无机材料学报 ›› 2021, Vol. 36 ›› Issue (4): 411-417.DOI: 10.15541/jim20200426

所属专题: 【结构材料】热障与环境障涂层 【结构材料】高熵陶瓷

• 研究论文 • 上一篇    下一篇

稀土钽酸盐(RETaO4)高熵陶瓷的制备与热学性能研究

朱嘉桐, 楼志豪, 张萍, 赵佳, 孟轩宇, 许杰(), 高峰   

  1. 西北工业大学 材料学院, 凝固技术国家重点实验室, 西安 710072
  • 收稿日期:2020-08-05 修回日期:2020-09-14 出版日期:2021-04-20 网络出版日期:2020-10-30
  • 通讯作者: 许 杰, 副教授. E-mail: xujie@nwpu.edu.cn
  • 作者简介:朱嘉桐(1997-), 男, 硕士研究生. E-mail: zhujiatong@mail.nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(51702259);国家自然科学基金(52072301);陕西省基础研究计划(2019JM-432)

Preparation and Thermal Properties of Rare Earth Tantalates (RETaO4) High-Entropy Ceramics

ZHU Jiatong, LOU Zhihao, ZHANG Ping, ZHAO Jia, MENG Xuanyu, XU Jie(), GAO Feng   

  1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China
  • Received:2020-08-05 Revised:2020-09-14 Published:2021-04-20 Online:2020-10-30
  • Contact: XU Jie, associate professor. E-mail: xujie@nwpu.edu.cn
  • About author:ZHU Jiatong(1997-), male, Master candidate. E-mail: zhujiatong@mail.nwpu.edu.cn
  • Supported by:
    Natural Science Foundation of China(51702259);Natural Science Foundation of China(52072301);Natural Science Basic Research Program of Shaanxi Province(2019JM-432)

摘要:

采用固相法制备了三种具有单斜结构的单相固溶体稀土钽酸盐高熵陶瓷(Nd1/6Sm1/6Eu1/6Gd1/6Dy1/6Ho1/6)TaO4 (6RETaO4)、(Nd1/5Sm1/5Eu1/5Gd1/5Dy1/5)TaO4(5RETaO4)和(Nd1/4Sm1/4Eu1/4Gd1/4)TaO4(4RETaO4), 扫描透射电子显微镜- X射线能谱(STEM-EDS)的分析表明掺杂的稀土元素分布均匀。通过扫描电子显微镜(SEM)观察到由四方-单斜的二级铁弹相变形成的铁弹畴。热膨胀测试表明RETaO4高熵陶瓷在1200 ℃以下具有良好的热稳定性, 其中6RETaO4的热膨胀系数可以达到9.25×10-6 K-1 (1200 ℃)。由于高熵效应带来的声子散射增加, RETaO4高熵陶瓷具有较低的晶格热导率(2.98~1.23 W·m-1·K-1, 100~1000 ℃), 并且表现出良好的力学性能(6RETaO4, (9.97±2.2) GPa), 是潜在的下一代热障涂层材料。

关键词: 热障涂层, 稀土钽酸盐, 高熵陶瓷, 热学性能

Abstract:

Single-phase solid solution monoclinic structure high-entropy tantalates (Nd1/6Sm1/6Eu1/6Gd1/6Dy1/6Ho1/6) TaO4(6RETaO4), (Nd1/5Sm1/5Eu1/5Gd1/5Dy1/5)TaO4(5RETaO4), (Nd1/4Sm1/4Eu1/4Gd1/4)TaO4(4RETaO4) were prepared by solid state method. STEM-EDS result shows the rare earth elements are uniformly distributed without segregation. The ferroelastic domain observed through SEM derived from the second ferroelastic phase transition. The thermal expansion experiment suggests the good thermal stability below 1200 ℃, where the thermal expansion coefficient of 6RETaO4 reaches 9.25×10-6K-1 at 1200 ℃. Due to the increase of phonon scattering derived from high-entropy effect, RETaO4 ceramics exhibit lower intrinsic thermal conductivity (2.98-1.23 W·m-1·K-1, 100-1000 ℃) and enhanced mechanical properties (6RETaO4, (9.97±2.2) GPa), which indicates that it is a potential material for thermal barrier coatings.

Key words: thermal barrier coating, rare earth tantalate, high-entropy ceramics, thermal property

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