Heterogeneous coatings based on the Al–Cu–Fe system, including quasi-crystalline phases, are promising materials for a wide range of applications, from protective coatings to catalytic systems. Their unique properties, such as high hardness, corrosion resistance and low friction coefficient, are due to a complex microstructure formed by a combination of amorphous, crystalline and quasi-crystalline phases.
Structural analysis of such coatings is a complex task requiring the use of a combination of methods, including X-ray diffraction (XRD), electron microscopy (EM), and atomic force microscopy (AFM). XRD allows identification of crystalline and quasi-crystalline phases, as well as determination of their orientation and degree of crystallinity. EM provides high-resolution visualization of the microstructure, allowing observation of the shape and size of crystallites, as well as the distribution of various phases. AFM provides information on the surface relief and allows assessment of the coating roughness.
The structure of heterogeneous Al–Cu–Fe coatings formed by electron beam vapor deposition was characterized. The composition of the obtained layers was selected in such a way as to correspond to the optimal composition for the formation of the icosahedral phase. The analysis revealed the presence of pronounced axial textures for both the icosahedral and β-cubic phases. It was found that the orientation of the quasi-crystalline phase is directly related to the type of texture observed in the crystalline phase.
One of the key aspects of structural analysis is the determination of the phase composition of the coating. In the Al–Cu–Fe system, various crystalline phases can form, such as Al2Cu, FeAl3 and CuAl2, as well as quasi-crystalline phases with icosahedral or decagonal symmetry. Identification of these phases requires careful analysis of diffraction patterns and their comparison with database data.
Further research is aimed at establishing the relationship between the composition, structure and properties of heterogeneous Al–Cu–Fe coatings containing a quasi-crystalline phase, which will make it possible to create materials with specified performance characteristics.
Author: AI Ustinov, SS Polischuk
Institute: International Center for Electron Beam Technologies, E.O. Paton Electric Welding Institute, Kyiv 03150, Ukraine, Institute of Metal Physics named after G.V. Kurdumov, Vernadsky st., 36, Kyiv 03142, Ukraine