Lamellar-structured Al-based alloys with high strength and plasticity

Abstract We present a novel approach to fabricating lamellar-structured metal alloys with enhanced mechanical properties by hot extrusion of metallic glass ribbon precursors. Using Al-based alloys as an example, we found that hot extrusion of metallic glasses causes significant crystallization, associated with thermal and stress gradients that facilitate the formation of a lamellar structure comprised of ultra-fine-grained (UFG) regions and fine-grained (FG) regions. This heterogeneous lamellar structure allows cooperative yielding and plastic deformation that results in high yield strength (over 750 MPa) in combination with high plasticity (over 40%) under compression. The evasion of conventional strength-plasticity trade-off suggests that hot extrusion of metallic glasses offers a new toolbox to create lightweight and high-performance structural metal alloys.