The growing emphasis on sustainable manufacturing has intensified interest in direct solid-state recycling of lightweight metals. Magnesium, owing to its biodegradability and biocompatibility, is particularly promising for temporary biomedical implants. However, the transformation of its machining waste into biologically functional forms remains largely unexplored. This study investigates the direct solid-state recycling of commercially pure magnesium machining chips into consolidated bulk material via friction stir consolidation (FSC). The recycled billets exhibit a dense and homogeneous microstructure with effective inter-chip bonding, confirming successful consolidation. Mechanical performance is evaluated through microhardness measurements. In vitro cytocompatibility assessment with fibroblast cells revealed excellent cell viability and an absence of cytotoxic effects. Electrochemical testing in a simulated physiological environment reveals a stable corrosion potential, low corrosion current density, and high charge-transfer resistance, indicating controlled degradation behavior. These results demonstrate that FSC provides a sustainable and efficient single-step route to upcycle magnesium machining waste into bulk materials with suitable microstructural integrity, mechanical coherence, controlled corrosion response, and excellent biocompatibility for potential biodegradable implant applications.
Behnagh et al. (Wed,) studied this question.