Enhanced Wear Resistance of Ni/h-BN Composites with Graphene Addition Produced by Spark Plasma Sintering

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2019,（7）
• 页码范围: 876-886
• 页数: 11页
• 语种: 英文

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.