摘要
用扫描电镜观察了复合材料高温氧化后的表面形貌，通过对复合材料断面ＳＥＭ考察获得了复合材料氧化后表面陶瓷层的厚度，据此对复合材料氧化过程中的结构变化与其自愈合抗氧化的相关性进行了分析。结果表明：８００℃氧化时，复合材料表面的陶瓷层主要由Ｂ２Ｏ３／ＳｉＣ粒子组成，复合材料中Ｂ４Ｃ含量高及Ｂ／Ｓｉ比大时，可实现较好的自愈合抗氧化；１０００℃氧化时，ＢＳ２０１０和ＢＳ２０２０复合材料样品表面形成了熔融流动性好的硼硅酸玻璃相，有着良好的自愈合抗氧化性；１２００℃氧化时，随着复合材料中ＳｉＣ含量及陶瓷总含量的增加，复合材料（ＢＳ２０２０和ＢＳ１５３０）表面趋于形成致密的硼硅酸玻璃相，从而有利于高温自愈合抗氧化。
The surface morphology of B4CSiC/C composites after oxidation at high temperatures of 800℃, 1000℃and 1200℃was examined by SEM. The thickness of the ceramic layers was obtained from SEM observation of transverse section of the composites after oxidation. Based on these results, the relationship between oxidation resistance and structure changement of the composites was analyzed. It was suggested, that the ceramic layers of the composites were mainly composed by B2O3 and SiC particles after oxidation at 800℃. The composites with higher B4C content and bigger B/Si ratio was liable to possess better selfhealing properties to resist oxidation. After oxidation at 1000℃, the composites of BS2010 and BS2020 covered with borosilicate layers with excellent fluidity showed high oxidation resistance. When oxidized at 1200℃, the composites with higher content of SiC and total ceramic additives tended to form fused borosilicate glasslike layers on the surface, which were beneficial to oxidation resistance at high temperatures up to 1200℃.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
1998年第2期5-10,共6页
New Carbon Materials
关键词
结构
抗氧化
复合材料
碳
碳化硅
碳化硼
structure changement
selfhealing properties
oxidation resistance
relationship
