Author:Shinya Miyazaki, Shinji Kumai, Akikazu Sato
Institute: Department of Materials Science and Engineering, Tokyo Institute of Technology
It is known that icosahedral quasicrystals based on Al–Cu–Fe have high resistance to deformation at temperatures below 0.8 Tm. The mechanisms of their deformation under such conditions have not yet been sufficiently studied. Despite the fragility of quasicrystals at low temperatures, their deformation is possible if they are protected by more ductile materials. This paper presents various methods for deformation of the quasicrystalline material Al–Cu–Fe. The main objective of the study is to analyze the deformation at low temperatures and compare the results with those obtained at high temperatures.
There are data on plastic deformation of quasicrystals with five-dimensional symmetry, which occurs with “phason deformation” in addition to the usual deformation in three-dimensional space. The motion of dislocations at high temperatures was studied, which was experimentally confirmed. It was also suggested that the force required to move a dislocation increases with decreasing temperature. Burgers vectors in such quasicrystals are represented using six main vectors. Dislocations associated with plane faults were previously observed. One of the goals of the work is a detailed determination of the Burgers vectors of dislocations in an Al–Cu–Fe quasicrystal located in an Al2Cu matrix.
Plastic deformation of Al–Cu–Fe quasicrystals embedded in Al2Cu at low temperatures is a unique process that sheds light on the mechanical properties of these complex structures. Quasicrystals, with their non-orthogonal symmetry, exhibit unusual characteristics that distinguish them from traditional crystals, making them particularly interesting for study at low temperatures.
During deformation at low temperatures, a complex mechanism of accumulation of plastic deformations is established, associated with the activation of dislocations and the formation of new boundaries. Research shows that when the temperature decreases, a significant change occurs in the operation of plasticity mechanisms, which causes an increase in the strength and rigidity of materials. This phenomenon can be explained by the slowing down of the movement of low-energy dislocations and the formation of stable structural elements, which contributes to the improvement of mechanical characteristics.
Further studies of plastic deformation of Al–Cu–Fe quasicrystals at low temperatures show that the unique mechanical properties of these materials may be related to their microstructure and composition. The occurrence of complex morphological changes, such as the formation of various spatial configurations of dislocations, significantly affects the stress distribution and plasticity characteristics. At low temperatures, an increase in elastic deformations is observed, which opens up opportunities for the use of quasicrystals in highly loaded conditions.
In addition, a comparative analysis of the properties of quasicrystals and traditional crystalline materials indicates significant differences in their deformation mechanisms. In particular, the layered structure of quasicrystals promotes the formation of new deformation stages, which can be used for advanced technologies in metallurgy and materials science.
Understanding the processes occurring during plastic deformation has practical significance for the development of new alloys and composites with high strength and thermal properties. This facilitates the creation of materials capable of functioning under conditions requiring resistance to deformation and high thermal loads.
Thus, plastic deformation of Al–Cu–Fe quasicrystals embedded in Al2Cu serves as an important object of research in the field of materials science, opening new horizons in understanding the behavior of complex metallic systems under extreme conditions.