THE RECOIL COMPRESSIVE STRENGTH OF PITCH-BASED CARBON-FIBERS

The recoil compressive strengths of pitch-based carbon fibres with fol ded-radial and flat-layer textures were compared. Using the recoil tes t method, it was shown that the compressive strengths of pitch-based c arbon fibres with folded-radial textures are superior to pitch-based c arbon fibres with flat-layer textures at all modulus levels. Analysis of the failed fibre ends revealed that the folded-radial texture appea red to inhibit shearing of the basal planes. This may account for the superior compressive strengths of pitch-based carbon fibres with folde d-radial textures. Procedural differences in the recoil test were show n to influence the calculated recoil compressive strength of pitch-bas ed carbon fibres. Microscopic analysis of the recoil test specimens re vealed that some energy is absorbed in the area where the fibre is sec ured to the support tab.