Damping properties of loose 1-D-C/C composites prepared by CVI

Damping properties of several loose unidirectional carbon/carbon (1-D-C/C) composites were measured by a self-made multi-functional damping apparatus using twisting method. The composite specimens manufactured by chemical vapor infiltration (CVI) method were reinforced by two different kinds of carbon fibers, namely high modulus carbon fibers (T-50) and high strength carbon fibers (T300). The results show that the damping values of the loose 1-D-C/C composites decrease with the increase of their densities. Under the same process condition, the damping values of 1-D-C/ C composites reinforced by T-50 are higher than those reinforced by T300. Moreover, there appear sharp damping peaks between 80∼200 C in the damping curves of the former unidirectional composites. Carbon fiber types and interface microstructures are the main factors that affect damping properties of this kind of 1-D-C/C composites.