Boron‐dependent microstructural evolution, thermal stability, and crystallization of mechanical alloying derived SiBCN. Issue 7 (24th January 2018)

• Record Type: Journal Article
• Authors: Li, Daxin; Yang, Zhihua; Jia, Dechang; Cai, Delong; Wang, Shengjin; Chen, Qingqing; Zhou, Yu; Yu, Dongli; Tian, Yongjun
• Is Part Of: Journal of the American Ceramic Society. Volume 101:Issue 7(2018)
• Page Start: 3205
• Page End: 3221
• Publication Date: 2018-01-24
• Subjects: amorphous -- crystals/crystallization -- mechano‐chemical synthesis -- microstructure -- SiBCN; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.15428
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: Amorphous boron‐rich SiBCN were prepared by high‐energy ball‐milling of the mixtures of Si, graphite, h‐BN, and inorganic boron, which acted as extra boron source. The solid‐state amorphization, thermal stability, and crystallization of the boron‐rich SiBCN were studied in detail. It was suggested that mechanical alloying can drive solid‐state amorphization but also can be an initiation step for the nucleation of nanocrystals. The amorphous networks of Si‐C, C‐B, C‐C, C‐N, B‐N, and C‐B‐N bonds are detected by XPS; however, solid‐state NMR further confirms the formation of a new chemical environment around B atoms, BC3 . The increases in boron content improve the thermal stability of SiBCN ceramics but weaken their oxidation resistance. Nano‐SiC crystallizes first while BN(C) forms subsequently. Boron promoting SiC crystallization may result from the reduced hindering effects of B‐N‐C nanodomains that retard SiC crystallization.