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

Continuous dynamic recrystallization (DRX) associating with {101¯1}–{101¯2} double twin, {101¯1} compression twin and {101¯2} tensile twin is observe during the hot compression of Mg–9, 10 wt.% Al–0.8 wt.% Zn–1 wt.% Ca alloys. The pinning effect of Al–Ca compounds, eutectic and precipitated Mg17Al12 phase is observed at the DRXed grain boundaries. The pinning effect of Mg17Al12 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.