Anti-oxidation behavior of chemical vapor reaction SiC coatings ondifferent carbon materials at high temperatures
来源期刊:中国有色金属学报(英文版)2009年第5期
论文作者:杨鑫 黄启忠 邹艳红 常新 苏哲安 张明瑜 谢志勇
文章页码:1044 - 1050
Key words:carbon/carbon composites; graphite; coating; SiC
Abstract: To protect carbon materials from oxidation, SiC coatings were prepared on carbon/carbon(C/C) composites and graphite by chemical vapor reaction. SEM and XRD analyses show that the coatings obtained are composed of SiC grains and micro-crystals. The influence of different carbon substrates on oxidation behavior of coated samples was investigated, and then their oxidation mechanisms were studied. Oxidation test shows that the SiC coated graphite has a better oxidation resistance than SiC coated C/C composites at high temperatures (1 623 K and 1 823 K). In the oxidation process, the oxidation curves of SiC coated C/C composites are linear, while those of SiC coated graphite follow a quasi-parabolic manner. The oxidation mechanism of the former is controlled by chemical reaction while the latter is controlled by oxygen diffusion based on the experimental results. The variation of oxidation behavior and mechanism of SiC coatings on two kinds of carbon substrates are primarily contributed to their structure differences.
基金信息:the National Basic Research Program of China
the National Natural Science Foundation of China