【摘要】 采用薄膜沸腾气相沉积(film-boiling chemical vapor infiltration,FBCVI)工艺,制备原位碳纳米纤维增强碳/碳复合材料(carbon nanofibers-reinforced carbon/carbon composites,CNFs-C/C))。研究了致密化过程中CNFs的生长情况和催化剂的引入对材料组织结构和力学性能的影响。研究表明,致密化前期,原位生长CNFs困难;随着沉积时间延长,CNFs大量增多并被碳基体包覆,CNFs主要为碳纳米线(carbon nanowires,CNWs)。CNFs-C/C的碳基体结构为粗糙层(RL),且存在大量的生长锥。相比于未加催化剂的试样,CNFs-C/C的弯曲强度和模量分别提高了30.9%和39.1%,断裂模式为假塑性断裂。更多还原

【Abstract】 In-situ grown carbon nanofibers reinforced carbon /carbon( CNFs-C /C) composites were prepared by catalyze film-boiling chemical vapor infiltration( FBCVI). After investigating the growing process of CNFs,the influence of catalyst on microstructure and mechanical properties of C / C composites was studied in this paper. The results show that the growth of CNFs at the beginning of deposition was very difficult. As the deposition time increased,the number of CNFs increased sharply. The CNFs were wrapped by PyC matrix after deposition process. The PyC type was RL with a great quantity of cone-shaped PyC. The mechanical strength and modulus of CNFs-C / C composites increased by 30. 9% and 39. 1% respectively,compared to the pure one. The fracture mode of CNWs-C / C composites is pseudo plastic fracture.更多还原