Effect of surface nanocrystallization of MCrAlY coating on TGO

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.