Wydział Mechaniczny / Faculty of Mechanical Engineering / W1

Stały URI zbioruhttp://hdl.handle.net/11652/1

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20146

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Autorsearch.filters.applied.operator.equals: search.filters.author.Pacyniak, TadeuszMa przypisane plikisearch.filters.applied.operator.equals: Tak

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Teraz wyświetlane 1 - 6 z 6
  • 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 Cr and V alloy additions on the microstructure and mechanical properties of AM60 magnesium alloy
    (2014) Rapiejko, Cezary; Pisarek, Bogusław; Pacyniak, Tadeusz
    The paper presents the results of the investigation of the effect of Cr and/or V alloy additions on the microstructure and mechanical properties of the magnesium AM60 alloy. The examinations are performed within the frames of a project aiming at the elaboration of an experimental and industrial technology of producing constructively complex elements of machines and devices made of magnesium alloys with the method of investment casting. It has been proven that small numbers of Cr and V alloy additions improve the strength properties: Rm, A%, and the hardness HB of the obtained casts. The experimental casts were made in ceramic molds.
  • 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.
  • Pozycja
    Analysis of the crystallization of AZ91 alloy by thermal and derivative analysis method intensively cooled in ceramic shell.
    (2014) Rapiejko, Cezary; Pisarek, Bogusław; Czekaj, E.; Pacyniak, Tadeusz
    The work presents the test result of the influence of cooling rate on the microstructure of AZ91 alloy, Vickers micro-hardness and Brinell hardness. Studies cooling and crystallization of AZ91 alloy was cast into the ceramic shells pre-heated to 180 ° C and then air-cooled at ambient temperature or intensively super cooled in the liquid coolant. The TDA method was applied to record and characterize the thermal effect resulting from the phase transformations occurring during the crystallization of AZ91 alloy. The kinetics and dynamics of the thermal processes of crystallization of AZ91 alloy in the ceramic shells were determined. Metallographic tests were performed with the use of an optical microscope. A comparison of these test results with the thermal effect recorded by way of the TDA method was made. Influence of cooling rate of AZ91 on HV0, 01 micro-hardness and Brinell hardness alloy was examined.
  • Pozycja
    Analysis of AM60 and AZ91 alloy crystallisation in ceramic moulds by Thermal Derivative Analysis (TDA).
    (2014) Rapiejko, Cezary; Pisarek, Bogusław; Czekaj, E.; Pacyniak, Tadeusz
    The work presents the test results of the crystallisation and cooling of magnesium alloys: AM60 and AZ91, with the use of the TDA method. The tested alloys were cast into ceramic shells heated up to 180 C, produced according to the technology of the shell production in the investment casting method. The TDA method was applied to record and characterize the thermal effect resulting from the phase transformations occurring during the crystallisation of magnesium alloys. The kinetics and dynamics of the thermal processes of the crystallisation of AM60 and AZ91 in the ceramic shells were determined. Metallographic tests were performed with the use of an optical microscope as well as scanning microscopy, together with the EDS chemical analysis of the phases present in the tested casts. A comparison of these test results with the thermal effect recorded by way of the TDA method was made.