V.P. Rotshtein

Publications (15)4.7 Total impact

• Source

  Available from: Alexey B. Markov

  Article: Synthesis of Ti3Al and TiAl based surface alloys by pulsed electron-beam melting of Al(film)/Ti(substrate) system

  V. P. Rotshtein, Yu. F. Ivanov, Yu. A. Kolubaeva, X. Mei, A. B. Markov, E. P. Naiden, G. E. Ozur, K. V. Oskomov, S. A. Popov, E. L. Pryadko, A. D. Teresov, V. A. Shulov
  [show abstract] [hide abstract]
  ABSTRACT: Phase formation and surface hardening in the 100-nm-thick Al(film)/Ti(substrate) system under conditions of pulsed electron-beam melting (∼15 keV, ∼3 μs, 3–4 J/cm2) have been studied depending on the number of film deposition-melting cycles. Using this method, submicrocrystalline and nanocrystalline surface alloys with thicknesses ≥3 μm based on Ti3Al and TiAl intermetallics have been obtained on the titanium substrate.
  Technical Physics Letters 04/2012; 37(3):226-229. · 0.56 Impact Factor
• Article: High-Current Pulsed Vacuum-Arc Evaporator for Surface-Alloying Technologies

  S.A. Popov, D.I. Proskurovsky, E.L. Pryadko, A.V. Batrakov, A.B. Markov, G.E. Ozur, V.P. Rotshtein
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  ABSTRACT: Plasma sources based on vacuum-arc discharge have a big disadvantage due to the high fraction of droplets in plasma flow produced during the operation of cathode spots. To avoid droplets, various kinds of curved magnetic filters are used. We have suggested one more approach to reduce the droplet content in an arc-discharge plasma basing on the intense evaporation of droplets caused by the ignition of ldquodroplet spotsrdquo in a discharge cell. A Penning-type arc discharge provides favorable conditions for the ignition and operation of droplet spots. In such a cell, a uniform plasma column is formed, whose temperature and density are much higher than those of a usual vacuum arc at the same discharge current. A further increase in energy density in the plasma of a reflective-discharge cell could be achieved by means of both the increase in discharge current and B-field optimization. This paper presents the results of the development and characterization of the pulsed plasma-source model combining a well-known high-current vacuum-arc evaporator with a Penning discharge cell. It has been recognized that the ion-current amplitude at the source output is as high as 800 A, plasma density is as high as 10¹⁴ cm^-3, and electron temperature range is 6-8 eV. Those conditions lead to an intensive evaporation of droplets on the fly. The copper film-deposition rate was measured to be at 1.5 nm/pulse, which corresponds to an instantaneous deposition rate of 2000 nm/s. The first results of the use of the evaporator for surface alloying are also presented.
  IEEE Transactions on Plasma Science 09/2009; · 1.17 Impact Factor
• Article: Surface alloying of metallic substrates with pre-deposited films through a pulsed electron-beam mixing

  A. V. Batrakov, A. B. Markov, G. E. Ozur, D. I. Proskurovsky, V. P. Rotshtein
  [show abstract] [hide abstract]
  ABSTRACT: Microstructure and properties of the surface alloys resulted from a pulsed liquid-phase mixing of metallic substrates with pre-deposited films were studied. As a tool for the liquid-phase mixing, a low-energy (~30 keV), high-current (~30 kA) pulsed (0.8–3 µs) electron beam of energy density ranging from 1 to 15 J cm−2 has been employed. Three immiscible systems (Ta/Fe; Al/Si/Al/Si/Al/Si/Al; Al/C/Al/C/Al) and two systems with different solid solubility of components (Cu/316 stainless steel; Zr/Ti/Ti-6Al-4V) were chosen for the surface alloying investigation.
  The European Physical Journal Applied Physics 08/2008; 43(03):283 - 288. · 0.77 Impact Factor
• Source

