The effect of composition of carbon fibre on the mechanical and morhpological properties of carbon fibre reinforced polyamide 6 (PA6/CF)

A study to investigate the mechanical property-morphology relationship of polyamide 6 reinforced-carbon fibre composites has been carried out. The composites were prepared by melt mixing in an internal mixer, in a composition of wt% PA6/wt%carbon fibre with the following composition: 95/5, 90/10, 85/15, 80/20 respectively. The length of the fibre was 500μm. The mechanical properties measured were tensile and impact strengths as well as hardness. These properties were correlated to the morphology. In general, the mechanical properties suggest that carbon fiber has the potential to reinforce polyamide 6; hence an increase in strength recorded in all, displaying that strength is a function of the volume of the reinforcement (fibre). Morphological study of the tensile fractured surface showed the mechanism of failure to be the dispersed domain pulling out of a continuous matrix as well as the percentage of fibre breakage; voids were observed in the PA matrix. The size of the voids seems to correspond to the size of the fibrils, making the inference that the voids observed were space left by the pulled-out fibre randomly distributed.