Affiliation:
1. Faculty of Materials Science and Engineering Kunming University of Science and Technology Kunming Yunnan China
2. Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and Technology Kunming Yunnan China
3. Faculty of Information Engineering and Automation Kunming University of Science and Technology Kunming Yunnan China
Abstract
AbstractSix rare‐earth tantalate high‐entropy ceramics of (5RE.2)Ta3O9 (RE represents any five elements selected from La, Ce, Nd, Sm, Eu, Gd) were designed and prepared by spark plasma sintering process at 1400°C in this study. The (5RE.2)Ta3O9 ceramics only consist of a single‐phase solid solution with perovskite structure. Their relative densities are all above 90%, and the average grain size is in the range of 1.47–2.92 μm. The thermal conductivity of (5RE.2)Ta3O9 ceramics is in 2.24–1.90 W m−1 K−1 (25°C–500°C), which is much lower than that of yttria‐stabilized zirconia. In six samples, (La.2Nd.2Sm.2Gd.2Eu.2)Ta3O9 possesses a thermal conductivity of 1.90 W m−1 K−1, a thermal expansion coefficient of 3.47 × 10−6 K−1 (500°C), a Vickers hardness of about 7.33 GPa, and a fracture toughness of about 5.20 MPa m1/2, which are suitable for its application as thermal barrier coatings.
Funder
National Natural Science Foundation of China
Subject
Materials Chemistry,Marketing,Condensed Matter Physics,Ceramics and Composites