In order to investigate the nature of the dislocation structures, icosahedral single quasicrystals were plastically deformed between 821 and 580C (where quasi-steady state deformation was possible) and down to 482C (involving strong work-hardening) during loading at up to 1.6GPa. The dislocation structures were imaged in a 1000kV high voltage transmission electron microscope. At high temperatures, the dislocations were arranged in a 3-dimensional network of low dislocation density. At low temperatures, the dislocations formed narrow bands of high dislocation density. Some dislocations strongly bowed out between obstacles, dislocation debris or jogs. Other dislocations consisted of segments which were oriented crystallographically and were connected by smoothly bent segments. In other samples, the dislocation loops were arranged close to many different planes, but parts of them bowed out onto inclined faces. Many of the observed features could not be interpreted in terms of the present understanding of dislocation behavior.

Temperature Dependence of Dislocation Processes during Plastic Deformation of i-Al-Pd-Mn Single Quasicrystals. U.Messerschmidt, L.Ledig, M.Bartsch: Journal of Non-Crystalline Solids, 2004, 334-335, 436-43