钛铝碳陶瓷载流滑动下的摩擦磨损行为

FRICTION AND WEAR BEHAVIOR OF Ti_3AlC_2 CERAMICS UNDER CURRENT-CARRYING SLIDING SITUATION

研究了高纯度Ti3AlC2块体材料载流滑动下的摩擦磨损行为。试验在盘-块式载流摩擦磨损试验机上进行,以低碳钢盘为摩擦配对物,滑动速度为20～60m/s,法向压强为0.4～0.8MPa,通电电流为0,50,100A。结果表明:Ti3AlC2具有良好的载流摩擦磨损特性,但摩擦系数和磨损率都比无电流时的大,且电流密度越大,摩擦系数和磨损率越大。在滑动速度为20m/s,通电电流为100A,法向压强为0.4MPa的条件下,摩擦系数达到最大值0.35。在速度为60m/s,法向压强为0.7MPa,电流为100A的条件下,磨损率达到最大值8.3×10-6mm3/(N·m)。与相同速度和压强但不通电情况下的摩擦系数0.17和磨损率2×10-6mm3/(N·m)相比,分别增大了大约1.1倍和3.2倍。观察和分析的结果表明:载流条件下摩擦系数的增大与Ti3AlC2摩擦面上TiC和Fe2.25Ti0.75O4及AlFeO3结晶相的生成有关,而Ti3AlC2磨损率的增大主要归因于放电电弧的烧蚀作用。

The sliding friction and wear behavior of highly pure Ti3AlC2 bulk against low carbon steel were studied in the presence of an electric current. Tests were carried out on a block-on-disk type friction tester with electric current, different sliding speeds from 20-60 m/s and different normal pressures from 0.4-0.8 MPa. The electric currents were set to 0, 50 A and 100A. The results show that Ti3AlC2 exhibits good friction and wear characteristics with an electric current, but the friction coefficient and wear rate are higher than without an electric current, and the higher the electric current density is, the more the friction and wear rate are; the friction coefficient reached the maximum value 0.35 when the sliding speed, electric current and normal pressure respectively were set to 20 m/s, 100A and 0.4 MPa, The maximum value of wear rate is 8.3×10^4 mm^3/（N.m） when the sliding speed, electric current and normal pressure are set to 60 m/s, 100 A and 0.7 MPa. The friction coefficient and wear rate grow to about 1.1 and 3.2 times respectively compared with that of samples without electric currents under the same situation of sliding speed and normal pressure. The observation and analysis show that the increase of the friction coefficient under current-carrying conditions is related to the formation of crystalline of TiC, Fe2.25Ti0.7504 and AlFeO3, while the increase of the wear rate is ascribed to the ablation of the electric arc.