INSTITUTE  OF  PULSE  PROCESSES  AND  TECHNOLOGIES

NATIONAL  ACADEMY  OF  SCIENCE  OF  UKRAINE
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MAIN  RESULTS  OF  SCIENTIFIC  ACTIVITIES
in  2012

© 2012  Institute of pulse processes and technologies NAS of  Ukraine.   All rights reserved.
MAIN  RESULTS  OF  SCIENTIFIC  ACTIVITIES  IN  2013     >>>

The analysis of the conversion of electrical energy in the process of electro-hydraulic sheet metal forming is carried out, which allows reaching 2.5 times higher degrees of plastic deformation of alloys compared to static deformation (straining).
Schematics and conditions for high-speed deformation of blanks are found, which enables increasing the efficiency of a single pulse energy from 10% to 15-30 %, thus promoting more effective implementation of the process of obtaining formed parts made of the latest grades of high-strength steels with a deep degree of stretching and using parts of a complex shape.
Research "To investigate the influence of parameters and schemes of pulse electrohydraulic straining on ductile properties of high strength sheet steels and to develop effective technological methods and schemes for cold forming".

The work is done by targeted research program prepared by Institute of Physics and Mathematics of NAS of Ukraine.
Research "Study of physico-chemical processes of interaction of aluminum melt with modifiers in conditions of pulse loading and development of effective integrated technological schemes of modifying the hypereutectic silumins".

The study is carried out in frames of the department's main research topic
It is proved that integrated tools that combine introducing phosphorous copper in a melt and electrohydropulse treatment of a melt, in contrast to sole modification, guarantees for twice stronger grinding of brittle structural components in hypereutectic silumins and an elongation index more than 1%. Using the dispersed silicocarbide powder as a modifier contributes to grinding of crystals of primary silicon to a level of 20 m with full involvement of modifier particles in the crystallization process due to electrohydropulse treatment.
It is established that electrohydropulse treatment of alloy A390 contaminated with iron to 0.9 to 2.6 % in combination with microalloying of Mn causes transformation of brittle intermetallic phases into compact morphological varieties and improvement of mechanical properties of an alloy to meet the standards.
Research "Search for process schemes and necessary parameters of electrical discharges and high-voltage electrochemical explosions (HVEE) for local weakening of a given volume of soils".

The work was carried out under the prospecting topic.

Key regularities are determined for the high-voltage electrochemical explosion which, unlike conventional explosives,

ensures destruction of natural and synthetic non-metallic materials (soil) of strength above 40 MPa in a precisely

predetermined cylindrical volume without side cracking. Maximum energy of local destruction does not exceed 500 kJ,
                  
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the specific chemical energy conversion efficiency is 0.38 ·10    J/kg, the specific value of combustion efficiency of an

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exothermic mixture is 1.65 ·10  J/kg, the field strength is 1.67 ·10   V/m. The method can be implemented for crushing


of monolithic non-metallic materials, particularly in construction.

Research "Development of methods of treatment and consolidation of composites based on iron and titanium carbides and borides by highly concentrated energy flows"

The work is being carried out in frames of the contest of joint scientific projects of the National Academy of Sciences of Ukraine and the Russian Foundation for Fundamental Research.
Research "Development of a new method of electrodischarge synthesis of composite powders containing carbon and metals, and equipment models for plasma-spark compacting of these powders".

The study is carried out in frames of the department's main research topic
Process related recommendations are developed for the production of fine micro-, nano-sized carbides and low-melting eutectics in the Fe-Ti system by electrodischarge treatment of powder mixtures of Fe - Ti - C and WC - Co in hydrocarbon liquids. The element base is created for the generator model used in plasma-spark sintering of  synthesized composite powders, the use of which, compared with conventional sintering of composites, provides conditions for increasing the rate of diffusion processes and obtaining sintered material with high physical-mechanical properties regardless of the content of Fe and Co.

The regularities of changes in morphometric characteristics and kinetics of dispersion of the mixture of source powders 75 % Fe + 20% Ti + 5% B  C,
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80 % Fe +20 % Ti , Fe and Ti powders in lighting kerosene are established depending on the parameters of the electrodischarge treatment, which is

accompanied by the synthesis of powders of pseudoalloys and allows to obtain highly dispersed (with a particle size of 0.05 to 1 m) and homogeneous

charge for carbide steels.

