1. Highly Dense Amorphous Si2BC3N Monoliths with Excellent Mechanical Properties Prepared by High Pressure Sintering.
- Author
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Liang, Bin, Yang, Zhihua, Rao, Jiancun, Cai, Delong, Duan, Xiaoming, Jia, Dechang, Zhou, Yu, Yu, Dongli, Tian, Yongjun, and Riedel, R.
- Subjects
AMORPHOUS substances ,SILICON compounds ,MECHANICAL properties of metals ,HIGH pressure (Technology) ,SINTERING ,CRYSTALLIZATION - Abstract
The fabrication of dense amorphous Si-B-C-N monoliths is a processing challenge given that it is hard to avoid crystallization at the sintering temperatures needed to attain full density up to 1900°C for conventional hot pressing and SPS methods. We report here successful densification of amorphous Si
2 BC3 N monoliths achieved by heating at 1100°C and 5 GPa. The relationships between microstructure, types of chemical bonding, and mechanical properties were investigated. The strong amorphous 3-D networks of Si-C, C-B, C-N (sp³), N-B (sp³), and C-B-N bonds provide high densities at high applied pressure and thus amorphous Si2 BC3 N monoliths show high hardness of 29.4 GPa and elastic modulus of 291 GPa. The amorphous structure is lost with crystallization of β-SiC and BN(C) reducing contributions from Si-C, C-N (sp³), and C-B-N bond networks thereby decreasing mechanical properties. [ABSTRACT FROM AUTHOR]- Published
- 2015
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