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The effect of thermal exposure under high vacuum conditions on the chemical composition of the surface layers of the VT6 alloy with the mixed implantation of N+ ions by a carbon film is investigated. It is shown that under the conditions of thermal exposure the change in the concentration profiles of the distribution of elements is determined by the processes of chemical interaction, in which the diffusion of carbon and nitrogen into deeper layers does not occur. On the contrary, their concentration decreases and this is due to the formation of volatile compounds CO, CO2, or (CH)2 under thermal exposure. Titanium in the surface analyzed layer is in an oxidized state with various degrees of oxidation. Up to a depth of about 10 nm, the oxidation states of titanium are Ti4+ and Ti3+; in the transition region of the film/substrate, Ti2+. [ABSTRACT FROM AUTHOR]

We study the effect of the implantation of N+ ions on the chemical composition and atomic structure of the surface layers of VT6 titanium alloy. Nitrogen is accumulated in the surface layers up to concentrations of 30 at % or more, and chemical compounds of titanium nitride TiN are formed as phase inclusions. Presumably, this phenomenon is attributed to certain chemical processes, particularly, the chemical reactivity of titanium atoms and their propensity to interact with nitrogen atoms. Although the integral concentration of oxygen in the surface layers decreases under ion bombardment due to sputtering, oxidation of the components of the VT6 titanium alloy is observed in deeper layers. Oxygen from both the natural-oxide layer and the residual atmosphere in the vacuum chamber, penetrating deeper into surface layers during irradiation, is involved in the oxidation of titanium-alloy components. The accumulation of nitrogen, the formation of titanium nitrides, and the oxidation of the components of the VT6 titanium alloy testify to the significant role of chemical processes in the formation of the structural-phase state of the surface layers of the VT6 titanium alloy under N+-implantation conditions. [ABSTRACT FROM AUTHOR]