等离子喷涂Ni/h-BN复合涂层的制备及其摩擦学性能

Preparation and Tribological Properties of Plasma Sprayed Ni/h-BN Composite Coating

Ni/h-BN涂层因其兼有抗氧化、耐腐蚀、保证涂层自身与基底之间一定结合强度作用的金属相,以及起润滑作用的非金属相两种的优点而在航空发动机领域有着广阔前景。采用大气等离子喷涂技术在不锈钢基材上制备了Ni/h-BN涂层。考察了喷涂工艺对涂层结构、力学性能及摩擦学性能的影响。结果表明:最佳喷涂工艺为电流500 A、电压55 V、主气60 L/min、送粉速度30 r/min、相应的喷涂功率为27 kW,在此基础上进一步研究了优化工艺参数条件时制备的Ni/h-BN涂层在不同载荷及滑动速度测试条件时的摩擦磨损性能,摩擦系数为0.60~0.70、磨损率为10^(-4)mm^(3)/(N·m)且随载荷增大而升高,以3 N载荷为界点,3 N后磨损率迅速减小。主要磨损机理为磨粒磨损和疲劳磨损。

Ni/h-BN coating has the advantages of both oxidation resistance,corrosion resistance,a metal phase that guarantees a certain bonding strength between the coating itself and the substrate,and a non-metallic phase that plays a lubricating role,which is used in the field of aeroengines,it has broad prospects.Ni/h-BN coating was prepared on the stainless steel substrate by atmospheric plasma spraying technology.The influences of the spraying process on the coating structure,mechanical properties and tribological properties were investigated.The results show that the best spraying process is obtained as current of 500 A,voltage of 55 V,main gas of 60 L/min,and a powder feeding speed of 30 r/min.The corresponding spraying power is 27 kW.On this basis,the friction and wear properties of Ni/h-BN coating prepared when the process parameters are optimized under different load and sliding speed test conditions are furtherly studied.The friction coefficient is 0.60-0.70.The wear rate is 10^(-4)mm^(3)/(N·m)and increases with the increase of the load.Taken 3 N load as the boundary point,the wear rate decreases rapidly after 3 N.The main wear mechanisms are abrasive wear and fatigue wear.