  Available from: pppl.gov

  Conference Proceeding: HV hold-off of large surface area stainless steel electrodes with pulsed electron beam treatment

  D.I. Proskurovsky, A.V. Batrakov, V.P. Rotshtein, K.V. Karlik, D.J. Johnson
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  ABSTRACT: Large area stainless steel electrodes have been treated with a pulsed electron beam for the avoidance of electron emission and plasma induced arcs that limit high voltage hold-off. High-voltage tests have shown that for electrodes of area ∼100 cm² this treatment can provide pulsed (∼100 ns) breakdown fields over 1 MV/cm. The results obtained suggest that this way of preparation of the surface of the convolute system and other parts of pulsed power systems holds promise.
  Pulsed Power Conference, 2003. Digest of Technical Papers. PPC-2003. 14th IEEE International; 07/2003
• Conference Proceeding: Metallic materials processing with intense pulsed electron beams

  V.P. Rotshtein
  [show abstract] [hide abstract]
  ABSTRACT: The paper reviews the results of studies of the mechanisms for modification of the structure and properties of metals and alloys with intense pulsed electron beams over wide ranges of beam parameters (10-10 ³ keV 0.02-300 μs, 1-2000 J/cm²). For pure metals (Fe and Cu) and Fe-C alloys used as examples, if has been demonstrated that increasing the amount and input rate of the energy delivered to a target allows various conditions for the formation of the beam-affected zone to be realized: from fast melt quenching to shock-wave loading. This makes it possible to produce various nonequilibrium structure-phase states, including nanocrystalline and shock-wave induced structures. It has been shown that low-energy, high-current electron beams are most convenient for the study of microstructural processes at pulsed melting. The sources of this type of beams are most suitable for the surface treatment of articles made of constructional and tool alloys aimed at improving their performance
  High-Power Particle Beams, 1998. BEAMS '98. Proceedings of the 12th International Conference on; 02/1998
• Conference Proceeding: Application of the pulsed electron-beam treatment of electrode surfaces for increasing the electric strength of vacuum gaps

  A.V. Batrakov, D.H. McDaniel, S.D. Korovin, G.E. Ozur, S.A. Popov, D.I. Proskurovsky, V.P. Rotshtein
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  ABSTRACT: A method for preliminary treatment of electrodes with a low-energy, high-current electron beam of microsecond duration is proposed. This method, combined with subsequent conditioning of the vacuum gap by pulsed discharges, makes it possible to achieve high values of the breakdown electric field. Projected uses of the method for increasing the electric strength of high-power electrodynamic systems are described
  High-Power Particle Beams, 1998. BEAMS '98. Proceedings of the 12th International Conference on; 02/1998
• Article: Increasing the electric strength of vacuum insulation by irradiating the electrodes with a low-energy high-current electron beam

  A.V. Batrakov, D.S. Nazarov, G.E. Ozur, S.A. Popov, D.I. Proskurovsky, V.P. Rotshtein
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  ABSTRACT: The paper describes how irradiation of the electrode surface with a LEHCEB (low-energy high-current electron beam) affects the prebreakdown current and the electric strength of vacuum insulation. This study is an extension of a study described earlier. Experiments have been performed for 0.1 mm vacuum gaps formed by refractory metal electrodes and for millimeter vacuum gaps with a pulsed voltage of amplitude 250 kV and duration 30 to 100 ns, both in a high oil-free vacuum and in technical-grade oil vacuum. Based on the results obtained, it is stated that the LEHCEB irradiation of electrode surfaces is a promising technique for increasing the electric strength of vacuum insulation over a wide range of voltages and under varied vacuum conditions
  IEEE Transactions on Dielectrics and Electrical Insulation 01/1998; · 1.09 Impact Factor
• Conference Proceeding: Increasing the electric strength of vacuum insulation by treatingthe electrodes with a low-energy, high-current electron beam

