A thermo-insulating moulding sand with a binder made of aluminosilicate microspheres with organic binder was subjected to testing. The aim of the analysis was to determine selected technological properties of the developed compounds. Compressive strength, friability and gas permeability were determined. The binder content was changed within a range of 5÷20 wt% with a 5% step. The applied matrix is characterized by good thermo-insulating properties and a small size of grains, while synthetic organic binder has favourable functional properties, among which the most noteworthy are the extended life and setting time, good rheological properties as well as high resistance to chemical agents. The intended use of the compound is the casting of 3D CRS (Composite Reinforced Skeletons), which are characterized by a well-developed heat transfer surface area, good absorption of impact energy, low mass and a target thickness of connectors within a range of 1.5÷3 mm. The construction of 3D CRS castings is an original concept developed by the employees of the Department of Foundry Engineering at the Silesian University of Technology.
Preliminary tests aimed at obtaining a cellular SiC/iron alloy composite with a spatial structure of mutually intersecting skeletons, using a porous ceramic preform have been conducted. The possibility of obtaining such a composite joint using a SiC material with an oxynitride bonding and grey cast iron with flake graphite has been confirmed. Porous ceramic preforms were made by pouring the gelling ceramic suspension over a foamed polymer base which was next fired. The obtained samples of materials were subjected to macroscopic and microscopic observations as well as investigations into the chemical composition in microareas. It was found that the minimum width of a channel in the preform, which in the case of pressureless infiltration enables molten cast iron penetration, ranges from 0.10 to 0.17 mm. It was also found that the ceramic material applied was characterized by good metal wettability. The ceramics/metal contact area always has a transition zone (when the channel width is big enough), where mixing of the components of both composite elements takes place.
Using the available analytical methods, including the determination of chemical composition using wavelength-dispersive X-ray fluorescent spectroscopy technique and phase composition determined using X-ray diffraction, microstructural observations in a high-resolution scanning microscope equipped with an X-ray microanalysis system as well as determination of characteristic softening and sintering temperatures using high-temperature microscope, the properties of particular chromite sands were defined. For the study has been typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the grinding process. Using these kinds of sand in foundries resulted in the occurrence of the phenomenon of the molding mass sintering. Impurities were identified and causes of sintering of a moulding sand based on chromite sand were characterized. Next, research methods enabling a quick evaluation of chromite sand suitability for use in the preparation of moulding sands were selected.
W artykule przedstawiono wyniki analiz mikrostruktur żeliwa szarego EN-GJL-HB155. Formy wykonano z różnych mas formierskich – klasycznej bentonitowej, piaskowej z żywicą chemoutwardzalną oraz termoizolacyjnej o osnowie z mikrosfer glinokrzemianowych. Do wykonania odlewów próbnych i formowania wykorzystano czterostopniowy model schodkowy według tzw. „próby schodkowej” o grubości stopni: 3, 5, 10, 20 mm. Podjęte badania stanowią wstęp do analizy mikrostruktur szkieletowych odlewów żeliwnych. Odlewy szkieletowe powinny się charakteryzować niewielką grubością łączników tworzących szkielet (docelowo poniżej 3 mm), wysoko rozwiniętą powierzchnią oddawania ciepła, dobrymi własnościami mechanicznymi oraz z góry ustaloną geometrią komórek elementarnych. Odlewy szkieletowe stanowią oryginalne opracowanie Katedry Odlewnictwa Politechniki Śląskiej.
EN
The article presents results of EN-GJL-HB155 grey cast iron microstructure analysis. Moulds were prepared with use of different moulding sands – classic with bentonite, quartz with chemical hardened resin and heat-insulating with aluminosilicate microspheres matrix. To perform experimental casting and forming four-step pattern according to step test bar with a thickness of: 3, 5, 10, 20 mm were used. The study are the introduction of cast iron skeleton casting microstructure analysis. Skeleton castings should be characterized by a small thickness of connector making the skeleton (the target of less than 3 mm), the highly developed surface of the heat give-up, good mechanical properties and predetermined geometry of elementary cells. Skeleton castings are the original development of the Department of Foundry Engineering of the Silesian University of Technology.
The production of thin-walled castings with wall thickness in the range of 1.5 to 3 mm and below requires the development of insulation moulding sands and/or core materials. The test has been taken to develop these kind of materials. The study included a description of their thermophysical properties. Authors described problems related to the heat flow in the casting-mould system, i.e. mathematically described the main dependence of heat give-up during crystallization of the casting. The influence of the content of polyglicol on the thermophysical properties of the mould with gypsum and cement binder was examined. Using the ATD method determined were the increments ΔT1 and ΔT2 describing the temperature changes in the mould during crystallization of hypoeutectic alloy of AlSi6 and the temperature difference between casting material and mould during the crystallization. In the considered range of technological parameters a description of the heat flow kinetics was given.
