Hybridization of Carbon Fiber Using Ultra-High-Molecular-Weight Polyethylene Fibers: How It Affects Density, Bending, and Impact Strength

The potential of improving the impact strength and reducing the density of carbon-fiber-composite products (CFCs) is explored as a function of the content of introduced ultra-high-molecular-weight polyethylene (UHMWPE) roving. The roving feature high tensile and impact strength and low density. The carbon fiber composite consists of carbon-fiber (CF) roving. It is additionally reinforced using D800 and SK75 roving with UHMWPE fibers. CF and UHMWPE roving are mixed in different ratios to make unidirectional hybrid (three-component) samples in two types of epoxy matrices (HT-2 and L285). In addition to hybrids, two-component samples are made using individual CF, D800, and SK75 roving. The amount of roving in the volume of hybrid samples is changed with a 25% increment to obtain CF and UHMWPE roving ratios of 0.25/0.75, 0.50/0.50 and 0.75/0.25. The required quantity of roving having the above ratios is calculated using the CF and UHMWPE roving constants. The impact strength, density and bending strength are estimated. The density of the samples is determined by calculation accounting for the roving constants. The results of the strength tests in hybrids are compared with CFC strength indicators. When the amount of UHMWPE roving increases, the bending strength and the density of hybrids decreases at different rates if compared to CF. The impact strength sharply increases under the same conditions followed by a sharp decline. The density of hybrids decreases by about 8% with each incremental step, and the rate of bending strength decline is approximately twice the rate of the density decrease. The impact strength of hybrids containing 25 and 50% UHMWPE roving shows an average increase by 3.28 and 3.4 times, respectively.