File:AZ31RolledSheetOpticalMicroscopy.jpg

Bin Li. Figure 4. Through-thickness (1.0 mm) optical microscopy with the differential interference contrast (DIC) illumination during three-point bending. The load remained on the specimen when the images were taken. (a) Alternating twin bands can be clearly observed. From the indenter toward both ends of the strip, the length and width of the twin bands decreases because the plastic strain decreases. The longest twin band (indicated by the dark arrow) passes the center line. (b) As the bending angle increases, the twin bands widen by lateral growth. Meanwhile, new bands (indicated by the arrow) that are nearly perpendicular to the original bands are formed.