莫来石抗氧化外涂层的制备及抗氧化性能  

Preparation and Anti-oxidation Property of Mullite Protective Outer Coating

作　　者：杨强[1] 黄剑锋[1] 杨婷[2] 曹丽云[1] 吴建鹏[1] 

机构地区：[1]教育部轻化工助剂化学与技术重点实验室陕西科技大学材料科学与工程学院,西安710021 [2]西安交通大学材料科学与工程学院,西安710049

出　　处：《无机化学学报》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

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%.

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 

分 类 号：O613.71[理学—无机化学] O613.72[理学—化学]