Enhancing tensile properties of Cu and Cu-Al alloys cryogenically processed by high pressure torsion

The influence of alloy concentration with different stacking fault energy (SFE) on tensile properties of Cu and Cu-Al alloys processed by high pressure torsion (HPT) at room temperature (RT) and liquid nitrogen temperature (LNT) was investigated. With decreasing SFE, the twinning capability, the dislocation density and grain refinement were enhanced at LNT, however, tensile strength and uniform elongation were not simultaneously improved. The enhanced tensile properties are explained in terms of the twinning capability, the grain size and the dislocation density independent of the short range order (SRO). [Display omitted] •Cu-Al alloys were processed by HPT at liquid nitrogen temperature.•Decreasing SFE enhances the twinning capability and the grain refinement.•A decrease of deformation temperature and SFE improves tensile strength.•Tensile strength and uniform elongation in Cu-Al alloys by HPT at LNT are not simultaneously improved.