石墨相尺寸与分布对镍-石墨可磨耗封严涂层摩擦学性能影响

The Influence of Size and Distribution of Graphite on the Tribological Property of Ni-graphite Abradable Seal Coatings

本文采用普通等离子喷涂(APS)与高效能超音速等离子喷涂(SAPS)两种工艺在2Cr13基体上制备75wt.%Ni+25wt.%石墨(Ni-C)可磨耗封严涂层,对涂层的摩擦学性能进行评价。结果表明:APS Ni-C涂层中石墨相的平均长度与宽度分别为11.4μm和5.4μm,而SAPS Ni-C涂层则分别为10.1μm和4.6μm,且分布更为均匀。石墨相尺寸对涂层性能具有显著的影响作用,表现为细小的石墨相更利于在涂层表面形成石墨润滑膜,使得SAPS涂层在60N载荷下与1Cr18Ni9Ti对磨90min过程中平均摩擦因数与APS涂层相比下降约28%,对磨材料1Cr18Ni9Ti单位时间磨损率降低了57%。

In this study, 75 wt.%Ni＋25 wt.%graphite（Ni-C） abradable seal coatings were deposited by general atmospheric plasma spraying system（APS） and a high-efficiency supersonic atmospheric plasma spraying system（SAPS）. The tribological properties of the coatings was then studied. The result showed that the average length and width of the graphite phase were 11.4μm and 5.4μm for the APS Ni-C coating, 10.1μm and 4.6μm for the SAPS Ni-C coating, respectively. The size of the graphite a prominent effect on the tribological property of coatings. The fine graphite phase was beneficial for the formation of lubricating film on the surface of the coating during friction and wear. Compared to APS Ni-C coating, the average friction coefficient of SAPS Ni-C coating was decreased by 28 %, and the wear rate of friction couple（1 Cr18 Ni9 Ti） was decreased by 57 % under a load of 60 N in 90 min.