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1
Content available 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
|
2019
|
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.
2
Content available Measurement of Molding Sand Elasticity
Major-Gabryś K., Grabarczyk A., Dobosz S.M., Jakubski J., Morek J., Beňo J.
Journal of Casting & Materials Engineering
|
2018
|
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.
3
Content available Thermally Hardened Moulding and Core Sands with Hydrated Sodium Silicate Designed for Al Alloy Castings
Major-Gabryś K. A., Grabarczyk A. P., Dobosz S. M.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 3
132--137
EN
The necessity of obtaining high quality castings forces both researchers and producers to undertake research in the field of moulding sands. The key is to obtain moulding and core sands which will ensure relevant technological parameters along with high environmental standards. The most important group in this research constitutes of moulding sands with hydrated sodium silicate. The aim of the article is to propose optimized parameters of hardening process of moulding sands with hydrated sodium silicate prepared in warm-box technology. This work focuses on mechanical and thermal deformation of moulding sands with hydrated sodium silicate and inorganic additives prepared in warm-box technology. Tested moulding sands were hardened in the temperature of 140ºC for different time periods. Bending strength, thermal deformation and thermal degradation was tested. Chosen parameters were tested immediately after hardening and after 1h of cooling. Conducted research proved that it is possible to eliminate inorganic additives from moulding sands compositions. Moulding sands without additives have good enough strength properties and their economic and ecological character is improved.
4
Content available The Tendency of Moulding Sands to Generate Core Cracks
Grabarczyk A., Dobosz S. M., Kusiński J., Major-Gabryś K.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 1
157--161
EN
The constant growth of foundry modernization, mechanization and automation is followed with growing requirements for the quality and parameters of both moulding and core sands. Due to this changes it is necessary to widen the requirements for the parameters used for their quality evaluation by widening the testing of the moulding and core sands with the measurement of their resistance to mechanical deformation (further called elasticity). Following article covers measurements of this parameter in chosen moulding and core sands with different types of binders. It focuses on the differences in elasticity, bending strength and type of bond destruction (adhesive/cohesive) between different mixtures, and its connection to the applied bonding agent. Moulding and cores sands on which the most focus is placed on are primarily the self-hardening moulding sands with organic and inorganic binders, belonging to the group of universal applications (used as both moulding and core sands) and mixtures used in cold-box technology.
5
Content available Modification of Foundry Binders by Biodegradable Material
Major-Gabryś K., Grabarczyk A., Dobosz S. M.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 2
31--34
EN
The paper presents the impact of biodegradable material - polycaprolactone (PCL) on selected properties of moulding sands. A self-hardening moulding sands with phenol-furfuryl resin, which is widely used in foundry practice, and an environmentally friendly self-hardening moulding sand with hydrated sodium silicate where chosen for testing. The purpose of the new additive in the case of synthetic resin moulding sands is to reduce their harmfulness to the environment and to increase their “elasticity” at ambient temperature. In the case of moulding sands with environmentally friendly hydrated sodium silicate binder, the task of the new additive is to increase the elasticity of the tested samples while preserving their ecological character. Studies have shown that the use of 5% PCL in moulding sand increases their flexibility at ambient temperature, both with organic and inorganic binders. The influence of the new additive on the deformation of the moulding sands at elevated temperatures has also been demonstrated.
6
Content available Mechanical and Thermal Deformation of Hot-box Moulding Sands
Grabarczyk A., Major-Gabryś K., Dobosz S. M., Jakubski J.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 4
55--58
EN
The constantly developing and the broadly understood automation of production processes in foundry industry, creates both new working conditions - better working standards, faster and more accurate production - and new demands for previously used materials as well as opportunities to generate new foundry defects. Those high requirements create the need to develop further the existing elements of the casting production process. This work focuses on mechanical and thermal deformation of moulding sands prepared in hot-box technology. Moulding sands hardened in different time periods were tested immediately after hardening and after cooling. The obtained results showed that hardening time period in the range 30-120 sec does not influence the mechanical deformation of tested moulding sands significantly. Hot distortion tests proved that moulding sands prepared in hot-box technology can be characterized with stable thermal deformation up to the temperature of circa 320 °C.
