超音速电弧喷涂Ti-Al涂层抗滑动磨损性能研究

采用二次正交回归试验设计原理和钛铝双丝超音速电弧喷涂Ti-Al合金复合涂层方法，对LY12铝合金进行了表面强化研究，并采用金相、XRD、SEM、硬度和磨损试验方法，对涂层的组织结构及力学性能进行了表征，考察了喷涂工艺参数对涂层孔隙率、显微硬度和耐滑动磨损性能的影响，研究结果表明：在本文的实验条件下，涂层的体积磨损量、孔隙率、显微硬度与喷涂电压和喷涂距离之间的变化规律，可用回归模型进行描述；随喷涂电压的增大，涂层磨损量逐渐下降；喷涂距离小于220mm时，随喷涂距离的增大涂层磨损量逐渐增大；喷涂距离为220mm时，磨损量达到最大，继续增加喷涂距离，涂层的磨损量逐渐下降；在干摩擦条件下，Ti-Al合金涂层的磨损机制主要以化合物相剥落引起的磨粒磨损和氧化磨损为主。

Study on slide-wear resistance of supersonic wires arc sprayed Ti-Al composite coatings

IThe surface strengthen of model LY12 aluminum alloy was investigated by using the orthogonal regression experiment design theory and the method of supersonic wires arc spraying Ti-Al alloy composite coatings by titanium and aluminum wires. The effects of spraying parameters on microstructure, porosity, micro-hardness and wear resistance of the arc sprayed composite coatings was studied by microscopy, SEM, hardness and wear experiments methods. The slide wear mechanisms of the coatings were discussed as well. The research results showed that the relationship of abrasive volume (Y_a/mm~3), porosity (Y_p/%),and micro hardness (Y_h/HV_(0.2)) with the spraying voltage(U/V) and spraying distance(L/m) can be expressed by followed regression models, which are prominent respectively at 0.25,0.10,and 0.01 level. Under the certain conditions, the abrasive volume decreases with spray voltage and varies weakly when the spray distance is (150 mm.) The abrasive volume of coatings increases with spray distance when spray distance is less than (220 mm,) obtains maximum at 220 mm and decreases gradually with spray distance lengthened. This results from the microstructure and hardness of coatings. The wear mechanism may be the abrasive wear and/or the oxidation wear caused by the desquamation of the hard compound phases.