The sandwich-like multilayer structure containing large-scale faceted quasicrystalline Al–Cu–Fe grains exhibits a unique combination of strength and ductility, making it promising for applications in a variety of fields, from aerospace to biomedicine. Synthesis of such materials requires precise control of deposition parameters, such as substrate temperature, deposition rate, and gas composition. The slightest deviations can lead to the formation of undesirable phases or defects that reduce performance.
The use of electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) allows for detailed microstructure investigation and the identification of the relationship between process parameters and the resulting properties. Particular attention is paid to the study of grain boundaries, since they have a significant impact on the mechanical behavior of the material. The presence of coherent boundaries can contribute to increased strength, while incoherent boundaries can serve as crack initiation centers.
To improve the performance characteristics of Al–Cu–Fe layered structures, modification of the composition by alloying with other elements, such as manganese, chromium or zirconium, seems promising. These elements can stabilize the quasi-crystalline phase, increase its resistance to high temperatures and corrosion. In addition, the use of heat treatment allows optimizing the microstructure, reducing residual stresses and increasing the homogeneity of the material. Thus, a deep understanding of the processes of formation and modification of Al–Cu–Fe layered structures opens up broad opportunities for creating materials with specified properties.
Unlike conventional crystals, faceted quasicrystals are characterized by a unique internal organization. Despite initial predictions of their widespread use, the limited impact on the facets prevented the widespread use of these materials. We have developed a simple heat treatment method that allows the creation of a multilayer sandwich structure, each layer of which consists of large pentagonal dodecahedrons formed by Al-Cu-Fe quasicrystals. Remarkably, channels are formed between adjacent Al-Cu-Fe layers, which significantly increase the surface area of the quasicrystalline material.
Author: Dongxia Wei, Zhanbing He
Institute: State Key Laboratory of Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China