Materials, Methods & Technologies, Volume 17, 2023

Abstract: This work focused on the strain rate-dependent mechanical behavior of Mg-3%Al alloy fabricated via powder metallurgy. The effects of ball milling for different durations are also discussed in this study. Powder metallurgy approach integrating sintering at inert atmosphere followed by hot extrusion was used to fabricate Mg-3%Al alloys. Microstructural analysis and X-ray diffraction (XRD) studies demonstrated that the alloy of the solid solution of Mg and 3%Al were successfully fabricated using the powder metallurgy route. Both the milled powder and their extruded bulk samples revealed evidence of the formation of second-phase particles. Tensile tests were carried out at different strain rates, and the yield strength, tensile strength, and elongation to failure of samples made from milled and un-milled powders were measured and compared. The findings demonstrated that the strain rate and the grain sizes of the extruded samples have a significant impact on the strength and ductility of the bulk samples. The possible deformation mechanisms for each sample are discussed. It is hypothesized that the grain boundary movement mechanism and the geometrically necessary dislocations primarily governs the deformation process. The possible fracture mechanisms were predicted from the microstructural study of the fracture behaviors of the deformed samples. The micro-mechanical properties of each sample were analyzed using the loading-unloading curves of the micro-indentation test.