7
Content available Utilisation of mould temperature change in eliminating the Al5FeSi phases in secondary AlSi7Mg0.3 alloy
Bolibruchová D., Richtárech L., Dobosz S. M., Major-Gabryś K.
Archives of Metallurgy and Materials
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2017
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Vol. 62, iss. 1
339--344
EN
This article describes the impact of the metal mould temperature change in eliminating the adverse effect of iron in the AlSi7Mg0.3 alloy. The kind of phases based on iron to be formed in aluminium alloys is determined by the alloy chemical composition, the melt overheating temperature prior to casting, and the cooling rate during crystallisation. In the experiment, we used three various mould temperatures, and their impact on the possible change in the adverse Al5FeSi phase, excreted in a needle form to a more compact form of Chinese writing or skeleton units. The experimental part did not use melt overheat that would result in impairment of the melt, for example due to increased gassing of the melt, as well as in a greater load on the smelting unit, thus resulting in increased energy expenditure. We can conclude from the obtained results that the mould temperature change does not have an adequate effect in eliminating the adverse effect of iron in Al-Si-Mg alloys.
8
Content available The thermal and structural analysis of new bicomponent binders for moulding sands consisting of furfuryl resin and polycaprolactone (PCL)
Major-Gabryś K., Bobrowski A., Grabarczyk A., Dobosz S. M.
Archives of Metallurgy and Materials
|
2017
|
Vol. 62, iss. 1
369--372
EN
The aim of the article is thermal and structural analysis of new two-component binders for foundry moulding sands. The previous research showed the possibility of using biodegradable materials as binders or parts of binders’ compositions for foundry moulding and core sands. This paper is concentrated on estimating the influence of PCL on phenol-furfuryl resin thermal destruction (measured by derivatographic research) and its structure (measured by FTiR technology). The research proved that addition of new biodegradable additive PCL in the amount of 5-15% to the phenol-furfuryl resin doesn’t change the resin thermal destruction course but it results in appearance of a new band in two-component binder structure. What’s more there has been noticed a growth of intensity for band at wavenumber 1730 cm-1 (C = O) with the increasing addition of PCL.
9
Content available Elasticity of cores manufactured in cold box technology
Dobosz S. M., Grabarczyk A., Major-Gabryś K., Bolibruchova D.
Archives of Metallurgy and Materials
|
2017
|
Vol. 62, iss. 1
351--354
EN
In the foundry industry, as in many other fields we seek to achieve the best quality with the least losses and the lowest cost. To meet these demands numerous plants increased automatization of their manufacturing processes. However, with changes in the production process it is necessary to change also the materials used. Not only casting alloys that are used in production, but also applied moulding and core sands are important. Proper selection and evaluation of the properties of used moulding mixtures is crucial in order to achieve a highly efficient production. In this article a new issue concerning the use of flexibility in foundry molding and core was mentioned. It explains the principles of measurement and interpretation of the obtained results for the cold-box moulding sands.
10
Content available Elasticity of Moulding Sands – a Method of Reducing Core Cracking
Dobosz S. M., Grabarczyk A., Major-Gabryś K.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 1
31--36
EN
This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new parameter of moulding sands is investigated. With the use of presented testing equipment it is possible to determine force kinetics and deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws, caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this property, presents methods of measuring and continues earlier research.
11
Content available remote Nowe stanowisko do badań elastyczności mas formierskich
Dobosz S. M., Grabarczyk A., Major-Gabryś K., Morek J.
Stal, Metale & Nowe Technologie
|
2016
|
nr 7-8
63--65
PL
W artykule przedstawiono opis nowego stanowiska do pomiaru odporności mas formierskich na odkształcenia mechaniczne (elastyczność) oraz termiczne (hot distortion). Szczegółowo wyjaśniono zasady pomiaru, sposób przygotowania próbek do badań oraz opis i interpretację otrzymanych wyników.
