Multiscale defect engineering for synergistic strength, electrical and thermal conductivity in aluminum alloys: A review

Advanced aluminum alloys face an inherent trade-off between strength and electrical/thermal conductivities, creating a challenge for next-generation applications in electric vehicles (EVs) and aerospace. Moving beyond the traditional paradigm of defect elimination, this review presents a visionary roadmap for multiscale defect architectural design. This review synthesizes key strategies from the perspective of defect engineering, elucidating how zero-to three-dimensional defects fundamentally govern the competition between mechanical response and charge/heat transport. Crucially, this review establishes a framework for transitioning from passive defect control to active synergistic design, emphasizing strategies such as precipitate pinning, interface engineering, and gradient structures that strengthen the alloy while minimizing electron scattering. Finally, the review outlines a future trajectory driven by the convergence of multi-scale physics modeling, in-situ characterization, and machine learning. The objective is to establish a predictive capability that links atomic-scale defect configurations to macroscopic performance, providing a practicable pathway for determining the upper limits of synergistic strength-conductivity optimization.