Ni-Cr/hBN自润滑复合材料的摩擦学性能研究

摘要

采用粉末冶金技术制备Ni-Cr/hBN自润滑复合材料，研究hBN含量及摩擦载荷对Ni-Cr/hBN复合材料的性能及摩擦磨损行为的影响。结果表明：随hBN含量增大，Ni-Cr/hBN复合材料的密度、抗弯强度和摩擦系数均逐渐减小。当载荷为20 N时，Ni-Cr/hBN复合材料的磨损速率随hBN含量的增大而减小；当载荷为60 N和100 N时，磨损速率随hBN含量增大呈先减小后增大的趋势。当hBN含量不变时，磨损速率随载荷增大而逐渐增大。通过探讨Ni-Cr/hBN自润滑复合材料的润滑与磨损机理可知，材料的摩擦系数取决于hBN的含量，而磨损速率与材料的力学性能有关。当hBN含量为9%（质量分数），摩擦载荷为60 N时，Ni-Cr/hBN自润滑复合材料具有最佳的摩擦学综合性能。%The Ni-Cr/hBN self-lubricating composites are prepared by the powder metallurgy technology. The influences of the hBN contents and working load on the properties and tribological performance of the Ni-Cr/hBN composite are investigated. The results show that the density, bending strength and friction coefficient of the Ni-Cr/hBN composites decrease with the increasing of the hBN contents. Under the working load of 20 N, the wear rate of the Ni-Cr/hBN composite decreases with the increasing of hBN contents. However, under the loading of 60 N and 100 N, the wear rate declines first, and then increases with the increasing of hBN contents. The wear rate increases with the increasing of working load, when the hBN content remains constant. According to the lubrication and wear mechanism of the Ni-Cr/hBN self-lubricating composite, the friction coefficient depends on the hBN content, and the wear rate is related with the mechanical properties. The best tribological properties are obtained when the hBN content is 9%( mass fraction) and working load is 60 N.