Interfacial and mechanical properties of domestic T800 carbon fiber/bismaleimide composites

Japan Toray T800H and domestic T800 carbon fibers were used as reinforcements to prepare bismaleimide resin matrix composites by autoclave process. Surface physical and chemical states of the two kinds of carbon fibers, as well as micro interfacial properties and mechanical properties of the composites were studied. The results show that the domestic T800 carbon fibers can form better physical adhesion with the resin matrix, which have more grooves on the surface and higher surface roughness. Simultaneously, the domestic T800 carbon fibers can form better chemical adhesion with the resin matrix, as they have more oxygenic functional groups. Hence, the interfacial shear strength of domestic T800 carbon fibers is higher than that of T800H carbon fibers by about 27%. Moreover, the mechanical properties of domestic T800/HT-280 composites are generally higher than those of T800H/HT-280 composites. The 90° tensile strength improves by about 25%, the in-plane shear strength and bending strength improves by about 12%, and the interlaminar shear strength improves by about 7%.