Effect of carbon contents on microstructure of B4C/SiC composites
XIAO JU GAO1,2,
LAI FEI CHENG1,
JIAN WU CAO2,
DONG MING YAN2,3,
CONG ZHANG2,
PENG MAN2,
JUN FENG QU2,
YA WEI ZHOU2,
SU JIE SUN2
Affiliation
- Science and Technology on Thermostructural Composite Mater ials Laboratory, Northwestern Polytechnical University, Xi’an 710072, China
- No. 52 Institute of China North Industry Group, Yantai 264003, China
- Yantai Jinli New Materials Co., Ltd
Abstract
B4C/SiC composites were obtained by reaction sintering between C/B4C green body and liquid Si, and the effect of carbon contents on microstructure was investigated by OM and SEM. Results show that B4C/SiC composites consist of three new phases, namely, SiC, B13C2, and B12(C, Si, B)3. Compared with composites without carbon addition, microstructure becomes more even and smaller with increased carbon contents ranging from 0 vol.% to 10 vol.%, which may be due to the generation of a small amount of SiC and the increase in grain boundary. However, when the carbon contents exceeded 10 vol.%, residual carbon can forms defects, and abnormal grain growth is clearly observed. Meanwhile, increased carbon addition, more SiC is generated results in poor distribution uniformity of each phase..
Keywords
SiC/B4C composite, Reaction sintering, Microstructure, Abnormal grain growth.
Citation
XIAO JU GAO, LAI FEI CHENG, JIAN WU CAO, DONG MING YAN, CONG ZHANG, PENG MAN, JUN FENG QU, YA WEI ZHOU, SU JIE SUN, Effect of carbon contents on microstructure of B4C/SiC composites, Optoelectronics and Advanced Materials - Rapid Communications, 9, 3-4, March-April 2015, pp.482-487 (2015).
Submitted at: Dec. 31, 2014
Accepted at: March 19, 2015