In low-Ag Cu matrix alloys, the presence of coarse discontinuous precipitates may limit strength. We demonstrated that discontinuous precipitation was suppressed, and continuous precipitation was enhanced by the doping of Cu-6 wt%Ag with Sc. A high-volume fraction of continuous precipitates, which nucleated on {111} planes, led to a 55 MPa increase in strength, with only a slight decrease in electrical conductivity. The addition of Sc inhibited the nucleation of discontinuous precipitates by causing the Sc and the Ag to co-segregate onto grain boundaries, thus forming a thin intermetallic compound layer between grains. After deformation, both discontinuous and continuous precipitates were drawn into Ag fibers. The combination of deformation strain and doping caused an increase in density and a decrease in the diameter of Ag fibers, resulting in about 205 MPa increase in doped samples when the deformation strain reached 4.9. The thinner, denser Ag fibers in the doped samples also caused higher electron scattering at interfaces, leading to electrical conductivity that was 11% IACS lower than in non-doped samples. For reference, 100% IACS (International Annealed Copper Standard) is equivalent to 1.7241 μΩ cm.

在低银铜基体合金中，粗大不连续析出物的存在可能会限制强度。我们证明了通过用 Sc 掺杂 Cu-6 wt%Ag 抑制了不连续沉淀，并增强了连续沉淀。在 {111} 面上成核的大量连续析出物导致强度增加 55 MPa，而电导率仅略有下降。Sc的添加通过使Sc和Ag在晶界上共偏析来抑制不连续析出物的形核，从而在晶粒之间形成薄的金属间化合物层。变形后，不连续和连续的析出物都被拉入银纤维中。变形应变和掺杂的结合导致Ag纤维的密度增加和直径减小，当变形应变达到 4.9 时，导致掺杂样品增加约 205 MPa。掺杂样品中更细、更致密的银纤维也会导致界面处的电子散射更高，导致电导率比非掺杂样品低 11% IACS。作为参考，100% IACS（国际退火铜标准）相当于 1.7241 μΩ cm。