含h-BN的钛合金激光熔覆自润滑耐磨涂层的摩擦学行为

Tribological Properties of Self-Lubricating Anti-Wear Composite Coating with 10% h-BN on Ti6Al4V Alloy by laser cladding

为提高Ti6Al4V合金的摩擦学性能,采用激光熔覆技术在钛合金表面制备以Ti C、Ti B2、Cr B等为增强相、γ-Ni基固溶体为增韧相、h-BN为固体润滑相的自润滑耐磨复合涂层;分别在不同载荷下测试复合涂层和Ti6Al4V合金基体的干滑动磨损性能。结果表明,该复合涂层的摩擦因数及磨损率随着载荷的增大呈现先减小后略增大的趋势,并且摩擦因数和磨损率均比Ti6Al4V合金基体显著降低;在中等载荷下,复合涂层中的润滑颗粒被挤出磨损表面形成润滑膜,因而具有较好的自润滑耐磨性能,磨损后表面光滑平整。

In order to improve the tribological behavior of Ti6Al4V, a self-lubricating wear resistant composite coating reinforced with hard TiC ,TiB2, CrB, 7-Ni solid solution and self-lubricate phase h-BN was fabricated by laser cladding.Dry sliding wear tests of the composite coating and substrate were conducted at different load, respectively.The results indicate that both the friction coefficient and wear of composite coating, which are lower than that of the Ti6Al4V at the test load, are decreased firstly and then slight increased with the increasing of load.Under moderate normal load ,the lubricating particles are extruded from the worn surface of the composite coating to form lubricating film, thereof the composite coating has excellent properties of self-lubricating and anti-wear, the worn surface of the composite coating appears smooth under moderate normal load.