The effect of annealing and additional deformation on the mechanical properties of ultrafine-grained Al–1.5Cu alloy

The mechanical properties of the ultrafine-grained (UFG) Al–1.5Cu (wt.%) alloy were investigated. The UFG structure was obtained using high pressure torsion (HPT) technique. UFG alloy demonstrates high values of microhardness (1690 MPa), yield strength (515 MPa) and ultimate tensile strength (655 MPa), but low ductility ($\sim$3%). Subsequent short-term annealing at 150$^{\circ}$C and additional HPT deformation to 0.25 rotations resulted in some decrease in ultimate tensile strength to 450 MPa, which was $\sim$70% of the value before annealing but provided high ductility ($\sim$22%). The results suggests a high potential for practical application of the material. The proposed approach can be an universal effective way to achieve combination of high strength and high ductility for various UFG materials.