Enhanced mechanical strength of Cu-Sn alloy by Mg addition

In recent years, the commercially available Cu-Sn alloy has attracted great interest within the new energy vehicles and industrial robots industries because of its relatively excellent comprehensive performance as compared to those of Cu-Ag and Cu-Mg alloys. In this work, we study the possibility of improving the tensile strength of Cu-Sn alloy via Mg addition. Our results show that, the addition of Mg could significantly improve the strength of the Cu-Sn alloy, the tensile strength of the Cu-Sn alloy was increased from 399MPa to 427MPa by 0.02 wt.% Mg addition after 80% cold-rolled reduction. This can be ascribed to the combined effect of the acceleration of the grain refinement and the promotion of the sub-structures formation by Mg addition during cold rolling process. Larger number density and more uniformly distributed sub-structures with an average size of 120 nm were formed in Mg-contained alloy than that in Mg-free alloy after 80% reduction. However, the Mg addition slightly decreased the electrical conductivity (EC) of the alloy (1.5%IACS), because of the lattice distortion caused by Mg atoms.