Plastic deformation properties of the orthorhombic ?'-(Al-Pd-Mn) quasicrystal approximant

The macroscopic plastic deformation behaviour of orthorhombic ξ'-(Al-Pd-Mn), an approximant of the icosahedral phase in the Al-Pd-Mn alloy system, has been investigated in the high-temperature regime between 650 and 775°C. Uniaxial deformation tests at a constant strain rate of 10 -5 s -1 were performed on single-crystal samples. Stress relaxation tests, strain-rate changes and temperature changes were carried out in order to determine the thermodynamic activation parameters of the deformation process.