Mechanical properties of Al–Cu–Fe quasicrystalline and crystalline phases: An analogy

• Mechanical property analogies of quasicrystalline Al–Cu–Fe and ω-Al7Cu2Fe phases.
• Quasiperiodicity is not essential for modelling QC-Al–Cu–Fe phase plasticity.
• Plasticity is controlled by dislocation climb.

The mechanical properties of the ω-Al7Cu2Fe crystalline phase have been investigated over a large temperature range (650–1000 K). Despite of its antinomic structure with the icosahedral Al–Cu–Fe quasicrystalline phase, i.e. periodic vs non-periodic, its mechanical properties are very similar to those of the quasicrystalline phase, which strongly suggest similar deformation mechanisms. Consequently, as for the quasicrystalline structure, we propose that dislocation climb might control the plastic deformation of the ω-phase. However, in the present case, the specificities of the quasicrystalline structure cannot be invoked to justify the predominance of dislocation climb, which questions the role of quasiperiodicity on dislocation mobility. We suggest that this deformation mode certainly results from specific non-planar extensions of the dislocation core.