Microstructure, mechanical properties and superplasticity of the Al-Cu-Y-Zr alloy

The phase composition, mechanical properties, and superplastic deformation behavior of a novel Al-4.7Cu-1.6Y-0.3Zr alloy were analyzed. The precipitation of Al-3(Zr,Y) dispersoids was observed during a homogenization treatment. The precipitates have an L1(2) structure and a mean size of 17 and 19 nm at 540 and 590 degrees C, respectively, The sheets exhibit a yield strength of 292 MPa, an ultimate tensile strength of 320 MPa, and an elongation of 5.3% after simple thermomechanical treatment and annealing at 100 degrees C. The Al-4.7Cu-1.6Y-0.3Zr alloy exhibits superplasticity with m > 0.4 and elongation of 300-400% within a temperature range of 550-580 degrees C and a strain rate range of 1 x 10(-4) to 1 x 10(-3)s(-1).