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Tests of Mechanical and Thermal Deformation of Moulding Sands Produced in Various Technologies

Grabarczyk Aleksandra, Major-Gabryś Katarzyna, Jakubski Jarosław, Dobosz Stanisław Marian, Bolibruchová Dana, Pastirčák Richard

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

933--937

EN

Casting industry has been enriched with the processes of mechanization and automation in production. They offer both better working standards, faster and more accurate production, but also have begun to generate new opportunities for new foundry defects. This work discusses the disadvantages of processes that can occur, to a limited extend, in the technologies associated with mould assembly and during the initial stages of pouring. These defects will be described in detail in the further part of the paper and are mainly related to the quality of foundry cores, therefore the discussion of these issues will mainly concern core moulding sands. Four different types of moulding mixtures were used in the research, representing the most popular chemically bonded moulding sands used in foundry practise. The main focus of this article is the analysis of the influence of the binder type on mechanical and thermal deformation in moulding sands.

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The Influence of Moulding Sand Type on Mechanical and Thermal Deformation

Grabarczyk A., Major-Gabryś K., Dobosz S. M., Jakubski J., Bolibruchová D., Brůna M., Pastirčák R.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

347--351

EN

Casting industry has been enriched with the processes of mechanization and automation in production. They offer both better working standards, faster and more accurate production, but also have begun to generate new opportunities for new foundry defects. This work discusses the disadvantages of processes that can occur, to a limited extend, in the technologies associated with mould assembly and during the initial stages of pouring. These defects will be described in detail in the further part of the paper and are mainly related to the quality of foundry cores, therefore the discussion of these issues will mainly concern core moulding sands. Four different types of moulding mixtures were used in the research, representing the most popular chemically bonded moulding sands used in foundry practise. The main focus of this article is the analysis of the influence of the binder type on mechanical and thermal deformation in moulding sands.

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Measurement of Molding Sand Elasticity

Major-Gabryś K., Grabarczyk A., Dobosz S.M., Jakubski J., Morek J., Beňo J.

Journal of Casting & Materials Engineering

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2018

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Vol. 2, no. 2

38--44

EN

The progressive mechanization and automation of industrial equipment is the driving force of progress, not only in the field of production but also in the measuring and control equipment. In mold production, the automation of processes such as forming molds and cores along with their assembly has led to increases in serial production, reductions in defects, and the shortening of molding times, among others. Thanks to automation in mold and core departments and the use of all sorts of manipulators, mold production in foundries has gained momentum. Unfortunately, in addition to the mentioned advantages, there are also new challenges as to the quality and properties of the molding and core sands used in highly automated foundries.This article presents recent research on molding sand elasticity. The topic was introduced as an attempt to answer the new needs of highly mechanized foundries. The article discusses a new method of measuring the resistance of molding materials to undergoing mechanical deformation (molding sand elasticity), with an additional analysis of the bending strengths of the tested samples. Precise measurements, test sample preparation, and interpretation of the received results are presented in the article.

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Pomiary odpowiedzi częstotliwościowej uzwojeń transformatora w warunkach kontrolowanej deformacji

Banaszak S., Szrot M.

Przegląd Elektrotechniczny

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2008

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R. 84, nr 10

128-131

PL

Artykuł omawia wyniki rejestracji krzywych FRA w warunkach kontrolowanej deformacji uzwojeń, na których wykonywano odkształcenia poosiowe symetryczne i niesymetryczne oraz promieniowe. Dokonano także rejestracji po przerwaniu uzwojenia regulacyjnego. Na podstawie porównania przebiegów zidentyfikowano wstępnie charakterystyczne zakresy częstotliwości w których zachodzą zmiany. Po potwierdzeniu wyników na innych jednostkach opracowany zostanie algorytm oceniający stopień mechanicznego uszkodzenia uzwojenia.

EN

The paper describes results of FRA curves measurements during controlled mechanical deformations of windings. The winding has been deformed along its axis, both symmetrically and asymmetrically, and along radius. Measurements has also been taken after breaking regulation winding. The comparison of results allowed to identify basic ranges of frequencies characteristic for changes in curves. Confirmation of these results on other units will lead to developing an algorithm for mechanical condition of windings assessment.

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Zmiany wartości parametrów umocnienia i struktury dyslokacyjnej stopu na osnowie Fe40Al odkształconego w przedziale temperatur 20/800 stopni Celsjusza

Barcik J., Nieśpiałowski N., Prewendowski M.

Inżynieria Materiałowa

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2003

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R. XXIV, nr 6

768-771

PL

Stop o składzie Fe40Al5Cr0,2Zr0,02B wykazuje tendencję do znacznego umocnienia odkształceniowego w temperaturach od pokojowej aż do około 550 stopni Celsjusza. Badano proces odkształcenia mechanicznego stopu z prędkością odkształcania 0,5x10 do -4 s do -1, w zakresie temperatur 20/800 stopni Celsjusza. Na krzywej umocnienia stopu można wyróżnić dwa etapy umocnienia, przy czym w celu scharakteryzowania parametrów skupiono uwagę wyłącznie na pierwszym etapie. Badany stop wykazuje wzrost umocnienia odkształceniowego w zakresie temperatur 370-500 stopni Celsjusza, z charakterystycznym maksimum. Powyżej temperatury 500 stopni Celsjusza stop wykazuje tendencję do rozmiękczania, które prowadzi do zaniku efektów umocnienia odkształceniowego ze wzrostem temperatury. Obserwacje struktury dyslokacyjnej materiału odkształcanego w wybranych temperaturach badanego przedziału, nie wykazują istotnych zmian. Dyslokacje dominujące w procesie odkształcenia plastycznego mają wektor Burgesa typu <111>. W pracy podjęto próbę powiązania zmian struktury dyslokacyjnej ze zmianami parametrów umocnienia.

EN

The Fe40Al5Cr0.2Zr0.02B alloy shows a tendency to an appreciable strengthening by deformation at a temperature from 20 to about 550 degrees centigrade. The alloy mechanical deformation process was carried out under a deformation rate of 0.5x10 to the -4 s to the -1 in the temperature range of 20-800 degrees centigrade. Two strengthening stages in the alloy work-hardening curve have been distinguished. In order to parameters characterization, only the first stage was considered. The tested alloy exhibits a rise of the deformation strengthening in the temperature range of 370-500 degrees centigrade; a characteristic maximum was observed. Above 500 degrees centigrade, the alloy exhibits a tendency to be soften what leads to a disappearance of the deformation strengthening effects with a temperature rise. Observations of the dislocations structure in a material being deformated at chosen temperatures of a tested range, did not reveal any considerable changes. The Burgers vector for dislocations dominant in a plastic strain was of <111> type. The attempt of a connection of the dislocation structure and strengthening parameters changes has been presented in this paper.