Precipitation Behavior of Al₃(Sc, Zr) Particles in Al-Mg-Zn Alloy during Two-stage Homogenization

Abstract

The precipitation of secondary Al3(Sc, Zr) particles in Al-Mg-Zn-Sc-Zr alloy during the two-stage homogenization has been studied by OM, SEM, and TEM. The results indicated that Al3(Sc, Zr) particles grew gradually with the first-stage homogenization temperature ranging from 380°C to 440°C. The first-stage homogenization temperature greatly affected the particle size of Al3(Sc, Zr). The lower the first-stage homogenization temperature was, the smaller the particle size of Al3(Sc, Zr) was. After the same second-stage homogenization treatment, the particles were coarsened, and the size was 15.2 nm, 15.9 nm, and 19.7 nm, respectively. Meanwhile, the Al3(Sc, Zr) particles exhibited a legume-like morphology and maintained a coherent relationship with the Al matrix after different homogenization treatments.