Influences of pre-existing Mg17Al12 particles on static recrystallization behavior of Mg-Al-Zn alloys at different annealing temperatures

摘要

The present work revealed a potential to control the static recrystallization kinetics through regulating the feature of pre-existing Mg17Al12 particles in Mg-Al-Zn alloys. The AZ31 (Mg-3Al-1Zn) with rarely dispersoids exhibits the fastest recrystallization rate, while the AZ61 (Mg-6Al-1Zn) with only fine particles (similar to 100 nm) recrystallizes slower than AZ91 (Mg-9Al-1Zn) containing Mg17Al12 precipitates with scattered size distribution (ranging from less than 100 nm to above 0.6 mu m). Especially, we found that coarse Mg17Al12 particles in AZ91 are easier to trigger particle stimulated nucleation (PSN) at 275 degrees C than 175 degrees C, which compensates the strong recrystallization inhibition of fine dispersoids, leading to the recrystallization dramatically transforms from retarded to accelerated. (C) 2019 Elsevier B.V. All rights reserved.