Research on the Microstructural Evolution of a Novel AlMgZnErZr Alloy during the Cold Stretching Process

The study examines the effects of cold stretching, ranging from 1% to 7%, on the microstructure, mechanical properties, and corrosion resistance of AlMg alloy extruded profiles. Microscopic observations reveal that deformation introduces a high density of dislocations, substantially enhancing the alloy's strength, with dislocation strengthening being the primary mechanism. However, the corrosion resistance of the alloy decreases postcold stretching, which is attributed to the increased dislocation density and the proportion of high-angle grain boundaries, leading to an increase in β-phase precipitates along grain boundaries. The findings suggest that while cold stretching enhances the strength of the alloy, it adversely affects its corrosion resistance. In consideration of comprehensive performance, the cold stretching range is determined to be between 1 and 3%.