高能高速等离子喷涂MCrAlY涂层的抗高温氧化性能

为提高Ni3Al基高温合金IC6的抗高温氧化性能,采用高能高速等离子喷涂设备在其表面制备了MCrAlY涂层,测试了1 000℃高温条件下经300h氧化后涂层的抗氧化性能。结果表明:300h试验后,涂层的单位面积氧化增重为5.584g/m2,氧化速率为0.019g/m2·h,达到了完全抗氧化级。分析认为:高能高速等离子喷涂工艺制备的MCrAlY涂层与基体结合紧密,孔隙、裂纹及氧化物夹杂含量少,有效的阻隔了氧气的扩散通道,使得氧化物的生长缓慢。同时在高温氧化过程中,涂层表面生成了大量的Al2O3膜,阻碍了金属原子与氧原子的扩散,降低了涂层的氧化速率。另外涂层中含有的Y及Y2O3增加了氧化膜的粘附性,对氧元素的扩散具有抑制作用。

Performance of High Temperature Oxidation Resistance of MCrAlY Coating Prepared by High-energy and High-speed Plasma Spraying

To improve the high temperature oxidation resistance of Ni3Albased alloy IC6, the MCrAlY coating was prepared by highenergy and highspeed plasma spraying equipment. After oxidation for 300 hours under hightemperature, the antioxidant property was tested. The results show that the oxidation weight is 5.584 g/m2 and the oxidation rate is 0.019 g/ m2·h, reaching the complete antioxidant level. It is analyzed that the coating is tightly combined with the base and the fewer pores, cracks, and oxide inclusions effectively block off the oxygen, which slows down the growth of oxide. A large amount of Al2O3 films exist on the surface of the coating, which hinders the diffusion of the metal and oxygen and decrease the oxidation rate. Moreover, the element Y and Y2O3 in the coating increase the adhesion of the oxide and restrain the diffusion of oxygen.