不同温度下γ-NiCrAlTi/TiC/CaF_2自润滑耐磨复合涂层的摩擦磨损性能

Tribology and Wear Properties of γ-NiCrAlTi/TiC/CaF_2 Self-lubricating Wear-resistant Composite Coating at Different Temperatures

为提高Ti6Al4V合金的摩擦学性能,采用激光熔覆技术在Ti6Al4V表面制备出以Ti C为增强相、γ-Ni Cr Al Ti固溶体为增韧相、Ca F2为自润滑相的γ-Ni Cr Al Ti/Ti C/Ca F2自润滑耐磨复合涂层。分别在室温、300℃和600℃时测试了复合涂层和Ti6Al4V合金基体的干滑动磨损性能,并且讨论了其与对磨球的磨损机理。结果表明:从室温到600℃,γ-Ni Cr Al Ti/Ti C/Ca F2自润滑耐磨复合涂层的摩擦系数和磨损率均比Ti6Al4V合金基体显著降低,该复合涂层具有较好的自润滑耐磨性能;对偶件Si3N4陶瓷球的磨损也有一定程度的降低。600℃时,Ti6Al4V基体的磨损机理为氧化塑性变形,γ-Ni Cr Al Ti/Ti C/Ca F2磨损机理为润滑转移层的形成。

In order to improve the tribological behavior of Ti6A14V, a γ-NiCrA1Ti/TiC/CaF2 wear resistant composite coating reinforced with hard TiC carbide, γ-NiCrA1Ti solid solution and self-lubricate phase CaFE was fabricated by laser cladding. Sliding wear tests of the composite coating and substrate were conducted at ambient room-temperature, 300 ℃, and 600 ℃, respectively. The counter-body effect of the coating was investigated. Results indicate that both the friction coefficients and wear rates of the composite coating decrease compared with Ti6A14V alloy from ambient room-temperature to 600 ℃. The friction and wear of the counter-body SigN4 ball decrease slightly. The composite coating has excellent temperare self-lubricating and wear resistant properties. At 600 ℃, Ti6A14V alloy＇s wear mechanism is the severe oxidation and plastic deformation, while the wear mechanism of the composite coating is the formation of lubricative continuous transfer films.