The bonding mechanism of thermal sprayed ceramic coating was not clear due to the complicated profile of blasted surface and microstructure of the coating. The objective of this study is to investigate the effect of interfacial roughness on the adhesive strength of yttria-stabilized zirconia coatings sprayed by atmospheric plasma spraying. Tensile adhesive test and interfacial indentation test were carried out for evaluating their bonding properties. Stainless steel was used as a substrate, and blasted in three different pressures by fused alumina abrasives with three different particle sizes. Our measurement revealed that the residual amount of the coating on the substrate after tensile adhesive test was increased with increasing the blasting pressure, which indicated that high roughness caused the increase in anchor effect of the coating. It was also found that the dependency of surface roughness on bonding property disappeared if broken at the area apart from the interface. It was concluded that root mean square slope(RΔq), which was proportional to surface blasting area, was well correlated with bonding property rather than arithmetic mean deviation(Ra).

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