High-temperature crack resistance of yttria-stabilized zirconia coatings enhanced by interfacial stress transfer

This study investigated the high-temperature crack resistance properties of yttria-stabilized zirconia (YSZ) coatings prepared in electrolytes with varying amounts of Y³⁺ addition, within a temperature range from 800 °C to 1000 °C. The flexibility-enhanced YSZ coating enabled by obtaining tetragonal zirconia (t-ZrO₂) and cubic zirconia (c-ZrO₂) coherent interfaces with high stress transfer efficiency, which is achieved by adjusting the phase composition in ZrO₂ coatings. The high-quality toughened YSZ coating with 59 % lower crack density compared with traditional ZrO₂ coating. This phenomenon is attributed to the c-ZrO₂/t-ZrO₂ coherent interface alleviates interfacial deformation at high temperatures and maintains a good stress transfer capability through its stable structure, which helps to disperse the thermal stress within the coating and inhibits crack propagation. This work provides a straightforward strategy for tailoring ZrO₂ coatings crack propagation resistance property at high temperatures by interface enhancement.