Thermophysical Propertes Of Multi-rare Earth Doping Stabilized ZrO₂ And High Temperaturecorrosion Behavior Of CMAS

Severly sintering and phase transformation behavior occurred to the widely used yttria partially stabilized zirconia when exposed to 1200 ? or a long time.And is also susceptible to corrosion by environmental deposits(CMAS),resulting in failure of the ceramic coating and loss of protection.Sc2O3,Gd2O3,Y2O3 co-doped stabilized zirconia ceramics(ScGdYSZ)were prepared by chemical coprecipitation method.The phase composition and mechanical properties of SGYSZ ceramics were studied by XRD,RAMAN and SEM,and their phases were observed under CMAS corrosion conditions.Composition,tissue evolution and surface residual stress changes.It comes to the following conclusions:1.The increase in the total amount of rare earth doping affects the phase composition of ScGdYSZ.The tetragonal phase of ScGdYSZ decreases with the increase of the total doping amount,and the cubic phase increases.Due to the large ionic radius of Gd3+,the cubic phase of the ScGdYSZ ceramic material was increased by 78.8%by replacing 1 mol of Y2O3 with 1 mol of Gd2O3.2.The hardness and fracture toughness of ScGdYSZ materials increase with the increase of Sc2O3 content.Increasing the Y2O3 component can improve the fracture toughness of ScGdYSZ material but the hardness decreases.The effect of Gd2O3 is opposite to that of Y2O3.The reason is the ion of Gd3+.3.The high temperature corrosion performance of CMAS of ScGdYSZ material increases with the increase of total doping.When the total amount of rare earth doping is greater than 10.5 mol%,ScGdYSZ exhibits good high temperature CMAS corrosion resistance.4.Corrosion time and rare earth doping amount will affect the residual stress change on the surface of ceramic materials.The stress trends of 4.5Sc1.5Gd3.5YSZ,6.5Sc1.5Gd3.5YSZ,6.5Sc2.5Gd3.5YSZ ceramic materials are similar.The surface of the ceramics is corroded for 1h,and the residual tensile stress state is observed.The 4h and 8h ceramic surfaces have residual compressive stress and 8h compressive stress.Lower than 4h.YSZ and 5.5Scl.5Gd3.5YSZ have residual compressive stress state during the corrosion process,and the stresses of different corrosion time change little.