激光熔覆Al_2O_3/CaF_2陶瓷基高温自润滑耐磨复合材料涂层组织与耐磨性研究

Microstructure and Tribological Properties of Laser Clad CaF_2 /Al_2O_3 Self - lubrication Wear - resistant Ceramic Matrix Composite Coatings

航空航天、热能、电力工业装备中许多在高温腐蚀性气氛条件下工作的摩擦运动副零部件,不仅要求材料具有优异的高温耐磨性与抗氧化性,同时由于高温条件下无法实现外加润滑而必须具有优异的高温自润滑性能。采用先进的表面工程手段在高温结构材料工件表面制备具有优良高温自润滑性能的先进氧化物陶瓷基高温自润滑耐磨复合材料涂层,是解决上述问题的有效方法之一。本文采用激光熔覆技术上制备出了以氧化物陶瓷Al_2O_3为基、以CaF_2为高温自润滑相的陶瓷基高温自润滑耐磨复合材料涂层,在干滑动磨损试验条件下测试了涂层的耐磨性能。结果表明,激光熔覆Al_2O_3/CaF_2陶瓷基高温自润滑耐磨复合材料中,具有优异高温耐磨性能及高温稳定性的Al_2O_3以片状初生相形式析出形成连续的基体骨架、而具有优异高温自润滑性能的CaF_2则呈球状均匀分布于基体骨架中之间;摩擦磨损试验结果表明,由于激光熔覆Al_2O_3/CaF_2陶瓷基高温自润滑耐磨复合材料集中了Al_2O_3先进氧化物陶瓷材料优异的高温耐磨性、高温抗氧化性及CaF_2高温自润滑相的优异高温自润滑性能,激光熔覆Al_2O_3/CaF_2陶瓷基高温自润滑耐磨复合材料涂层具有优异的摩擦学性能,同激光熔覆Al_2O_3陶瓷涂层相比,激光熔覆Al_2O_3/CaF_2陶瓷基高温自润滑耐磨复合材料?

Tribological components working in high- temperature aggressive environments in aerospace, energy processing and power generation industries demand materials with excellent combinations of high- temperature wear, oxidation and self - lubrication properties. Fabrication of high - temperature self - lubrication wear - resistant coatings on tribo-logical components using some advanced surface modification methods is one of the most efficient and economic ways to solve the problem. In this paper, self- lubrication wear resistant CaF2/Al2O3 ceramic matrix composite coatings were produced on substrate of Al2O3 by laser cladding CaF2 - Al2O3 mixed powder blends. Compared with laser clad monolithic Al2O3 coatings, the CaF2/Al2O3 coatings have much superior wear resistance and noticeably lower friction coefficient under dry sliding wear test conditions.