EN
The article describes a new measuring station focused on the resistance of molding sands to mechanical (elasticity) and thermal (hot distortion) deformation. The principles of the measurement, how to prepare the samples for testing, as well as the description and interpretation of the results, are explained in detail.
12
Content available Wpływ dodatku materiału biodegradowalnego jako komponentu dwuskładnikowego spoiwa odlewniczych mas formierskich i rdzeniowych na właściwości spoiwa oraz mas z jego zastosowaniem
Major-Gabryś K., Grabarczyk A., Dobosz S. M., Drożyński D.
Prace Instytutu Odlewnictwa
|
2016
|
Vol. 56, no. 4
391--399
PL
Rosnące wymagania dotyczące emisji substancji szkodliwych zmuszają przemysł odlewniczy do poszukiwania nowych, bardziej przyjaznych dla środowiska rozwiązań. Do rozwiązań takich mogą należeć: technologie sporządzania mas formierskich i rdzeniowych z zastosowaniem organicznych materiałów biodegradowalnych jako spoiw. Należy jednak pamiętać, że nowe technologie muszą zapewnić wysokie właściwości technologiczne mas formierskich i rdzeniowych. W niniejszym artykule przedstawiono wyniki badań nowych dwuskładnikowych spoiw formierskich, w których część powszechnie stosowanej w praktyce odlewniczej żywicy fenolowo-furfurylowej zastąpiono materiałem biodegradowalnym w postaci polikaprolaktonu (PCL). W artykule przedstawiono badania wpływu materiału biodegradowalnego jako komponentu nowego dwuskładnikowego spoiwa na degradację termiczną spoiwa, jego lepkość oraz na wybrane właściwości technologiczne badanych mas z zastosowaniem nowego spoiwa, w tym ich deformację cieplną oraz elastyczność w temperaturze otoczenia. Przeprowadzone badania wykazały, że zastąpienie w spoiwie części żywicy fenolowo-furfurylowej materiałem biodegradowalnym PCL nie wpływa na degradację termiczną nowego spoiwa, zwiększa natomiast jego lepkość. Masy z zastosowaniem dwuskładnikowego spoiwa charakteryzują się zbliżonymi właściwościami technologicznymi do mas zawierających tylko żywicą fenolowo-furfurylową.
EN
The increasing requirements concerning the emission of hazardous substances force the casting industry to search for new, more environment-friendly solutions. Such solutions may include technologies of developing moulding and core sands with the use of organic biodegradable materials as binders. We should, however, remember that the new technologies must ensure high technological properties of the moulding and core sands. This article presents the results of investigations of new binary moulding binders, where part of the phenol-furfuryl resin commonly applied in casting, was replaced by a biodegradable material in the form of polycaprolactone (PCL). The article discusses the investigations of the effect of the biodegradable material as a component of a new binary binder on the thermal degradation of the binder, its viscosity as well as the selected technological properties of the examined moulding sands, including their thermal deformation and elasticity at ambient temperature. The performed examinations showed that replacing a part of the phenol- furfuryl resin in the binder with the PCL biodegradable material does not affect the thermal degradation of the new binder, while increasing its viscosity. The moulding mixtures with the applied binary binder are characterized by similar technological properties to the moulding sands with the phenol-furfuryl resin only.
13
Content available The Compositions: Biodegradable Material – Synthetic Resins as Moulding Sands Binders
Major-Gabryś K., Grabarczyk A., Dobosz S. M.
Archives of Foundry Engineering
|
2016
|
Vol. 16, iss. 4
75--78
EN
Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials as binders. However, not only environmental requirements grow but also those related to the technological properties of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands. Low elasticity may cause defects during assembly of cores or moulds by the manipulators. The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of self-hardening moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and increases their flexibility at room temperature.
14
Badania laboratoryjne odlewniczych mas formierskich
Major-Gabryś K., Dobosz S. M., Grabarczyk A.
