Influence of Surface Modification by Carbon Nanotube on C/C Composite Brazing Joints

The carbon nanotube grows on the C/C composite by using PECVD method. Influence of the parameters(e.g. catalyst concentration, growth temperature, growth time, gas pressure and gas flow) on carbon nanotube morphology are investigated. The carbon nanotube is detected by Raman spectra, SEM and TEM technology. Under the optimal parameters, the grown carbon nanotube is multiwall carbon nanotube. The number of nanotube walls is 15. The diameter and length of the carbon nanotube are 18.9 nm and 2.5 μm respectively. The C/C composite is brazed with Nb and Ti600. Two kinds of brazing joints with and without carbon nanotube are investigated. After growing carbon nanotube, the wettability of the brazing filler and the joints shear strength are both improved.