Grain boundary dislocation structures in (001) symmetric tilt boundaries in aluminum
Grain boundary dislocation (GBD) structures were studied in (001) symmetric tilt boundaries in aluminum bicrystals of controlled geometry using transmission electron microscopy. The intrinsic GBD structure of near-..sigma..1, ..sigma..5 and ..sigma..13 boundaries consisted of families of straight edge GBDs with Burgers vectors b = <100> or 1/2<110>, 1/10<310> and 1/26<510>, respectively. In each case the system chose GBDs with the smallest perfect Burgers vector perpendicular to the boundary in agreement with previous computer simulations using the method of molecular statics and a pairwise pseudo potential model. In addition, the b = <100> GBDs were straight and not serrated due to dissociations into partial GBDs and patches of stacking fault, as they are in gold according to earlier work. This result was attributed to the higher stacking fault energy of aluminum. Observations were also made of extrinsic GBD structures produced by the superposition of lattice dislocations on the intrinsic GBD arrays. The results were consistent with structures which could be obtained by a sequence of reactions in which each lattice dislocation dissociated into GBDs possessing Burgers vectors corresponding to the boundary DSC Lattice which then interacted in various ways with the intrinsic array.
- Research Organization:
- Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Materials Science and Engineering
- DOE Contract Number:
- FG02-84ER45116
- OSTI ID:
- 6149901
- Report Number(s):
- DOE/ER/45116-8; ON: DE86007003
- Country of Publication:
- United States
- Language:
- English
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