超音速颗粒轰击处理对MCrAlY涂层TGO生长的影响

Effect of surface nanocrystallization of MCrAlY coating on TGO

摘要: 采用超音速火焰喷涂方法在镍基高温合金(GH99)上制备了MCrAlY涂层,并进行超音速颗粒轰击处理,研究了超音速颗粒轰击工艺对MCrAlY涂层显微结构和热生长氧化物(TGO)的影响。结果表明,通过表面轰击处理,增加了涂层中Al元素的扩散通道;高温氧化过程中MCrAlY涂层表面很快形成连续致密的Al₂O₃膜,保护了Ni,Cr等元素避免被氧化,从而避免了Ni(Cr,Al)₂O₄,NiO等大颗粒氧化物的生成;这样减少了涂层中的裂纹产生和扩展的可能性,从而提高涂层抗高温氧化性能。

Abstract: Thermal barrier coating, obtained by high velocity oxygen furel thermal spraying (HOVF) on GH99 high-temperature alloy was treated by supersonic fine particles bombarding, and its influence on microstructure and thermally grown oxide (TGO) of MCrAlY bond coating was studied.The experimental results show that the diffusision access of Al-element increased with supersonic treating, then Al₂O₃ formed quickly onMCrAlY surface, and Ni, Cr were prevented from oxidizing.For this reason, Ni(Cr,Al)₂O₄, NiO avoided forming, and flaw decreased, so that the high temperature oxidation resistance of coating con be improved.