摘要
Ni-based self-lubricating composites containing a fixed amount of hexagonal boron nitride (h-BN)(5 wt%) and different amounts of graphene (0-1.5 wt%) were prepared by ultrasonic dispersion, high-energy ball milling, and spark plasma sintering. The effects of the graphene content on the physical, mechanical, and wear properties of the Ni/h-BN composites were evaluated. These properties were first enhanced with increasing graphene content, reaching optimal behavior for a graphene content of 1 wt%, and then degraded with further graphene addition. Compared to the pure Ni/h-BN composite, the relative density, hardness, and bending strength of the composite with 1 wt% graphene increased by 2.7%, 7.4%, and 6.3%, respectively, while the friction coefficient decreased by 56% to 0.31, and a reduction in wear rate by a factor of 5-15 was observed. The mechanism for improving the wear properties of the composite with added graphene was due to the formation of a graphene lubricating film on the worn surface, which increased the load bearing capacity of the surface and enhanced lubrication during wear.
Ni-based self-lubricating composites containing a fixed amount of hexagonal boron nitride(h-BN)(5 wt%)and different amounts of graphene(0-1.5 wt%)were prepared by ultrasonic dispersion,high-energy ball milling,and spark plasma sintering.The effects of the graphene content on the physical,mechanical,and wear properties of the Ni/h-BN composites were evaluated.These properties were first enhanced with increasing graphene content,reaching optimal behavior for a graphene content of 1 wt%,and then degraded with further graphene addition.Compared to the pure Ni/h-BN composite,the relative density,hardness,and bending strength of the composite with 1 wt% graphene increased by 2.7%,7.4%,and6.3%,respectively,while the friction coefficient decreased by 56% to 0.31,and a reduction in wear rate by a factor of 5-15 was observed.The mechanism for improving the wear properties of the composite with added graphene was due to the formation of a graphene lubricating film on the worn surface,which increased the load bearing capacity of the surface and enhanced lubrication during wear.
基金
Program of the Ministry of Education in China (2011)