Effects of Carbon Nanotubes by Electrophoretic Deposition on Interlaminar Properties of Two Dimensional Carbon/carbon Composites

Carbon nanotubes (CNTs) were deposited uniformly on carbon cloth by electrophoretic deposition (EPD). Thereafter, CNT-doped clothes were stacked and densified by pyrocarbon via chemical vapor infiltration to fabricate two-dimensional (2D) carbon/carbon (C/C) composites. Effects of EPD CNTs on interlaminar shear performance and mode. interlaminar fracture toughness (G(IIc)) of 2D C/C composites were investigated. Results showed that EPD CNTs were uniformly covered on carbon fibers, acting as a porous coating. Such a CNT coating can obviously enhance the interlaminar shear strength and G(IIc) of 2D C/C composites. With increaing EPD CNTs, the interlaminar shear strength and G(IIc) of 2D C/C composites increase greatly and then decrease, both of which run up to their maximum values, ie, 13.6 MPa and 436.0 J.m(-2), when the content of EPD CNTs is 0.54 wt%, 2.27 and 1.45 times of the baseline. Such improvements in interlaminar performance of 2D C/C composites are mainly beneficial from their increased cohesion of interlaminar matrix, which is caused not only by the direct reinforcing effect of EPD CNT network but also by the capacity of EPD CNTs to refine pyrocarbon matrix and induce multilayered microstructures that greatly increase the crack propagation resistance through "crack-blocking and -deflecting mechanisms".