Eu^(3+)掺杂对YSZ热障涂层隔热性能与涂层界面断裂韧性的影响研究

Effect of Eu^(3+) Doping on Thermal Insulation Property and Interfacial Fracture Toughness of YSZ Thermal Barrier Coatings

使用大气等离子喷涂法制备传统YSZ涂层与2mol%Eu^(3+)掺杂YSZ涂层。使用扫描电镜观察并测量2种涂层的微观形貌与孔隙率。采用闪光导热仪分别测量2种涂层在100~1100℃范围内的热导率。采用氧化循环试验箱分别对YSZ涂层与YSZ:Eu涂层进行30次、50次的氧化循环处理并计算2种涂层未处理试样与氧化循环试样的界面断裂韧性,氧化循环试验环境温度为1100℃。结果表明,在相同温度下,YSZ:Eu涂层热导率低于YSZ涂层热导率,说明2mol%Eu^(3+)掺杂可有效降低YSZ热障涂层的热导率;YSZ:Eu涂层与YSZ涂层的界面断裂韧性均随氧化循环次数的增加而下降,TGO厚度随氧化循环次数的增加而增大;相同热处理条件下YSZ:Eu涂层界面断裂韧性大于YSZ涂层,TGO厚度更小,说明2mol%Eu^(3+)掺杂抑制了TGO的生长,提高了涂层界面性能。

Traditional YSZ coating and Eu^(3+)doped YSZ coating were prepared by atmospheric plasma spraying APS method.SEM was used to observe and measure the morphology and porosity level of the two coatings.The thermal conductivity of the two coatings in the range of 100-1100℃was measured by a flashlight heat conducting system.30 cycles and 50 cycles of oxidation cycle treatment for both YSZ coating and YSZ:Eu coating were conducted by oxidation cycle test equipment at 1100℃,and the interfacial fracture toughness of as-received and heat treated specimens were then calculated.The results show that the thermal conductivity of the YSZ:Eu coating is lower than that of the YSZ coating at the same temperature,indicating that 2 mol%Eu^(3+)doping can effectively reduce the thermal conductivity of the YSZ TBCs.For both types of coating,interfacial fracture toughness decreases while the TGO thickness increases with the oxidation cycle number increasing.At the same heat treatment conditions,the interfacial fracture toughness of the YSZ:Eu coating is greater than that of the YSZ coating,and the TGO thickness is thinner,indicating that 2 mol%Eu^(3+)doping inhibits the growth of TGO and improves the coating’s interfacial properties.