陶瓷热障涂层的热导率和热扩散率测量

Thermal conductivity and thermal diffusivity measurements of thermal barrier coatings

提出了应用3ω法进行等离子喷涂热障涂层材料的热导率和热扩散率测量的方法。测试了室温下2种典型的热障涂层材料Y2SiO5和La2Zr2O7的热导率和热扩散率,测试结果与文献中的结果吻合良好。实验中对不同孔隙率的样品的热导率在室温附近的温度区间内进行测试,结果表明,孔隙率的变化对热导率有明显的影响。另外,孔隙率对热扩散率有双向的影响,即存在某一孔隙率值使得涂层样品的热扩散率最大。

We measured the thermal conductivity and thermal diffusivity of plasma-spray thermal barrier coatings,Y2SiO5 and La2Zr2O7,using a 3ω method similar to a four-probe resistance measurement.The results agree well with those showed in literatures.Three Y2SiO5 samples with different porosities as well as two La2Zr2O7 samples with different porosities are determined near room temperature.The results show that porosity plays an important role in the performance of thermal transport.Furthermore,porosity has a two-way relationship with the thermal diffusivity;the thermal diffusivity of a specific thermal barrier coating is largest at a certain porosity.