Micro-and nanostructured processes in the surface layers of the structural alloys under conditions of the high-energy processing.
The complex of the experimental studies which enabled us to establish the influence of the ultrasonic shock treatment (USST) regimes in the air, in an inert atmosphere and liquid nitrogen on microhardness, fine microstructure, phase and chemical composition of the aluminum alloy D16 and Ti6Al4V titanium alloy surface layers was performed. It was determined that the maximum effect of the hardening in the processing on the air and in argon and helium does not exceed 200% for alloy D16 at the short duration of ultrasound exposure is characterized by a significant increase in microhardness (strengthening effect), and for the longer handling - reduced to the initial values of the microhardness (loss of strength). USST technique in the liquid nitrogen with the full compression of the sample offered for the first time - the effect of the alloy D16 hardening was with ~ 500%; reduction of the microhardness values with increasing of the treatment duration was not observed. Cryodeformation causes crushing of the alloy to 15-20 nm, while maintaining a certain number of the micron size grains.
Worked of USST regimes for the composite coatings formation with a high (up to 5 times) microhardness through the introduction to the of D16 alloy surface layers of the carbon nanotubes, dispersed particles of Al2O3, Ti, Ni or BC.
The physical nature of the changes in the chemical composition of the low-alloy steel surface layers under the influence of the gas-discharge plasma in different environments was revealed. Mechanisms of the ion-induced surface segregation of the elements and anomalous penetration of the atoms of a gas-discharge plasma in the bulk of the material was proposed. The treatment regimes to improve of the corrosion properties was determined.
The formation of the structure and chemical composition regularities of the medical Co-Cr-Mo alloys surface layers by laser treatment in the different environments was investigated. It is established that the heterogeneity of the chemical composition in the plane of the melted surface is associated with different rates of the recrystallization and the surface segregation of the alloy elements during laser irradiation. Laser treatment of the Co-Cr-Mo alloys in an argon atmosphere leads to the formation of the periodic surface relief ring, wave period depends on the power density of the laser irradiation. It was first observed the formation of the nanocrystallites with the symmetry axis of the fifth order. It is proved that the main factor in reducing of the electrochemical potentials values on the surface is the formation of a continuous layer of the chromium oxide Cr2O3.