Plastic deformation of icosahedral Zn-Mg-Dy single quasicrystals

Plastic deformation experiments have been performed on Zn-Mg-Dy icosahedral single quasicrystals at temperatures between 490 and 530 degrees C and at strain rates of 10(-5) and 10(-6) s(-1). 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%. Thermodynamic activation parameters of the deformation process were determined and are discussed in comparison with those found for icosahedral Al-Pd-Mn. Microstructural investigations by transmission electron microscopy on deformed samples were performed and indicate a deformation mechanism mediated by dislocations