The effect of implantation of argon, oxygen and nitrogen ions on the physicochemical structure of the surface and the corrosion-electrochemical behavior of chromium-nickel steel 03Cr18Ni11has been studied. Methods of electrochemical polarization (EP), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used. Ion implantation of argon, oxygen and nitrogen leads to an increase in the corrosion resistance of steel 03Cr18Ni11 both in a neutral environment and in the presence of a corrosion activator (chloride anions), while irradiation with argon ions is most effective. It was found that after implantation of argon ions, a partial etching of the steel surface occurs, i.e. an increase in the true surface. This, in turn, facilitates the onset of the passive state. At the same time, the use of oxygen and nitrogen ions leads to smoothing of the surface. AFM data indicate that the studied steel treated with argon ions exhibits the greatest resistance to local corrosion. The implantation of oxygen and argon ions reduces the overall corrosion to the greatest extent. It is important to note that deep craters and traces of pitting corrosion do not form on the surface of the steel. The XPS data show that after ion implantation, there was a change in the concentration of the elements that make up the steel in the near-surface layers of the material in the depth of the implanted layer compared with the non-irradiated sample. It is established that the surface layers of steel are enriched with chromium atoms during ion implantation. This process occurs most intensively when samples are treated with argon ions. In this case, mixed chromium and iron oxides are formed, contributing to the passivation of the steel surface. Also, the process of ion implantation is accompanied by oxidation of the surface of the steel under study. This is confirmed by an increase in the oxygen content in the surface layers. To the greatest extent, this process occurs during implantation of oxygen ions. After corrosion tests, an increased chromium content is also observed on the surface of steel treated with Ar+ ions, which confirms the formation in this case of strong chromium oxides that remain on the surface during the corrosion of steel. The analysis of the fine structure of the XPS spectra showed that under the action of argon ions, the oxygen of surface oxides is redistributed in favor of chromium atoms and the formation of strong mixed iron and chromium oxides of the spinel type, including Fe2+, Fe3+, Cr3+ and Cr6+ compounds. It is important to note that although chromium oxides are also formed during oxygen implantation and in the same quantities as during argon implantation, the protective properties of the resulting compounds are noticeably lower. Therefore, not only the chemical composition is important, but also the structure of the resulting layers. It can be assumed that the high kinetic energy of heavy argon ions affects both the formation of a developed surface relief and the formation of strong mixed iron and chromium oxides of the spinel type.

The chemical composition, surface morphology, and electrochemical properties of Ti–Al–V alloys in the initial state and after irradiation with О+ ions and alternating irradiation with О+ and N+ ions differing in the irradiation dose of N+ ions are studied. Under irradiation with О+ ions, the active oxidation of Ti atoms is shown to occur, which is accompanied by the formation of titanium oxides and hydroxides. In the course of subsequent irradiation with N+ ions, the accumulation of nitrogen and formation of titanium nitride TiN are found to occur to lower concentrations as compared to those observed without the preliminary irradiation with О+ ions. It is assumed that this is due to the higher chemical activity of oxygen with respect to titanium atoms, as compared to that of nitrogen.

In this work, the surface of N18 alloy is modified with argon ions in a pulse-periodic mode. In situ electron spectroscopy methods are used to study changes in the chemical composition and local atomic structure caused by ion action on the surface. The chemical composition is determined by Auger electron spectroscopy using argon-ion profiling. Analysis of the local atomic structure is carried out by the method of spectroscopy of extended thin structures of electron energy losses. The excitation spectra of the M2,3 edge of iron and the K edge of oxygen are obtained in the geometry of backscattering from the surface. A variation in the energy of the incident electron beam makes it possible to obtain a signal from the excitation of oxygen and iron atoms from the same depth. The analysis of experimental data is carried out by the method of solving the inverse problem for finding pair correlation functions using regularization according to Tikhonov. The study of the local atomic structure is carried out at profiling depths of 5, 25, and 50 nm. It is shown that the ion-modified layer within the projective range of argon ions consists mainly of iron oxides. At a profiling depth of 50 nm, the parameters of the local environment of Fe atoms are close to those of unoxidized iron. Nickel as a result of surface diffusion is found at a depth of more than 50 nm.

