Simultaneous Improvement in Strength and Electrical Conductivity of Al–Mg–Si–Fe–Cu Alloys by Cryogenic Thermomechanical Treatment

The increasing demand for high‐strength and high electrical conductivity (EC) aluminum alloys in aerospace and automotive industries makes the simultaneous enhancement of both properties increasingly urgent. This work investigates the improvement in mechanical strength and EC in an Al–Mg–Si–Fe–Cu alloy plate processed by cryogenic rolling (CR) and subsequent aging. Compared to room‐temperature rolling (RTR), CR imposed more severe plastic deformation on the solution‐treated alloy, resulting in an increase in strength due to significant grain refinement, elevated dislocation density. During subsequent aging, nanoscale β″ and Q precipitates formed uniformly, contributing to the strength via precipitation strengthening. At an 80% rolling reduction, the CR alloy plate possessed enhanced mechanical properties over to the RTR alloy plate, with the ultimate tensile strength increasing from 357 to 374 MPa, the yield strength from 334 to 352 MPa, the elongation from 6.9% to 9.1%, and the EC from 54.59% IACS to 54.87% IACS. This was attributed to enhanced precipitation during aging, which increased the strengthening role on the matrix induced by Orowan strengthening and reduced the scattering effect of solid solution atoms on electrons. This work offers valuable insights into the design of high strength–conductivity aluminum alloys for advanced engineering applications.