Dislocation Cell Wall Patterns
March Meeting 2010
Cell wall patterns for the relaxed, stress-free state of an initially random distortion
Presented Monday, March 15, 2010
Yong S. Chen
James P. Sethna
The Laboratory of Atomic and Solid State Physics (LASSP)
Ithaca, New York
Cell wall patterns for the relaxed, stress-free state of an initially random distortion. Top: Dislocation climb is allowed; Bottom: Glide only.
Left: Net dislocation density |ρ|. (A) When climb is allowed, the resulting grain boundaries are sharp, regular, and at the system scale; there is little substructure. (C) When climb is forbidden, there is a hierarchy of walls on a variety of length scales, getting weaker on finer length scales.
Right: Corresponding local orientation maps, with the three components of the orientation vector mapped onto RGB values. Notice the clear grains in (B), and the fuzzier cell walls in (D).
Bending crystals: The evolution of grain boundaries and fractal dislocation structures, Yong S. Chen, Woosong Choi, Stefanos Papanikolaou, and James P. Sethna.
Reporters may freely use this image as long as they include the following credit: "Image courtesy of Yong S. Chen/Cornell University".
For further information, contact: