O. V. Krysina

Numerical Simulation of Thermal Processes Involved in Surface Alloying of Aluminum with Titanium by an Intense Pulsed Electron Beam

The temperature fields arising in a Ti film – Al substrate system and bulk Ti specimen irradiated with a submillisecond intense electron beam are calculated in the one-dimension approximation. It is found that the temperature fields in the irradiated bulk Ti specimen and Ti film – Al substrate system differ greatly. Electron beam irradiation conditions which allow solid-phase and liquid-phase alloying of aluminum with titanium are defined

Generation of low-temperature gas discharge plasma in large vacuum volumes for plasma chemical processes

In the paper the principles of generation of low temperature capacitively coupled in a vacuum chamber of a large size with the use of original low-pressure arc discharges are considered. The designs of plasma sources and their main parameters are described. Examples of effective use of the generated plasma in plasma chemical modification of the surfaces of materials and products are presented.

Structure and properties of surface alloys synthesized by pulsed electron-beam treatment of a coating-substrate system

Nanostructured multiphase Al-Ti-Cu surface alloys are synthesized by pulsed electron-beam treatment of the coating-substrate system. In certain conditions, the strength and tribological characteristics of the initial material may be greatly improved.

Influence of Plasma Assistance on Arc Deposited MoN Coatings

The paper reports on a study to optimize the modes of plasma-assisted vacuum arc deposition of molybdenum nitride (MoN) coatings. It is shown that the parameters of plasma assistance influence the coating properties and that varying the ion current ratio in the metal-gas plasma makes possible MoN coatings with high hardness and high wear resistance.

Structure, phase composition, and properties of the titanium surface modified by electron-ion-plasma methods

The results of studying the phase and elemental compositions, imperfect substructure, and mechanical and tribological properties of commercially pure VT1-0 titanium subjected to combined treatment, which involves nitriding in low-pressure gas-discharge plasma and nitride coating deposition, are presented. The regularities are analyzed, the physical mechanisms of structural modification are discussed, and the optimal impact modes allowing a multiple increase in the microhardness and wear resistance of the material are revealed.

Modification of the titanium film–aluminum substrate system by a high-intensity pulsed electron beam with a submillisecond duration

Numerical simulation of the thermal processes that occur during doping of an Al surface with titanium by the method of liquid-phase mixing of a film–substrate system using an intense pulsed electron beam is carried out. As a result of our studies, it is shown that melting of the Ti-film–Al-substrate system makes it possible to form a multiphase submicrocrystalline structure with high strength and tribological properties in the surface layer.

Surface-alloy formation in film–substrate melting by intense pulsed electron beam. Part 2

The elemental and phase composition and defect structure of the surface layer on 5140 steel is considered after alloying by melting of a film–substrate (5140 steel) system under irradiation by intense pulsed electron beam; the film consists of aluminum or titanium. Treatment of the titanium–5140 steel system results in alloying to the depth of the molten layer (about 15 μm); polycrystalline structure (with submicron grains) based on α-phase hardened by titanium-carbide nanoparticles is formed. For the aluminum–5140 steel system, only a thin surface layer (about 2 μm) is alloyed, on account of the evaporation of aluminum from the steel surface. Martensit structure hardened by iron-aluminide nanoparticles is formed.

Modification of the surface layer of the system coating (TiCuN)/substrate (A7) by an intensive electron beam

In order to study the conditions of modification of the surface layer of the system coating (TiCuN)/substrate (A7) an analysis of processes occurring in the surface layer of the system wear-resistant coating/substrate irradiated by an intensive pulsed electron beam at a submillisecond exposure time has been carried out on the example of aluminum and titanium nitride. Irradiation has been carried out under conditions ensuring melting and crystallization of the surface layer of the material by a nonequilibrium phase diagram. It has been experimentally established that irradiation of the system coating (TiCuN)/substrate (A7) by an intensive electron beam is accompanied by changes in the phase composition of the material. It is evident that nanostructuring of the aluminum layer adjacent to the coating, and formation in it of nitride phase particles will contribute to hardening of the surface layer of the material, creating a transition sublayer between a solid coating and a relatively soft volume. The carried out analysis shows that binary nitrides based on TiN1-x are most likely to form under nonequilibrium conditions, since the homogeneity range of this compound is rather large. On the other hand, formation of the ternary compound Ti3CuN, which can be formed after an arc plasma-assisted deposition of titanium nitride of the composition TiCuN and by the subsequent intensive pulsed electron beam exposure, cannot be excluded.

Modification of Hypereutectic Silumin by Ion-Electron-Plasma Method

Hypereutectic silumin is aluminum-silicon alloy. It is widely used as the material for producing pistons and sliding bearings. The samples were obtained in Belorussian State University and in the Physical-Technical Institute of the National Academy of Sciences. The percentage of silicon is 18-20 wt.%. The structure has a large number of pores and cracks. The size of pores is 100 μm. The method of modification have been carried out in two steps. The first step is ion-plasma deposition ZrTiCu coating. The second step is melting the coating into the substrate. After modification microhardness is 3.2 GPa, wear resistance is 1.8 times less than in the untreated samples. The crystallites size is 0,2-0,4 μm. Thus, this method allows to obtain alloys in the near-surface layer, grinding the structure and increasing mechanical characteristics.

Electron-Ion-Plasma Doping of Aluminum Surface with Copper and Titanium - A Comparative Analysis of the Formed Structure and Properties

Deposition of a titanium or a copper film onto the surface of commercially pure A7 aluminum and irradiation of the “film/substrate” system with an intense pulsed electron beam are carried out in a single vacuum cycle. Formation of a surface doped layer with a thickness of (20-30) μm is revealed. It is shown that the modified layer has a multiphase structure of a cellular rapid solidification of the submicron-nanosized range. Irradiation parameters are determined. It is established that the developed modification method allows forming a surface doped layer with the microhardness more than 4 times (Ti-Al alloy) or more than 3 times (Cu-Al alloy) greater than the microhardness of A7 aluminum; the wear resistance of the surface alloy Ti-Al exceeds the wear resistance of the initial aluminum in ≈2.4 times; doping of aluminum with copper is accompanied with an increase in the wear resistance of the material in ≈1.5 times.