It is shown in this work that the effect of laser action on nanostructured coatings can be quite diverse. In this case, the decisive role is played by the initial structure of the coating, which sets the mechanism and direction of its transformation under external, including laser, influences. It is shown that for a CrMnSiCuFeAlTi coating in an argon atmosphere, the friction coefficient after laser treatment decreases, while the microhardness increases. We associate the first effect with a decrease in the roughness of the coating when it is melted by a laser beam. The second effect is due to the formation of the dislocation structure of the coating upon sharp heatingcooling.

In our proposed empirical model, the anisotropy of the surface energy and the thickness of the surface layer of the high-entropy FeCrNiTiZrAl alloy are calculated. The thickness of the surface layer of this alloy is about 2 nm, which is an order of magnitude greater than the thickness of the surface layer of complex crystals, but is of the same order of magnitude as that of metallic glasses. The hardness and other properties of the high-entropy alloy are the same as for metallic glasses, but are 2-3 times higher than the hardness of stainless steels. The surface energy of the high-entropy FeCrNiTiZrAl alloy is about 2 J/m2, which corresponds to the surface energy of magnesium oxide and other crystals with a high melting point. However, unlike these crystals, the friction coefficients of a high-entropy alloy (~ 0.06) are much lower than that of ordinary steels (~ 0.8). We have theoretically shown that the friction coefficient is proportionally dependent on the surface energy and inversely proportional to the Gibbs energy, which significantly decreases for a high-entropy alloy, leading to low friction. The high hardness and low coefficient of friction of the high-entropy alloy facilitates the deposition of coatings from them on structural metal products, which contributes to their widespread use.

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Current instability phenomena in a tunnel diode and electron self-organization processes In the article the mechanisms of electric instability in semiconductors are considered. The origin of negative differential conductivity of different types are described. On the example of functioning of the tunnel diode the mechanism of formation of the concentrated instability in semiconductors resulting in N-shaped voltampere characteristic of the diode is considered. It is shown that the «semiconductor structure consisting of two layers of semiconductors with different type of conductivity and an external source of electric energy» system can be considered as an open non-equilibrium thermodynamic system in which self-organization processes are possible. Operation of the tunnel diode in terms of the theory of self-organization in semiconductor structures is analysed. Processes of self-organization are resulted by change of concentration of carriers of a charge in power zones of p-and n-semiconductors of types which make the tunnel diode and therefore the direction of streams of electrons changes. The description of the movement of carriers of a charge in the considered semiconductor structure at various values and external shift is given: in an equilibrium state, at the return shift; at the direct shift and tension which have values less peak value; and tension exceeding «voltage dip». In a thermodynamic non-equilibrium system there can be processes of self-organization of various nature-tunneling and injection of electrons. At the same time the direction of processes of self-organization is defined by features of power ranges of the semiconductors making the tunnel diode and intensity of interaction between system elements.