WS_2含量对超音速等离子喷涂KF301/WS_2润滑耐磨涂层摩擦学行为的影响

Effect of Content of WS_2 on Friction and Wear Behavior of Supersonic Plasma Sprayed KF301/WS_2 Composite Lubricating and Wear-Resistant Coatings

常规固体润滑涂层高温下不具备稳定的摩擦系数和较低的磨损率。为此,采用超音速等离子喷涂技术制备了KF301/WS2复合润滑耐磨涂层,探讨了复合润滑涂层中WS2润滑膜所呈现的自润滑效果及其作用机理。结果表明:涂层的磨损率随着WS2含量的变化而呈现较大的波动,WS2含量为30%时达到最小值,为1.22×10-4 mg/h;涂层经过最初的跑合后的最终摩擦系数随着WS2含量的增加而降低,不同WS2含量(20%,30%4,0%)的涂层中,WS2含量为30%时具有最低的摩擦系数,为0.09;KF301/WS2基耐磨自润滑涂层的自润滑机理:涂层中的自润滑相在摩擦过程中先剥落填充使涂层摩擦面趋于平整,然后储存在涂层凹陷区域的自润滑相转移到涂层的表面形成低剪切强度的薄膜。本复合润滑涂层200℃下摩擦1.5 h后具有稳定的摩擦系数和较低的磨损率。

KF301/WS2 composite lubricating and wearresistant coatings were prepared by supersonic plasma spraying. The self-lubricating capacity and action mechanism of WS2 as a lubricating phase in the composite coatings were investigated. It was found that the wear rate and friction coefficient of the composite coatings varied significantly with varying content of WS2, and the composite coatings containing 30% (mass fraction) WS2 had the smallest wear rate (1.22×10-4mg/h)and friction coefficient (0.09).The self-lubricating phase, WS2, in the composite coatings was peeled off during sliding and got access to area with surface defects,followed by transfer onto the worn surface of counterpart, forming a lubricating layer with low shear strength. As-prepared composite coatings showed a stable friction coefficient and a relatively small wear rate after shding at 200 ℃ for 1.5h.