2022 Volume 59 Issue 1 Pages 19-26
The bonding mechanism of thermal sprayed ceramic coating was not clear due to the complicated profile of blasted surface and microstructure of the coating. Especially, adhesive mechanism on light metal substrate is not clear because of little previous research. The objective of this study is to investigate the effect of surface roughness on the adhesive strength of yttria-stabilized zirconia coatings sprayed by atmospheric plasma spraying on aluminum alloy (JIS A5052) substrate. Tensile adhesive test and interfacial indentation test were carried out for evaluating their bonding properties. The substrates were blasted in three different pressures and seven different blast angles by fused alumina abrasives with three different particle sizes. Our measurement revealed that tensile adhesive strength was decreased with increasing the substrate roughness (root mean square slope RΔq) . Fracture surfaces after tensile strength test are observed by FE-EPMA analyzer and analyzed by X-ray fluorescence analyzer. It was found from the elemental analysis that the fractured part shifted to the substrate with increasing the RΔq. It was concluded that tensile adhesive strength was decreased with increasing the surface roughness due to the low strength substrate.
