Shear deformation of an icosahedral model quasicrystal at high temperatures was simulated by using molecular dynamics. The generation of a dislocation loop was studied with a new visualization technique and a critical stress almost as large as the theoretical shear strength was measured. Built-in dislocations began to move at a temperature-dependent critical stress that was lower by an order of magnitude. At zero temperature the dislocation propagated intermittently via large jumps, but its motion became viscous as the temperature increased. The dislocation cores bulged considerably due to pinning at obstacles inherent in the structure. A calculation of the energy of a Peierls-Nabarro

dislocation moving rigidly through the sample permitted the determination of the dominant obstacles. The results were considered in relation to 2 different models of quasi-crystalline plasticity.

Dislocation Motion in Icosahedral Quasicrystals at Elevated Temperatures - Numerical Simulation. G.D.Schaaf, J.Roth, H.R.Trebin: Philosophical Magazine, 2003, 83[21], 2449-65