A continuous sintering extrusion recycling process for high-quality recycling bars of LA103Z Mg-Li alloy chips

Solid state recycling is extensively employed for lightweight metal chip recycling due to its cost-effectiveness and low loss. Nevertheless, the existing solid state recycling process typically involves multiple stages and temperatures, which makes it unsuitable for recycling metal chips that are highly prone to oxidation and temperature sensitivity. To address the issue, the continuous sintering extrusion recycling process is proposed by integrating the sintering process and extrusion process into a continuous operation, and the LA103Z Mg-Li alloy chips are recycled through a specially designed die. The mechanical properties, microstructure, strengthening mechanism, and interface bonding process in the continuous sintering extrusion recycling process are explored systematically. The results indicated that all recycling specimens exhibit superior ultimate tensile strength and yield strength compared to the as-extruded bulk billet. The strengthening effect in the recycling specimens is mainly attributed to the fine grain size and second phase precipitation, in which the grain boundary strengthening is the most dominant mechanism. The fracture mode of the recycling specimen exhibits quasi-cleavage fracture characteristics. This work provides new ideas and insights for the high-strength recycling of lightweight alloy chips.