Microstructure of NiCoCrAlY component in Plasma sprayed ZrO_2/NiCoCrAlY graded coating

摘要

NiCoCrAlY alloy component in ZrO_2/NiCoCrAlY graded coating forms heterogeneous mi- crostructure after plasma spraying, which consists of γ(Ni) matrix phase and some ε-Co phase, as well as a little γ'(Ni_3Al) phase. Moreover, owing to the impaction of molten NiCoCrAlY droplets on the substrate at high speed, the alloy particles experience severe deformation at a high strain rate, producing a lot of disloca- tions. During rapid solidification, NiCoCrlY alloy reacts with oxygen in air, and some NiO, Cr_2O_3 Al_2O_3 form in the alloy.