An experimental study on the physical and mechanical properties of B₄C/PI/AA6061 hybrid composites with various concentrations

Abstract

The effects of boron carbide (B4C) concentrations on the physical properties and interfacial adhesion of hybrid composites were systematically investigated. B4C/polyimide (PI) resin blends were composed of PI resin and B4C particles at weight ratios of 90:10, 80:20, 70:30, 60:40, and 50:50. The effects of alkoxysilane coupling agent KH550 on the chemical structures of B4C particles were performed using Fourier transform infrared Spectroscopy. The testing results illustrated that, the addition of alkoxysilane coupling agent was conducive to improve the interfacial adhesion between PI resin and B4C particles, while the peak at 2,932.12 cm−1 was emerged which corresponded to the C‐H anti‐symmetric stretching vibration peak of ‐CH2 group. Single‐lap‐shear strength of the specimens was firstly increased and then decreased with the increasing of B4C content, while the maximum value appeared at 30 wt% of B4C particles. Lap‐shear strength of the specimens with precoated primer layer was 12.2 MPa, which was 6.09% higher than that without primer layer. It was also corroborated that physical crosslinking reaction between B4C particles and PI resin was formed, which can effectively prevent the formation of crack and fracture in the adhesive layer under the action of tensile stress. POLYM. COMPOS., 40:3140–3148, 2019. © 2019 Society of Plastics Engineers