Processability of Mg-Gd Powder via Friction Extrusion

Friction extrusion (FE) is a solid-state processing technique based on heat and shear introduction via friction at the die-feedstock interface. FE can be used to process feedstock of different forms, such as solid billets, chips or powder as well as being applicable to a variety of Al-, Mg- and Cu-alloys. The relative rotation between die and feedstock makes preheating obsolete and the induced plastic deformation has the potential of not only energy-efficient consolidation but also grain refinement for improved extrudate properties. In this study, the processability of Mg-Gd powder via FE is investigated. Mg-Gd alloys have their main use in aerospace as well as being promising candidates for biomedical applications. In these fields the homogeneity in terms of mechanical and chemical properties, respectively, is a critical factor. Consequently, the application of FE in this study aims to provide insight on a new possible processing route for Mg-Gd alloys by investigating the mechanical properties of the extruded, fully consolidated wires, i.e. hardness and compressive properties, as well as the microstructural features of the feedstock during processing, i.e. void volume, grain structure and morphology changes.