孔隙对等离子喷涂YSZ涂层热导率的影响

Effects of Porosity on Thermal Conductivity of Plasma Sprayed YSZ Coatings

采用包覆型的聚苯酯颗粒混合在YSZ原料粉末中,以提高YSZ涂层的孔隙率。利用氙灯导热仪测量了不同孔隙率涂层的热导率,并将热导率测量值与理论计算值进行了比较。结果表明:当包覆型聚苯酯含量增加到30%时,涂层的孔隙率增加到28.5%;当包覆型聚苯酯的含量继续增加时,涂层的孔隙率增加并不显著。随着孔隙率的增加,涂层的热导率下降。当涂层773 K时的孔隙率增加到28.5%时,涂层的热导率为0.77 W·m^(-1)·K^(-1)。热导率的理论计算结果与测试结果具有相同变化的趋势。当温度由773 K上升到1173 K时,孔隙率为2.1%的涂层的热导率下降17.2%,而孔隙率为28.5%的YSZ涂层的热导率下降5.2%。

The cladded PHB was added into YSZ powder to gain YSZ coatings with high porosities.Xenon lamp thermal conductivity meter was used to measure the thermal conductivity of the coatings with diffierent porosities.The calculated results of thermal conductivity were compared with the measured results.The results show that the porosity of the coating increases to 28.5%when the content of cladded PHB increases to 30%.When the content of claded PHB continuously increases,the increase of porosity of the coating is not obvious.The thermal conductivity of the coating decreases with the increase of porosity.When the porosity of the coating increases to 28.5%,the thermal conductivity of the coating at 773 K is 0.77 W·m^(-1)·K^(-1).The same tendency of the conductivily is found in test results and calculated results.The thermal conductivity of the coating with 2.1%porosity decreases by 17.2%,when the temperature increases from 773 K to 1173 K,and the thermal conductivity of YSZ coating with 28.5%porosity decreases by 5.2%.