Fig. 4—Optical micrographs showing the microstructure on a section perpendicular to the fractured surface of the AlMgSi alloy, (a) over all microstructure, (b) the skin region, (c) the band zone, and (d) the central region.

Fig. 4—Optical micrographs showing the microstructure on a section perpendicular to the fractured surface of the AlMgSi alloy, (a) over all
microstructure, (b) the skin region, (c) the band zone, and (d) the central region.