Andrzej Baliński
AbstractThe article presents the basic characteristics of the pollutants emitted in the process of foundry mould manufacture. A method to reduce harmful emissions through the application of advanced oxidation was described. The occurrence of structural changes occurring in the dust waste treated with ultrasounds in the environment of natural water, and changes in the value of electrolytic conductivity under the effect of ultrasounds, in both natural and ozone-saturated water were stated.
Keywords: moulding sand, dust waste, advanced oxidation, ultrasounds, FTiR spectroscopy,
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Jerzy Tybulczuk, Krzysztof Jaśkowiec, Andrzej Gwiżdż
AbstractIn the course of the executed project, a series of investigations has been made to establish what effect a refined inoculant applied on the mould surface can have on changes in the surface structure of castings made from ductile iron and alloyed cast steel. During preliminary research it was decided to use a cheap and readily available FeSi75T inoculant for cast iron, while for the austenitic SUS316 (LH17N17M3) cast steel, a FeNbC inoculant after special melting and treatment was selected. The inoculation process consisted in dissolving the applied layer of inoculant, thus requiring the choice of a best amount of the inoculant of proper granulation to induce the inoculation process along with all the expected effects, i.e. raising the number of graphite precipitates in cast iron combined with their refinement, and grain refinement in cast steel.
Keywords: inoculation, methods of inoculation, thin-wall castings, ductile iron, alloyed cast steel,
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Stanisław Pysz, Zdzisław Żółkiewicz, Robert Żuczek, Zbigniew Maniowski, Zbigniew Sierant, Mariusz Młyński
AbstractUsing available thermo-physical parameters, the paper describes the simulation studies of metal flow in mould filled with an evaporative pattern. The final properties of casting made in a lost-foam process are greatly dependent on the way by which the metal is fed to mould cavity, on the way by which gases are taken off, and also on the properties of the lost foam pattern itself, that is, on its thermophysical parameters. The gating system should be designed in a way such as to let metal flow into mould cavity with an even front surface, enabling a uniform evaporation of pattern made from, e.g., foamed polystyrene. The configuration of a gating system and the technique of metal pouring affect the rate at which the mould cavity is being filled with metal, and hence the kinetics of pattern evaporation under the molten metal effect. When lost foam patterns are used in a casting process, it is necessary to allow for the variable physico-chemical properties, which depend on pattern itself and affect the metal flow behaviour in mould cavity as well as the pattern evaporation process.
Keywords: thermophysical data, simulation of metal flow, filling system, gasification model,
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Piotr Długosz, Paweł Darłak, Aleksandra Siewiorek, Jerzy J. Sobczak
AbstractThe paper presents the results of examinations of composite samples in which the reinforcement is waste fly ash from power plants, while matrix is an aluminium (A8). The agglomerates of master composite obtained by mechanical alloying were subjected to hot plastic consolidation to transform the powder into a solid material, and thus formed compacts were heated to a temperature of 430-450°C and squeezed into 14 mm diameter rods. Thus obtained cylindrical samples were analysed by computed tomography, which revealed a satisfactory level of the distribution of the reinforcing phase at a 25 wt.% fly ash concentration, and absence of the areas characterised by too high concentration of ceramic particles, which may act as a source of the adverse phenomenon of agglomeration. An improvement in the mechanical properties of composite samples compared made from the sole matrix material.
Keywords: ALFA composites, fly ash, mechanical alloying, computed tomography,
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