MICROSTRUCTURE AND MECHANICAL CHARACTERIZATIONS OF BUCKYPAPER AND CARBON FIBER HYBRID COMPOSITES

摘要

Carbon nanotube (CNT) buckypaper possesses excellent mechanical and physical propertiesrnwhich show great potential for use in the fabrication of multifunctional structural compositernmaterials. This paper reports on a study of CNT buckypaper integrated into traditional carbonrnfiber composites to create interply hybrid composite materials with high CNT content. Thernquality of hybrid composites was analyzed by investigating different manufacturing parameterrnsetups of autoclave processes, nano/micro resin flow behavior, and the influences of process andrnstructural parameters. Tensile properties and failure modes of the resultant composites werernstudied. The study found that resin bleeding along the through-thickness direction was inhibitedrndue to extra-low permeability and high resin absorbing capacity of the buckypaper, which wasrnthe major contributing factor to void formation and resin starvation defects. Buckypaper/resinrnlayers showed consistent thicknesses in all hybrid composites, which were about double thernthickness of the dry, pristine buckypaper due to absorbency and swelling effects. Control andrnhybrid composites showed similar local fiber volume fractions in the carbon fiber plies. Thernbuckypaper/unidirectional carbon fiber hybrid composites with 4.95 wt% CNTs showed therntensile strength and modulus of 2519±101 MPa and 149±18 GPa, respectively, which are onlyrn4.1% and 6.3% reductions, respectively, compared to the control sample. In contrast to thernexplosive failure mode of the unidirectional control sample, delamination was the main failurernmode for the BP/CF hybrid composites.