High-Speed Friction Extrusion of ZK60 Magnesium Alloy for Enhanced Mechanical Performance and Corrosion Resistance

In this work, high-speed friction extrusion was employed as a solid-phase processing technique to modify the microstructure of ZK60 magnesium alloy, with the objective of improving mechanical performance and corrosion resistance. Friction extrusion utilizes a rotating die to generate localized frictional heating and high shear strains, enabling efficient extrusion without the need for external heating. In this study, 5 mm diameter rods that were at least 2 m in length were extruded at speeds of 12.4 m/min and 14 m/min at temperatures of 380°C and 450°C, respectively, significantly higher than conventional processing conditions reported for magnesium alloys. The processed ZK60 exhibited refined equiaxed grains and altered basal textures, which contributed to a reduction in yield asymmetry between tension and compression, as well as enhanced corrosion resistance. The as-extruded rods had tensile strength and hardness of 90 HV, similar to the as solutionized and aged condition, indicating potential cost benefits in avoiding the heat treatment. The improved corrosion performance was attributed to a more uniform microstructure, reduced residual strain, and suppression of microgalvanic coupling through second-phase redistribution. The ability to achieve such high extrusion speeds and ratios with reduced energy input highlights the potential of friction extrusion for scalable, sustainable manufacturing of high-performance magnesium components.