Influence of plasma spray parameters on mechanical properties of yttria stabilized zirconia coatings. I: Four point bend test

Yttria (8 wt.%) stabilized zirconia (YSZ) with a NiCrAlY bond coat was atmosphere plasma sprayed on mild steel substrates. The bond coat thickness (100–250 μm), YSZ coating thickness (300–500 μm), stand off distance (80–100 mm), and substrate temperature (273–393 K) were changed in a four by 17 experimental design matrix to investigate the influence of each spray parameter on the mechanical properties of coatings. Coatings were tested using a four point bend test arrangement. Coatings sprayed with thinner bond coat on a cold substrate exhibited higher yield strength and stiffness under bending. Change in the stand off distance and the top coat thickness did not statistically influence either yield strength or stiffness of the coatings.