Abstract
This paper examines the microstructure and morphology of zirconia coatings and demonstrates the calculation of elastic modulus and Martens hardness based on instrumented indentation test results. Coatings samples varying in microstructure, phase content, and chemical composition were deposited by suspension plasma spraying using different torches and different suspension formulations. Coatings produced from low-concentration suspensions with submicron-size powders had a columnar structure with long vertical pores between the columns and fine spherical pores within the columns. Coatings made from suspensions with high concentrations of solids and coarser, more irregular powders, on the other hand, were more uniform and their surfaces smoother. They are also shown to be harder and have higher elastic modulus based on indentation test results.