CAJ | 학술논문

以天然气为前驱气体，整体碳毡和2D针刺碳毡为预制体，采用热梯度化学气相渗积技术制备了两种C/C复合材料，其表观密度均为1.74 g/cm3。借助光学显微镜和扫描电子显微镜观察了热解碳基体的生长特征和微观形貌，采用热膨胀仪测量了两种材料的热膨胀系数（ CTE），研究了由不同预制体增强C/C复合材料的CTE，解释了造成材料不同方向 CTE 差异的主要原因。结果表明，随着温度升高，材料A和 B的CTE是逐渐升高的，且Z向CTE值均大于XY向。当两种材料在Z向的纤维体积分数接近时，随着 XY方向纤维体积分数增大，材料在Z向的CTE增大，在 XY向的CTE降低，两种材料在XY和 Z向的 CTE呈如下分布：αB-Z ＞αA-Z ＞αA-XY ＞αB-XY。 C/C复合材料的CTE 主要取决于纤维体积分数和排布、碳基体及材料中的孔隙分布情况，前者起决定作用。
이천연기위전구기체，정체탄전화2D침자탄전위예제체，채용열제도화학기상삼적기술제비료량충C/C복합재료，기표관밀도균위1.74 g/cm3。차조광학현미경화소묘전자현미경관찰료열해탄기체적생장특정화미관형모，채용열팽창의측량료량충재료적열팽창계수（ CTE），연구료유불동예제체증강C/C복합재료적CTE，해석료조성재료불동방향 CTE 차이적주요원인。결과표명，수착온도승고，재료A화 B적CTE시축점승고적，차Z향CTE치균대우XY향。당량충재료재Z향적섬유체적분수접근시，수착 XY방향섬유체적분수증대，재료재Z향적CTE증대，재 XY향적CTE강저，량충재료재XY화 Z향적 CTE정여하분포：αB-Z ＞αA-Z ＞αA-XY ＞αB-XY。 C/C복합재료적CTE 주요취결우섬유체적분수화배포、탄기체급재료중적공극분포정황，전자기결정작용。
Using natural gas as precursor gas, intergrated carbon felt and 2D needle carbon felt as preforms, two kinds of C/C composites were prepared by thermal gradient chemical vapor infiltration , and both of them have a same density of 1.74 g/cm3 .With help of optical microscope and scanning electronic microscope , the growth characteristic and micro-structure of pyrolytic carbon matrix were observed , and thermal expansion testing machine was employed to measure their thermal expansion coefficient (CTE).The CTE of C/C composites reinforced by different preforms was studied, and the CTE difference in different direction was explained.The results show that, the CTEs of composite A and B gradually in-creases with increasing temperature, and the CTE in Z direction is higher than that in XY direction.When the fiber volume fraction of two composites in Z direction is near, with the fiber volume fraction in XY direction increasing, their CTEs in-crease in Z direction and decrease in XY direction displaying αB-Z >αA-Z>αA-XY >αB-XY .The CTE of C/C composites mainly depends on the volume fraction and arrangement of carbon fiber in preform , carbon matrix and porous distribution, and the former has decisive function.