Composition: Mg-8,8%Al-0,68%Zn-0,30%Mn-0,01%Si-<0,001%Cu-0,004%Fe, 0,008%-Ni<0,30%other.

Processing: Casting.

Etching: 10-30s immersion in 2% nital.

The alloy shows a microstructure of α-Mg dendritic grains and a completely divorced  eutectic (α-Mg + β-Mg₁₇Al₁₂) at the interdendritic spaces due to non-equilibrium solidification. Some regions, where the cooling rate was slower, show a partially divorced eutectic or even a lamellar aggregate due to cellular solid state transformation (see AZ80 alloy). Small and polygonal Al-Mn intermetallics are also observed, preferentially at the interdendritic spaces.

Mg-Al diagram

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.