Solid-state recycling of brass wire scrap into hexagonal bars by hot extrusion

This study explores the solid-state recycling of brass wire scrap into hexagonal bars using hot extrusion. Brass wire cut pieces, obtained from used thin electrode wires, were cold-compacted into cylindrical billets and successfully extruded into hexagonal bars at 923 K under two different extrusion ratios, 4.4 and 9. Tensile and Vickers hardness tests reveal that higher extrusion ratios significantly enhance the ultimate tensile strength of the recycled materials, although yield strength and hardness remain relatively stable across both extrusion ratios. Finite element analysis shows that the overall effective strain introduced is notably higher at the extrusion ratio of 9, with an approximate 45% increase at the centre position compared to the ratio of 4.4. This increased strain results in finer grain structures and improved bonding among individual brass wire pieces, contributing to observed tensile strengths exceeding 300 MPa. Additionally, the excellent machinability of the recycled bars permits precise shaping through lathe turning, enabling further processing into machinery parts.