Rapid chemical vapor infiltration of C/C composites
(1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Department of Biological Engineering and Environmental Science, Changsha College, Changsha 410003, China)
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Department of Biological Engineering and Environmental Science, Changsha College, Changsha 410003, China)
Abstract: With liquid petrol gas (LPG) as carbon source, carbon felt as porous perform and hydrogen as diluent, C/C composites were fast fabricated by using a multi-physics field chemical vapor infiltration (MFCVI) process in a self-made furnace. A set of orthogonal experiments were carried out to optimize parameters in terms of indices of density and graphitization degree. The results show the optimal indices can be achieved under the conditions of temperature 650 ℃, LPG concentration 80%, gas flux 60 mL/s, total pressure 20 kPa, infiltration time 15 h. The verification experiment proves the effectiveness of the orthogonal experiments. Under the optimal conditions, the graphitization degree of 75% and bulk density of 1.69 g/cm are achieved with a uniform density distribution. At the same time, a new structure is obtained.
Key words: C/C composites; chemical vapor infiltration(CVI); graphitization degree; bulk density; orthogonal experiment