Plasticity of icosahedral Zn–Mg–Dy single quasicrystals

We present the results of first deformation experiments on Zn–Mg–Dy icosahedral single quasicrystals. The samples were produced by the flux growth technique. The plastic deformation experiments were performed at temperatures between 490 and 530°C at strain rates of 10−5 and 10−6 s−1. The thermodynamic activation parameters of the deformation process were determined. The stress–strain curves show strong yielding followed by a steady state regime with a constant flow stress level up to strains of about 8%. Microstructural investigations by transmission electron microscopy on deformed samples indicate a deformation mechanism mediated by dislocations. We found a high density of planar defects which were interpreted as slip planes of moving dislocations.