Mechanisms of plastic deformation of icosahedral quasicrystals
نویسندگان
چکیده
Icosahedral quasicrystals deform plastically by dislocation motion. The deformation behaviour can be modelled by simple equations of dislocation mobility, the damage of the quasicrystal structure and the kinetics of dislocation evolution, but fundamental questions are still discussed, like the mode of dislocation motion (glide or climb) and the role of phason defects. 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
منابع مشابه
Direct observation of solid-state reversed transformation from crystals to quasicrystals in a Mg alloy
Phase transformation of quasicrystals is of interest in various fields of science and technology. Interestingly, we directly observed unexpected solid-state epitaxial nucleation and growth of Zn6Mg3Y icosahedral quasicrystals in a Mg alloy at about 573 K which is about 300 K below the melting point of Zn6Mg3Y, in contrast to formation of quasicrystals through solidification that was usually fou...
متن کاملLarge-scale Molecular Dynamics Simulations of Shock Waves in Laves Crystals and Icosahedral Quasicrystals
Quasicrystals and ordinary crystals both possess long-range translational order. But quasicrystals are aperiodic since their symmetry is non-crystallographic. The aim of this project is to study the behavior of shock waves in periodic and aperiodic structures and to compare the results. The expectation is that new types of defects are generated in the aperiodic materials. The materials studied ...
متن کاملAn analysis of elementary dislocations in icosahedral Al-Pd-Mn by Large Angle Convergent-Beam Electron Diffraction (LACBED)
Large Angle Convergent Beam Electron Diffraction (LACBED) experiments on dislocations located in the mirror planes of icosahedral AlPdMn single grains show that – as previously inferred from standard image contrast technique – the direction of the Burgers vector is perpendicular to the mirror plane of movement, thus confirming the fact that climb should be an important process for the plasticit...
متن کاملSuperior room-temperature ductility of typically brittle quasicrystals at small sizes
The discovery of quasicrystals three decades ago unveiled a class of matter that exhibits long-range order but lacks translational periodicity. Owing to their unique structures, quasicrystals possess many unusual properties. However, a well-known bottleneck that impedes their widespread application is their intrinsic brittleness: plastic deformation has been found to only be possible at high te...
متن کاملMn Self-Diffusion in Single Grain Icosahedral Al70Pd21.5Mn8.5 Quasicrystals.
The self-diffusivity of 54Mn in single grain icosahedral Al70Pd21.5Mn8.5 quasicrystals has been determined by a precision grinding technique. In the range from 870 to 1093 K the temperature dependence of the Mn selfdiffusivity D follows the Arrhenius equation with an activation energy Q = (180.8±4.6)kJmol-1 and a preexponential factor D0 = 3.4×10-4m2s-1. The experimental results are discussed t...
متن کامل