Impact of partial rolling on structural integrity and mechanical properties of AA7075 Tailor Alloyed Blanks

This study investigates partial rolling as a post processing method to improve the microstructure and formability of Tailor Alloyed Blanks (TAB) fabricated from AA7075 via laser-induced element evaporation and filler wire alloying. While prior work demonstrated the feasibility of adapting the alloying concept to enhance ductility in targeted regions, process-induced porosity, surface irregularities and insufficient process robustness continue to limit industrial applicability. To overcome these limitations, partial rolling was applied to the modified region. A parametric study identified rolling pass as the dominant factor influencing work hardening, surface smoothing and defect closure. Applying a 0.35 mm rolling pass led to a 92% reduction in surface irregularities, complete closure of hydrogen-related porosity and a 38% improvement in true strain compared to the unrolled condition. The enhanced process robustness was confirmed by a significant reduction in true stress deviation, determined by upsetting tests on miniaturized specimens extracted from the adapted zone. 3-point bending tests further validated the improvement in formability, revealing a 50% increase in bending angle compared to the unrolled TAB and double the value observed in the base material. Rolling speed had no measurable impact, whereas longitudinal rolling outperformed transverse rolling in achieving uniform strain and hardness distributions. These results establish partial rolling as an effective and scalable refinement step for TAB. It enables the translation of localized compositional tailoring into functional mechanical performance, thereby expanding the process window for high-strength aluminum alloys in forming applications. • Partial rolling as a transferable post-processing step to reduce defects and significantly extend the forming limits of Tailor Alloyed Blanks (TAB) • Upsetting tests with miniaturized cylindrical specimens of the modified zone enable characterization of the element adapted material behavior • 3-point bending tests confirm the improved formability of partially rolled TAB, doubling the performance of the base material • Process robustness is increased across all tests through defect closure and surface quality improvement