热梯度化学气相沉积工艺中避免了等温沉积工艺中预制体表面孔隙过早堵塞的现象,适合制备轴对称的环形、管型件.利用热梯度化学气相沉积工艺制备了炭/炭复合材料管型制件,研究了材料的微观组织结构,测试了其力学性能以及热物理性能,实验结果表明所制备的炭/炭复合材料制件能够满足高温热结构材料的使用要求.%The plugging of the surface pores in the preforms which often occurs in isothermal CVI technology seldom happens in the thermal gradient CVI process, namely, the overcrusting is avoided.The thermal gradient CVI process is well suitable for fabricating symmetrical rings, tubes, so the preparation of carbon/carbon composites tubes by the thermal gradient chemical vapor infiltration (CVI) process was discussed in this paper. The microstructure of composites was analyzed and their mechanical properties, thermal expansion, and thermal conductivity were measured, which indicated that the carbon/carbon tubes were of high performance and were absolutely competent for the thermostructure composite materials.
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