Nanoscale precipitates evolution and strengthening mechanism of the aged Cu-Mg-Fe-Sn-P-Y electrical contact wire
Bingjie Wang, Yi Zhang, Baohong Tian, Yanlin Jia, Alex A. Volinsky, Vladislav Yakubov, Yong Liu, Kexing Song, Ming Fu
Abstract
The evolution and strengthening effect of nanoscale precipitates of the aged Cu-Mg-Fe-Sn-P-Y alloy were investigated via aging treatment in the 400–480 °C temperature range and the 10–480 min aging time range. Nanoscale γ-Fe particles uniformly distributed in the matrix caused dispersion strengthening in the peak-aging stage and transformed to α-Fe at the over-aging stage. The Mg3P2 secondary phase hindered the appearance of coarse Fe3P and formed definite orientation relationship (OR) of cubic to cubic with the Cu matrix after 480 min aging, <110>Cu||<110>Mg3P2, (002)Cu||(008)Mg3P2. The optimal aging parameter for the Cu-Mg-Fe-Sn-P-Y alloy is 60% cold deformation and aged at 460 °C for 20 min. The corresponding tensile strength is 599 MPa with the conductivity of 71.1%IACS and the elongation of 6.9%. Compared with the current contact wire, the ultimate tensile strength and conductivity of the studied alloy increased by 20% and 15%, respectively.