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    双相高熵陶瓷(La0.2Eu0.2Gd0.2Y0.2Yb0.2)2Zr2O7的制备与热物理性能

    Preparation and Thermophysical Properties of Dual-phase High-Entropy Ceramics (La0.2Eu0.2Gd0.2Y0.2Yb0.2)2Zr2O7

    • 摘要: 以La2O3、Eu2O3、Gd2O3、Y2O3、Yb2O3和ZrO2粉末为原料,采用高温固相反应法制备(La0.2Eu0.2Gd0.2Y0.2Yb0.2)2Zr2O7高熵陶瓷,确定了制备工艺,研究了其显微组织、物相组成以及热物理性能,分析其高温热稳定性。结果表明:在1500℃烧结5h炉冷条件下,能得到固溶反应完全的双相高熵陶瓷,其呈现烧绿石/萤石双相共存特征,晶粒尺寸在200~800nm,且元素分布均匀;其800℃下的热导率约为8YSZ陶瓷的50%,热膨胀系数与8YSZ陶瓷相当,并具有良好的高温热稳定性。

       

      Abstract: High-Entropy ceramics (La0.2Eu0.2Gd0.2Y0.2Yb0.2)2Zr2O7 were prepared by high-temperature solid state reaction method with La2O3, Eu2O3, Gd2O3,Y2O3, Yb2O3 and ZrO2 powder as raw materials. The preparation process was determined and the microstructure, phase composition, thermophysical properties of the high-entropy ceramics were studied. The high temperature thermal stability was analyzed. The results show that the dual-phase high-entropy ceramics with complete solid solution were obtained by sintering at 1 500 ℃ for 5h followed under furnace cooling. The high-entropy ceramics presented the dual-phase coexistence characteristics of pyrochlore/fluorite with grain size of 200—800 nm; the element distribution was uniform. The thermal conductivity at 800 ℃ of the high-entropy ceramics was 50% of currently used 8YSZ ceramics, and the thermal expansion coefficient was equivalent to that of 8YSZ ceramics. the high-entropy ceramics also showed excellent high temperature thermal stability.

       

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