Abstract
In order to investigate by transmission electron microscopy the same type of deformation band before and after annealing a study was made of the microstructure of a twisted <111> aluminium crystal. Between the mainly single slip regions, bands of multiple slip were observed, with the development of misoriented deformation bands between the single and multiple slip regions. For one of the two types of deformation band, with a local misorientation of 25° over 15–25 μm the subgrains in the section studied were found to be equiaxed with a small spread of subgrain sizes but a large spread in subgrain angles (0.5–10°). On annealing, large subgrains developed which were somewhat elongated along the band, and these subgrains, which had the orientation of the single slip region, invaded the multiple slip regions. The nucleation mechanism was equivalent to straininduced boundary migration of the artificial 25° boundary produced by the deformation. The evidence of the microstructural changes indicated that a subgrain coalescence process was apparently occurring. The observed rate of the subgrain growth was however compatible with either a coalescence or a boundary migration process.
Get full access to this article
View all access options for this article.