摘要:
用球盘式摩擦试验机及原子力显微镜在大气中常温下对YBa2Cu3O7 (YBCO) 高温超导试样的宏观和微观摩擦学特性进行了研究,并与Cu基固体润滑复合材料进行比较。结果表明:对于Cu基复合材料,固体润滑剂含量不足将使摩擦系数增大,含量过高将导致磨损增大,含40％固体润滑剂的4060Cu在几种载荷和速度下都表现出很低的摩擦和磨损,而YBa2Cu3O7的摩擦系数与4060Cu相似,磨损率却只有其1/2。XRD及TEM的检测结果表明:YBa2Cu3O7结构中的CuO层结合较弱,在剪切应力的作用下易滑移,对外表现出较低的摩擦。基体中含Y2O3较多的YBa2Cu3O7相阻碍位错滑移,强化基体,使其耐磨性能大幅提高。用粉末熔化法制备的样品中Y2O3颗粒更细小、弥散,其耐磨性更好。
Abstract:
The micro and macro tribology characters of sintered YBa2Cu3O7 ( YBCO)in the air were investigated by using ball on disc tester and atomic force microscope(AFM), and a comparison with Cu based solid lubricant composite was prepared. The results indicate that excessive amount of solid lubricant will lead to decrease friction coefficient and increase wear rate for solid lubricant composite. The specimen 4060Cu containing 40%WS2 exhibits the lowest friction and relatively lower wear rate under the condition of different loads ( P), speeds ( v) and pv values. The friction coefficient of the YBCO specimen is similar to that of 4060Cu, but the wear rate is greatly lower than that. The results of XRD and TEM show that CuO distributes in the YBCO’s out layer and the binder with the body is not strong enough, so they can slip easily under shear stress with a low friction coefficient. In YBCO sample, Y2O3 nano particles distribute in the substance dispersedly, which strengthens the matrix and decreases the wear rate greatly. Due to the finer and more disperse Y2O3 particles of the specimen prepared by powder melting process, YBCO2 displays better wear-resistance.
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