钛合金表面激光熔覆TiB_2-TiC/Ni复合涂层的真空摩擦磨损性能

Tribological properties in vacuum of TiB_2-TiC/Ni laser clad layer on titanium alloy substrate

采用激光熔覆技术在TC4钛合金表面制备以反应合成TiB2和TiC颗粒为增强相的Ni基复合涂层,利用УТИТВ-100型销-盘摩擦磨损试验机研究了激光熔覆层在真空(10-5Pa)中的干滑动摩擦磨损性能,利用光学显微镜和扫描电子显微镜观察了摩擦偶件的磨损表面形貌,讨论了激光熔覆层的磨损机制。结果表明,激光熔覆层的摩擦系数在0.25～0.5之间,明显低于TC4合金的摩擦系数(0.45～0.8),磨损体积约为TC4合金的40%。随法向载荷和滑动速度的增加,激光熔覆层的磨损体积增加,激光熔覆层的磨损机制主要为粘着磨损和粘附转移物引起的磨粒磨损。

Ni based composite layer reinforced by in situ synthesized TiB2 and TiC on Ti-6Al-4V alloy substrate was prepared by laser cladding.The friction and wear properties in vacuum（10-5 Pa） of the laser clad layer were investigated on a УТИ ТВ-100 wear tester.The worn surfaces of wear couple were observed by scanning electron microscope（SEM） and optical microscope（OM）,and the wear mechanisms were discussed.The results show that the friction coefficient of the laser clad layer is 0.25-0.5,obviously lower than that of Ti-6Al-4V alloy,which is 0.45-0.8,and the worn volume of the laser clad layer is 40% as that of Ti-6Al-4V alloy.The worn volume increases with increasing of sliding velocity and normal load.The wear mechanism of the laser clad layer in vacuum is adhesion wear and abrasion wear due to adhesive material transferring.