Magnesium and Magnesium Alloy Powder Processing Towards the Development of Near Shape Structural Materials

Near shape forming of magnesium (Mg) alloys offers a significant opportunity for structural material lightweight. In this work, conventional press and sinter near shape processing has been applied to commercial AZ91D and pure Mg powders. Results indicate these powders are reasonably compressible achieving green densities of 88 to 98% ρ_Th with limited cracking. Sintering of these compacted powders is challenging and requires both solid state and transient liquid phase mass transport apparently due to the inherent powder particle surface oxide layer. Resultant press and sintered materials are characterized for density, porosity distribution, hardness, microstructure, and phase development. Throughout this effort, specific attention is paid to the affect oxygen, as an adsorbed contaminant and a surface thin film, presents as an impediment to solid and transient liquid state densification. Results of this work are intended to advance near shape processing of Mg alloy and Mg powders for potential structural applications.