R A Valikov

The multicomponent doping of surface layers of materials under the influence of ion beams with a broad energy spectrum

The paper discusses the various factors that influence the efficiency of ion mixing. It was found that in the base of penetration of atoms multilayer films in polycrystalline substrate is the process of energy transfer from ions and primary knocked-on atom (PKA) of films to subsequent displacement cascade. At the same time the penetration of implanted atoms to great depths determined by the density of defects, radiation-stimulated migration of interstitial atoms and their physico-chemical interaction with the atoms of the matrix, which can be described by the model of an isotropic mixing. It is shown that doping atoms of the multilayer films, possibly the formation of gradient layers, which are determined by radiation traces in the substrate implanted atoms and their migration under irradiation by the ion beam with a broad energy spectrum.

Effect of ion polishing on corrosion resistance of the cladding of fuel elements from E110 alloy in the steam water environment

The method of modification of the outer surface of the cladding of fuel elements from E110 Zr alloy by means of irradiation with a radial beam of Ar+ ions with a broad energy spectrum is proposed. It is shown that the use of ion beam treatment at the final stage of the cladding production can improve the surface quality owing to removal of a large part of surface defects after mechanical polishing. The kinetics of the growth of oxide films on ion-beam-treated (cleaning or polishing by Ar+ ions) tubular Zr alloy specimens in a steam environment (350, 375, and 400°C up to 3000 h) was investigated. Monoclinic zirconia layer formation is found to occur on the specimen surface oxidized at 350°C in water and steam environments. Oxidation of the fragments of the alloy fuel-element cladding in steam under pressure contributes to the formation of a thicker and more friable oxide film in comparison with the oxidation in water.

Finish ion beam treatment of the longrange cylindrical products outer surface in automatic mode

The results of using of ion-beam technologies methods for finish treatment of metal products are presented. The experiments were performed at the installation ILUR-03, which allows the operation of cleaning, polishing and surface layers doping of the material of unlimited length cylindrical samples by radial Ar+ ions beam with energy up to 5 keV. The tubes from zirconium alloy E110 up to 500 mm length were used as samples for investigation. It is shown that selected automatic treatment modes reduce the surface roughness over the entire length of the samples and increase uniformity of the surface layer without observable effect on the bulk properties of material. Treatment promotes the formation of oxide films with improved defensive properties.

The impact of the initial state on the kinetics of oxidation ion- modified fuel cladding alloy E110

The paper examines the impact of the initial state (the presence of impurities, surface preparation), and surface alloying on the kinetics of the oxidation of fuel cladding alloy E110. The studies concluded that the use of ionic polishing instead of traditional chemical polishing helps to reduce the rate of oxidation of zirconium alloys. Also studied the effect of alloying elements introduced in the surface layers of claddings by ion mixing on the kinetics of the oxidation of the alloy E110.

Influence of thin oxide layers on tribological properties of E110 alloy tubular specimens under dry friction conditions

Experiments to simulate wear process of fuel cladding in case its contact with spacing grid. System «sphere-plane» selected as friction pair. Tubular parts of fuel claddings from E110 alloy diameter of 9.15 mm and length of 50 mm (wall thickness 1 mm) were used for investigations. Some claddings were subjected to ion cleaning and polishing under the influence of Ar+ ion beam with average energy of 3 keV. Samples were oxidized in steam- water conditions (T=300° C, p=17 MPa, time up to 100 h) to create thin oxide layers with a thickness of 1 mkm on the tubes surface. It is found that wear of the metallic samples takes place in elastically plastic deformation conditions at initial stage (2-5 min). Presenceof thin oxide layer (of thickness up to 200 nm) on the samples surface contributes to reduce wear due to the uniform redistribution its fragments on the friction track, and wear also samples takes place in elastically plastic deformation conditions. Presence of oxide layer with thickness of 700 nm on the samples surface increases wear in conditions of abrasion friction.

Modifying a cylindrical surface irradiated with a radial beam of argon ions with energies of up to 5 keV

Aspects of the ion modification of the outer surfaces of tubular samples of E110 (Zr–1% Nb) alloy is studied. The samples are irradiated with a radial beam of argon ions (0.5–5.0 keV, (5–10) × 1018 ion/cm2) on the ILUR-03 setup. It is found that such ion bombardment smooths the relief formed by mechanical abrasive treatment. It is demonstrated that the effect of ion polishing is most pronounced for surface irregularities of a certain size.

Modification of the cylindrical products outer surface influenced by radial beam of argon ions at automatic mode

Obtaining surface with high purity and good roughness is important for increasing the corrosion resistance and wear resistance of products working in corrosion-active environment. Installation ILUR-03 with the coaxial ion beam wide energy spectrum source for cleaning, polishing and surface doping of long cylindrical items has been developed. Upgraded installation ILUR-03 provides effective technological defects cleaning (abrasives after mechanical polishing, acid residues after chemical etching, adsorbed gases), surface polishing, film deposition by using magnetrons and surface doping by ion mixing method in one technological cycle.

Enhancement of the wear resistance of a surface of E110-alloy tubular samples by the method of ion mixing under the action of a radial beam of Ar+ ions

This work is devoted to investigation of the action of ion-beam processing (cleaning, polishing, and alloying by the method of ion mixing) on the wear resistance of the outer surface of tubular samples of E110 zirconium alloy. The state of the outer surface of the samples is investigated by microhardness measurement, profilometry, and scanning ion microscopy. The positive effect of ion-beam processing on the wear resistance of zirconium-alloy cladding is shown for a “sphere-cylinder” friction pair.

Identification of emission peaks in the spectra of oxide films on a metal surface in the infrared wavelength range

An algorithm for the processing of infrared (IR) reflectance spectra is developed in order to simplify the analysis of the states of oxide films on a metal surface, which allows the types of molecular compounds in an oxide formed in an aqueous medium on the surface of samples pretreated with ion beams via different modes (cleaning, polishing) to be determined. Irregular local cracks and pores with sizes of more than 10–50 μm are found in the oxide films using the IR spectroscopy method. Chemical compounds with hydroxyl groups of the type Me-O and Me-OH are revealed.

Using a wide-aperture argon ion beam to finish the outer surfaces of tubular samples

The effect ion-beam treatment with a wide-aperture beam of argon ions has on the outer surfaces of tubular samples is investigated. Samples are treated on the specialized KVK-10 installation. Experiments are performed for tubes 500 mm in length (Ø9.15 mm; wall thickness, 0.65 mm) made of E110 zirconium alloy that are used in the nuclear power industry as the shells of fuel elements. Analysis of the samples shows that surfaces can cleaned and polished via ion-beam treatment, and roughness Ra can be reduced from 2.0 ± 0.5 μm to 0.6 ± 0.1 μm.