷(10N、20N、30N)、不同微动磨损幅值(50μm、150μm、250μm)、不同循环次数(5000、10000、15000)下的微动磨损性能及微动磨损机制。结果表明:所制备的MoNbTaVW难熔高熵合金涂层由Fe_(7)Ta_(3)型HCP固溶体相、FCC固溶体相及(Fe,Ni)基体相组成,其中FCC相为未熔的高熵合金粉末。根据正交实验极差分析可知,微动磨损幅值对磨损体积的影响最大,微动磨损载荷对磨损体积的影响次之,微动磨损循环次数对磨损体积的影响最小,其中MoNbTaVW难熔高熵合金涂层在15000次、20N、250μm微动磨损条件下的磨损体积达到最大值;微动磨损载荷对摩擦系数的影响最大,微动磨损幅值对摩擦系数的影响次之,微动磨损循环次数对摩擦系数的影响最小,其中MoN bTaVW难熔高熵合金涂层在10000次、30 N、150μm微动磨损条件下的摩擦系数达到最大值。MoNbTaVW难熔高熵合金涂层的微动磨损机制主要为氧化磨损和黏着磨损,磨损产生的磨损碎片主要为Ta、W的氧化物。

The fretting wear properties and fretting wear mechanism of MoNbTaVW refractory high-entropy alloy coatings prepared by laser cladding were studied under different loads(10 N,20 N,30 N),different fretting amplitances(50μm,150μm,250μm)and different cycles(5000,10000,15000).The results show that the prepared MoNbTaVW refractory high-entropy alloy coating is composed of Fe_(7)Ta_(3)-type HCP solid solution phase,FCC solid solution phase and(Fe,Ni)matrix phase,where the FCC phase is unmelted high-entropy alloy powder.According to the range analysis of orthogonal test,the effect of fretting amplitude on the wear volume is the largest,followed by the effect of load,and the effect of cycle number on the wear volume is the least.The wear volume of MoNbTaVW refractory high-entropy alloy coating reaches the maximum under the fretting wear conditions of 15000 times,20 N and 250μm.The effect of load on the friction coefficient is the largest,followed by the amplitude of fretting,and the number of cycles has the smallest effect on the friction coefficient.The friction coefficient of MoNbTaVW refractory high-entropy alloy coating reaches the maximum value under the fretting wear conditions of 10000 times,30 N and 150μm.The fretting wear mechanism of MoNbTaVW refractory high-entropy alloy coating is mainly oxidation wear and adhesive wear.The wear debris generated by fretting wear is mainly Ta-and W-oxides.