  A.V. Batrakov, D.S. Nazarov, G.E. Ozur, S.A. Popov, D.I. Proskurovsky, V.P. Rotshtein
  [show abstract] [hide abstract]
  ABSTRACT: The paper is devoted to the study of how the irradiation of the electrode surface with a low-energy, high-current electron beam affects the prebreakdown current and the electric strength of the vacuum insulation. This study is an extension of the work by A.V. Batrakov et al. (see Proc. XVI Int. Symp. on Discharges and Elect. Insul. in Vacuum, p.360, 1994). Experiments have been performed for 0.1-mm vacuum gaps formed by refractory-metal electrodes and for millimeter vacuum gaps with a pulsed voltage of amplitude 250 kV and duration 30-100 ns
  Discharges and Electrical Insulation in Vacuum, 1996. Proceedings. ISDEIV., XVIIth International Symposium on; 08/1996
• Article: The effect of pulsed electron-beam treatment of electrodes on vacuum breakdown

  A.V. Batrakov, A.B. Markov, G.E. Ozur, D.I. Proskurovsky, V.P. Rotshtein
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  ABSTRACT: A method for preliminary treatment of electrodes by a microsecond low-energy intense electron beam is proposed. It has been demonstrated that such a beam melts off the electrode surface and cleans the surface layers from impurities and dissolved gases. In combination with subsequent conditioning of the vacuum gap with low-current pulsed discharges, high breakdown electric fields can be attained
  IEEE Transactions on Dielectrics and Electrical Insulation 05/1995; · 1.09 Impact Factor
• Conference Proceeding: Enhancement of the electric strength of vacuum insulation by pulsed electron beam treatment

  A.V. Batrakov, D.H. McDaniel, D.S. Nazarov, G.E. Ozur, S.A. Popov, D.I. Proskurovsky, V.P. Rotshtein
  [show abstract] [hide abstract]
  ABSTRACT: The paper presents the results of a study of the pulsed electric strength of millimeter vacuum gaps with stainless-steel electrodes preirradiated with a low-energy, high-current electron beam. With 250 kV, 40 ns pulses, a breakdown strength of ≃2.2 MV/cm has been achieved. The possibility of using pulsed electron beam irradiation for treating parts of the Saturn system with a view to diminishing current leakage is discussed
  Pulsed Power Conference, 1997. Digest of Technical Papers. 1997 11th IEEE International;
• Article: Surface modification and alloying of metallic materials with low-energy high-current electron beams

  V.P. Rotshtein, D.I. Proskurovsky, G.E. Ozur, Yu.F. Ivanov, A.B. Markov
  [show abstract] [hide abstract]
  ABSTRACT: The paper presents a review of some new results of investigations on surface treatment of materials with pulsed (2–3 μs) low-energy (up to 10–40 keV), high-current (up to 30 kA, 1–40 J/cm2) electron beams (LEHCEB). Effect of pulsed melting on chemical and phase composition of the near-surface layers of a pre-quenched high-speed steel (HSS) as well as the wear resistance of cutting tools made of the HSS have been studied. The microstructural evolution and phase transformations occurring in the surface layers of hard alloys (WC–Co, WC-30% Hadfield's steel), the surface hardening and the wear behavior are considered. Depth profiles of the elements in the surface alloys formed by pulsed melting of film-substrate systems are given. A new promising method for surface modification of dental alloys based on LEHCEB treatment is presented.
  Surface and Coatings Technology.
• Article: Use of low-energy, high-current electron beams for surface treatment of materials

  D.I. Proskurovsky, V.P. Rotshtein, G.E. Ozur
  [show abstract] [hide abstract]
  ABSTRACT: This article describes the characteristics of original sources of low-energy (10–45 keV), high-current (up to 50 kA) electron beams of microsecond duration, designed for the surface thermal treatment of materials.Under the action of this type of beam, graded structures are formed which may impart improved physicochemicai properties and strength to the surface layers. This permits the use of these beams for improving the strength and electrochemical properties of pieces and tools, and for increasing the electric strength of vacuum insulation. Some technological operations, such as the deposition and removal of coatings and surface alloying, can be realized in the intense evaporation mode.
  Surface and Coatings Technology.
• Article: Surface alloying of metallic substrates with pre-deposited films through a pulsed electron-beam mixing

