Influence of fiber content on the structure and properties of short carbon fiber reinforced carbon foam

A novel carbon foam with high strength was produced from mixtures of short carbon fibers and Mitsubishi naphthalene-based mesophase pitch. These mixtures subsequently underwent foaming, carbonization and graphitization. Investigations were carried out to determine the effect on the structure and properties of the carbon foam through the addition of fibers to carbon foam. The results have shown that compressive strength increased linearly with fiber fraction, but decreased at higher fiber fractions. Thermal conductivity increased at lower fiber fraction, but dropped with more fibers addition to carbon foam. The predominant strengthening mechanism was attributed to the pulling-out effect based on the fiber–matrix interface.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlightsThe short carbon fibers affect the pore size and micro-cracks. ▶ They shoulder the stress and consume much fracture energy. ▶ The thermal conductivity of carbon foam is increased obviously. ▶ The strengthening mechanism is the pulling-out effect.