Tangled Dislocation Structures inside Dislocation Channels of Rapid-Cooled and Tensile-Deformed Aluminum Single Crystals

Tangled dislocation structures inside the dislocation channels of rapid-cooled and tensile deformed aluminum single crystals were investigated by using BF-STEM. Inside the dislocation channels, arrays of the prismatic dislocation loops belonging to the primary slip system, such as (1 1 1) [0 1 (1) over bar] and (1 1 1 )[(1) over bar 1 0 ], were activated due to the internal stresses caused by the primary dislocations pile-up inside the cleared channels. The activated primary coplanar dislocations leave the dislocation loops elongated along the edge dislocation directions behind them. Inter-dislocation-loop interactions take place especially at the arrays of the prismatic dislocation loops of the primary slip systems and produce butterfly shape dislocation loops. Since the butterfly shape dislocation loops have sessile junctions, they should act as obstacles against the following multiplications and glides of the dislocations. As the interactions proceed, the arrays are stabilized and grow as tangles.

Automated summary

BF-STEM was used to investigate the tangled dislocation structures inside the dislocation channels of rapidly cooled and tensile deformed aluminum single crystals. It was found that prismatic dislocation loops were activated inside the channels, and interactions between these loops formed butterfly shape dislocation loops, acting as obstacles against the dislocations.