• A sustainable solid-state recycling route, SolidStir Extrusion, is demonstrated. • Metallic chips are directly converted into dense, defect-free extrudates. • Refined microstructure in order of ∼5 µm achieved due to dynamic recrystallization. • Enhanced mechanical performance validates effective recycling. • Energy analysis shows a minimum of 19% energy saving over conventional methods. Metal recycling is essential for green manufacturing, yet conventional routes remain energy-intensive and complex. Reducing the carbon footprint of metal manufacturing requires the development of greener and more efficient recycling methods. This work introduces SolidStir® Extrusion (SSE), as an energy-efficient friction-stir-based process, for directly recycling AlSi10Mg waste into fully dense, defect-free rods. Microstructural analysis showed the extrudate is fully dense with fine, equiaxed grains (2.43 μm ± 1.5 μm) and uniformly distributed Si-rich particles, enhancing mechanical performance. The as-extruded material had a yield strength of 140 MPa and 26% ductility. Aging increased yield strength to 239 MPa and ultimate tensile strength to 346 MPa while retaining ductility of 19%. The energy efficiency and sustainability of SSE were assessed through analysis of process dynamics and mechanical work. Energy flow analysis indicated that SSE offers improved energy efficiency compared to conventional extrusion-based recycling approaches. This study demonstrates a solid-state pathway for metal reuse that enables direct conversion of aluminum waste into high-performance products, supporting circular manufacturing objectives.
Gumaste et al. (Sun,) studied this question.