Effects Of MoS₂ & Graphite On Microstructure And Properties Of Ni-Based Coating

Nickel-based coating has high friction coefficient and adhesive wear during the wear stage. So it was restricted in many friction circumstances. Nickel-Based solid lubrication coatings containing self-lubricants with nickel were produced on the steel substrate with High Velocity Oxygen Fuel spraying. The lubricants are MoS2 and graphite coated with nickel, the base materials of coating was Ni60. The microstructure and mechanical and tribological properties of coatings are studied. The experiment is designed by uniform formulation design to explore effects of cooperative impact and obtain the optimum formula. The results indicate that Ni-coated powders can prevent the burning loss of the lubricating agents (MoS2 and graphite). After the Ni60 coating was input by MoS2 and graphite coated with nickel, the nickel-based solid lubrication coatings'micro-hardness, binding strength and friction coefficient reduce when lubricants increase. When the solid lubricants contents were 30%, the comprehensive tribology property of solid lubrication coatings was optimum. The Ni60 coating main wear mechanism was adhesive and fatigue wear. The two lubricants help coating reduced the adhesive wear. The friction coefficient of lubrication coating contained MoS2 was independent with the load. With the increase of the load, the wear weight loss increased, the wear resistance lowered. But as to the lubrication coating contained graphite coated with nickel, with the increase of the load, friction coefficient reduced and wear weight loss raised. What is more, the coating's friction coefficient and wear weight loss were all raised. Calculated by uniform design software, MoS2 and graphite which are coated with nickel have effects of cooperative impact. They have distinct influence on the performance of Ni-based coating. The coating which contains both of lubricants have better tribology property than any coatings which contain one lubricant. When the content of MoS2 coated with nickel reach 33.06wt% and content of graphite coated with nickel is 13.00wt%, the coating owned best tribology property.