Abstract
Results of structural studies performed with light microscopy and transmission electron microscopy on plasma sprayed NiCrAlY coating isothermally exposed at 850 °C for 6 minutes are presented in this paper. The applied thermal treatment led to the decomposition of initial phases and to precipitation of α-Cr and γ'-Ni₃Al. It is shown that the precipitation of α-Cr and γ'-Ni₃Al as well as the decomposition of martensitic NiAl obeyed orientation relationships. Dissolution of Ni₅Y yttride was not observed. All the oxide inclusions remained amorphous and their transformation into crystalline structures is expected after longer exposures at 850 °C or at higher exposure temperatures.

Key words
NiCrAlY coating, microstructure, thermal treatment, TEM studies

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