Voloshko Svitlana M.

A new approach to the creation of composite wear-resistant coatings is proposed, which consists in realizing the advantages of combining the effect of mechanical nanocrystallization and mechanochemical reactions in the near-surface layers treated with ultrasonic impact treatment (UIT) in chemically active and inert media. This fundamentally distinguishes the proposed technique from the known methods of synthesis of bulk composite materials and provides more effective, compared to heat treatment and standard UIT schemes, surface hardening.

Essentially new scientific knowledge has been obtained on the physico-materials science basics and the laws of the surface layers hardening of the light structural alloys by ultrasonic shock treatment (UST) at cryogenic temperatures. These regularities are due to the suppression of the dynamic return processes and dynamic recrystallization, as well as the effect of the dislocations annihilation under the action of the deep cooling factor.

A comprehensive scientific approach to account for the "cross-effects" influence of physical and thermal deposition process parameters on structure and properties of nanoscale metal films Cu-Sn, Cu-Au, Cu-Mn, Cu-Sn-Mn, Al-Mn-Cr, Ni- Al, Ni-Au, Ti-Ag, Fe-Pt, and etc has been developed. The general regularities of diffusion processes due to subsequent thermal annealing in ultra-high vacuum, oxygen- and hydrogen containing atmosphere, ion-plasma and laser treatment have been discovered.

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.