150
Views
54
Downloads
0
Crossref
0
WoS
0
Scopus
0
CSCD
Rare-earth phosphates (REPO4) are regarded as one of the promising thermal/environmental barrier coating (T/EBC) materials for SiCf/SiC ceramic matrix composites (SiC-CMCs) owing to their excellent resistance to water vapor and CaO-MgO-Al2O3-SiO2 (CMAS). Nevertheless, relatively high thermal conductivity of REPO4 becomes the bottleneck for their practical application. In this work, novel xenotime‑type high entropy (Dy1/7Ho1/7 Er1/7Tm1/7Yb1/7Lu1/7Y1/7)PO4 (HE (7RE1/7)PO4) has been designed and synthesized for the first time to solve this issue. HE (7RE1/7)PO4 with a homogeneous rare-earth element distribution exhibits high thermal stability up to 1750 °C and good chemical compatibility with SiO2 up to 1400 °C. In addition, the thermal expansion coefficient (TEC) of HE (7RE1/7)PO4 (5.96 × 10-6/°C at room temperature to 900 °C) is close to that of SiC-CMCs. What’s more, the thermal conductivity of HE (7RE1/7)PO4 (from 4.38 W·m-1 K-1 at 100 °C to 2.25 W·m-1 K-1 at 1300 °C) is significantly decreased compared to those of single-component REPO4 with the minimum value ranging from 9.90 to 4.76 W·m-1·K-1. These results suggest that HE (7RE1/7)PO4 has the potential to be applied as T/EBC material for SiC-CMCs in the future.
© The Author(s) 2023.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.