Enhanced precipitation-hardening of Cu-Ag alloys through controlled chromium addition

Incorporating Cr into Cu-Ag alloys offers potential for enhancing mechanical properties, yet the intricate in-fluence of microstructural characteristics at varying Cr concentrations on performance remains unclear. In this study, Cu-3 %Ag-(0.1-4 %Cr) alloys were investigated, optimizing performance through sequential solution processing and aging. After aging at 450 degrees C/2h, Cu-3 %Ag binary alloys featured solely discontinuous Ag pre-cipitates, while Cr-containing alloys exhibited prominent continuous Ag precipitation. Modest Cr content significantly increased alloy hardness, with a 37.4 % improvement in the 0.5 % Cr alloy. Concurrently, Cr introduction caused a modest decline in electrical conductivity. These findings illuminate the strengthening mechanisms in Cu-Ag-Cr alloys, emphasizing the substantial presence of continuous Ag precipitates and fine Cr precipitates during aging, collectively enhancing the alloy's microstructure.