两步法制备具有自愈合能力的纯SiC涂层

为了提高碳/碳(C/C)复合材料的抗氧化性能,通过两步法在基体表面制备了具有自愈合能力的纯SiC涂层.首先,通过高含氢硅油(H-PSO)的高温热解在基体表面引入SiC纳米线,然后通过高温渗Si,在碳材料表面生成厚度约为100-200μm的涂层.通过X射线衍射(XRD)、扫描电子显微镜(SEM)表征了所制备的涂层形貌及相组成,并对所制备的试样进行了氧化实验.实验结果表明:涂层是由纯SiC构成的,且具有一定的自愈合能力;所制备的试样在1400℃下氧化4h,失重仅为0.71%,抗氧化性能得到提高.

Fabrication of a Self-Healing Pure SiC Coating by a Two-Step Technique

A self-healing pure SiC coating was prepared on a carbon/carbon (C/C) composite by a two-step technique to protect the C/C composite from oxidation.First,SiC nanowires were obtained on the substrate surface by the thermal decomposition of hydrogen silicone oil (H-PSO).Second,a coating with a thickness of 100-200 μm was produced by infiltrating with silicon at high temperature in an argon atmosphere.The morphology and phase composition of the coating were observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Oxidation tests were carried out on specimens and the results indicated that the obtained coating consisted of pure SiC and had a certain self-healing ability.The SiC self-healing coating significantly increased the antioxidant properties of the C/C composites and it protected the C/C composites from oxidation at 1400 ℃ in air over 4 h with a corresponding mass loss of only 0.71%.