Wyniki wyszukiwania - Biblioteka Nauki

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

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Goranskij G. G. , Pobol A. I.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2019

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tom 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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Konečno-èlementnaâ modelʹ èlektronno-lučevoj pajki tverdosplavnyh režuŝih èlementov k opravke

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Goranskij G. G. , Pobol A. I.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2020

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tom Z. 26 (176)

44-55

RU

Sozdany obobŝennye konečno-èlementnye (KÈ) modeli èlektronno-lučevoj obrabotki (ÈLO) poverhnostej dlâ materialov s suŝestvenno otličaûŝimisâ teplofizičeskimi svojstvami, pozvolâûŝie proizvoditʹ rasčet i optimizaciû režimov processa. Dlâ izdelij raznoj geometrii, učityvaâ termodinamiku processa i temperaturnye zavisimosti svojstv materialov, upravlââ geometriej èlektronnogo pučka i ciklogrammoj processa, optimizirovany diapazony ènergeti českih parametrov ÈLO. KÈ modelirovanie nagreva poverhnosti pri ÈLO provedeno dlâ detali ploskoj formy stacionarnym istočnikom so skaniruûŝej razvertkoj, a takže pri vozdejstvii v režime linejnogo peremeŝeniâ luča bez skaniruûŝej razvertki. Dlâ optimizacii èlektronno-lučevogo oplavleniâ pri pajke predložena termodinamičeskaâ KÈ modelʹ, učityvaûŝaâ geometričeskie osobennosti rezcovyh vstavok i teplofizičeskie svojstva sostavlâûŝih ih materialov. Pokazano, čto učet temperaturnoj zavisimosti teplofizičeskih svojstv materialov pozvolâet realizovyvatʹ shemy ÈLO s menʹšej prodolžitelʹnostʹû vozdejstviâ pučka bolʹšej moŝnosti.

EN

Generalized finite-element models for the electron-beam treatment of the surface of materials with significantly different thermophysical properties have been created, allowing the calculation and optimization of process conditions. For products of different geometries, taking into account the thermodynamics of the process and the temperature dependences of the properties of materials, controlling the electron beam geometry and the process cycloramas, the ranges of energy parameters of electron beam processing have been optimized. Finite-element modeling of surface heating during electron-beam processing was carried out for a flatshaped part by a stationary source with scanning, as well as when exposed to linear beam movement without scanning. To optimize electron beam reflow during soldering, a thermodynamic finite-element model is proposed that takes into account the geometric features of the cutter inserts and the thermophysical properties of their constituent materials. It is shown that taking into account the temperature dependence of the thermophysical properties of the materials makes it possible to realize electron beam processing schemes with a shorter duration of exposure to a beam of greater power.

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Модифицированные композиции на основе отходов твердого сплава для правящих фильер строительной арматуры

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Goranskij G. G. , Zornik V. I. , Pobol A. I.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2018

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tom Z. 24 (174)

95-101

RU

Целью работы являлось научное обоснование целесообразности модифицирования твердосплавных отходов для коррекции технологических режимов их электроконтактного спекания при изготовле- нии правящих и направляющих фильер строительной арматуры, исследование эволюции строения и свойств композиций, а также эксплуатационных характеристик изделий. Установлено, что введение аморфизированных модификаторов систем Fe–Ni–Mo–Co–Cr–В–Si и Ni–Cr–Si–В в состав композита на основе отходов твердого сплава ВК6 сопровождается легированием матричной фазы ß–Со атомами замещения с бoльшим атомным радиусом (Fe, Mo, Cr, Si) и примесями внедрения (В), приводящим к появлению атомных смещений в окрестностях атомов легирующей примеси и увели- чению искаженности кристаллической решетки ß–Со, что способствует упрочнению спеченного сплава, росту его механических и эксплуатационных свойств. Отмеченный эффект модифицирова- ния твердосплавных отходов позволяет вовлечь их в производство электроконтактным спеканием правящих и направляющих фильер для строительной арматуры, существенно снизив стоимость изделий при высоком уровне их служебных характеристик.

EN

The aim of the work was the scientific substantiation of the feasibility of modifying of hard alloy wastes to correct the technological modes of their electrical contact sintering in the manufacture of the straightening and guide dies of construction fittings; the study the evolution of the structure and properties of the compositions, as well as the operational characteristics of the products. It has been established that the introduction of amorphized modifiers of the systems Fe–Ni–Mo–Co–Cr–B–Si and Ni–Cr–Si–B into the composite, based on the hard alloy WCo6 wastes, is accompanied by doping the matrix ß–Co phase by atoms with more atomic radius (Fe, Mo, Cr, Si) and interstitial impurities (B), leading to the appearance of atomic displacements in the vicinity of dopant atoms and an increase the lattice distortion of ß–Co phase, which contributes to the hardening of the sintered alloy, the growth of its mechanical and operational properties. The noted effect of modifying of hard alloy wastes makes it possible to involve them in the production by electrocontact sintering of the straightening and guide dies for construction fittings, significantly reducing the cost of products at a high level of their performance characteristics.