目的 通过优化等离子喷涂工艺参数，提高铝合金表面等离子喷涂Al2O3-3%TiO2复合陶瓷涂层的结合强度和涂层表截面硬度。方法 用正交试验法，对影响喷涂涂层结合强度和硬度的4个关键喷涂参数进行优化，分别得到喷涂粘结底层Ni-5Al和工作表层Al2O3-3%TiO2的最佳优化参数。结果 通过正交试验确定影响Ni-5Al涂层综合指标的因素由主到次是喷涂电流、喷涂距离、辅气流量、主气流量，最优水平数为2、3、2、1；影响Al2O3-3%TiO2涂层综合指标的因素由主到次是喷距、辅气流量、电流、主气流量，最优水平数为2、3、2、1。Ni-5Al涂层的最佳喷涂工艺参数为：喷涂距离120 mm，喷涂电流520 A，主气流量42 L/min，辅气流量7.5 L/min。Al2O3-3%TiO2复合涂层最佳喷涂工艺参数为：喷涂距离90 mm，喷涂电流530 A，主气流量46 L/min，辅气流量7.8 L/min。最佳工艺下制备的Ni-5Al底层与基体的结合强度为25.2 MPa，Al2O3-3%TiO2复合涂层与Ni-5Al底层的结合强度为17.8 MPa，且其截面硬度在1000HV0.5以上。结论 对喷涂工艺参数进行优化可以得到质量高且稳定的Al2O3-3%TiO2复合喷涂涂层，与非最佳工艺参数喷涂涂层相比，各指标均有较大提高。

The work aims to improve the bonding strength and surface and section hardness of the Al2O3-3%TiO2 composite coating on aluminum alloy matrix by plasma spraying through the optimization of plasma spraying process parameters. Four key spraying parameters affecting the bonding strength and surface hardness of spray coating were optimized by orthogonal test, thus the optimal parameters of adhesive bottom coating Ni-5Al and working surface Al2O3-3%TiO2 were obtained respectively. The order of factors influencing the adhesive bottom coating quality was current, distance, H2 and Ar flow, and the preferable level was 2, 3, 2 and 1. The main sequence of factors influencing the comprehensive index of working surface coating was spray distance, H2 flow, current and Ar flow, and the optimal horizontal number was 2, 3, 2 and 1. The best spraying parameters of the adhesive layer Ni-5Al were: spraying distance of 120 mm, spraying current of 520 A, Ar flow of 42 L/min and H2 flow of 7.5 L/min. The optimal spraying parameters of Al2O3-3%TiO2 composite coating were: 90 mm spray distance, 530 A spray current, 46 L/min Ar flow and 7.8 L/min H2 flow. The bonding strength of the bottom layer reached 25.2 MPa and 17.8 MPa at the surface coating. The mean hardness of the optimized working surface coating was above 1000HV0.5. High quality and stable Al2O3-3%TiO2 composite coating can be obtained by optimizing the spraying process parameters. Compared with coating prepared by the non-optimal spraying process parameters, each index of the coating quality is greatly improved.