Quasi-crystalline alloys of the Al–Cu–Fe system, which have unique structural and physicochemical properties, attract considerable attention as promising materials for various applications, including protective coatings and functional elements. In particular, their high hardness, wear resistance and corrosion resistance make them attractive for use under conditions of increased mechanical loads. However, the mechanical properties of quasicrystals depend significantly on the grain size, and obtaining materials with submicron grains is a complex technological task.
This study is devoted to the investigation of the mechanical properties of quasicrystalline Al–Cu–Fe coatings obtained by the method [specify the method of obtaining, for example, magnetron sputtering] in order to form a submicron structure. Optimization of the deposition parameters made it possible to obtain coatings with an average grain size of [specify the grain size, for example, 500 nm].
Quasi-crystalline Al–Cu–Fe coatings with a submicron grain structure (approximately 400 nm) were fabricated using electron-beam vapor deposition (PVD). The mechanical properties of these coatings, as well as of a bulk sample of Al–Cu–Fe quasicrystal with an average grain size of approximately 50 μm, were studied using a combination of micro- and nanoindentation methods, including the construction of stress-strain curves. It was found that the hardening stage in the stress-strain curve at room temperature is significantly longer for the coating, and the softening effect is less pronounced than for the bulk sample. Possible causes of such a mechanical response of the coatings are discussed. Nanoindentation experiments revealed an intermittent nature of plastic deformation both in the bulk sample and in the coating.
The mechanical properties of the coatings, such as hardness and elastic modulus, were investigated using nanoindentation. The results obtained indicate high hardness of the coatings, reaching [specify the hardness value, e.g. 10 GPa], which significantly exceeds the hardness of conventional aluminum alloys. Analysis of the load-unload curves made it possible to determine the elastic modulus, the value of which was [specify the elastic modulus value, e.g. 150 GPa].
In conclusion, the obtained results demonstrate the potential of using quasicrystalline Al–Cu–Fe coatings with submicron grains to improve wear resistance and durability of various parts and structures. Further research will be aimed at optimizing the composition and structure of the coatings in order to achieve even higher mechanical characteristics.
Author: Yu.V. Milman, DV Lotsko, SN Dub, AI Ustinov, SS Polishchuk, SV Ulshin
Institute: Institute of Problems of Materials Science named after I.M. Frantsevich, Krzhizhanovsky str., 3, 03142, Kyiv, Ukraine,V.N. Bakul Institute of Superhard Materials, Avtozavodskaya St., 2, Kyiv, 04074, Ukraine, 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