Thermophysical and mechanical properties of YTaO4 ceramic by niobium substitution tantalum

• Published in: Materials letters 2020-06, Vol.268, p.127586, Article 127586
• Main Authors: Zheng, Qi, Wu, Fushuo, Chen, Lin, Qian, Feng, Yang, Kailong, Ge, Zhenhua, Song, Peng, Feng, Jing
• Format: Article
• Language: English
• Subjects: Ceramics; Materials science; Mechanical properties; Mechanical property; Modulus of elasticity; Niobium; Rare earth tantalates and niobates; Substitution reactions; Tantalum; TBCs; Thermal barrier coatings; Thermal conductivity; Thermal expansion; Thermal properties; Thermophysical properties
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.127586

•Nb substitution Ta can optimize the thermal/mechanical properties of YTaO4.•Point defects cause a decrease in the thermal conductivity of Y(Ta1-xNbx)O4.•The increase of Nb content reduced the Young's modulus of Y(Ta1-xNbx)O4. In this paper, the Y(Ta1-XNbX)O4 ceramics synthesized via a solid-state reaction were researched as promising thermal barrier coatings (TBCs). The Y(Ta1-XNbX)O4 exhibits far less thermal conductivity (~1.5 W·m−1·K−1, 900 °C) than 8YSZ (~2.5 W·m−1·K−1, 900 °C). The thermal expansion coefficients (TECs, ~11.0 × 10−6 K−1, 1200 °C) of Y(Ta1-XNbX)O4 ceramics are higher than the TECs of 8YSZ (~10.0 × 10−6 K−1, 1200 °C), La2Zr2O7 (~9.0 × 10−6 K−1, 1200 °C) and other TBCs. Besides, Y(Ta1-XNbX)O4 exhibits outstanding mechanical properties, including low Young's modulus (115–135 GPa) and high hardness (8–10 GPa). The excellent thermophysical and mechanical properties indicate that Y(Ta1-XNbX)O4 ceramics are promising as potential TBC materials for in-depth research.