The purpose of this paper is to investigate the effect of coating configuration and heat treatment on the thermal shock resistant properties of the ceramic plasma sprayed coatings including the graded coatings. The results obtained are summarized as follows; 1) The press sintered heat treatment induced a higher adhesion and cohesion strength between the substrate and Ni-based alloy by means of diffusion. However, similar results were not obesrved at the alloyalumina interface. 2) The graded

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... ing configuration, which consist of an alloy undercoat, an alumina overcoat and an intermediate graded layer, revealed superior thermal shock resistant properties. This was attributed to their better ability to relax the thermal stresses developed between the Ni-alloy and alumina layers.