Highly Dense Amorphous Si2BC3N Monoliths with Excellent Mechanical Properties Prepared by High Pressure Sintering
Highly Dense Amorphous Si2BC3N Monoliths with Excellent Mechanical Properties Prepared by High Pressure Sintering
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DOI：
10.1111/jace.13802
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发表时间：
2015-08
影响因子：
3.9
通讯作者：
B. Liang;Zhihua Yang;J. Rao;Delong Cai;X. Duan;D. Jia;Yu Zhou;D. Yu;Yongjun Tian
中科院分区：
文献类型：
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作者：
B. Liang;Zhihua Yang;J. Rao;Delong Cai;X. Duan;D. Jia;Yu Zhou;D. Yu;Yongjun Tian
致密的非晶Si-B-C-N单体的制造是一个加工挑战，因为传统的热压和SPS方法在达到高达1900°C的全密度所需的烧结温度下很难避免结晶。我们在此报告了在1100℃和5 GPa的加热下成功致密化非晶Si2BC3N单体。研究了微观结构、化学键类型与力学性能之间的关系。Si-C、C-B、C-N （sp3）、N-B （sp3）和C-B - n键的强非晶三维网络在高压下提供了高密度，因此非晶Si2BC3N单体具有29.4 GPa的高硬度和291 GPa的弹性模量。随着β-SiC和BN(C)的结晶，非晶结构丢失，Si-C、C- n （sp3）和C- b - n键网络的贡献减少，从而降低了力学性能。
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 Si2BC3N 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 Si2BC3N 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.