La2Ce2O7/YSZ复合热障涂层制备及高热循环寿命机理研究OA

La2Ce2O7(LC)/yttrium partially stabilized zirconia(YSZ)composite thermal barrier coating is deposited by supersonic plasma spraying technology to solve the problem of low thermal cycling lifetime of YSZ thermal barrier coating under CMAS corrosion.The double powder feeding mode is used to realize the composite of LC and YSZ,and the problem of sudden drop of the thermal expansion coefficient of LC material at low temperature is effectively solved based on the mutual influence of the residual stress between LC and YSZ.In addition,the composite coating has better thermal insulation performance and CMAS corrosion resistance.The CMAS corrosion resistance and thermal cycling failure behavior of LC/YSZ composite coating with CMAS corrosion are studied by high temperature static corrosion test and thermal cycling test.The results show that the thermal cycle life of LC/YSZ composite coating is nearly 90%higher than that of traditional YSZ coating,which can be attributed to the following three aspects:(1)mixing LC with YSZ can effectively eliminate the sudden decrease of thermal expansion coefficient of LC material at low temperature;(2)the thermal insulation performance of LC/YSZ composite coating is better than that of YSZ coating;(3)LC/YSZ composite coating can react with CMAS to form a reaction layer composed of La-Ce apatite phase,CaAl2Si2O8,m-ZrO2 and t-ZrO2 phases,which can prevent the penetration of CMAS melt effectively.