Deformation Behavior, Microstructure and Mechanical Properties of new Al–Cu–Yb(Gd)–Mg–Mn–Zr Alloys

Deformation behavior, microstructure and mechanical properties of Al–Cu–Yb(Gd)–Mg–Mn–Zr alloy sheets are investigated. Based upon results of processing maps, optimum regimes for thermomechanical treatment at temperatures of 490–540°C and speeds of 0.01–1 sec–1 are determined. Annealing of cold-rolled sheets at temperatures up to 180°C leads to predominance of a strengthening effect due to aging over weakening from polygonization. Annealing of alloy sheets for 1 h at 400°C forms a partly recrystallized structure with a clear reduction in hardness from 145 HV to 75 HV. After 2 hours of annealing at 150°C, alloy combines a high yield strength of 412–417 MPa, a tensile strength of 441–449 MPa, and a good relative elongation of 2.7–3.2%. Sheet hardening followed by aging makes it possible to increase ductility by up to 5–8%, while the yield strength is 300–306 MPa with tensile strength of 364–389 MPa.