High Strength and Good Ductility in Cu-3Ag-0.5Zr Alloy by Cryo-Rolling and Aging

A combination of high strength and good ductility was achieved in a precipitation hardenable Cu-3Ag-0.5Zr alloy through cryo-rolling (80% reduction in thickness) and aging in the temperature range (200-500 °C). The high-strength sheets produced by cryo-rolling showed a threefold increase in yield strength compared to that of the solution-treated and aged (220 MPa) sample, while retaining good ductility. An optimum combination of high strength (614 MPa) and ductility (8%) was achieved by 80% cryo-rolling and aging at 320 °C for 1 h. The high strength and good ductility obtained was attributed to various microstructural factors such as deformation twins, ultra-fine grains, high dislocation density and fine nano-sized silver precipitates.