Методами АСМ, РФЭС, РСА, механических и электрохимических испытаний изучено влияние имплантации инертных и химически активных ионов на формирование состава, структуры и модификацию физико-химических свойств тонких поверхностных слоев нержавеющей стали 03Х18Н11, титанового сплава ВТ6, армко-железа с напыленной пленкой углерода и армко-железа с напыленными пленками титан-алюминий. Показано, что имплантация ионов аргона, кислорода и азота приводит к повышению коррозионной стойкости стали 03Х18Н11 как в нейтральной среде, так и в среде, содержащей сильные активаторы коррозии - анионы хлорида. Установлено, что в условиях имплантации ионов N+ в титановый сплав ВТ6 формирование структурно-фазового состояния поверхностных слоев определяется химической активностью атомов азота к атомам титана. Облучение с высокими частотами следования импульсов, углеродных пленок на поверхности армко-железа, ионной имплантацией приводит к проявлению радиационно-термического эффекта, приводящего к коагуляции мелкодисперсных частиц в более крупные образования, и это сопровождается увеличением микротвердости пленок. Исследовано влияние перемешивания ионами аргона на формирование поверхностных слоев покрытия пленок алюминия и титана на подложке армко-железа. Определены параметры ионно-лучевого перемешивания, позволяющие сформировать интерметаллидные соединения (TiAl) в поверхностных слоях напыленной пленки титан-алюминий на подложке армко-железа. The influence of implantation of inert and chemically active ions on the formation of the composition, structure and modification of the physicochemical properties of thin surface layers of stainless steel 03X18N11, titanium alloy VT6, armco-iron with a carbon film sprayed and armco-iron with titanium-aluminum films sprayed has been studied by AFM, RFES, RSA mechanical and electrochemical tests. It is shown that the implantation of argon, oxygen and nitrogen ions leads to an increase in the corrosion resistance of steel 03X18H11 both in a neutral medium and in an environment containing strong corrosion activators - chloride anions. It is established that under the conditions of implantation of N+ ions into the titanium alloy VT6, the formation of the structural-phase state of the surface layers is determined by the chemical activity of nitrogen atoms to titanium atoms. Irradiation with high pulse repetition frequencies, carbon films on the surface of armco-iron, ion implantation leads to the manifestation of a radiation-thermal effect leading to coagulation of fine particles into larger formations, and this is accompanied by an increase in the microhardness of the films...

The paper comparatively studies the effect of implanting O+ ions into the Cu50Ni50 and Cu56Mn44 alloys and M0 copper, as well as N+ ions into the VT6 titanium alloy, the 03Kh17N12M2T stainless steel, and Armco iron, on the formation of the chemical composition and changes in the structural and phase state of the surface layers. It is shown that, under conditions of implantation of ions of chemically active elements, the accumulation of the implanted impurity, the formation of chemical compounds, and their precipitation in the form of phase inclusions are determined by the chemical activity of the implanted element to the alloy components. The results obtained will allow the further development of scientific foundations for the formation of the chemical and structural-phase state in materials under nonequilibrium conditions of ion implantation.

The effect that implantation of argon and oxygen ions (both individually and in combination) has on the physicochemical structure of the surface of 14Cr17Ni2 steel and its corrosion and electrochemical behavior is studied by linear sweep voltammetry (polarization curve measurements), atomic force microscopy, and X-ray photoelectron spectroscopy. Treatment with Ar+ ions results is enrichment of the surface in Cr atoms and a reduction in the total corrosion losses of steel samples, but it essentially has no effect on localized corrosion. In terms of reduction in localized and general corrosion, treatment with O+ ions produces optimal results. With this treatment, the surface undergoes extensive oxidation to a depth of more than 20 nm. The physicochemical properties (i.e., microhardness) of surface layers of the steel are not significantly affected by ion implantation.

The N+ ion implantation effect on the surface morphology, nitrogen accumulation, formation of chemical compounds, and structural and phase state of 03Kh17N12M2T steel and VT6 titanium alloy surface layers has been investigated. Irradiation with N+ ions results in nitrogen accumulation up to 17 at % in stainless steel, and the formation of chemical compounds, such as CrN, Cr2N, MoN, TiN, and Fe4N, in the form of small clusters with the crater-shaped surface. Nitrogen in the titanium alloy is accumulated up to 32 at % to form titanium nitrides, in particular, TiN, in the form of phase inclusions, distributed over the entire surface. The surface morphology of stainless steel is shown to depend on sputtering processes, while that of titanium alloy is shown to depend on the formation of numerous titanium nitride inclusions.

The effect of oxygen ion implantation on the physicochemical structure of the surface and the corrosion-electrochemical behavior of high-chromium Fe13Cr steel has been examined by potentiometry, atomic force microscopy, X-ray photoelectron spectroscopy, and microhardness measurements. Ion implantation leads to a significant reduction in corrosion losses. Optimal from the point of surface passivation and, consequently, reduction of corrosion losses of the material is the regime of steel treatment with oxygen ions with a dose of D = 5 × 1016 cm–2, after which the sample demonstrates the most stable behavior during local and general corrosion. It has been shown that the increase in the corrosion resistance of steel is due to the redistribution of elements in the surface layers caused by ion implantation and the intense formation of spinels of variable composition consisting of iron and chromium oxides with different oxidation states. In this case, the microhardness of the surface layers of the steel after ion implantation does not change significantly.

