Dislocation Mechanisms and Plasticity of Quasicrystals: TEM Observations in Icosahedral AlPdMn
|
| Journal |
Materials Science Forum (Volume 509) |
| Volume |
Advanced Structural Materials II |
| Edited by |
H. Balmori-Ramírez, M. Brito, J.G. Cabañas-Moreno, H.A. Calderón-Benavides, K. Ishizaki and A. Salinas-Rodríguez |
| Pages |
49-56 |
| DOI |
10.4028/www.scientific.net/MSF.509.49 |
| Online since |
March, 2006 |
| Authors |
Daniel Caillard
|
| Keywords |
Al-Pd-Mn Alloys, Dislocation, Plasticity, Quasicrystal, Transmission Electron Microscopy (TEM) |
| Abstract |
Quasicrystals can deform Plastically at high temperatures by the movement of
dislocations like in crystals. Little is known, however, on the mechanisms that control dislocation movements in these structures. In a first part, the crystallography of quasicrystals is introduced as the projection, in the physical space, of a periodic structure in a hyperspace with more than three dimensions (6 in the case of icosahedral structures). The main properties of dislocations are defined
in the physical space and in the six-dimensional space. New results are then presented, showing that dislocation movements may have a large component of climb, in contrast with all existing models that are based on glide processes only. Dislocation movements in two-fold and five-fold planes are
compared and discussed in connection with macroscopic mechanical properties. |
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