Microwave assisted chemical vapor infiltration for the rapid fabrication of carbon/carbon composites

Microwave assisted chemical vapor infiltration for the rapid of carbon/carbon (C/C) composites was investigated at 1000-1150 degrees C for different times using carbon felts as substrates and methane as carbon precursor. The temperature and density distribution in the felts were measured and the densification kinetics were investigated. It is found that the density of the C/C composite prepared by this method is 1.84g/cm(3) with a densification rate of 0.063g.cm(-3).h(-1). The mechanism of the effective and rapid densification is accounted for by a densification from the inside to the outside of the felts under and inverted temperature gradient, an increase of the available active sites for carbon deposition, and increase of collision probability between hydrocarbon species and carbon fibres, and a catalytic effect of microwaves for the pyrolysis of methane.