The Influence of Different Fillers on the Properties of Carbon-Matrix Composites

AbstractThe inherent cracks of carbon-matrix composites are important factors that affect the properties. Adding fillers is an effective way to reduce cracks in order to enhance the properties of composites. Herein, reinforced carbon-matrix composites were prepared by introducing nanodiamonds (NDs) and strong alkali-modified carbon fibers (CFs) into the powders by blending, respectively. Compared with CFs, NDs could effectively fill cracks with the volume expansion in composites, which promoted the deflection of the crack propagation path. It also had excellent thermal conductivity, and the electrical conductivity was improved after high-temperature sintering. Compared with the properties of original sample (OS), the compressive strength (97.833 MPa), flexural strength (21.342 MPa), thermal conductivity (2.809 W/(m·K)), and electrical conductivity (141.2 S/cm) of the composite sample with 0.05 wt% NDs (SNDs) increased by 78.2%, 67.1%, 16.03%, and 7.72%, respectively. NDs is a kind of filler to efficiently enhance the performance of carbon-matrix composites, which can achieve higher performance at low addition.KeywordsCarbon-matrix compositeCrackFillerNanodiamondCarbon fiber