Tuning of the high temperature behaviour of Si–C–N ceramics via the chemical crosslinking of poly(vinylmethyl-co-methyl)silazanes with controlled borane contents
Tuning of the high temperature behaviour of Si–C–N ceramics via the chemical crosslinking of poly(vinylmethyl-co-methyl)silazanes with controlled borane contents
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DOI：
10.1016/j.oceram.2021.100055
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发表时间：
2021-03
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影响因子：
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通讯作者：
Mélanie Wynn;David Lopez-Ferber;Antoine Viard;Diane Fonblanc;Marion Schmidt;F. Rossignol;P. Carlès;G. Chollon;C. Gervais;S. Bernard
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作者：
Mélanie Wynn;David Lopez-Ferber;Antoine Viard;Diane Fonblanc;Marion Schmidt;F. Rossignol;P. Carlès;G. Chollon;C. Gervais;S. Bernard
研究了一系列不同硼含量的聚乙烯基甲基-共聚甲基硅氮烷在1000-1800 °C氮气气氛下热处理后的Si-B-C-N陶瓷的热稳定性、元素/相组成演变和晶化行为。在1000 ° C和1400 °C下制备的陶瓷中，硼含量的增加导致β-SiC形核，抑制α-Si 3 N4晶化，并改变了sp2杂化碳相的活性。在1800 °C下，低硼含量的Si-B-C-N陶瓷逐渐向主要通过非晶Si 3 N4的碳热反应形成的主要SiC相演变，而高硼含量的Si-B-C-N陶瓷导致具有由SiC制成的复杂微观结构的高度稳定的材料，Si_3N_4和富含BN的B（C）N相抑制了sp2-杂化碳对非晶Si 3 N4的碳热反应，并显着减少SiC的结晶过程。
The thermal stability, elemental/phase composition evolution and crystallization behaviour of Si–B–C–N ceramics obtained by the pyrolysis of a series of poly (vinylmethyl-co-methyl)silazanes displaying various boron contents were investigated through annealing in the temperature range 1000–1800 °C under nitrogen atmosphere. The increase of the boron content in the early stage of the process involved the nucleation of β-SiC, inhibited the crystallization of α-Si3N4and modified the activity of the sp2-hybridised carbon phase in the derived ceramics obtained at 1000 and 1400 °C. At 1800 °C, low boron content Si–B–C–N ceramics gradually evolved toward a major SiC phase mainly formed via the carbothermal reaction of amorphous Si3N4whereas high boron content Si–B–C–N ceramics led to highly stable materials with a complex microstructure made of SiC, Si3N4and a BN-rich B(C)N phase that inhibited the activity of sp2-hybridised carbon toward the carbothermal reaction of amorphous Si3N4and significantly reduced the SiC crystallization process.