Achieve high ductility and strength in an Al-Mg alloy by severe plastic deformation combined with inter-pass annealing

Metallic materials processed by severe plastic deformation generally possess very high strength but a rather low uniform elongation, usually <5%. In the present Al-7Mg alloy processed by room temperature equal channel angular pressing combined with inter-pass annealing, impressive combination of high ductility (elongation~14.5%) and high strength (UTS~600 MPa) was achieved. The high ductility was rationalized by an enhanced work hardening originated from the pronounced dynamic strain aging effect and a bimodal grain structure. The high strength was mainly due to a prominent grain refinement and high dislocation density.