HVAF制备形变镁合金Al-WC/Al复合涂层的微观组织研究

Study on Microstructure of Deformed Mg Alloy Al-WC/Al Composite Coating Prepared by HVAF

采用超音速火焰喷涂(HVAF)工艺在AZ31镁合金表面制备Al-WC/Al复合涂层,通过扫描电镜和电子能谱对复合涂层的微观组织特征进行研究。结果表明,制备的复合涂层结构致密,Al涂层孔隙率为0.3%左右,WC/Al复合涂层孔隙率为0.7%左右。基体接近于结合面的部分地方出现了孪晶组织,Al涂层与镁合金基体结合处产生了元素扩散,复合涂层内部产生了少量WC与Al的元素扩散,大部分WC颗粒与Al颗粒为机械结合。

Al-WC/Al composite coating was prepared on the surface of AZ31 magnesium alloy by high-velocity air-fuel(HVAF). The microstructure of the composite coating was studied by SEM and EDS. The results show that the structure of the prepared composite coating is compact, the porosity of Al coating is about 0.3%, and that of WC/Al composite coating is about 0.7%. Twins appears in parts of the matrix closing to the bonding surface, Al coating produces element diffusion at the junction with magnesium alloy substrate, WC and Al in the composite coating produces a small amount of element diffusion,and most WC particles and Al particles are mechanically bonding.