Effect of Volume Ratio on Microstructure and Properties of Layered Steel–Aluminum Low-Density Composites Prepared by Hot Pressing

A multilayer lightweight composite material, comprising 316L steel and Al 6061, was meticulously developed using the hot pressing technique. This investigation primarily focused on the mechanism of dissimilar metal bonding, examining samples with varying volume ratios. The mechanical properties of both the whole and cross-sectional samples were rigorously evaluated through tensile testing and microhardness testing, respectively. Scanning electron microscopy (SEM) and energy-dispersive spectrometer (EDS) were used to observe the interface morphology, diffusion, and tensile fracture morphology of the material. The diffusion width of the sample with a volume ratio of 1.2 reached 4.29 μm. Moreover, the texture of the material is analyzed and it is found that the dislocation density and texture strength of the material change obviously. Overall, the sample with a volume ratio of 1 exhibits excellent comprehensive properties, including a tensile strength of 473 MPa, an elongation of 53%, and a density 34% lower than that of steel. These promising findings underscore its significant potential for practical applications.