Development of dense ZrO2-coatings with high toughness, Part 1: Material and coating development

The applicability of the material ZrO2 for sintered ceramics and for coatings is determined by the transformations of its three modifications (monoclinic, tetragonal and cubic) and their stabilization. While for thermal spray coatings the most important application are thermal barrier coatings (TBC) the so-called transformation toughening enables the manufacture of ceramics with high toughness. The aim of the work presented in this paper was the development of dense coatings with high toughness in order to enable the substitution of full ceramic parts by coated ones. Extensive coating development using experimental powders and suspensions resulted in the deposition of dense Y2O3-stabilized ZrO2 coatings with low crack density.