In-situ observation of dislocation motion in icosahedral Al-Pd-Mn single quasicrystals

Abstract

The plastic deformation of icosahedral Al-Pd-Mn single quasicrystals has been studied by in situ straining experiments in a high-voltage electron microscope at elevated temperatures. The results provide the first direct evidence for dislocation motion in quasicrystals. The dislocation velocity, for an applied stress of 390 MPa, was determined as 7×10⁻⁷ms⁻¹. It was found that the dislocation motion takes place in planes which are perpendicular to threefold and fivefold lattice directions.