Ag/DyBa_2Cu_3O_(7-δ)超导陶瓷的摩擦学特性

Tribological Properties of Ag/DyBa_2Cu_3O_(7-δ) Superconducting Ceramics

利用摩擦实验机从液氮温度至室温对超导陶瓷Ag/DyBa2Cu3O7-δ(Ag/Dy123)的摩擦学性能进行研究。结果表明:当温度降到液氮温度后,10%(质量分数)Ag/Dy123超导陶瓷与不锈钢盘对摩,摩擦因数明显下降,最后稳定在0.20以下。对制备的Ag/Dy123超导陶瓷进行X射线衍射、扫描电子显微镜、高分辨电子显微镜、能量散射X射线分析,结果表明:Ag没有影响Dy123的超导电性,明显改善了常温下Dy123的摩擦学性能,在正常载荷和滑行速率下,(5%～10%)Ag/Dy123超导陶瓷的摩擦因数为0.25,5%Ag/Dy123超导陶瓷磨损率最低,为4.02×10-5mm3/(N.m)。分布在基体中的Ag微粒能有效抑制裂纹萌生和扩展,并在摩擦作用下形成Ag转移膜,陶瓷硬基底承载和软金属转移膜润滑的协同作用,使材料表现出良好的减摩耐磨性能。

The tribological properties of the Ag/DyBa2Cu3O7-δ（Ag/Dy123） superconducting ceramics were investigated via a fric- tion/wear tester from liquid nitrogen temperature to ambient temperature. The friction coefficient of 10% （in mass） Ag/Dy123 ceram- ics against stainless steel is 〈 0.2, and is stable when the temperature reduces to liquid nitrogen temperature. The microstructure and morphology of the Ag/Dy123 ceramics were investigated by X-ray diffraction, scanning electron microscope, high-resolution trans- mission electron microscope and energy dispersive X-ray analysis, respectively. The results show that the silver particles distribute in the Dy123 matrix, improving the toughness of Ag/Dy123 ceramics due to the formation of a soft silver film on the surface of Ag/Dy123 ceramics during friction process. Ag/Dy123 superconducting ceramics exhibited improved tribologieal properties at ambi- ent temperature. The friction coefficient of 5%-10% Ag/Dy123 ceramics against stainless steel is 0.25, and the wear rate of 5%Ag/ Dy123 ceramics is 4.02 × 10^-5 mm^3/（N-m）.