Mechanical properties and microstructural evolution of a Cu-Cr-Ag alloy during thermomechanical treatment

The microstructure and mechanical properties of a Cu-Cr-Ag alloy at the different processing stages were investigated using hardness measurements, scanning electron microscopy, and transmission electron microscopy. The combined effects of dislocation strengthening and precipitation strengthening were shown to remarkably enhance the hardness of the alloy. Coherent Cr-rich precipitates with a face-centred cubic structure, formed during aging, were shown to be the main source of age strengthening, and the introduction of pre-deformation led to acceleration of their precipitation. Nevertheless, recovery occurring during aging caused significant softening in the cold-drawn samples. Analysis of the microstructural evolution during cold drawing and aging was used as an effective tool to optimise the thermomechanical process and improve the mechanical properties.