Ag/SmBa_2Cu_3O_(7--δ)金属陶瓷的摩擦特性

Tribological Properties of Ag/SmBa_2Cu_3O_(7--δ) Ceramics

以Sm2O3、BaCO3和CuO为原料,采用固相法合成SmBa2Cu3O7--δ(SmBaCuO)粉体。将银粉添加到SmBaCuO中,制备出Ag/SmBaCuO金属陶瓷。借助于X射线衍射、扫描电子显微镜、透射电子显微镜和X射线能谱仪分析Ag/SmBaCuO陶瓷的显微结构和形貌,利用摩擦实验机测试了Ag/SmBaCuO陶瓷与对偶件钢的摩擦性能。结果表明:添加银粉后,SmBaCuO金属陶瓷的结构没有改变,银分布在SmBaCuO基底中,Ag/SmBaCuO仍具有超导电性。从室温至液氮温度,SmBaCuO的摩擦系数正常态下为0.31,超导态下为0.2左右。常温下测试(5%~10%)Ag/SmBaCuO摩擦系数为0.23,15%Ag/SmBaCuO磨损率最低为6.340×10--5 mm3/(N·m)。Ag/SmBaCuO金属陶瓷中银微粒在摩擦过程中向对偶表面转移,起到固体润滑剂的作用,改善了Ag/SmBaCuO陶瓷的摩擦性能。

The SmBa2Cu3O7-δ(SmBaCuO)powder was synthesized by a solid state reaction method with Sm2O3,BaCO3 and CuO as raw materials.The Ag/SmBaCuO ceramic composites were prepared by sintering SmBaCuO with Ag at different mass fractions.The microstructure and morphology of the Ag/SmBaCuO ceramics were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy and energy dispersive X-ray analysis,respectively.The results indicate that the Ag/SmBaCuO ceramic has a superconductivity.The structure of SmBaCuO is unchanged.Silver particles distribute in the SmBaCuO matrix.The tribological properties of Ag/SmBaCuO ceramic were determined on a friction and wear tester.It is indicated that the friction coefficient of SmBaCuO is 0.31 at ambient temperature and it decreases to 0.2at a lower superconducting transition temperature.The friction coefficient of(5%--10%)Ag/SmBaCuO is 0.23 and the wear rate of15%Ag/SmBaCuO is 6.340×10--5 mm3/(N·m)at ambient temperature.A soft silver film is formed on the surface of Ag/SmBaCuO ceramic during friction process,which reduces the friction coefficient and wear rate.