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1

Konečno-èlementnoe modelirovanie èlektrokontaktnogo spekaniâ pravâŝih fil’er stroitel’noj armatury

Goranskij G.G., Pobol A.I

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2019

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Z. 25 (175)

40-49

RU

Razrabotana matematičeskaâ model’ processa èlektrokontaktnogo spekaniâ ÈKS) tverdosplavnyh kompozicij pri izgotovlenii pravâŝih fil’er stroitel’noj armatury. Model’ pozvolâet rassčitat’ uplotnenie pressovki, diagrammu poslojnogo raspredeleniâ plotnosti, diagrammy polej temperatur i davlenij, raspredelenie plotnosti toka po sečeniû pressovki i egoizmenenie v zavisimosti ot otnositel’noj plotnosti. Aprobirovannye v modeli analitičeskie zavisimosti rasprostraneny na proizvol’nuû geometriû fil’er pri pomoŝi konečno-èlementnogo modelirovaniâ s korrektirovkoj svojstv materiala po analitičeskim zavisimostâm, ishodâ iz plotnosti pressovki. Ocenka adekvatnosti modeli provedena po krivoj pressuemosti. Rezul’tatami rasčetov dokazan i èksperimental’no podtveržden èffekt sniženiâ termobaričeskih parametrov kompaktirovaniâ spekaemoj tverdosplavnoj kompozicii pri ee modificirovanii termoaktiviruûŝej dobavkoj, blagodarâ čemu povyšena stojkost’ keramičeskih press-form i na 40% snižen procent koničeskoj poverhnosti zagotovki fil’ery.

EN

A mathematical model of the process of electrocontact sintering of carbide compositions in the manufacture of straightening dies of construction fittings has been developed. The model allows to calculate the compression of the compact, the diagram of the layer-by-layer density distribution, the diagrams of temperature and pressure fields, the distribution of current density over the cross-section of the compact and its change depending on the relative density. The analytical dependences, tested in the model, are extended to arbitrary geometry of the dies, using finite element modeling with adjustment of material properties according to analytical dependencies, based on the density of pressing. An assessment of the adequacy of the model was carried out by the compressibility curve. The results of calculations proved and experimentally confirmed the effect of reducing the thermobaric parameters of compacting the sintered carbide composition, when it is modified with a thermosetting additive, which increased the resistance of ceramic molds and reduced the percentage of rejects by 40%. The tensile radial deformations along the conical surface of the die blank are predicted.

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Tribological Properties and Microstructure of the Metal-Polymer Composite thin Layer Deposited on a Copper Plate by Electrocontact Sintering

Kovtun V., Pasovets V., Pieczonka T.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

51--58

EN

The properties of the electrocontact sintered metal-polymer composite materials are strongly determined by the heat flow taking place during sintering, which, in turn, is influenced by the amount and initial distribution of the polymer particles in the metal matrix. In case of the metal-polymer powder mixture in the form of a thin layer deposited on the bulk metal substrate, the influence of the latter is also taken into consideration. Thus, the model simulating the heating and sintering of the thin layer made of metal-polymer powder mixture on a metal plate is proposed. Based on mathematical calculations relating to the model describing the thermal state of the system, it is shown how heat flow fields are formed within the layer, depending on the polymer content and its distribution. These theoretical simulations seem to be useful in optimising the production of the antifriction metal-polymer layer on a bulk copper substrate by electrocontact sintering. The results of the tribological experiments and microstructural observations are in a good agreement with the theoretical model.

3

Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

Kovtun V., Pasovets V., Pieczonka T.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 1

51--55

EN

Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

PL

Materiały kompozytowe o osnowie miedzi zawierające nanocząstki węgla wytwarzano metodą spiekania elektrostyko-wego. Spieki poddano badaniom właściwości fizyko-mechanicznych oraz badaniom strukturalnym. Obserwacje przełomów za pomocą mikroskopu skaningowego wykazały korzystny wpływ mechanicznej aktywacji mieszanki proszków na rozmieszczenie nanocząstek węgla w osnowie metalowej. Aktywacja prowadzona w wysokoenergetycznym młynie wibracyjnym doprowadza do mechanicznego połączenia nanocząstek węgla z powierzchnią cząstek miedzi, dzięki czemu możliwe jest wytworzenie spiekanego kompozytu o wysokich właściwościach fizyko-mechanicznych.

4

Correlation between tribological properties of powder coatings and electrocontact sintering process parameters

Kovtun V. A., Pleskachevsky Yu. M., Dmitriev V. V., Zhirnov E. A., Shalobalov O. M.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

291-296

EN

Investigation has been carried out in the effect of technological factors of electrocontact sintering (force of electrode pressing, velocity of material motion, strength of sintering current, etc.) on the structure and triboengineering characteristics of thin-film 50-100 mm thick coatings from copper-graphite systems. A multiple-factor experiment has been undertaken to optimize regimes for coating formation with 1-4% porosity and to range parameters of technological process by degree of their action on the coating performances. The calculated optimum parameters of electrocontact sintering ensured most perfect characteristics of thin-film copper-graphite coatings. Most essential parameters proved to be strength of sintering current and force of electrode pressing.