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Elimination of Zinc from Aluminum During Remelting in an Vacuum Induction Furnace

Smalcerz Albert, Blacha Leszek, Węcki Bartosz, Desisa D. G., Łabaj Jerzy, Jodkowski Maciej

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 3

11--18

EN

In this paper, the results of the study on aluminium evaporation from the Al-Zn alloys (4.2% weight) during remelting in a vacuum induction furnace (VIM) are presented. The evaporation of components of liquid metal alloys is complex due to its heterogeneous nature. Apart from chemical affinity, its speed is determined by the phenomena of mass transport, both in the liquid and gas phase. The experiments were performed at 10-1000 Pa for 953 K - 1103 K. A significant degree of zinc loss has been demonstrated during the analysed process. The relative values of zinc loss ranged from 4 to 92%. Lowering the pressure in the melting system from 1000 Pa to 10 Pa caused an increase in the value of density of the zinc evaporating stream from 3.82x10-5 to 0.000564 gxcm-2xs-1 at 953 K and 3.32x10-5 to 0.000421 g xcm-2 for 1103 K. Based on the results of the conducted experiments. it was found that evaporation of zinc was largely controlled by mass transfer in the gas phase and only for pressure 10 Pa this process was controlled by combination of both liquid and gas phase mass transfer.

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Wykonanie indukcyjnego pieca próżniowego do wytwarzania stopów z pamięcią kształtu

Węcki Bartosz, Maciąg Tomasz

Hutnik, Wiadomości Hutnicze

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2021

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Vol. 88, nr 3-4

14--18

PL

Ciągły rozwój techniki powoduje zapotrzebowanie na coraz nowsze materiały, spełniające określone wymagania stawia-ne przez konstruktorów i inżynierów. Jednocześnie rozwijają się nowe technologie wytwarzania i przetwórstwa. W przypadku wytwarzania stopów metali o szczególnych właściwościach, takich jak stopy wykazujące efekt pamięci kształtu, szczególnie istotna jest precyzja w doborze składu chemicznego i zapewnienie atmosfery ochronnej przed warunkami utleniającymi. W ramach przedstawionej pracy zaproponowano wykorzystanie indukcyjnego pieca próżniowego VIM 20-50 produkcji SECO/WARWICK. W pracy zaprezentowano eksperyment mający na celu otrzymanie stopu o składzie chemicznym odpowiadającym stopowi z pamięcią kształtu Ni-Ti, którego handlowa nazwa to Nitinol. Jako materiały wsadowe wykorzystano metale o wysokiej czystości: Ni 99,95% i Ti 99,8%. Z otrzymanego wlewka wykonano próbki do badań analizy składu chemicznego, analizy fazowej i analizy termicznej DTA.

EN

Continuous development of requires materials having specific properties. In simultaneusly, new technologies develop focused on manufacturing and processing. In case of alloys production of certain properties, such as shape memory alloys, in which precision of selecting the chemical composition and ensuring a protected atmosphere from oxidising conditions is the most important parameter. For purposes of this paper the tests were performed with the use of a VIM 20-50 furnace (manufactured by SECO-WARWICK). For this paper, an experiment was carried out with the objective of achieving an alloy with a chemical composition equivalent to a shape memory alloy Ni-Ti, for which the retail name is Nitinol. The alloy described has been chosen due to the shape memory property taking effect from a low range of temperatures. The input materials used were high purity metals: Ni 99.95% and Ti 99.80%. From the obtained ingot samples were made for analysis of the chemical composition, phase analysis and differential thermal analysis.

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Influence of the Power of Various Types of Induction Furnaces on the Shape of the Metal Bath Surface

Smalcerz Albert, Węcki Bartosz, Blacha Leszek

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 3

34--42

EN

The work shows the results of examinations conducted to ascertain the influence of the working power of a vacuum induction crucible furnace (ICF) and a furnace with a cold crucible(CCF), on the surface area of liquid Al-Zn alloy molten within these devices. It was determined that the increase of the value of this parameter causes the increase of the liquid alloys surface area. In the case of smelting alloy inside a crucible furnace the increase of power from 8 to 22 kW causes the increase of liquid alloy surface from 88 to 155 cm2. For a furnace with a cold crucible, the power increase from 70 to 130 kW causes the increase of the alloy surface from 280 to 330,3 cm2. For all power values a larger increase in surface area was observed in crucible furnaces (around two times). In cases of cold crucible furnaces, this increase was around 20%. Additionally, based on the examination results the way in which the surface area of liquid alloy can intensify the undesirable process of zinc fuming away, was discussed. It has been demonstrated that the process of zinc elimination from the examined alloy is more intensive while using a cold crucible induction furnace.