Thin-plate lattices in AlSi10Mg alloy via laser additive manufacturing: Highly enhanced specific strength and recovery

Metallic lattices have emerged as a class of lightweight, strong, and multifunctional materials with growing applications. However, their specific strengths (strength-to-density ratios) often fall significantly short of those of their bulk metal counterparts. Thin-plate lattices (TPLs), featuring submillimeter-thick metal plates, present a promising solution. Yet, traditional manufacturing methods have long hindered their development. This study investigates laser additive manufacturing and the mechanical properties of axially isotropic AlSi10Mg alloy TPLs, designed with various unit cells, including cubic, cuboctahedron, truncated-octahedron, rhombicuboctahedron, and sphere structures. With densities ranging from 0.57 to 1.13 g/cm(3), these TPLs achieved exceptional specific yield strengths up to 90 % of the base alloy-significantly surpassing the performance of strut-based metallic lattices, which typically achieve 50-60 %. Additionally, under uniaxial compression, the TPLs demonstrated remarkable near-complete peak stress recovery, even at high strain levels (>50 %) or during fragmentation, offering a unique safety mechanism. This recovery was driven by distinct failure modes: at lower densities, fractures progressed layer by layer, leaving intact layers, while at higher densities, crack deflection enhanced resilience. These findings position TPLs as a transformative advancement, combining exceptional specific strength with robust recovery characteristics to outperform conventional lattice designs in multifunctional, highperformance applications.