Evolution of Zr-Bearing Dispersoids during Homogenization and Their Effects on Hot Deformation and Recrystallization Resistance in Al-0.8%Mg-1.0%Si Alloy

The precipitation behavior of Zr-bearing dispersoids in an Al-0.8%Mg-1.0%Si alloy was investigated for different homogenization treatments (450-550 °C). effect on the recrystallization resistance also studied during post-deformation annealing. With addition 0.2 wt.% Zr, two were observed depending conditions. Homogenization at 450 °C 2 h resulted fine and dense L12-Al3Zr (8-10 nm), which found to be coherent with matrix. In contrast, extended times, such as 12 °C, or increasing temperature 500-550 produced elongated DO22-(Al,Si)3Zr a larger size. During hot compression testing, Zr combined increased high-temperature flow stress by 20% relative base free revealing their potential inhibit dislocation motion dynamic recovery. Both have positive impact retardation annealing, but Al3Zr more effective than coarse incoherent (Al,Si)3Zr dispersoids.