Fabrication and flexural strength of porous Si3N4 ceramics with Li2CO3 and Y2O3 as sintering additives

作     者：HU Hai-long LUO Shi-bin 胡海龙;罗世彬

作者机构：School of Aeronautics and AstronauticsCentral South UniversityChangsha 410083China Research Center in Intelligent Thermal Structures for AerospaceCentral South UniversityChangsha 410083China 

出 版 物：《Journal of Central South University》 (中南大学学报（英文版）)

年 卷 期：2020年第27卷第9期

页      面：2548-2556页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Project(202045007)supported by the Start-up Funds for Outstanding Talents in Central South University China 

主　　题：sintering additive flexural strength porosity glassy phase Si3N4 porous ceramics 

摘      要：By employing sintering additives of Li2CO3 and Y2O3,porous Si3N4 ceramics are prepared after experiencing the processes of sintering and post-vacuum heat treatment at 1680 and 1550°C,*** experimental results demonstrate the completed phase transformation fromαtoβ-Si3N4 in Si3N4 ceramic samples with a amount of 1.60 wt%Li2CO3(0.65 wt%Li2O)and 0.33 wt%Y2O3 *** as-synthesized porous Si3N4 ceramics exhibit high flexural strength((126.7±2.7)MPa)and high open porosity of 50.4%at elevated temperature(1200°C).These results are attributed to the significant role of added Li2CO3 as sintering additive,where the volatilization of intergranular glassy phase occurs during sintering ***,porous Si3N4 ceramics with desired mechanical property prepared by altering the addition of sintering additives demonstrate their great potential as a promising candidate for high temperature applications.