The Failure Characteristics and Mechanical Interaction of YSZ TBC Fabricated via APS under Extreme Temperature Conditions

Purpose Based on the pursuit of improving the temperature endurance capabilities of conventional superalloys for hot-end components, this paper aims to investigate the failure mechanisms of yttria-stabilized zirconia (YSZ) coatings fabricated by the atmospheric plasma spraying method at 1220 °C and 1260 °C. Design/methodology/approach Thermal spraying techniques are applied to produce thermal barrier coatings (TBCs) that offer superior thermal insulation, thermal shock resistance and thermal stability. The oxidation kinetics, the propagation patterns of cracks and the phase stability prior to failure of the coating were analyzed in detail. Findings The failure of coatings during static isothermal oxidation process is caused by slow crack initiation and propagation in the densification stage. External stress induces rapid initiation and propagation of cracks, leading to coating phase transformation. Cracks create pathways for oxygen diffusion and accelerate the growth of oxide layers. Originality/value This work aims to provide reliability data on the failure of TBCs, elucidate the high-temperature service characteristics of TBCs and provide theoretical basis for its performance improvement under extreme conditions.