The Impact of Direct-Current Electro-Treatment on the Microstructure and Mechanical Behavior of Cold-Rolled 2014 Aluminum Alloys

Abstract Electrically assisted post-processing is proposed as an energy-efficient alternative to conventional thermal annealing for tailoring the mechanical properties of cold-rolled AA2014 aluminum alloys. Cold-rolled strips were subjected to direct current at current densities ranging from 1.4 to 2.0 × 10 4 A/cm 2 for 60 min, and the resulting microstructural evolutions were characterized by electron backscatter diffraction, focusing on grain microstructures, residual strain, grain-boundary characteristics, and textures. The results revealed a distinct transition from recovery-dominated processes at relatively low current densities (1.4–1.6 × 10 4 A/cm 2 ) to recrystallization and grain growth accompanied by texture randomization at higher current densities (1.8–2.0 × 10 4 A/cm 2 ). Significant micro-hardness reductions, up to 48.7% relative to the cold-rolled state, were achieved, reaching values comparable to the solution-treated benchmark at 500°C. Thermal benchmark experiments further demonstrated that the observed microstructural transformation was attributed to the synergistic thermal and athermal effects, highlighting that Joule heating alone could not reproduce the extent of recrystallization. These findings confirm electro-treatment (ET) as a potential route for efficient microstructure control and mechanical property tailoring in AA2014, offering both performance benefits and reduced energy consumption of 95.7% compared to conventional thermal annealing treatment for advanced manufacturing applications.