A simple and efficient method for the synthesis of SiBNC ceramics with different Si/B atomic ratios. Issue 10 (July 2017)

• Record Type: Journal Article
• Authors: Ji, Xiaoyu; Shao, Changwei; Wang, Hao; Wang, Jun; Cheng, Jun; Long, Xin; Mao, Tengfei
• Is Part Of: Ceramics international. Volume 43:Issue 10(2017)
• Page Start: 7469
• Page End: 7476
• Publication Date: 2017-07
• Subjects: SiBNC ceramics -- Polymer -- Si/B ratio -- Crystallization -- High temperature; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.03.022
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The high-temperature durability of SiBNC ceramics is significantly influenced by Si/B ratios and the synthetic procedures. Single-source synthetic routes can yield homogeneous ceramics at the atomic level, but the Si/B ratio cannot be efficiently adjusted. In this paper, a simple and efficient method for the synthesis of SiBNC precursor polyborosilazanes (PBSZs) with different Si/B ratios has been established via a one-pot reaction involving boron trichloride, dichloromethylsilane and hexamethyldisilazane in different molar ratios. The Si/B ratios of the derived SiBNC ceramics were consistent with that of the precursor PBSZs. When pyrolysed at 1000 °C, PBSZs with 0.52, 0.94 and 2.12 Si/B ratios transformed into SiB2.6 N5 C2.2, SiB0.9 N2.7 C1.3 and Si2 BN3 C1.4 ceramics respectively. The polymer-to-ceramic process was also studied and featured ceramic yields of 43.2 wt%, 50.1 wt% and 62.2 wt%, respectively. The derived ceramic SiB0.9 N2.7 C1.3 resisted crystallization up until 1700 °C, whereas the SiB2.6 N5 C2.2 and Si2 BN3 C1.4 could remain amorphous up to 1600 °C only. Using the precursor with 0.94 Si/B ratio, the SiBNC ceramic fibres were also obtained.