The stored energy in processed Cu–0.4 wt.%Cr–0.12 wt.%Zr–0.02 wt.%Si–0.05 wt.%Mg

Cold drawing was conducted at room temperature to impose high strain on Cu–0.4 wt.%Cr–0.12 wt.%Zr–0.02 wt.%Si–0.05 wt.%Mg. The microstructure was studied by X-ray diffraction and transmission electron microscope. The thermal analysis was carried out for the alloy at different draw ratios and then the stored energy was calculated to estimate the dislocation density and the flow stress. Results indicate that the microstrain gradually increases and the 〈1 1 1〉 texture is formed with the draw ratio rising. Meanwhile, the stored energy also increases with the draw ratio rising and a peak is reached with draw ratio of 6.7. The release of stored energy is primarily due to the decrease of dislocation density. The flow stress estimated from the stored energy has a similar variation trend with the measured data with a stress difference ∼20 to 120 MPa. The main strengthening effect is attributed to dislocation mechanism.

Research highlights
► The crystal orientation in processed Cu–0.4 wt.%Cr–0.12 wt.%Zr–0.02 wt.%Si–0.05 wt.%Mg is deviating from the as-cast specimens and microstrain of the alloy is gradually increasing as the draw ratio rising before η ≤ 6.7.
► The dynamic recovery has taken place as 6.7 < η ≤ 7.4, which is confirmed by the change of the crystal orientation, microstrain, stored energy, flow stress and dislocation density.
► The release of stored energy is primarily due to the decrease of dislocation density and the main strengthening effect of Cu–0.4 wt.%Cr–0.12 wt.%Zr–0.02 wt.%Si–0.05 wt.%Mg is attributed to dislocation mechanism.