Evaluation of functionally gradient coatings produced by plasma-spray technique

Abstract

The results showed that there are no certain transition lines between the bond layer, the cermet layer, and the ceramic layer. The SEM results indicated the presence of porosity, oxide, inclusion and unmelted particles. Surface roughness values decreased with increasing MgZrO3 content. It was also found that the microhardness below a depth of 245 mu m from the coating surface decreased and followed first a linear function in the ceramic, cermet and bond coatings. Tn addition to this, the microhardness of steel substrate showed a parabolic function due to the blasting operation and heat effect during the coating process. (C) 1999 Elsevier Science S.A. All rights reserved.