Oxidation microstructure studies of reinforced carbon/carbon
Oxidation microstructure studies of reinforced carbon/carbon
复制标题
DOI：
10.1016/j.carbon.2005.11.013
复制
发表时间：
2006-06-01
期刊：
影响因子：
10.9
通讯作者：
Curry, DM
中科院分区：
文献类型：
--
作者：
Jacobson, NS;Curry, DM
实验室氧化研究的增强碳/碳（RCC）进行了讨论，特别强调所得的微观结构。这项研究涉及实验室炉（500-1500摄氏度）和电弧接点暴露（1538摄氏度）的各种形式的RCC。由于沿着纤维边缘的优先侵蚀，在800和1100 ℃下氧化的无氧化保护的RCC呈现尖的和直径减小的纤维。800 ℃的样品显示出均匀的侵蚀，表明氧化过程的反应控制;而1100 ℃的样品显示出边缘的侵蚀，表明氧化过程的扩散控制。具有SiC转化涂层的RCC在500、700和1500摄氏度下对碳基材的侵蚀有限。然而，在900、1100和1300摄氏度下氧化的样品在SiC涂层中的贯穿厚度裂纹下方的SiC/碳界面处显示出小的氧化空腔。外缘的这些空腔表明存在扩散控制。空腔具有粗糙的边缘，纤维裸露，可以很容易地与加工过程中产生的空腔区分开来。在1538摄氏度下的电弧喷射测试显示，当SiC涂层和玻璃密封剂完好无损时，氧化侵蚀有限。当SiC/密封剂保护系统被损坏时，侵蚀是广泛的并且通过裂纹进行，在裂纹中和沿着裂纹产生裸露的纤维。即使在扩散控制占主导地位的1538摄氏度下，侵蚀也是不均匀的，纤维边缘优先氧化。(c)2005爱思唯尔有限公司保留所有权利。
Laboratory oxidation studies of reinforced carbon/carbon (RCC) are discussed with particular emphasis on the resulting microstructures. This study involves laboratory furnace (500-1500 degrees C) and arc-jct exposures (1538 degrees C) on various forms of RCC. RCC without oxidation protection oxidized at 800 and 1100 degrees C exhibits pointed and reduced diameter fibers, due to preferential attack along the fiber edges. The 800 degrees C sample showed uniform attack, suggesting reaction control of the oxidation process; whereas the 1100 degrees C sample showed attack at the edges, suggesting diffusion control of the oxidation process. RCC with a SiC conversion coating exhibits limited attack of the carbon substrate at 500, 700 and 1500 degrees C. However samples oxidized at 900, 1100, and 1300 degrees C show small oxidation cavities at the SiC/carbon interface below through-thickness cracks in the SiC coating. These cavities at the outer edges suggest diffusion control. The cavities have rough edges with denuded fibers and can be easily distinguished from cavities created in processing. Arc-jet tests at 1538 degrees C show limited oxidation attack when the SiC coating and glass sealants are intact. When the SiC/sealant protection system is damaged, attack is extensive and proceeds through cracks, creating denuded fibers in and along the cracks. Even at 1538 degrees C, where diffusion control dominates, attack is non-uniform with fiber edges oxidizing preferentially. (c) 2005 Elsevier Ltd. All rights reserved.