含BaSO4钴基自润滑复合材料的制备及高温摩擦学性能

Preparation and high temperature tribological properties of cobalt BaSO4 self-lubricating composites

采用热压烧结技术制备3种含不同BaSO4质量分数的钴基自润滑复合材料,研究其在室温到1000℃范围内的摩擦学性能。在载荷为15N、滑动速度为0.19m/s的条件下,采用球盘式高温摩擦试验机与Si3N4陶瓷球配副研究复合材料的高温摩擦学性能。采用X线衍射仪和扫描电镜等分析复合材料的物相成分和摩擦表面形貌。研究结果表明:随着BaSO4质量分数的增加,复合材料的硬度和密度逐渐降低。从室温到800℃,复合材料的摩擦因数逐渐降低,这是由于随着温度的上升,复合材料的摩擦表面逐渐形成了由铬酸盐、钼酸盐和氧化物等组成的润滑膜,使得复合材料在高温条件下具有了较优良的减摩耐磨性能。在3种钴基复合材料中,含10%BaSO4的钴基自润滑复合材料在400~800℃范围内的摩擦学性能较好。

Three kinds of cobalt-based self-lubricating composites with different mass fractions of BaSO4 were prepared by hot pressing sintering technique.The tribological properties were studied from room temperature to 1 000 ℃.Under the load of 15 N and sliding speed of 0.19 m/s,the high-temperature tribological properties of composites sliding against Si3N4 ceramic ball were studied by using ball-on-disk high-temperature tribo-tester.The phase and worn surfaces of composites were analyzed by X-ray diffractometry and scanning electron microscopy.The results show that the hardness and density of the composites decrease with the increase of mass fractions of BaSO4 in the composites.The friction coefficient of composites gradually decreases from room temperature to 800 ℃,because the friction surfaces of composites gradually form the lubricating film which is composed of chromate,molybdate and oxide as the temperature rises,and the composites have superior anti-friction and wear resistance at high temperature.By comparing the three composites,the tribological properties of cobalt-based self-lubricating composites containing 10% BaSO4 are better in the range of 400-800 ℃.