  A.V. Batrakov, A.B. Markov, G.E. Ozur, D.I. Proskurovsky, V.P. Rotshtein
  [show abstract] [hide abstract]
  ABSTRACT: Microstructure and properties of the surface alloys resulted from a pulsed liquid-phase mixing of metallic substrates with pre-deposited films were studied. As a tool for the liquid-phase mixing, a low-energy (~30 keV), high-current (~30 kA) pulsed (0.8–3 $\mu $s) electron beam of energy density ranging from 1 to 15 J cm$^{-2}$ has been employed. Three immiscible systems (Ta/Fe; Al/Si/Al/Si/Al/Si/Al; Al/C/Al/C/Al) and two systems with different solid solubility of components (Cu/316 stainless steel; Zr/Ti/Ti-6Al-4V) were chosen for the surface alloying investigation.
  http://dx.doi.org/10.1051/epjap:2008070.
• Article: Physical foundations for surface treatment of materials with low energy, high current electron beams

  D.I. Proskurovsky, V.P. Rotshtein, G.E. Ozur, Yu.F. Ivanov, A.B. Markov
  [show abstract] [hide abstract]
  ABSTRACT: The paper presents a review of original investigations on the surface modification of metallic materials with low energy (up to 40 keV), high current (up to 40 J/cm2) electron beams of microsecond duration. Based on material research and on simulations of temperature and stress fields, the regularities and mechanisms for the changes in the defect structure and in the strain–stress state of pure metals (Fe) on pulsed heating are considered. The peculiarities of the formation of non-equilibrium structure-phase states and graded structures on pulsed melting of film–substrate (Fe–Ta, Al–Si, and Al–C) systems have been studied. For a broad spectrum of structural and tool materials (steels, aluminum and titanium alloys, hard alloys) it has been shown that the most pronounced changes in the structure-phase state occur in the near-surface layer quenched from the liquid state, where the velocity of the crystallization front reaches its maximum. In this layer, the second phases are partially or completely dissolved, and oversaturated solid solutions and nanosized second-phase segregates are formed. This substantially improves the electrochemical and strength properties of the surface layer. It has been established that the action of dynamic stresses has the result that the modified layer with enhanced strength properties is substantially thicker than the heat-affected zone.
  Surface and Coatings Technology.
• Article: Pulsed electron-beam treatment of WC–TiC–Co hard-alloy cutting tools: wear resistance and microstructural evolution

  Y.F. Ivanov, V.P. Rotshtein, D.I. Proskurovsky, P.V. Orlov, K.N. Polestchenko, G.E. Ozur, I.M. Goncharenko
  [show abstract] [hide abstract]
  ABSTRACT: The mechanisms for changes in the structure-phase state, microhardness, and wear resistance have been investigated for carbide inserts made of type T15K6 (WC–15TiC–6Co) hard alloy, irradiated with a low-energy (20–30 keV, high-current (∼102 A cm−2) electron beam of duration 2.5 μs. Using transmission electron microscopy, it has been established that the pulsed melting of the near-surface (∼1 μm) layer results in the formation of a subgrain structure in the binding phase, segregation of nanosized carbide particles in the near-boundary regions, and the allotropic transformation of WC. The irradiation increases by about three times the durability of the inserts at elevated cutting rates for steels. The increase in durability is associated with the efficient hardening of the Co binder immediately on irradiation and with its high thermal stability being retained in the process of cutting due to the stability of the dislocation substructure provided by second-phase segregates.
  Surface and Coatings Technology.