LAUSR

ABSTRACT The microstructure and mechanical properties of the Al–4Cu–2.7Er–0.3Zr alloy were investigated. The precipitates of the L12 structured phase with sizes 37 ± 12 nm were formed in lines and homogenously distributed inside the aluminium matrix after annealing at 605°C for 1 h. The as-rolled Al–4Cu–2.7Er–0.3Zr alloy developed an increased hardness after 1 h annealing at 100–550°C and 0.5–6 h annealing at 150–250°C due to precipitation of the Al3(Er,Zr) phase. Addition of Zirconium improved the tensile properties relative to those of the Zr-free alloy by approximately 20 MPa: yield strength = 273–296 MPa and ultimate tensile strength = 296–328 MPa in the alloys annealed at 100–150°C. GRAPHICAL ABSTRACT