Recrystallization mechanism and the relationship between grain size and Zener-Hollomon parameter of Mg-Al-Zn-Ca alloys during hot compression

摘要

Continuous dynamic recrystallization (DRX) associating with { 10 11}-{ 1 0 1 2} double twin, { 10 1 1} compression twin and {1012} tensile twin is observe during the hot compression of Mg-9, 10 wt.% A1-0.8 wt.% Zn-1 wt.% Ca alloys. The pinning effect of Al-Ca compounds, eutectic and precipitated Mg17A112 phase is observed at the DRXed grain boundaries. The pinning effect of Mg_(17)Al_(12) precipitates is greatly influenced by compression temperature, leading to a stronger influence of compression temperature on DRXed grain size than strain rate. Addition of 1 wt.% Ca to Mg-Al-Zn alloys reduces these influences.