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.由于碳扩散的振动能最低并且跃迁距离最短,而供硅扩散的空位不足,碳和硅在反应产物TiCx中具有最小的内禀扩散系数,分别为8.9403×10-16和4.7747×10-16 m2·s-1.研究表明,在SiC/Ti6AL4V复合材料界面反应的过程中,反应元素通过反应层TiCx的扩散是一个主要的控制步骤. 关键词:Ti基复合材料; SiC纤维; 界面反应; 扩散系数; 微观机理; Ti-matrix composites; SiC fiber; interfacial reaction; diffusion coefficients; micro-mechanism; [全文内容正在添加中] ......
SiC whisker reinforced MoSi2 composite prepared by spark plasma sintering from COSHS-ed powder XU Jian-guang(许剑光)1, 2, ZHANG Hou-an(张厚安)1, JIANG Guo-jian(江国健)2 ZHANG Bao-lin(张宝林)2, LI Wen-lan(李文..., China Received 10 April 2006; accepted 25 April 2006 Abstract: SiC whisker reinforced MoSi2 composite powder was synthesized by a novel process, referred to the literature as chemical oven self......
of the best candidates of the reinforcements available for continuous-fiber-reinforced ceramic-matrix composites(CMCs)[1]. SiC fibers derived from polymer pyrolysis have the spectral advantages..., Marons R, Stamatoff J B, ROBE J. Thermal degradation of Nicalon SiC fiber [J]. Ceramic Engineering & Science Process, 1985, 6(7－8): 576-578. [6] Yu Y X, Li X D, Cao F. Advances in the polymer-derived......
石墨抗氧化SiC涂层的制备与性能姜岩,叶超超,茹红强,岳新艳,王伟东北大学材料各向异性与织构教育部重点实验室摘 要:以SiC,Si和酚醛树脂为主要原料,通过浸涂和气相渗硅两步法在石墨表面制备了SiC抗氧化涂层.利用XRD,SEM研究了涂层的相组成与形貌.结果表明,气相渗硅后涂层的主相为α-SiC,β-SiC和Si,其中Si是气相渗硅过程中残留的.涂层与基体之间具有过渡结构,致密度良好.抗氧化和抗热震实验表明:由气相渗硅工艺制备的SiC涂层结构致密,具有良好的抗氧化性能,1200℃空气条件下氧化16 h后试样每小时增重量约为2.18 mg/cm2.涂层具有良好的抗热震性能,经100025℃循环热震15次后试样质量变化率仅为–0.17%.关键词:SiC涂层;石墨;显微组织;抗氧化;......
C/C-SiC复合材料的制备与性能 余惠琴1,闫联生1,邹武1,陈长乐1 (1.陕西非金属材料工艺研究所) 摘要:采用化学气相渗连(CVI)法和液相浸渍有机物先驱体混合工艺制备了C/C-SiC复合材料,并对复合材料力学性能,抗烧蚀性能和抗氧化性能进行表征.结果表明:制备的C/C-SiC复合材料在基本保持C/C复合材料力学性能的基础上,抗氧化和抗烧蚀性能得以大幅度提高,提出了制备兼具C/C复合材料与陶瓷材料优良性能的碳陶结构复合材料的技术途径. 关键词:C/C一SiC复合材料; 制备工艺; 抗氧化; [全文内容正在添加中] ......
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Improved properties of carbon fiber paper as electrode for fuel cell by coating pyrocarbon via CVD method XIE Zhi-yong(谢志勇), JIN Gu-yin(金谷英), ZHANG Min(张 敏) , SU Zhe-an(苏哲安), ZHANG Ming-yu(张明瑜... by using PAN-based carbon fiber felt as the precursor followed by impregnation with resin, molding and heat-treatment. SEM characterization indicates that pyrocarbon is uniformly deposited on the surface......
SiC微粉含量对2D-SiC_f/SiC复合材料力学性能影响 程海峰1,郑文伟1,刘海韬1,周旺1,唐耿平1,王军1 (1.国防科技大学,新型陶瓷纤维及其复合材料国防科技重点实验室,湖南,长沙,410073) 摘要:对PIP法制备2D-SiC_f/SiC复合材料成形浆料中惰性填料SiC含量对2D-SiC_f/SiC复合材料孔隙率,纤维体积分数以及力学性能影响进行研究.研究表明,SiC微粉含量较低时,浆料粘度过低,导致层间存在较大气孔,纤维体积分数不高,致使复合材料力学性能不佳,当SiC微粉含量过高时,浆料粘度过大,层间基体厚度增加,纤维体积分数下降,并且浸渍效率降低,孔隙率增大,复合材料力学性能下降.当SiC微粉含量为33.3%时,复合材料具有较低的孔隙率和较高的纤维体积分数,复合材料具有较好的力学性能,弯曲强度和断裂韧性分别达到211.7 MPa和8.56 MPa·m~(1/2......
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