Hałas jest zjawiskiem niepożądanym, występującym zarówno w życiu prywatnym jak i zawodowym człowieka , który w niesprzyjających warunkach może prowadzić do nieszczęścia. Celem niniejszej publikacji jest określenie poziomu natężenia hałasu emitowanego przez pracujący piec indukcyjny do poziomego ciągłego odlewania aluminiowego wlewka o średnicy 30 mm, chłodnicy oraz współpracującej piły tarczowej wykorzystywanej do cięcia wytworzonego wyrobu. Analiza wyników pozwoli na wskazanie, które spośród stanowisk roboczych operatora linii technologicznej mieści się w granicach normatywów higienicznych dotyczących dopuszczalnego natężenia hałasu, a które przekracza dozwolone wartości. Pozwoli to na dobór odpowiednich i skutecznych metod zabezpieczenia operatora przed niekorzystnym wpływem warunków pracy na jego zdrowie oraz przyczyni się do poprawy warunków pracy w ramach przyjętych standardów BHP.
EN
The noise is undesirable effect, occurring in private and professional life of a man which in unfavourable conditions can lead to disaster. The aim of the paper is to determine the level of noise emitted by induction furnace working for horizontal continuous casting of aluminium ingot with a diameter of 30 mm, a cooler and mating circular saw used to cut the manufactured product. Analysis of the results will indicate which of the operator workstations technological line is in the range of hygienic standards relating to the permissible noise level, which exceeds the allowed values. This will allow the selection of appropriate and effective methods to protect the operator from the adverse effects of working conditions on the health and contribute to the improvement of working conditions within accepted safety standards.
W pracy przedstawiono analizę jednej z podstawowych własności technologicznych mas formierskich jaką jest ścieralność. Pierwsza część badań wykonana została bez wykorzystania promiennika, druga – z jego wykorzystaniem, co pozwoliło na nagrzanie próbek do temperatury 95°C. Do badań wykorzystano jako osnowę masy formierskiej lekkie kruszywo ceramiczne o bardzo wysokich własnościach termoizolacyjnych, które jest wytwarzane w Polsce i na bazie polskich surowców (LECA® KERAMZYT). W badaniach wykorzystano masę, w której zawartość lepiszcza bentonitowego mieściła się w granicy 7÷35%. Przesłanką podjęcia tematyki badawczej jest brak uregulowań normatywnych dotyczących procesów technologicznych klasycznych metod wytwarzania odlewów cienko- jak i supercienkościennych, których grubość ścianki nie przekracza 3 mm, o znacznie rozwiniętej powierzchni oddawania ciepła podczas krystalizacji. Bezpośrednim przeznaczeniem podobnych mas formierskich jest wykonywanie rdzeni i form do wytwarzania odlewów szkieletowych CRS (Odlewy Wzmacniane Przestrzennie). Wykorzystany materiał badawczy pozwala na spełnienie obydwu kryteriów.
EN
The paper presents an analysis of one of the fundamental properties of moulding technology which is abrasion. The first part of the study was performed without the use of the heater, the second - with its use, which allowed to warm up the samples to temperature of 95°C. During the study a moulding lightweight ceramic aggregate with very high thermal insulation properties, which are manufactured in Poland and Polish-based raw materials (LECA® KERAMZYT) was used as a matrix. The study utilizes the mass, wherein the content of bentonite binder was in the range of 7÷35%. The reason for taking the research subject is the lack of regulations on normative processes of classical methods of producing thin-walled and superthin-walled castings whose thickness is less than 3 mm, with significantly expanded area of heat dissipation during crystallization. The direct purpose of similar sands is the manufacturing of cores and moulds in skeletal castings production by CRS (Casting Reinforce Spatially) method. The research material is sufficient to comply with these two criteria.
Until now, the mould sand in general use in the foundry industry are based on bentonite, which resulted from the fact that a good recognition properties and phenomena associated with this material. Come to know and normalized content of montmorillonite and carbonates and their important role in the construction of bentonite, and mass properties of the participation of compressive strength or scatter. Halloysite is widely used in industry and beyond them. However, little is known about its use in the foundry in Poland and abroad. This article presents preliminary research conducted at the Foundry Department of Silesian University of Technology on this material. Will raise the question of the representation of this two materials, which contains information connected with history and formation of materials, their structure and chemical composition. In the research, the results of compressive strength tests in wet masses of quartz matrix, where as a binder is used halloysite and bentonite in different proportions.
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