Study On Thermophysical Properties And Corriosion Resistance Of Sc₂O₃ And Y₂O₃ Co-stabilized ZrO₂ Thermal Barrier Coating Materials

At present,with the rapid development of aerospace technology,the operating temperature of aircraft engines and gas turbines continues to increase,the traditional 6-8wt.%YSZ thermal barrier coating material cannot meet the working requirements of high-performance engines due to its phase change at high temperatures,low thermal conductivity,and poor resistance to molten salt corrosion.Therefore,the research and preparation of new thermal barrier coating materials is the focus of the field of high temperature protective coating.In this study,the Sc₂O₃-ZrO₂ material system and the Sc₂O₃-Y₂O₃-ZrO₂ material system were prepared by solid-phase synthesis.First,the components of the Sc₂O₃-ZrO₂material system were optimized,and its high-temperature phase stability,comprehensive mechanical properties and thermophysical properties were optimized.For testing,further doping with Y₂O₃ on the basis of the optimized composition,and further testing the resistance to molten salt corrosion of the optimized composition of the Sc₂O₃-Y₂O₃-ZrO₂material system.In the Sc₂O₃ doped ZrO₂ system,the experimental results show that the appropriate amount of Sc₂O₃ doping can improve the high temperature phase stability and comprehensive physical properties of ZrO₂.Among them,the best component 8SSZ has good high temperature phase stability,and its thermal conductivity is about 5.8%lower than that of 4.5YSZ,and the lowest can reach 2.13 W/m·K(800?).Sc₂O₃,Y₂O₃ co-stabilized ZrO₂,with the increase of Y₂O₃ doping,the t-phase decreases and the c-phase content increases.According to the comprehensive test results of mechanical properties and thermophysical properties,the optimal composition is7.5Sc0.5YSZ,which has the most excellent hardness and fracture toughness,and its low thermal conductivity can reach 2.07W/m·K(800?).Select 7.5Sc0.5YSZ component for further resistance to molten salt corrosion performance test.In the corrosion of V₂O₅ molten salt at 900?,the content of m phase and YVO₄ phase of 7.5Sc0.5YSZ after corrosion for 80 h is much lower than 4.5YSZ.The thickness of the corrosion layer of 7.5Sc0.5YSZ is within 10?m,and the thickness of the corrosion layer of4.5YSZ is within 30?m.The anti-V₂O₅ corrosion performance of 7.5Sc0.5YSZ is far better than that of 4.5YSZ.