Mechanical characterization of sandwich composite structures with Alumix231 foam core between Al2024/B₄C composite plates

Abstract The study investigates the production of lightweight B 4 C particle-reinforced aluminum sandwich foam (ASF) materials, crucial for high impact and corrosion resistance, particularly in defense and automotive sectors. These materials are manufactured via powder metallurgy. Five different combinations of ASF materials, layered and unlayered with B 4 C, were examined. Alumix231 served as the primary material in the Al foam, with TiH 2 as the blowing agent. In layered ASF materials, Al2024 powder acted as the main material, reinforced by B 4 C particles. Samples with various configurations, including foam, foam/Al2024 layers, and 5-10–20 % B 4 C particle-reinforced Al2024 layers, were produced. After powder mixing, they were filled into a hot pressing mold, pre-pressed at 25 MPa, dwelled at 550 °C for 30 min, then hot pressed at 200 MPa to form foamable preform material. B 4 C particle-layered ASF materials were generated by foaming the preforms in a steel mold at 750 °C for 11 min. Microstructure, density, pore size, and morphology analyses were conducted. Al2024 exhibited the highest density at 99 %, decreasing with increased B 4 C ratio. With more B 4 C, compressibility decreased, and agglomeration increased. Pores were observed around TiH 2 and Si particles in B 4 C-lacking materials. The material with the best homogeneity and spherical pore resemblance was noted as Alumix231.