The technology of producing highly wear-resistant composites of carbide steels using hot forming of porous blanks is developed: compared to

liquid-phase sintering it provides omission of the annular transition zone at the interface of a carbide grain and a base metal, more dispersed structure of

the matrix alloy, the presence of the grains texture of the base metal in the direction perpendicular to punching force, and also a higher level of physical

and mechanical properties of composites.

Research "Study of the processes of electrodischarge impact on  dispersed metal-carbon composite powders in liquid carbohydrate".
The work was carried out under the grant of NAS of Ukraine for young scientists.
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The optimum parameters (current growth rate of di/dt > 24 GA/s and specific energy of treatment W = 2.67 MJ/dm  ) of electrodischarge dispersion of

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source powders of Fe, Ti and mixtures of 75 % Fe + 20% Ti + 5% B  C in a carbohydrate liquid are determined: they serve for grinding of powders to

the size of 0.5-0.8 µm, and promoting the accompanying process of synthesis of carbides, borides, intermetallics and other dispersed reinforcers for

manufacturing of steels.

Research "Study of synthesis of carbon nanomaterials in the process of electrodischarge treatment of organic liquids using catalysts and precursors".

The work was carried out in frames of the department's main research topic.

The conditions of catalytic synthesis of carbon nanomaterials are established, dependencies of their output and phase composition in the two-stage

process of electrodischarge treatment of organic liquids of different chemical nature are determined.

It is shown that the use of metal catalysts (Ni, Fe, Cu, Nb, Al) and precursors (adamantane powder, solutions of fluorene or ferrocene) allows targeted

development of carbon nanotubes and nanofibers and increasing the yield of carbon nanomaterials from two to ten times. The use of silicon, silicon

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oxide and tungsten catalytic surfaces promotes the formation of diamond-like films. The method of determining the number of carbon atoms with sp  -

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or sp   - hybridization contained in the obtained carbon nanomaterials taking into account their conductivity is offered.

Research "Development of methods for producing carbon nanomaterials and integrated electrofiltration of environmentally hazardous industrial emissions using discharge-pulse technologies".

The work is carried out in frames of the department's main research topic.

It is determined that the use of high-frequency (1-20 kHz) electrodischarge treatment of a liquid mixture of hydrocarbons 3 times increases the

efficiency of recycling of organic solvents and their waste to carbon nanomaterials, and treatment of gaseous hydrocarbons by a high frequency

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method causes changes in the degree of hybridization of carbon atoms from sp   - to sp    - and sp-, and also allows obtaining amorphous

nanocarbon in the absence of other chemical impurities.

Pulse parameters are established which are required for implementation of a corona discharge on a multi-electrode system in a dust aerosol flow.

They provide for more comprehensive destruction of gas emissions during gas treatment than existing modes of electrofiltration.

Research "Development of theoretical bases for designing and optimization of parameters of discharge-pulse technologies, determining the structure of the equipment and its operating modes".

The work is carried out in frames of the department's main research topic.
The approaches for optimization of power parameters of discharge-pulse technologies (DPT) for various implementation ways are developed. Mathematical modeling of all stages of energy conversion in DPT is carried out and methodology is elaborated for optimizing the operating parameters and modes of electrodischarge devices for specific DPT based on the solution of inverse problems. For this purpose, algorithms and computational methods are developed.
Research "To investigate the electrical characteristics of dielectric film systems and to find design process solutions for creating a series of high-voltage pulse capacitors based on a single insulating casing".

The work was carried out under the prospecting topic.

The dielectric system based on a combination of bilateral rough and smooth polyethylene terephthalate films impregnated with transformer oil is

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determined, and it is characterized by dielectric strength at 500-550 kV/mm and a loss tangent of no more than 5 10    . Moreover, a universal design

of an insulating body is developed on the basis of which a series of 11 high-voltage pulse capacitors can be manufactured at significantly shorter time

for the design stage.