The chemical composition and structure of the Cu–Mn alloy after modification with oxygen ions with an energy of 10–30 keV and a dose of 1017 cm–2 have been investigated. Changes in the type of chemical bonding and atomic structure in irradiated Cu–Mn samples have been studied by X-ray photoelectron spectroscopy and X-ray diffraction. Electrochemical studies of ion-modified surfaces have been performed by measuring the anodic potentiodynamic polarization curves in a neutral borate buffer solution, hydrochloric acid, and potassium hydroxide.

In this work, we consider the effect of irradiation in Ar+ -> O+ and O+ -> Ar+ sequences on changes in the chemical compound, type of chemical bond and the local atomic structure of ultrathin (similar to 20 nm) iron surface layers. Investigation of the chemical compound and the type of chemical bond of the ion-modified surface was carried out by the XPS (X-ray photoelectron spectroscopy) and Auger electron spectroscopy. The study of changes in the local atomic structure was carried out by an XAFS-like method - electron energy loss fine structure (EELFS) spectroscopy. The parameters of the local atomic environment of oxygen and iron - partial interatomic distances, dispersion parameters, and coordination numbers - were obtained by analyzing atomic pair correlation functions. Analysis of experimental data showed that the two-stage irradiation of iron significantly changes the chemical compound and local atomic structure of the initial surface. This leads to formation of an oxide layer of greater depth than in the case of irradiation with only oxygen ions.

Abstract—The chemical composition and structure of thin surface layers of the Cu80Mn20 alloy before and after argon-ion irradiation in a pulse-periodic mode have been studied using X-ray electron spectroscopy and X-ray diffraction. It has been shown that the ion-beam action leads to the substantial redistribution of alloy components at depths exceeding the average path of projective range of argon ions. At the relative manganese concentration exceeding the content corresponding to the boundary of solid solution (Cu, γMn) homogeneity, the fcc structure, whose lattice parameters differ in depth, remains in the surface area of the irradiated Cu80Mn20 alloy. According to X-ray electron spectroscopy data, oxide forms of manganese are accumulated at the alloy surface; this leads to the improvement of passivation characteristics of the alloy. This may be related to the increase in the electrochemical activity of the alloy in the reaction of electoreduction of oxygen.

The composition and certain properties of the surface layer produced by oxygen-ion implantation into the Cu50Ni50 alloy are studied. Oxygen-ion implantation is shown to result predominantly in the oxidation of nickel, which is the more electronegative component of the alloy. Different forms of nickel oxide are concentrated mainly on the alloy surface. These oxide layers enhance the propensity of the alloy to passivation and a decrease in anodic currents in alkaline media. The effect of oxygen-ion implantation on the behavior of the alloy in neutral and acidic media is less obvious. Oxygen-ion implantation enhances the electrochemical activity of the alloy toward the oxygen-reduction reaction.

Implantation of argon and oxygen ions into the surface of iron in a pulse-periodic mode has been carried out. The chemical compound of ion-modified layers of iron has been studied by energy-dispersive X-ray spectroscopy (EDX), the local atomic structure of the surface has been studied by XAFS (X-ray Absorption Fine Structure) and spectroscopy of electron energy loss fine structures (EELFS). It is shown that irradiation by ions in the oxygen-argon sequence leads to more significant changes in both the chemical state of iron and the local atomic structure of a thin surface layer than irradiated by an argon ion alone.

Abstract—The influence of ion beam mixing of carbon on the surface morphology, chemical composition, atomic structure, and microhardness of the surface layers of samples of a VT6 titanium alloy is investigated. It is found that conditions for the formation of titanium carbides are created in the transition layer of the film/substrate system during ion beam mixing. The formation of titanium carbides with both stoichiometric and nonstoichiometric ratios of the components occurs. The concentration of titanium carbides increases with the increase in the irradiation dose and reaches 20 at % at a dose of 4 × 1017 ion/cm2. The mixing manifests itself in the mutual penetration of carbon atoms into the target and target atoms, mainly titanium, into the film. However, a thin surface layer with a depth of about 20 nm which is mainly composed of carbon atoms remains. It is shown that, in this layer, carbon atoms are in a disordered state with both sp2 and sp3 hybridization of the C–C bonds. The formation of titanium carbides in the transition layer and the disordered structure of carbon on the surface of the film during ion beam mixing determines the hardening of the surface layer, and as a result, an increase in the microhardness of the samples by 100% or more occurs. It is shown that the growth in the microhardness is associated with the layer formed as a result of mixing rather than the influence of irradiation on the titanium alloy substrate.