Solid-state-recycled aluminum profile with notable fatigue and corrosion fatigue properties made by chip extrusion

Solid-state recycling by hot extrusion of AA6060 machining chips avoids remelting, but fatigue-critical reliability remains uncertain. This study benchmarks T6 heat-treated tubular profiles extruded from chip-based billets against cast-billet extrusions using two extrusion parameter sets. A steady-state Eulerian FE simulation coupled to a modified Bay weld model predicts spatial weld integrity and identifies defect-prone zones, showing minimum bonding of 93.8% (Batch#1) versus 98.9% (Batch#2). Experiments confirm that higher extrusion ratio, die venting during upsetting, and lower ram speed prevent post-aging chip decohesion and enable cast-like fatigue and improved corrosion-fatigue in 3.5 wt.% NaCl. Transferable process rules are provided for industry.