3D thixo-printing: A novel approach for additive manufacturing of biodegradable Mg-Zn alloys

Abstract A simple and widely used additive manufacturing technique for polymeric materials is fused filament fabrication (FFF). In the semi-solid state, metallic materials may show rheological features comparable to those of polymers. Thus, they can be processed accordingly. The use of biodegradable Mg-based materials is an interesting approach to avoid removal surgeries and release of toxic corrosion products and wear debris. Therefore, in this study, the FFF technique was applied using a biodegradable Mg-Zn alloy in the semi-solid state. Some preliminary compositions were investigated through thermodynamic simulations to verify their compatibility with the process. Among them, Mg-38Zn was selected to be experimentally evaluated. Metallic filaments were produced via hot extrusion, which also aided in obtaining a globular microstructure in the semi-solid state. FFF was performed at 420 °C without any obstruction at the nozzle channel, which allowed the production of sound parts with acceptable welding between the deposited layers. This indicated that this technique (termed as “3D thixo-printing”) provides a promising additive manufacturing route to produce biodegradable Mg-based implants.