Cryogenic rolling synergistically enhances mechanical properties and electrical conductivity of an Al-0.7Mg-0.4Si-0.1Fe alloy

Balancing strength and electrical conductivity (EC) is key to broadening the applications of conductive aluminum alloys. This study systematically investigates how cold deformation regulates this balance in an Al-0.7Mg-0.4Si-0.1Fe alloy. Results show that with increasing deformation, the yield strength markedly improves from 43.5 MPa to 199.9 MPa, albeit with an expected decline in ductility. While the electrical conductivity is further increased to 57.9% IACS (from 55.2% IACS) by 70% deformation. So, a 70% deformation provides the optimal balance between EC and mechanical properties. Mechanism analysis indicates that dislocation strengthening induced by cold deformation is the dominant factor for the increase in YS. Collectively, these three mechanisms-dislocation strengthening, precipitation strengthening, texture strengthening from <1 0 1> and <1 1 1> oriented grains-contribute predominantly to the yield strength increment, accounting for 78.7% of the total increase. Meanwhile, The rolling process triggers Mg/Si precipitation and drives the development of elongated fibrous grain boundaries, while also inducing the preferential alignment of β-Al 5 FeSi and Mg 2 Si phases. These factors reduce the probability of electron scattering and improve EC. In summary, this study provides a process reference and theoretical basis for preparing medium-strength, high-conductivity Al-Mg-Si-Fe alloys.