Artykuły (WM)

Stały URI dla kolekcjihttp://hdl.handle.net/11652/206

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20143

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Autorsearch.filters.applied.operator.equals: search.filters.author.Szymczak, Tomasz

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  • Pozycja
    Selected Aspects of Nitrogen Refinement of Silumin 226
    (2014) Szymczak, Tomasz; Gumienny, Grzegorz; Pacyniak, Tadeusz
    The work presents the results of the investigations of the effect of the nitrogen (N2) refining time „τraf” and the gas output on the course of the crystallization process, the microstructure and the gassing degree of silumin 226 used for pressure casting. The refinement of the examined silumin was performed with the use of a device with a rotating head. The crystallization process was examined by way of thermal analysis and derivative analysis TDA. The performed examinations showed that the prolongation of the N2 refining time causes a significant rise of the temperature of the crystallization end of the silumin, „tL”, as well as a decrease of its gassing degree, „Z”. An increase of the nitrogen output initially causes an increase of the temperature „tL” and a drop of the gassing degree „Z”, which reach their maximal values with the output of 20 dm3/min. Further increase of the output causes a decrease of the value „tL” and an increase of „Z”. The examined technological factors of the refining process did not cause any significant changes in the microstructure of silumin 226.
  • Pozycja
    Effect of Modification on Characteristic Values of TDA Curves
    (2014) Gumienny, Grzegorz; Szymczak, Tomasz; Pacyniak, Tadeusz
    The work presents the examination results of the effect of strontium and antimony modification on the microstructure of a cast and the characteristic values of the TDA curves. Strontium and antimony modifiers were added to silumin 226 in a melting crucible furnace, separately, in the amounts of 0.1; 0.2 and 0.3% of the mass of the modified metal. After modification, the silumin was refined with the solid refiner ECOSAL-Al 113 in the amount of 0.5% of the charge mass.
  • Pozycja
    Effect of the Hold Time and Temperature on Characteristic Quantities of TDA Curves
    (2014) Szymczak, Tomasz; Gumienny, Grzegorz; Pacyniak, Tadeusz
    This paper presents the effect of the temperature and hold time in the holding furnace of 226 silumin on the characteristic quantities of TDA curves. The temperature of phase transformations and the cooling rate were tested.It has been shown that increasing both the hold time and the temperature in the holdingfurnace cause the decreasethe end ofα+Al9Fe3Si2+β and α+Al2Cu+βternary eutectics crystallizationtemperature in the tested silumin. This is due to the fact an increase in amounts of impurities as a result of reacting theliquid alloy with the gases contained in the air.It has been shown, however, that examined technological factors ofthe metal preparation do not cause systematic changes in the cooling rate.