等离子喷涂Al/BN涂层工艺研究

采用正交实验设计方法研究了等离子喷涂Al/BN涂层过程中涂层硬度、化学成分与等离子喷涂参数之间的响应关系,利用建立的响应公式,通过排列组合,优选出最佳工艺参数,并进行了验证。在实验参数区间内:涂层布氏硬度与氩气流量、氢气流量及电流成正比,与喷涂距离及送粉速率成反比;BN含量与氩气流量、氢气流量、电流、送粉速率及喷涂距离成反比;SiO2含量与氩气流量、氢气流量、电流成正比,与送粉速率和喷涂距离成反比。在最优工艺参数范围下:获得的涂层硬度压痕直径在5.5~6.1之间,涂层结合强度均值≥4.0MPa,涂层经100小时,450℃热处理后的硬度值在5.5~6.2之间,制备的涂层能满足航空发动机长期使用需求。

Study on the Process of Plasma Spraying Al/BN Coating

The relationship among hardness,chemical composition and plasma spraying parameters in the process of plasma spraying Al/BN coating was studied by orthogonal experiment design method.The optimal process parameters were selected through established response formula and permutation.In the range of experiment parameter,the coating hardness is directly proportional to argon flow,hydrogen flow and current,and inversely proportional to spraying distance and powder feeding rate;the BN content is inversely proportional to argon flow,hydrogen flow,current,powder feeding rate and spraying distance;the SiO2 content is directly proportional to argon flow,hydrogen flow and current,and inversely proportional to powder feeding rate and spraying distance.Under the optimum process parameters,the obtained hardness indentation diameter of the coating is between 5.5 and 6.1,the adhesive strength of the coating is above 4.0 MPa,the coating hardness after heat treatment at 450℃ for 100 hours is between 5.5 and 6.2.The coating can meet the long term demand of aero-engines.