Delamination Property of Modeled Air Plasma Sprayed-Thermal Barrier Coatings under Shear Loading: Effect of Difference in Chemical Composition of Bond Coat

In order to understand the effect of the difference in chemical composition and microstructure of bond coat (BC) layer on delamination properties, pushout tests were performed on modeled air plasma-sprayed thermal barrier coatings (APS-TBCs). Nickel-platinum-aluminides (Ni-Pt-Al), hafnium modified nickel-platinum-aluminides (Ni-Pt-Al-Hf) and NiCoCrAlY alloys were used as BC alloy. Hafnium and aluminum oxide were formed in needle like shape when the Ni-Pt-Al-Hf alloy was used. Vickers hardness of BC alloy decreased up to 50 hours heat exposure and then increased with increasing heat exposure time. Interfacial delamination toughness increased and then decreased with the increase in heat exposure time.