Research on Cu and Sr Addition to Modified EN AW-6082-Based Alloy and Analysis of Mechanical and Electrical Properties of Obtained Materials

This study investigates Cu and Sr microalloying as two mechanistically different strategies to improve the strength-conductivity balance of a modified EN AW-6082-type Al-Mg-Si alloy for load- and current-carrying railway traction components. A Si-rich base composition (AlMg0.6Si1), selected from a prior Mg/Si optimization, was produced by metallurgical synthesis and then alloyed with Cu (0.4 wt.% and 0.6 wt.%) or Sr (0.02 wt.% and 0.05 wt.%). After casting, the materials were subjected to homogenization/solution treatment followed by artificial aging at 170–200°C for up to 24 h to map precipitation-response kinetics. Hardness and electrical conductivity were measured in the as-cast condition, after solution/homogenization, and throughout aging. The results show that Cu additions increase peak hardness but reduce conductivity, whereas Sr provides a measurable increase in hardness with a much smaller penalty in conductivity. The systematic time-temperature dataset enables a quantitative comparison between Cu and Sr modifications and identifies aging conditions that maximize the hardness-conductivity trade-off.