文献类型：期刊文献

英文题名：First-principles calculations and thermal-mechanical experimental studies on middle-entropy rare-earth disilicates

作者：Li, Kaibin[1];Wang, Weize[1,2];Yang, Shilong[1];Liu, Yangguang[1];Yang, Ting[1]

机构：[1]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]Shanghai Inst Aircraft Mech & Control, Shanghai 200092, Peoples R China

年份：2024

卷号：50

期号：13

起止页码：22290

外文期刊名：CERAMICS INTERNATIONAL

收录：;EI(收录号：20241515888496);WOS:【SCI-EXPANDED(收录号:WOS:001241934900001)】；

基金：This research was funded by the National High Technology Research and Development Program of China (2023YFB3711200) , National Natural Science Foundation of China (52175136, 52130511) , Science Center for Gas Turbine Project (P2021-A-IV-002) , Shanghai Joint Innovation Program in the Field of Commercial Aviation Engines, Shanghai Gaofeng Project for University Academic Program Development, and Key Research and Development Projects in Anhui Province (No. 2022a05020004) .

语种：英文

外文关键词：Ytterbium disilicate; Medium-entropy disilicates; Environmental barrier coatings; First-principles calculations; Thermal-mechanical properties

摘要：Dense environmental barrier coatings (EBCs) are urgently needed to protect SiC-based ceramic matrix composites (SiC CMCs) in future gas turbine engines, and multi -component rare-earth (Re) disilicates are attracting attention due to their excellent thermal -mechanical properties and chemical compatibility. In this paper, firstprinciples calculations were performed on ten different crystal structures and elastic constants of (Re 0.5 Y- b 0.5 ) 2 Si 2 O 7 (Re - - Sc, Y, Ho, Er, Tm, Yb, Lu) and (Sc x Yb 1-x ) 2 Si 2 O 7 (x = 0, 0.25, 0.5, 0.75, 1.00) disilicate materials. Meanwhile, five bulk disilicate ceramics of Yb 2 Si 2 O 7 , (Sc 0.5 Yb 0.5 ) 2 Si 2 O 7 , (Er 0.5 Yb 0.5 ) 2 Si 2 O 7 , (Sc 0.33 Er 0.33- Yb 0.34 ) 2 Si 2 O 7 , and (Sc 0.25 Ho 0.25 Er 0.25 Yb 0.25 ) 2 Si 2 O 7 were prepared and tested for thermal -mechanical properties. The prepared bulk ceramics exhibit superior thermal stability at 1823 K, with no phase transformation or grain coarsening occurring. Compared to Yb 2 Si 2 O 7 , (Sc 0.5 Yb 0.5 ) 2 Si 2 O 7 exhibits a smaller unit cell volume, average Re - O bond length, grain size, and thermal conductivity. It also shows increased ion mass disorder, lattice distortion, ion radius disorder, coefficient of thermal expansion (CTE), microhardness, and Young ' s modulus. However, (Er 0.5 Yb 0.5 ) 2 Si 2 O 7 mainly exhibits opposite behaviors. Most of the thermal -mechanical properties of (Sc 0.33 Er 0.33 Yb 0.34 ) 2 Si 2 O 7 and (Sc 0.25 Ho 0.25 Er 0.25 Yb 0.25 ) 2 Si 2 O 7 are intermediate between those of (Sc 0.5 Yb 0.5 ) 2- Si 2 O 7 and (Er 0.5 Yb 0.5 ) 2 Si 2 O 7 . These findings of this study may accelerate the development of medium -entropy or high -entropy disilicates with controlled polymorphic phases and customized thermal -mechanical properties.