Author: AI Ustinov, SS Polishchuk, VS Skorodzievskii, VV Bliznuk

Institute: Electric Welding Institute named after E.O. Patona, st. Bozhenko, 11, Kyiv, 03680, Ukraine, G.V. Kurdyumov Institute of Metal Physics, Vernadsky St., 36, Kyiv, 03142, Ukraine

The influence of grain size on the damping capacity of quasicrystalline materials of the Al–Cu–Fe system is an important aspect of the study of their mechanical and physical properties. Quasicrystals are characterized by the unique ability to exhibit order at the atomic level, but without periodicity, which leads to unique characteristics including high strength and low thermal conductivity.

Thick quasicrystalline Al–Cu–Fe coatings obtained by electron beam physical vapor deposition (EB-PVD) on titanium substrates at different temperatures were used for damping analysis. The measurements performed using free damped oscillations on flat cantilever samples in the strain amplitude range from 10 to 10^-3 and temperatures of 290-620 K showed that the internal damping capacity of quasicrystalline materials increases with increasing temperature and strain amplitude. We also found that decreasing the grain size to nanoscale results in a significant increase in damping properties at temperatures above 520 K. The mechanisms of mechanical energy dissipation in nanostructured quasicrystals at elevated temperatures are discussed. 

The use of damping coatings can significantly increase the service life of high-strength components subjected to cyclic loading. The effectiveness of these coatings increases if they protect the surface from mechanical damage and corrosion. However, highly damping materials, such as aluminum-based alloys, often have low mechanical properties. At the same time, improving the strength through the addition of particles or thermomechanical treatment often reduces the damping capacity. Therefore, a more effective approach is to increase the damping of already strong materials. Quasi-crystalline materials are promising due to their high hardness and wear resistance, but they show difficulties in mechanical damping due to low dislocation mobility. This study focuses on the effect of QC grain size on their damping properties.

Reducing the grain size in quasicrystalline materials can significantly improve their damping properties. Smaller grains provide a higher density of grain boundaries, which helps dissipate dislocations and increases internal friction. This is important for the technology of creating materials that can absorb vibrations and reduce noise.

The studies found that grain size optimization in quasicrystalline Al–Cu–Fe alloys leads to improved damping properties, which can be used in various applications, from building materials to electronics. Thus, grain size control is a key mechanism for achieving the desired properties of quasicrystalline materials.