Achieving Mechanical–Electrical Property Synergy in 8076‐Derived Alloy by Erbium Microalloying and Homogenization Annealing Treatment

Microalloying aluminum alloys have exhibited excellent conductivity and ductility, which can meet the increasing requirements of applications in high‐speed train electric equipment as well as the goals for energy conservation. However, the low tensile strength, because of the lack of precipitation, has limited these potential applications of microalloying aluminum alloy. The present work has proposed microalloying of the rare earth Er element in an Al‐based alloy combining homogenization annealing treatment to break the disproportionate match between tensile property and electrical conductivity of the alloys. The results demonstrate that microalloying with the Er element inhibits the intrinsic growth of α‐Al, promoting a significant grain refinement of the alloy. Besides, the shape of Al 13 Fe 4 particles has also been modified. The subsequent homogenization annealing treatment at 550 °C for 1 h has resulted in a synergistic increase of the tensile property and electrical conductivity in the Al–0.7Fe–0.4 Mg–0.1Si–0.5Er alloy, where the ultimate tensile strength has reached 114 MPa, the elongation to failure has remained 28.2%, and the electrical conductivity has regained 58.8 %IACS. Based on the yield strength expression calculation, the emergence of the Al 3 Er phase primarily contributes to the strengthening of the 0.5 wt% Er alloy.