Problems connected with a change of Zeta potential values of soluble sodium silicate are presented. Soluble sodium silicate was made from sodium-silicate glass to thermally conditioned at a temperature of 1350°C for 60, 90 and 120 minutes. It was found that particles in all types of the soluble sodium silicate have similar electrokinetic properties. In the soluble sodium silicate made from the sodium-silicate glass subjected to thermally conditioned for 120 minutes, particles with the highest value of the Zeta potential were present. They provide the most intense laser light scattering.
Keywords: soluble sodium silicate, sodium silicate glass, Zeta potential,
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Piotr Dudek, Aleksander Fajkiel, Tomasz Reguła, Marzena Lech-Grega, Marek Nowak, Mieczysław Opyrchał
The article presents the results of investigations of a technology for fabrication of decorative and protective chromate coatings on die castings made from AZ91 (MgAl9Zn1) magnesium alloy. As a result of the investigations, parameters of machining were developed as well as compositions of the bath of solutions to obtain satisfactory chromate coatings on products cast from magnesium alloys. Based on the casting surface topography, it was found that the chemical and phase compositions in the sub-surface layer of casting have a decisive influence on the quality of produced coatings.
Keywords: magnesium alloys, conversion coatings, protective-decorative chromate coatings, die casting,
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Zdzisław Żółkiewicz, Wiesław Jankowski
One of the main parameters determining proper course of the pattern evaporation process, which takes place in parallel with pouring of the foundry mould with metal, are properties of the ceramic coating applied on a polystyrene pattern. These properties include the permeability and mechanical as well as thermal resistance of the coating. The paper presents the developed measuring apparatus and the results of experimental studies of selected properties of the ceramic coatings applied on a polystyrene pattern used in the lost foam process.
Keywords: evaporative patterns, lost foam, permeability, strength, ceramic layer,
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Andrzej Gwiżdż, Stanisław Pysz, Paweł Gonera
The results of computer simulation carried out on MAGMAsoft and MAGMAiron programmes were presented for the technology of pouring and solidification of 35GSM steel castings and GJS400-15 and GJS600-3 ductile iron castings. Based on the assumed starting technology guidelines, the results of this simulation were presented in the form of 3D drawings of the casting technology, including also the selected successive stages of solidification and final porosity in the examined castings. Based on the results of the simulation, changes were introduced to the casting technology, computer simulation was performed once again for the revised technology, and new results were compared with the starting ones.
Keywords: computer-aided casting manufacture, simulation of solidification, cast iron and cast steel,
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