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

Dislocation motion in icosahedral Al-Pd-Mn quasicrystals has been observed in situ in a transmission electron microscope between 700 and 750degreesC. Contrast analyses show that it takes place by pure climb in twofold, threefold and fivefold planes. Moving dislocations exhibit polygonal shapes with edges parallel to twofold directions, in agreement with a difficult jog-pair nucleation. Dislocation multiplication, annihilation and local pinning are described and discussed, as well as the role of the phason faults trailed in the wake of dislocations, at the lowest investigated temperatures

Dislocation climb in icosahedral quasicrystals

Abstract We discuss here some arguments in favor of climb being the dominant mode of dislocation motion responsible for the plastic deformation of icosahedral quasicrystals