Comparative studies of the irradiation effects of ZrWn coating with helium and krypton ions at low and high temperatures

The effect of irradiation with low-energy helium and krypton ions on the surface structure, hardness, and corrosion resistance of ZrWN coatings was studied. Magnetron sputtering was used to form ZrWN coatings on structural steel substrates. Irradiation was carried out at room temperature and 600 °C. It was shown that the structure and properties of coatings degrade under irradiation with helium and krypton ions. Irradiation temperature affects the degree of degradation – with increasing temperature, corrosion resistance and strength characteristics of the coating decrease

Distribution of local deformations on the near-surface layers and scale effects of low-alloy steel specimens

This paper presents data on the study of the evolution of local microdisplacements on the surface of specimens made of ferritic-austenitic steel during compressive deformation. The experiment was performed on the test machine “Universal Testing Machine 4500” using a digital optical system Vic-3D for deformation of the specimen surface. It was found that the transition from stage III to stage IV is accompanied by an increase in the area of the region with high values of microregion displacements in the center of the specimen, which corresponds to the parabolic stage

Binary phase diagrams based on elements VIIIA and IB periods of the D. I. Mendeleev's table and features of crystallographic parameters

The data obtained as a result of the analysis of crystallogeometric parameters and the structure of state diagrams of binary systems from elements VIIIA and IB periods of the D. I. Mendeleev's table are presented. It is shown that the classification of the evolution of phase diagrams of binary systems by types, proposed by T. A. Lebedev, correlates with features of concentration dependences of the deviation of atomic volumes in solid solutions from Zen law

The application of an assisting gas plasma generator for low-temperature magnetron sputtering of Ti-C-Mo-S antifriction coatings on titanium alloys

The positive effect of assisting influence of high-density gas plasma formed by an independent plasma generator PINK on mechanical and tribological characteristics of Ti-C-Mo-S magnetron coating on titanium alloys at lowered to 350°С temperature of coating regardless of alloy structural condition was revealed by methods of calotest, nanorecognition, scratch testing and frictional material tests. The coating formed by means of a combined magnetron plasma method reduces titanium alloys friction coefficient in multiple times and increases wear resistance by two orders of magnitude. At the same time the mechanical properties of ultra-fine-grained titanium alloys obtained by nanostructuring do not deteriorate

Effect of irradiation with low-energy alpha particles on the structural-phase state of coatings of triple nitride systems based on titanium and vanadium on steel

The paper presents the results of studies of the effect of alpha-particle irradiation on the structural-phase composition of nitride coatings CrTiN, MoTiN and NbTiN on the surface of a steel substrate. The coatings were formed by vacuum-arc condensation in a gas medium with N2 using ion bombardment with the use of Ti, Cr, and Mo cathodes. In addition, coatings in a N2 gas medium on a steel substrate were produced by magnetron sputtering from Ti and Nb metals. Experimental data and the analysis of state diagrams of ternary systems of nitrides based on titanium and vanadium with transition metals of IVA-VIA groups have allowed deriving criteria for choosing materials for production of nitride coatings with a fairly high radiation stability

Structure peculiarities of binary state diagrams of vanadium with neighboring elements of Mendeleev’s periodic table

Data on search for correlations between a structure of state diagrams of binary systems based on V-Me (Me = Ti, Zr, Hf, Nb, Ta, Cr, Mo, W) and crystal-geometric and crystal-chemical parameters were presented. Manifestation of both positive and negative deviations in experimental concentration dependences of the atomic volume in solid solutions in systems V-Me (Me = Ti, Nb, Ta, Cr, Mo) from Zen's law was established. It was found that in the systems with unbounded regions of solid solutions, the deviation from Zen's law is insignificant. A correlation was found between the types of state diagrams and the difference in atomic volumes of alloy-forming elements in systems V-Me (Me = Ti, Nb, Ta, Cr, Mo)

The interaction potential of an open nanotube and its permeability: molecular dynamics simulation

The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized

Crystallographic parameters of compounds and solid solutions in binary systems Cu-Pt and Ga-Pt

The study establishes that the packing index in compounds of the system Cu-Pt is close to the value 0.74 against a slight deviation from the Zen law of atomic volumes. The compounds in the system Ga-Pt have the highest values of the packing index in the range of the equiatomic composition, which greatly exceed ψ for close-packed structures based on FCC and HCP lattices for compounds made of the same kind of atoms. A correlation between singular points on the phase diagram of the system Ga-Pt and high values of the packing index in compounds is established

About a permeability of graphene pores

The present paper theoretically studies helium and helion passage through pores in a graphene sheet using classical molecular dynamics. It was found that, within the frame of the suggested model, for considerably large pores with the diameter of 0.75 nm, helium permeates much better than helion, which is quite an unexpected result in itself

Steel surface TiCrN, TiMoNcoatings structural phase state change features after low-energy alpha particles irradiation

The low-energy alpha particles irradiation impact on structural phase composition and 321S31 steel surface TiCrN and TiMoN coatings morphology have been summarized. The samples irradiation has been carried out in the DTs-60 (the Dubna cyclotron) heavy-ion accelerator by the{4}He{+2} low-energy ions (40 keV) into a 1.0•10{17} ion/cm{2} fluence. It has been established thatthe 321S31 steel alpha particles implantation having energy of 40 keV results in the austenite initial γ-structurepartial transfer, stimulated by the irradiation, to the martensiteα-structure. The low-energy alpha particles irradiation within the fluencies range from 10{16} to 10{17} ion/cm{2} for the TiCrN and TiMoN coatings formed by the ionic bombardment condensation method doesn't result in the phase transfers with a coating crystal lattice type change