(LaxYb1-x)2Zr2O7热障涂层材料力学性能研究

Mechanical Properties of(LaxYb1-x)2Zr2O7Thermal Barrier Coatings

摘要:

采用氧化锆、氧化镱和氧化镧固相合成法制备了3种不同成分的热障涂层材料(La_xYb_1-x)₂Zr₂O₇(x=0,0.5,1.0),经高温无压烧结制备出相对理论密度≥97%的力学性能测试样品。通过三点弯曲法和热机械分析法分别测试了材料的室温弯曲强度和高温杨氏模量。实验结果表明,焦绿石结构的La₂Zr₂O₇和萤石结构的Yb₂Zr₂O₇互相掺杂形成的有限固溶体LaYbZr₂O₇具有细晶结构,其材料的室温弯曲强度比纯La₂Zr₂O₇相的有所提高,也有利于减缓热障涂层材料在1200℃以上的高温杨氏模量降低程度。

Abstract:

Three different components of (La_xYb_1-x) ₂Zr₂O₇ (x = 0, 0.5, 1.0) thermal barrier coating materials were prepared by solid state synthesis method using zirconia, ytterbium oxide and lanthanum oxide. The relative theoretical densities were above 97% for all samples, which were prepared by pressureless sintering for mechanical properties test. The room temperature bending strength and high temperature Young "s modulus of the materials were tested by three-point bending method and thermomechanical analysis method respectively. The experimental results show that LaYbZr₂O₇, which is a finite solid solution consisting of La₂Zr₂O₇-based pyrochlore and Yb₂Zr₂O₇-based fluorite with fine grains, could improve room temperature bending strength compared with that of pure La₂Zr₂O₇. It also benefits the high temperature Young"s modulus above 1200℃.