爆炸喷涂WC-Co/MoS_2-Ni多层复合自润滑涂层的摩擦学行为

采用爆炸喷涂技术研制WC-Co/MoS_2-Ni多层复合自润滑涂层,系统研究涂层的微观结构、元素分布、结合强度和摩擦磨损性能。结果表明:在高温爆炸喷涂过程中,少量MoS_2发生氧化分解,生成SO_2气体,残留在涂层内的SO_2气体可使局部形成微小孔洞。在摩擦测试中,WC-Co涂层在预磨阶段摩擦因数迅速上升,进入稳定阶段后,摩擦因数缓慢增加;而多层复合涂层的摩擦因数在经历预磨阶段迅速上升后,很快进入稳定阶段,直至表层WC-Co涂层被磨穿后,摩擦因数开始逐渐下降。添加自润滑涂层MoS_2-Ni后,WC-Co涂层的内聚结合强度略有下降,但减摩效果显著,摩擦因数下降了约40%,耐磨性能略有提升。

Tribological Behavior of Multi-layered WC-Co/MoS2-Ni Self-lubricating Coating Fabricated by Detonation Gun Spraying

The multilayered composite WC-Co/MoS2-Ni self-lubricating coatings were prepared by detonation gun spraying technology.The coating microstructure,element distribution,adhesive strength,and tribological properties were studied systematically.The results show that a little of MoS2 is oxidized and decomposed into gas of SO2 during the high-temperature spraying process.The SO2 left in the coating and can form into the micro porosities.The friction coefficient of the WC-Co coating first increases rapidly in the initial running-in phase,and then gradually increases slightly after entering into the steady-state phase;whereas the friction coefficient of multilayer composite coating steps in the steady-state phase soon and starts to decline gradually when the top WC-Co coating became perforated.By comparison,the coating cohesion declines slightly after adding the self-lubricating layer MoS2-Ni,but the friction coefficient decreases by about 40 ％,and the wear resistance is also improved slightly.