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。
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.
参考文献
| [1] | 李贺军.炭/炭复合材料[J].新型炭材料,2001(02):79-80. |
| [2] | Golecki I .Rapid Vapor Phase Densification of Refractory Com-posites[J].Materials Science and Engeering R,1997,20(02):37-124. |
| [3] | Ke-Zhi Li;Xue-Tao Shen;He-Jun Li .Ablation of the carbon/carbon composite nozzle-throats in a small solid rocket motor[J].Carbon: An International Journal Sponsored by the American Carbon Society,2011(4):1208-1215. |
| [4] | 陈汝训.Study & Design of Solid Rocket Motor:below(固体火箭发动机设计与研究(下[M].Beijing:Aer-ospace Press,1993 |
| [5] | 李崇俊,郑金煌,苏红,邓红兵.二维C/C复合材料高温力学、热物理性能研究[J].宇航材料工艺,2004(01):33-37. |
| [6] | 廖晓玲,李贺军,孙国栋,李克智.3D C/C复合材料的热膨胀性能[J].新型炭材料,2010(01):60-64. |
| [7] | Luo RY;Liu T;Li JS;Zhang HB;Chen ZJ;Tian GL .Thermophysical properties of carbon/carbon composites and physical mechanism of thermal expansion and thermal conductivity[J].Carbon: An International Journal Sponsored by the American Carbon Society,2004(14):2887-2895. |
| [8] | 赵建国,李克智,李贺军,孙国栋,王闯.炭/炭复合材料热膨胀性能的研究[J].材料热处理学报,2006(06):1-4. |
| [9] | 姚学锋,杨桂,姚振汉.编织结构复合材料热膨胀特性的实验研究[J].复合材料学报,2000(04):20. |
| [10] | 梁军,杜善义,陈晓峰.含圆币型微裂纹三维编织复合材料的热膨胀系数预报[J].复合材料学报,1998(03):103-107. |
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