Thermodynamic descriptions of the light rare‐earth elements in silicon carbide ceramics. Issue 6 (3rd February 2020)

• Record Type: Journal Article
• Authors: Xu, Kai; Chang, Keke; Zhou, Xiaobing; Chen, Leilei; Liu, Junwen; Deng, Zixuan; Huang, Feng; Huang, Qing
• Is Part Of: Journal of the American Ceramic Society. Volume 103:Issue 6(2020)
• Page Start: 3812
• Page End: 3825
• Publication Date: 2020-02-03
• Subjects: CALPHAD -- first‐principles calculations -- light rare‐earth elements -- silicon carbide ceramics -- sintering aids; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.17031
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: The Y3 Si2 C2 coating on the silicon carbide (SiC) powders is reported to improve the sintering process, but the relatively high sintering temperature (1600°C) restricts the engineering application. A series of thermodynamic descriptions for the SiC with light rare‐earth elements are desired to develop potential SiC‐RE3 Si2 C2 core‐shell structures as sintering aids with lower temperatures. Coupling the CALPHAD (CALculation of PHAse Diagram) approach and first‐principles calculations, we have investigated the RE‐Si‐C (RE = La, Ce and Pr) systems. In the SiC‐RE3 Si2 C2 core‐shell structures, the RE3 Si2 C2 phases can react with SiC via ternary eutectic reactions at 810°C, 747°C, and 1148°C respectively. The predicted thermal behaviors of the Pr3 Si2 C2 phase were further confirmed by our key experiments. Therefore, our database can be used to predict promising sintering aids and guide the subsequent processes.