Fabrication and mechanical characterization of carbon/SiC-epoxy nanocomposites

A systematic study has been carried out to investigate matrix properties by introducing micro- and nanosized SiC fillers into an epoxy matrix. The study has revealed that with equal amount of loading; nanoparticle infusion brings about superior thermal and mechanical properties to the matrix than what is usually given by the microfillers infusion. The nanophased matrix is then utilized in a vacuum assisted resin transfer molding set up with satin weave carbon preforms to fabricate laminated composites. The resulting structural composites have been tested under flexural and tensile loads to evaluate mechanical properties. The fillers were nano- and micron-size silicon carbide particles which were mixed with the SC-15 epoxy resin using an ultrasonic processor. Amount of particle loading varied from 1.5% to 3.0% by weight of the resin. Ultrasonic mixing utilized high energy sonic waves to force an intrinsic mixing of particles with the matrix via sonic cavitations. In parallel, control panels were also fabricated without particle infusion. It has been observed that nanoparticle infusion increases the thermal stability of the system by enhancing cross-linking in the polymer. Nanoparticles also tend to reduce void content of the as-fabricated composites and thus translate into increased mechanical properties. With 1.5 wt.% loading, an average of 20-30% increase in mechanical properties has been observed. Fatigue tests were also performed under flexural loading, and the performance of the nanoinfused system was seen to be superior to that of the neat system.