【摘 要】
：
制备了针刺毡、短纤维树脂模压、碳布叠层3种预制体,其碳纤维体积含量均为40%.采用化学气相沉积工艺制备了4种C/C复合材料: 针刺毡+粗糙体热解碳(具有两种定向热解碳组织)、
【机 构】
：
College of Science
论文部分内容阅读
制备了针刺毡、短纤维树脂模压、碳布叠层3种预制体,其碳纤维体积含量均为40%.采用化学气相沉积工艺制备了4种C/C复合材料: 针刺毡+粗糙体热解碳(具有两种定向热解碳组织)、短纤维+树脂和热解碳、碳布+光滑体热解碳复合材料,对其进行2500℃保温2h的高温热处理.在0～900℃,研究了预制体结构和热解碳组织对二维C/C复合材料的热膨胀系数、比热容、热扩散率、导热系数等热物理性能影响.研究发现:预制体和热解碳结构对C/C复合材料热物理性能有强烈影响.0～900℃,4种材料的热膨胀系数都非常小,与温度近似的成线性关系,且几乎具有相同的斜率,在一定条件下,其值呈现负热膨胀性质;0～900℃,4种材料都有高的导热系数,但作为温度的函数,其值随预制体结构、热解碳组织和传热方向而变化, x-y向的导热系数(25.6～174W/(m·℃))比z向的(3.5～50W/(m·℃))高几倍.
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