Nanostructured surfaces
Structure and peculiarities formation of high-entropy alloys coatings
Proshak A.V., Volosevich P.Yu.
G.V. Kurdyumov Institute for Metal Physics of NAS of Ukraine,
Acad. Vernadskii Blvd. 36, 03680, Kyiv Ukraine
E-mail: lukazesss@gmail.com

Necessity of adapting high-entropy alloys for using, led to attempt of obtaining the coatings and films from this alloys, which would maximally correspond the properties of initial state. 
 	In the article [1] the spin casting of alloy AlCuCoFeNiCr was conducted. As a result, the grain structure has been obtained with a dimension less than 1µm. At that time, our team have choosen the other approach, namely the coating by the PVD CAE method on the substrates and the study of the effect of substrates on the formation of these coatings.  Two coverages was deposited on substrates with stainless steel and on the copper, then the size of the forming elements has been determined. The coverages deposited on copper substrates had a grain structure of hexagonal form. The transversal size of grains has been in the range of 50-250 nm and longitudinal size has been in the range of 0.25-0.45 nm, with passing to the fine-grained area near-by the surface of substrates. In return the grain structure of coverages deposition on stainless steel was characterized by the size parameters of order of 2,5-15 nm. The form of the grains has been approximately spherical, except the cases where a drop fell on substrates. In this area the grain began to acquire a staggered form. To our opinion, a high difference of thermal conductivity of materials is the reason of forming of these structures. Bigger temperature on copper results in the overheat of coverage and activating of collective crystallization. Unlike copper, the non-high temperature of the substrates of stainless steel leads to a significant dispersion of the coating structure.
[1] Kourov N.I., Pushin V.G., Korolov A.V., Knyazev Yu.V., Kuranova N.N., Ivchenko M.V., Ustyugov Yu.M., Vanderka N. // Fizika tverdogo tela. 57., 8  1579-1589 (2015).