抄録
A plasma spraying method was applied to deposit the coating materials. A NiCoCrAlY alloy was used as the bond coat, a ZrO_2 ceramic partially stabilized with Y_2O_3 as the top coat, and a stainless steel selected as the substrate. In-situ optical microscope combined with SEM observation was made, and load-displacement curves were recorded synchronically. Cracking and fracture behavior in the as-deposited coating system were evaluated using a sandwiched uni-axial tensile testing method. It was found that initial cracking was followed by multiple cracking transversely propagating in the coatings. After the saturation of the multiple cracks, decohesion occurred at the bond coat/substrate interface. Finally, a model was proposed to describe the fracture processes.
