Exploring the potential of Mg–2%Gd alloy through the multi-angular twist extrusion (MATE) technique for enhanced performance

Low density and an excellent strength-to-weight ratio make magnesium alloys attractive for electronics, automotive, and aerospace applications. Adding rare-earth gadolinium improves resistance in magnesium-gadolinium (Mg-Gd) alloys, making them viable for aviation, though their strength-to-weight ratio requires further enhancement. This study investigates a novel single-pass severe plastic deformation technique called Multi-angular Twist Channel Extrusion (MATE) process applied to an Mg-2Gd (wt.%) alloy. Finite element analysis at 150°C confirmed process feasibility, ensuring defect-free extrusion. Using a full factorial experimental design, the effects of ram speed, lubricant type, and annealing temperature on Vickers hardness, hardness inhomogeneity, and ultimate tensile strength were evaluated. Parameter optimization via the TOPSIS technique produced a 27.9% increase in tensile strength and a 65.9% rise in hardness. Electron backscatter diffraction (EBSD) revealed substantial grain refinement, yielding average grain sizes of 4.5 µm in the lateral region and 4.9 µm in the central region, alongside a distinct S-type crystallographic texture. These improved mechanical properties are directly attributed to the grain refinement and texture development induced by the MATE process.