SiC nanowire reinforced carbon/carbon composites with improved interlaminar strength

摘要

SiC nanowires with surface dentations were in-situ grown on carbon fiber cloths and then they were stacked to form 2D carbon preform. After that, the preform was densified via chemical vapor infiltration to prepare SiC nanowire reinforced carbon/carbon (SiCNW-C/C) composites. Introduced SiC nanowires significantly change the crystallite orientations of pyrocarbon matrix. Coaxial pyrocarbon with higher optical activity and larger crystallite size has been deposited around the nanowires. The interlaminar shear strength of SiCNW-C/C composites increases by 32% compared with the baseline. The increase of interlaminar strength could be ascribed to a synergistic effect of SiCNWs and coaxial pyrocarbon inter-layer. SiC nanowires with dentations construct nanoscale mechanical interlocking with the matrix and improve the load transfer efficiency. Besides, the pyrocarbon interlayer helps deflecting the cracks out of the basal shear plane under shear stress.