Elastic anisotropy effect on the stability of a subgrain boundary defect in a C16 crystal

• Published in: Advanced engineering materials Vol. 4; no. 8; pp. 595 - 597
• Main Authors: Loubradou, M, Lay, S, Bonnet, R, Belgacem, C H, Fnaiech, M
• Format: Journal Article
• Language: English
• Published: 01.01.2001
• ISSN: 1438-1656

A low-angle tilt-boundary separating two thin Al sub 2 Cu (C16) lamellae of the Al-Al sub 2 Cu eutectic grown by directional solidification has been observed by high resolution electron microscopy (HREM). The dislocations run parallel to a < 113 > direction. Two kinds of defects are observed: isolated mixed dislocations with Burgers vectors b = < 001 > or (1/2) < 111 > , and a group of three close and strongly interactive mixed dislocations. The detailed structures of these latter dislocations have been analyzed from a transmission electron micrograph. Calculations using isotropic and anisotropic elasticity have been undertaken to understand the stability of the group of three dislocations. It is shown that only anisotropic elasticity is able to predict the observed positions of the dislocation cores.