Laboratorium - Przegląd Ogólnopolski
|
2015
|
nr 11-12
62--64
PL
W artykule zostały przedstawione stosowane laboratoryjne metody pomiaru wybijalności mas. Zaproponowano nową metodę oceny tej właściwości, której zalety wykazano, testując zmodyfikowane przez autorów odlewnicze masy formierskie z uwodnionym krzemianem sodu. Masy te cechuje mała szkodliwość dla środowiska, niestety ich wady to zła wybijalność oraz mała zdolność do regeneracji mechanicznej.
EN
The article presents commonly used methods of measuring moulding sands knock-out properties. A new method of estimation of this parameter is presented, its’ advantages are proved by tests of modified foundry moulding sands with hydrated sodium silicate. They are environmentally friendly, but unfortunatelythey have bad knock-out properties and low mechanical reclamation ability.
15
Content available The Compositions: Biodegradable Material - Typical Resin, as Moulding Sands’ Binders
Major-Gabryś K., Dobosz S. M., Drożyński D., Jakubski J.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1
35--40
EN
The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.
16
Content available New Materials in the Production of Moulding and Core Sands
Dobosz S. M., Major-Gabryś K., Grabarczyk A.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 4
25--28
EN
The article shows the influence of environment requirements on changes in different foundry moulding sands technologies such as cold box, self-hardening moulding sands and green sands. The aim of the article is to show the possibility of using the biodegradable materials as binders (or parts of binders’ compositions) for foundry moulding and core sands. The authors concentrated on the possibility of preparing new binders consisting of typical synthetic resins - commonly used in foundry practice - and biodegradable materials. According to own research it is presumed that using biodegradable materials as a part of new binders’ compositions may cause not only lower toxicity and better ability to reclaim, but may also accelerate the biodegradation rate of used binders. What’s more, using some kinds of biodegradable materials may improve flexibility of moulding sands with polymeric binder. The conducted research was introductory and took into account bending strength and thermal properties of furan moulding sands with biodegradable material (PCL). The research proved that new biodegradable additive did not decrease the tested properties.
17
Content available Influence of Quartz Sand Quality on Bending Strength and Thermal Deformation of Moulding Sands with Synthetic Binders
Dobosz S. M., Grabarczyk A., Major-Gabryś K., Jakubski J.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 2
9--12
EN
Modern techniques of castings production, including moulding sands production, require a strict technological regime and high quality materials. In the case of self-hardening moulding sands with synthetic binders those requirements apply mainly to sand, which adds to more than 98% of the whole moulding sand mixture. The factors that affect the quality of the moulding sands are both chemical (SiO2, Fe2O3 and carbonates content) and physical. Among these factors somewhat less attention is paid to the granulometric composition of the sands. As a part of this study, the effect of sand quality on bending strength Rgu and thermal deformation of self-hardening moulding sands with furfural and alkyd resin was assessed. Moulding sands with furfural resin are known [1] to be the most susceptible to the sand quality. A negative effect on its properties has, among others, high content of clay binder and so-called subgrains (fraction smaller than 0,1mm), which can lead to neutralization of acidic hardeners (in the case of moulding sands with furfuryl resin) and also increase the specific surface, what forces greater amount of binding agents. The research used 5 different quartz sands originating from different sources and characterized with different grain composition and different clay binder content.
18
Content available Elastyczność – nowe kryterium oceny jakości mas formierskich
Grabarczyk A., Dobosz S. M., Major-Gabryś K., Jakubski J., Morek J.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 4 spec.
39--42
PL
Współczesne odlewnictwo cechuje wysoki stopień automatyzacji w procesach produkcji masowej. Wspomaganie procesów zakładania rdzeni i składania form odlewniczych przez wszelkiego rodzaju manipulatory oraz roboty przyczynia się do pękania form oraz rdzeni podczas montażu. Często występujące uszkodzenia rdzeni są wynikiem niskiej elastyczności mas formierskich, nawet przy wysokiej wytrzymałości rdzeni. W celu zbadania tego zjawiska opracowany został specjalny moduł pomiarowy połączony z klasycznym pomiarem skłonności mas do odkształceń w wysokich temperaturach – hot distortion. W ramach niniejszej pracy przedstawiona zostanie szczegółowo metodyka pomiaru oraz wstępne badania elastyczności i deformacji cieplnej dla sypkich mas samoutwardzalnych ze spoiwem furfurylowym oraz alkidowym o określonych składach.
