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

Goranskij G.G., Pobol A.I

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2020

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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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Electron Beam Processing of SensorsRelevant Vacoflux-49 Alloy: Experimental Studies of Thermal Zones and Microstructure

Kumar Pawan, Yadav Anshul, Kumar Arvind

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 3

1147--1156

EN

Vacoflux-49 (Fe-49% Co-49% V-2%) is used in torque, sonar and gyroscopic sensors applications due to excellent magnetic properties (high saturation magnetisation, low coercivity and high Curie temperature). In this study, the shape, size and characteristics of different thermal zones and the microstructural evolution during electron beam melting and welding of Vacoflux-49 material are studied. The experimental studies on melting have been carried out with under-focussed, focussed and over focussed electron beam. In the case of the under-focussed and over-focused beam, no evaporated zone is found. In the case of focussed beam, a shallow conical-shaped evaporated zone, a choked funnel-shaped fusion zone, a conical shaped partially melted zone and the heat-affected zone are observed. The solidified melt pool in terms of shape, size and microstructure of different zones are investigated for the focussed beam. The grains in the fusion zone appear wavy having crest and trough. The fusion zone microstructure also shows the formation of solidification rings. From the electron beam welding experiments performed for joining two Vacoflux-49 plates (continuous welding), it is found that the weldment shape is similar to the spot melting and re-solidification experiments. The grain growth in different zones in the welding sample is also examined.

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Dispersion of Al-Si Alloy Structure by Intensive Pulsed Electron Beam

Konovalov S., Gromov V., Zaguliyaev D., Ivanov Y., Semin A., Rubannikova J.

Archives of Foundry Engineering

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2019

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iss. 2

79--84

EN

By the method of modern physical material science (optic microscopy scanning and transmission electron microscopy) the analysis of structural phase states, the morphology of the second phase inclusions and defect substructure of Al-Si alloy (silumin) of hypoeutectic composition, subjected to electron beam processing was done with the following parameters: energy density 25-35 J/cm2, beam length 150 μs, pulse number – 3, pulse repetition rate – 0.3 Hz, pressure of residual gas (argon) 0.02 Pa. The surface irradiation results in the melting of the surface layer, the dissolution of boundary inclusions, the stricture formation of high speed cellular crystallization of submicron sizes, the repeated precipitation of the second phase nanodimentional particles. With the increased distance from the irradiation surface the layer containing the second phase inclusions of quasi-equilibrium shape along with the crystallization cells was revealed. It is indicative of the processes of Al-Si alloy structure globalization on electron beam processing.