摘要
以莫来石粉体(3Al2O3·2SiO2)为原料,采用水热电泳沉积法在C/C-SiC复合材料表面制备了莫来石外涂层。借助XRD和SEM等对涂层的晶相组成和显微结构进行了表征。研究了水热沉积电压对莫来石外涂层相组成、形貌及高温抗氧化性能的影响。结果表明:外涂层主要由莫来石晶相组成。当沉积电压控制在120~180 V范围内时,莫来石外涂层的致密程度、厚度及抗氧化性能随着沉积电压的升高而提高。当沉积电压达到210 V时,制备的外涂层出现疏松、裂纹等缺陷,抗氧化性能减弱。抗氧化测试表明与包埋法制备的SiC-C/C涂层试样相比,莫来石-SiC-C/C涂层试样的抗氧化性能明显提高。当沉积电压为180 V时,制备的复合涂层试样可在1500℃的空气气氛下有效保护C/C复合材料164 h,其失重仅为1.75%。
Mullite coating was deposited on C/C-SiC composites by a hydrothermal electrophoretic deposition process using mullite powder as source material.The phase composition and microstructure of the as-prepared coating was characterized by X-ray Diffraction(XRD) and Scanning Electron Microscopy(SEM).The influence of hydrothermal deposition voltage on phase composition,microstructure and high temperature oxidation resistance of the as-prepared coating was investigated.Results show that the outer layer is mainly composed of mullite phase.The thickness,density and anti-oxidation property of mullite coating are improved when the deposition voltage is increased from 120 V to 180 V.However,loose coating with some cracks will be formed at a higher voltage of 210 V and the corresponding oxidation resistance ability is weakened.The anti-oxidation property of the mullite-SiC-C/C sample is obviously improved in comparation with SiC-C/C substrate.The mullite coating prepared at 180 V exhibits excellent auti-oxidation property,which can effectively protect C/C composites from oxidation in air at 1 500 ℃ for 164 h with a weight loss of 1.75%.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2011年第5期907-912,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.51072108)
教育部博士点基金(No.20070708001)
新世纪优秀人才支持计划基金(NECT-06-0893)
陕西省教育厅科研计划项目(No.2010JK444)
陕西科技大学科研创新团队基金(TD09-05)
陕西科技大学研究生创新基金资助项目
关键词
C/C复合材料
莫来石外涂层
水热电泳沉积法
沉积电压
carbon/carbon composites
mullite coating
hydrothermal electrophoretic deposition process
deposition voltage