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

• YSZ nano-coatings with various c-ZrO 2 content was achieved by regulating Y 3+ . • The correlation between the content of c-ZrO 2 and coating toughness was revealed. • The high stress transfer efficiency of t-ZrO 2 /c-ZrO 2 coherent interface was found. • Toughness of coatings at high temperatures improved 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 Y 3+ addition, within a temperature range from 800 ℃ to 1000 ℃. The flexibility-enhanced YSZ coating enabled by obtaining tetragonal zirconia (t-ZrO 2 ) and cubic zirconia (c-ZrO 2 ) coherent interfaces with high stress transfer efficiency, which is achieved by adjusting the phase composition in ZrO 2 coatings. The high-quality toughened YSZ coating with 59 % lower crack density compared with traditional ZrO 2 coating. This phenomenon is attributed to the c-ZrO 2 /t-ZrO 2 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 ZrO 2 coatings crack propagation resistance property at high temperatures by interface enhancement.