Strain Induced Grain Boundary Migration in High Purity Aluminum

Abstract

A method has been developed for the study of grain boundary migration in high purity aluminum, which allows positive determination of the direction of grain boundary movements. By means of this method it was confirmed that the migration of grain boundaries resulting from surface energy takes place in the direction toward the centers of curvature of the boundaries. On the other hand, strain induced grain boundary migration, such as occurs in recrystallization, proceeds in a direction away from the centers of curvature of the moving boundaries. It was also found that certain strained grains serve as nuclei for strain-free grains of the same orientation which grow at the expense of neighboring strained grains. Most of the strain-free grains formed during the annealing of high purity aluminum cold rolled up to about 40 percent are produced by this mechanism of strain-induced boundary migration, without the formation of new nuclei.

Deformation Structures and Recrystallization in Magnesium Alloys

“…In many metals, bulging is particularly important when deforming to low strains. In aluminum, for example, this mechanism is replaced when the rolling reduction exceeds 40% (Beck & Sperry, 1950). As the present work was restricted to low strain deformation, no conclusions can be drawn about the possible role of bulging in highly deformed magnesium alloys.…”

Effects of hot and warm rolling on microstructure, texture and properties of low carbon steel

“…This fact, together with the verification of the existence of an intense partial RD//<110> α fiber, with a peak of H component, and a weaker ND//<111> γ fiber, allow us to infer that the recrystallization of ferrite could be developed through a low stored energy mechanism known as SIBM (strain induced boundary migration). The mechanism involves the bulging or migration of part of a pre-existing grain boundary to the interior of a more deformed grain, leaving behind a region virtually free of dislocations (Beck & Sperry, 1950). This mechanism may be responsible for the exaggerated grain growth observed when the material is coiled at high temperature (Figure 2, a).…”

Development of nanocrystalline structure in Cu during friction stir processing (FSP)

“…Such a mixed substructure provides numerous opportunities for nucleation. Thus, nucleation may occur at prior high angle grain boundaries, between two deformation bands (i.e., in transition bands) or within shear bands [18][19][20][21], resulting in a heterogeneous distribution of nuclei in the deformed matrix. In the FS processed material in this study (Fig.…”