EN
Modern casting is characterized by a high degree of automation in the processes of mass production. Supporting the processes of inserting cores and composing the moulds with all kinds of manipulators and robots leads to breakage of both cores and moulds during installation. Common core damages are the result of low elasticity of the moulding sands, despite high strength resistance of the cores. In order to investigate this phenomenon a special measuring module, connected with a classical measurement of the tendency of moulding sands to deform in high temperatures-hot distortion, has been developed. Within the framework of this paper the methods of measurement and preliminary research of elasticity and thermal deformation of self-hardening moulding sands with furfuryl and alkyd binders will be presented.
19
Content available The Measurement of High-Temperature Expansion as the Standard of Estimation the Knock-Out Properties of Moulding Sands with Hydrated Sodium Silicate
Major-Gabryś K., Dobosz S.M., Jelínek P., Jakubski J., Beňo J.
Archives of Metallurgy and Materials
|
2014
|
Vol. 59, iss. 2
739--742
EN
The necessity of receiving high quality castings forces undertaking research to elaborate moulding and core sands ensuring obtaining the materials with relevant technological parameters and also with high environmental standards. The most important group here are moulding sands with hydrated sodium silicate. Unfortunately, their fundamental disadvantages are weak knock-out properties. The article presents the most commonly used methods of measuring the knock-out properties of moulding and core sands. The authors propose a new method for estimation this parameter. The method is based on the measurement of high-temperature expansion.
PL
Potrzeba uzyskiwania wysokiej jakości odlewów wymusza podejmowanie prac badawczych dla otrzymania mas formierskich i rdzeniowych zapewniających uzyskanie tworzyw o odpowiednich parametrach technologicznych, jednocześnie spełniających wysokie wymogi ochrony środowiska. Najważniejszą grupę stanowią tutaj masy z uwodnionym krzemianem sodu. Niestety jedną z ich podstawowych wad jest słaba wybijalność. W artykule zostały przedstawione najczęściej stosowane metody pomiaru wybijalności mas formierskich i rdzeniowych Autorzy zaproponowali nową metodę oceny wybijalności opierającą się na pomiarze ekspansji wysokotemperaturowej.
20
Content available The Influence of the Content of Furfuryl Alcohol Monomer on the Process of Moulding Sand's Thermal Destruction
Dobosz S. M., Drożyński D., Jakubski J., Major-Gabryś K.
Archives of Metallurgy and Materials
|
2014
|
Vol. 59, iss. 3
1093--1096
EN
The article discusses the issue of the influence of furfuryl alcohol content in resin binders on properties of moulding sand at elevated temperature. Reducing the share of this component - due to the requirements of the European Union regarding its toxicity - may cause a decrease in temperature of moulding sands’ destruction and, consequently, the thermal deformation of moulds and the creation of many casting defects. The study examined the impact of the furfuryl alcohol content of the thermal destruction processes and on the strength of the moulding sand at an ambient temperature and the tendency to thermal deformation.
PL
W artykule omówiono zagadnienie wpływu zawartości alkoholu furfurylowego w spoiwach żywicznych na właściwości mas formierskich w podwyższonej temperaturze. Zmniejszenie udziału tego składnika – spowodowane wymaganiami Unii Europejskiej odnośnie jego toksyczności – może powodować obniżenie temperatur destrukcji masy, a w konsekwencji deformację cieplną form i powstanie wielu wad odlewniczych. W pracy przebadano wpływ zawartości alkoholu furfurylowego na procesy cieplnej destrukcji spoiwa a także na wytrzymałość masy w temperaturze otoczenia oraz skłonność do deformacji cieplnej.
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