Mechanical and thermal properties of δ‐RE4Hf3O12 (RE = Yb, Lu). Issue 2 (13th September 2022)

• Record Type: Journal Article
• Authors: Hu, Wanpeng; Zhang, Guangheng; Lei, Yiming; Sun, Luchao; Zhang, Jie; Wang, Jingyang
• Other Names: Fukushima Manabu guestEditor.; Wang Jingyang guestEditor.; Balaya Palani guestEditor.; Kim Young‐Wook guestEditor.; Singh Mrityunjay guestEditor.
• Is Part Of: International journal of applied ceramic technology. Volume 20:Issue 2(2023)
• Page Start: 833
• Page End: 841
• Publication Date: 2022-09-13
• Subjects: mechanical property -- rare‐earth hafnate -- thermal and environmental barrier coating -- thermal property; Ceramics -- Periodicals; Ceramics -- Technological innovations -- Periodicals; 620.1405
• DOI: 10.1111/ijac.14194
• Languages: English
• ISSNs: 1546-542X

Abstract

Abstract: Rare‐earth (RE) hafnates are promising thermal and environmental barrier coating (TEBC) materials for SiCf /SiC ceramic matrix composites. In this study, pure‐phase and dense δ‐RE4 Hf3 O12 (RE = Yb, Lu) bulk ceramics have been fabricated via a hot‐pressing method. The crystal structure, microstructure, mechanical, and thermal properties of δ‐RE4 Hf3 O12 were systematically investigated in order to probe their potential application as TEBCs. The high‐temperature elastic moduli of δ‐Yb4 Hf3 O12 and δ‐Lu4 Hf3 O12 are measured to be 185 and 188 GPa at 1673 K, respectively, which are over 85% values of room temperature. The coefficients of thermal expansion are 7.64 × 10 −6 and 7.46 × 10 −6 K −1 for δ‐Yb4 Hf3 O12 and δ‐Lu4 Hf3 O12, respectively. The relatively low coefficient of thermal expansion and thermal conductivity as well as their excellent high‐temperature stability endow these hafnates as potential TEBC candidates.