Effects of in situ amorphous graphite coating on ablation resistance of SiC fiber reinforced SiBCN ceramics in an oxyacetylene flame. (December 2016)

• Record Type: Journal Article
• Authors: Li, Daxin; Wu, Daoxiong; Yang, Zhihua; Zhou, Yuanyi; Wang, Shengjin; Duan, Xiaoming; Jia, Dechang; Zhu, Qishuai; Zhou, Yu
• Is Part Of: Corrosion science. Volume 113(2016)
• Page Start: 31
• Page End: 45
• Publication Date: 2016-12
• Subjects: A. Ceramic matrix composites -- B. SEM -- B. XRD -- B. STEM -- C. High temperature corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2016.10.002
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: In situ amorphous graphite coating on SiC fibers are prepared. Effects of crystallization of SiC fiber leading to strength reduction on ablation resistance are explained. Effects of in situ amorphous graphite coating on ablation behavior are explored. Abstract: The effects of in situ amorphous graphite coating on ablation behavior of SiC fiber reinforced SiBCN ceramics in an oxyacetylene flame are explored. The ablation products for both the monoliths and composites are similar, comprising amorphous SiO2 and cristobalite. The ablation resistance stems from formation of dense, passivating oxide scale of B2 O3 containing amorphous SiO2 . In different ablation stages, the ablation rates are synergistically controlled by various mechanisms. Interfacial structure and degradation of SiC fibers both deteriorate ablation resistance. The crystallization of SiC fibers leading to strength reduction is the main reason for poorer performance vs monoliths.