Dislocation mechanism of high-temperature plastic deformation of Al–Cu–Fe and Al–Pd–Mn icosahedral quasicrystals

Microstructures in hot-impacted Al62.5Cu25Fe12.5 and Al70.4Pd21.2Mn8.4 icosahedral quasicrystals (IQCs) were studied by transmission electron microscopy (TEM). Densely distributed dislocations and stacking fault (SF) type contrast were observed for the first time in Al–Cu–Fe IQC. This result confirms that dislocation motion is an important deformation mechanism for Al–Cu–Fe IQC. Moving dislocations in quasicrystalline materials leave phason-type SFs behind. In situ TEM observation shows these phasonic SFs disappear due to intense diffusion at high temperatures.