Effect of Localized Deformation on Compression Properties of Additively Manufactured Al-Alloy Metamaterials

To address the dual requirements of lightweight and high-performance structural design, this study investigated the compressive properties of three aluminum-based mechanical metamaterials with different lattice structures but the same mass, which were fabricated by laser fusion additive manufacturing. The three structures are porous structure, truss structure, and gyroid structure. Through quasi-static compression tests, numerical simulations, and microstructure analysis, we examined the effects of geometric design, micro-defects, and local deformation on the mechanical response and deformation mechanism. The research results indicated that the uniformity of stress distribution, the defect sensitivity, and the grain refinement significantly affect the energy absorption capacity and strength of the material. Reducing local strain concentration, improving surface quality, and promoting grain fragmentation are the keys to enhancing the mechanical properties of the material during compression. These findings provide unique insights into the structure-performance relationship of alloy lattice metamaterials and offer support for the optimization design of aluminum-based metamaterials in lightweight structural applications.