Feasibility Study of Solid-State Recycling through Direct Hot Rolling of AA5754 Aluminum Chips for Automotive Applications

Recently, researchers have done a lot of efforts to develop new solid-state recycling processes, both experimentally and developing numerical models. This kind of process is energy-saving and environmentally friendly compared to the conventional aluminum recycling process because avoided the melting step. The purpose of this work is to evaluate the feasibility of an innovative solid-state recycling process through direct hot rolling in a non heat-treatable aluminum alloy for automotive applications. AA5754 chips have been produced by turning a bar without the usage of lubricants and compacted with a 150 kN load; the compacted billets were treated at 400 °C and directly hot rolled in several successive passes. Rolled samples are then analyzed in terms of Vickers microhardness and microstructure in both as-rolled and heat treatment conditions, this last was performed at 185°C simulating the process of paint-bake. The produced samples show an excellent bonding between chips.