Fabrication and mechanical properties of glass fibre carbon fibre polypropylene functionally gradient materials

摘要

Hybrid fibre mat reinforced polypropylene (PP) composites with carbon (CF) and glass fibre (GF) were prepared and four kinds of functionally gradient materials (FGM) were fabricated by changing the spatial distribution of GF and CF. To measure the mechanical properties of FGMs and hybrid composites, flexural tests and instrumented impact tests were performed. The flexural strengths and the flexural moduli of hybrid composites increased following the rule of mixture as the relative volume content of CF increased. On the other hand, the total impact absorption energy of hybrid composites decreased with the increment of CF relative volume content. Compared with GF-CF PP isotropic hybrid composite, the composites with compositional gradient showed similar flexural strengths, but characteristic flexural moduli. Especially, sandwich-type FGMs with a CF-rich outer layer and a GF-rich inner layer exhibited higher flexural moduli than others. Total impact absorption energies of four FGMs were also similar, but the ratios of crack initiation energy, E-i, to crack propagation energy, E-p, or ductility index, were quite different. (C) 1998 Kluwer Academic Publishers. [References: 11]