|Tomasz Reguła, Jerzy J. Sobczak, Jerzy Morgiel, Piotr Dudek, Piotr Długosz|
The paper presents the results of studies on the effect of external pressure, applied on metal during squeeze casting process, on the structure of AlSi7Mg alloy. The obtained results were completed with examinations of structure compactness and hardness tests. The specimens for tests were obtained by casting the tested AlSi7Mg alloy to a die under different pressures, i.e. 0.1 (atmoshpheric pressure), and 75 and 150 MPa, using a hydraulic press of PHM 160c type. A significant effect of pressure on the average grain size and hardness of the samples was stressed, thus demonstrating the usefulness of liquid-phase methods with application of external pressure in improvement of the properties of castings produced.
Keywords: external pressure, squeeze castring process, squeeze casting, liquid-phase methods,
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Jan Pielichowski, Jerzy J. Sobczak, Zdzisław Żółkiewicz, Edyta Hebda, Aleksander Karwiński
The article presents the results of thermogravimetric (TG) investigations of a polystyrene foundry model. The study was conducted for three polystyrenes - Owipian (Syntos Oświęcim), copolymer PS and PSX (France). Next, TG analysis was performed for the prepared PS foundry model and the results obtained show that PS fully degrades in the temperature range of 321-395°C. Finally, kinetics of gasification and intensity of gas volatilization were investigated for PS foundry model.
Keywords: casting, foundry models, polystyrene, polymers thermal decomposition,
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In this work, the course of peritectic L + Al6Mn(Fe) → α-Al + α-AlMnFeSi transformation taking place in AlFeMnSi alloys was traced. The specific microstructural effects in the transformed primary phase areas were revealed and identified. The transformation product situated inside the primary preperitectic Al6FeMn phase precipitates was identified as a lamellar mixture of the α-AlFeMnSi and α-Al phases, balanced volumetrically. The evolution of morphology in a peritectic α-AlMnFeSi phase observed in the examined specimens was related to the necessary exchange of components at interfaces, which are the site for nucleation and growth of transformation products. Both direction and range of the diffusion fluxes of individual components were identified. The distribution of transition metals between intermetallic phases during the progressing transformation was estimated and found to be related to both partition coefficient of components and alloy composition.
Keywords: aluminium alloy, intermetallic phase, transition metals, peritectic transformation, microstructure,
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Maria Żmudzińska, Janusz Faber, Katarzyna Perszewska, Zdzisław Żółkiewicz, Zbigniew Maniowski
The article presents the ecological aspects of the lost foam technology. The results of environmental tests carried out on an experimental stand for pouring of moulds with liquid metal and knocking out of castings in the lost foam process were presented. The influence of the lost foam technology on the work environment was determined.
Keywords: lost foam patterns, lost foam technology, work environment, MAC,
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