Plastic deformation of decagonal Al–Ni–Co single quasicrystals

Decagonal phases are quasicrystals which exhibit quasiperiodic order in two spatial directions and translational order along the third spatial direction. We present results of a series of uniaxial compression experiments on decagonal Al–Ni–Co single quasicrystals in two modifications, the type I superstructure and the basic cobalt-rich state. We have chosen different orientations of the deformation samples, parallel, inclined by 45° and perpendicular to the periodic axis. The samples were deformed at a strain rate of 10−5 s−1 at temperatures between 710 and 860°C corresponding to 70 and 81% of the melting temperature, respectively. Stress relaxation tests were carried out to determine the activation volume and the stress exponent. The two modifications show anisotropies in the plastic behaviour which differ distinctly. The macroscopic deformation tests are accompanied by a study of the microstructure of deformed material by means of transmission electron microscopy.