Carbon-carbon composite foams with high specific strength from sucrose and milled carbon fiber

• Carbon composite foams were prepared from molten sucrose and milled carbon fiber.
• The microstructure and mechanical properties depend on carbon fiber length.
• The highest compressive strength is achieved at low fiber concentration of 2 wt.%.
• Maximum of 125% improvement in the compressive strength was achieved.

Carbon composite foams prepared by the thermo-foaming of milled carbon fiber dispersions in molten sucrose were evaluated for microstructure and mechanical properties as a function of average fiber length and fiber concentration. The density and specific compressive strength of the carbon composite foams increased with a decrease of average fiber length and reached a maximum at an average fiber length of 33 μm. A maximum increase in compressive strength of 125% and specific compressive strength of 92% was obtained at a carbon fiber concentration of 2 wt.%.