电子束物理气相沉积热障涂层隔热性能的磷光寿命在线测量

Evaluation of Thermal Insulation Performance of EB-PVD YSZ Thermal Barrier Coatings by Phosphorescence Lifetime Online Measurement

精确在线测量热障涂层(TBCs)在热梯度环境下的真实隔热效果对热障涂层的设计以及开发具有重要意义.采用电子束物理气相沉积(EB-PVD)制备了含Eu掺杂的氧化钇部分稳定氧化锆(YSZ:Eu)表层、YSZ中间层与Dy掺杂YSZ(YSZ:Dy)底层的磷光传感热障涂层.利用磷光信号的热淬灭特性对温度梯度环境下YSZ涂层表面以及黏结层/YSZ层界面温度进行在线测量,对EB-PVD YSZ热障涂层的真实隔热效果进行评估.结果表明:平均厚度为113μm的YSZ涂层在高温温度梯度下能够实现的平均温降为66.5℃,在温度区间为400~700℃内的平均热导率为(0.87±0.15)W/(m·K),略小于传统激光脉冲法的测量值(0.95±0.02)W/(m·K).上述结果证实了磷光在线测温技术用于热障涂层隔热效果测量的可靠性,为热障涂层隔热效果的实时监控提供了一种有效方法.

Precise measurement of the thermal insulation performance of thermal barrier coatings(TBCs)under the thermal gradient environment is important for the design and development of TBCs.A phosphorescent sensor TBC which contains an Eu doped yttria-stabilized zirconia(YSZ:Eu)surface layer,a YSZ intermediate layer,and a YSZ:Dy bottom layer,is designed and prepared by electron beam physical vapor deposition(EB-PVD).Based on the thermal quenching characteristics of phosphorescence signal,the surface temperature of the YSZ coating and the interface temperature of the bond-coat/YSZ layer are measured online in a temperature gradient environment,and the real thermal insulation effect of the EB-PVD YSZ thermal barrier coating is evaluated.The results show that the EB-PVD YSZ coating with a thickness of 113μm can achieve an average temperature decrease of 66.5℃.The average thermal conductivity of the coating is(0.87±0.15)W/(m·K)in the temperature range between 400 and 700℃,which is slightly lower than the value(0.95±0.02)W/(m·K)obtained by using the traditional laser flash method.The above results validate the reliability of online phosphorescence temperature measurement technique,and provide an effective method to monitor the thermal insulation effect of TBCs in real time.