Improving Mechanical Properties of the Fe/epoxy Composite with a Novel Room Temperature-Thermal Curing Process

Abstract

A novel room temperature-thermal curing process was proposed to fabricate the Fe/epoxy composite easily and rapidly. The effect of thermal curing on the microstructure and mechanical properties were investigated. The results show that the thermal curing leads to the coarsening of Fe phase and the dense of Fe/epoxy interface. The average diameter of Fe increased from 36.03 μm to 64.91 μm after thermal curing, leading to the microstructure evolved from the island shape to the quasi reticular structure. The voids in the Fe phase and cracks along the phase boundary in the Fe/epoxy composite disappeared under the effect of diffusion. The tensile strength increased from 13.14 MPa to 53.72MPa and the elongation increased from 5.86% to 8.18% after thermal curing, with the improvement of 308.8% and 39.6%, respectively. The combination of brittle fracture in Fe and the crack elongation along the interface of Fe/epoxy improve both the strength and the plasticity of the Fe/epoxy composite. The Fe grains sustain fine with average size of 0.49 μm, contains abundant low-angle grain boundary (LAGBs) and deformed grains, but the density of dislocation and the value of texture are extremely low.