催化FBCVI制备碳纳米纤维增强碳/碳复合材料的组织与力学性能研究

Microstructure and Mechanical Properties of Carbon Nanofibers Reinforced Carbon / Carbon Composites Prepared by Catalyze FBCVI

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。

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 in- fluence of catalyst on microstructure and mechanical properties of C/C composites was studied in this paper. The re- suits show that the growth of CNFs at the beginning of deposition was very difficult. As the deposition time in- creased, 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 C/C composites is pseudo plastic fracture. , compared to the pure one. The fracture mode of CNWs-