"Creep deformation behavior during densification of ZrB2-SiBCN ceramics" by Bo FENG, Zhenhang WANG et al.

Article Title

Creep deformation behavior during densification of ZrB2-SiBCN ceramics with ZrO2 additive

Authors

Bo FENG, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
Zhenhang WANG, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
Yunhao FAN, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
Jinghua GU, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
Yue ZHANG, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China

Keywords

zirconium boride, polymer-derived SiBCN, creep deformation, densification mechanism, viscosity

Abstract

ZrB2-SiBCN ceramics with ZrO2 additive are hot-pressed under a constant applied pressure. The densification behavior of the composites is studied in a view of creep deformation by means of the Bernard-Granger and Guizard model. With determination of the stress exponent (n) and the apparent activation energy (Qd), the specific deformation mechanisms controlling densification are supposed. Within lower temperature ranges of 1300-1400 ℃, the operative mechanism is considered to be grain boundary sliding accommodated by atom diffusion of the polymer-derived SiBCN (n = 1, Qd = 123±5 kJ/mol) and by viscous flow of the amorphous SiBCN (n = 2, Qd = 249±5 kJ/mol). At higher temperatures, the controlling mechanism transforms to lattice or intra-granular diffusion creep (n = 3-5) due to gradual consumption of the amorphous phase. It is suggested that diffusion of oxygen ions inside ZrO2 into the amorphous SiBCN decreases the viscosity, modifies the fluidity, and contributes to the grain boundary mobility.

DOI

https://doi.org/10.1007/s40145-020-0393-6

Publisher

Tsinghua University Press

Recommended Citation

Bo FENG, Zhenhang WANG, Yunhao FAN et al. Creep deformation behavior during densification of ZrB2-SiBCN ceramics with ZrO2 additive. Journal of Advanced Ceramics 2020, 9(5): 544-557.

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