等离子内孔喷涂超致密Mo涂层的高温耐磨性能研究

High-Temperature Wear Behaviors of Ultra-Dense Mo Coating by Plasma Inner Hole Spraying

为提升铝合金的高温强度及耐磨性,采用等离子内孔喷涂技术制备超致密Mo涂层,解决了铝合金套筒等内壁耐高温及耐磨问题。采用金相显微镜、扫描电镜、能谱仪、X射线衍射仪表征了Mo涂层微观结构;评估了Mo涂层维氏硬度及与铝合金基体的拉伸结合强度;利用球-盘摩擦磨损试验机研究了Mo层的高温摩擦行为。结果表明:采用等离子喷涂在铝合金基体上得到了超致密Mo涂层,在喷涂过程中Mo涂层未发生明显氧化,结合强度为21.4 MPa,平均维氏硬度达469 HV3 N。摩擦磨损试验结果显示,Mo涂层在200℃、400℃时的摩擦系数和比磨损体积较铝合金基体大幅度降低,表现出良好的耐磨性,其高温磨损形式主要以氧化磨损、黏着磨损为主。

In order to improve the strength and wear resistance of aluminum alloy at high temperature,an ultra-dense Mo coating was prepared by plasma inner hole spraying technology,which solves the problems of high temperature resistance and wear resistance of the inner wall of aluminum alloy sleeve.The microstructure of Mo coating was analyzed by metallographic microscope,SEM,EDS and XRD,and the Vickers hardness of Mo coating and its tensile bond strength with aluminum alloy matrix were evaluated.In addition,the high temperature friction behavior of Mo coating was studied by ball-disk friction and wear tester.Results showed that the ultra-dense Mo coating was successfully prepared on the aluminum alloy by plasma spraying.During the spraying process,no obvious oxidation of Mo coating occurred.The bonding strength was 21.4 MPa,and the average Vickers hardness was 469 HV3 N.The friction and wear test results showed that the friction coefficient and specific wear rate of Mo coating were much lower than those of aluminum alloy at 200℃and 400℃,showing good wear resistance.Besides,the high temperature wear mechanisms of Mo coating were mainly adhesive wear and oxidation wear.