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1

Influence of Microwave Heating on the Molding Mass with Gypsum Binder Structure and Strength

Paduchowicz Patrycja J., Granat K., Biały P.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 1

113--118

EN

The paper presents results of influence microwave drying on strength and technological properties of molding sand with gypsum binder researches, which, immediately after making and after the natural initial setting in air for 1, 2 or 5 hours, was heated with 250 W microwave power for 3, 6, 9 and 12 min time periods. The test was carried out on a mass containing (% -wt.): 88% Grudzeń-Las quartz sand, 12% "Dolina Nidy" plaster gypsum and 6% water. The loss of moisture content during natural drying and then microwave drying was determined, significant from the point of view of using the mass with gypsum binder in the production of products, using an environmentally friendly technology without casting incompatibilities. Additionally, the compressive strength of the mass was measured. The influence of both drying methods on the binder crystallization process and the associated mass strength was demonstrated, especially in terms of the possibility of selecting parameters and / or intensifying a specific drying method for use in the technology of manufacturing molds and foundry cores.

2

Wybijalność mas ze szkłem wodnym modyfikowanym nanocząstkami MgO

Kmita A., Hutera B.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 4 spec.

55--58

PL

Przedmiotem pracy była modyfikacja szkła wodnego 5% mas. koloidalnym roztworem nanocząstek MgO w propanolu i dokładnej homogenizacji spoiwa. Celem przeprowadzonych badań było określenie wpływu modyfikacji szkła wodnego na wytrzymałość końcową na ściskanie Rctk oraz wybijalność mas z tym spoiwem oznaczonymi w próbie technologicznej zalecanej przez polską normę PN-85/H-11005. Wykazano, że zastosowana modyfikacja korzystnie wpływa na przebieg krzywej Rctk, powodując przesunięcie występowania II maksimum wytrzymałości masy w kierunku wyższych wartości temperatury. Pozytywne oddziaływanie zastosowanej modyfikacji szkła wodnego potwierdzone zostało próbami technologicznymi, w których stwierdzono poprawę wybijalności tych mas o 50% w porównaniu z wybijalnością mas ze szkłem wodnym niemodyfikowanym.

EN

Moulding sands with water glass belong to the group of environment friendly moulding sands. However, due to some disadvantageous technological properties of these sands, such as e.g. difficult knocking out and poor reclamation ability [1, 2], they are not widely applied in the foundry industry. Therefore numerous endeavours aimed at improving the quality of moulding sands with water glass are undertaken. Apart from the modification of the moulding sand matrix composition or controlling the hardening process the quality improvement of these sands can be achieved by means of binder modifications, either chemical or physicochemical. Reactions between water glass components and inoculants are essential in chemical processes. The progress of nanotechnologies occurring during last years, causes that nanomaterials are more and more often applied in several industries including also the foundry industry. Nanoparticles introduced into a binding material can react with it influencing and modifying its selected properties. The subject of the study is the water glass modification by the colloidal solution of MgO nanoparticles in propanol [3]. The aim of the performed investigations is the determination of the binder modification influence on the final compression strength Rctk and knock out property of moulding sands with the modified water glass (marked in the technological test according to the Polish standard: PN-85/H-11005).

3

Nowe żywice furfurylowe bardziej przyjazne dla środowiska

Holtzer M., Kmita A., Roczniak A.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 4 spec.

47--50

PL

Coraz ostrzejsze przepisy w zakresie ochrony środowiska wymuszają na producentach materiałów dla przemysłu odlewniczego opracowywanie nowych produktów, bardziej przyjaznych dla środowiska. Jednym z takich produktów są żywice furfurylowe, które obecnie mają największy udział w grupie mas no-bake. Wprowadzone w ostatnich latach w UE przepisy dotyczące ograniczenia zawartości wolnego alkoholu furfurylowego (< 25%) w żywicach oraz naciski w kierunku redukcji emisji SO2, formaldehydu, fenolu, benzenu i toluenu, jak również związków z grupy WWA, szczególnie na stanowiskach pracy spowodowały pojawienie się na rynku nowej generacji żywic furfurylowch oraz katalizatorów (o zmniejszonej zawartości siarki lub bezsiarkowych). W artykule dokonano analizy wpływu tych nowych produktów stosowanych w technologii mas z żywicami furfurylowymi na środowisko i warunki pracy.

EN

More and more strict regulations, concerning the environment protection, force the producers of materials for foundry industry to develop new products, more friendly for the environment. One of such products are furfuryl resins, which currently have the largest share within the group of no-bake moulding sands. Regulations introduced in the last years in the European Union concerning limitations of a free furfuryl alcohol content (< 25%) in resins as well as pressures to reduce SO2, formaldehyde, phenol, benzene, toluene and compounds from the PAHs group emissions, especially at work stands, caused an appearance of the new generation of furfuryl resins and catalysts (of a decreased sulphur content or even sulphur-free). The analysis of the influence of these new products, applied in the moulding sands with furfuryl resins technology, on the environment and work conditions was performed in the hereby paper.

4

The quality of compressed air as the necessary condition the improving the process efficiency in foundry plants

Wrona R., Ziółkowski E., Smyksy K., Brzeziński M.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 4

107--111

EN

A foundry plant as a manufacturing system operates in accordance with the methods and principles making up the entire process of casting production, involving the use of machines and installations. One of the factors transforming the foundry plant’s static structure into the dynamic – processing structure is the compressed air. Practically each procedure making up the casting manufacturing process involves compressed air. Its sources include compressor machines connected to the receiving tanks, making up the compressed air transport installation. Two major aspects are to be addressed in compressed air management: the engineering and economic ones. The engineering aspect involves the manufacturing of compressed air with the required quality features and in the amount balancing its demand, whilst the economic aspect is associated with cost minimisation. This paper investigates the engineering aspects: air quality, with the main focus on air treatment processes to satisfy the constructional and operational requirements of air receivers present in the casting processes.

5

Technological and ecological studies of moulding sands with new inorganic binders for casting of non-ferrous metal alloys

Izdebska-Szanda I., Szanda M., Matuszewski S.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 1

43-48

EN

The article presents the results of studies which form a part of broader research programme executed under the project POIG.01.01.02-00-015/09 "Advanced materials and technologies". In a concise manner, the results of studies on the effect of chemical modification of inorganic binders on the technological properties of moulding sands containing these binders were presented. Special attention was paid to the effect of modification of inorganic binders on their thermal destruction behaviour in the range of pouring temperatures of the non-ferrous metals and their alloys. Also the results of comparative studies of the thermal emission of toxic gases and odours from moulding sands with new inorganic and organic binders were discussed.

6

Possibilities of utilizing used moulding and core sands by microwave treatment

Granat K., Nowak D., Stachowicz M., Pigiel M.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 1

35-38

EN

The paper presents a semi-industrial reactor designed for microwave utilization of waste moulds and cores made of moulding sands prepared in furane resin technology. It was found that a possibility exists of effective incinerating this way prepared residues of cores separated from moulding sands or waste moulds left after casting. The preliminary tests evidenced that microwave heating is an effective way of disposing waste moulding sands and the applied apparatus permits effective control of the microwave heating process. The special structure permitting rotations of charge material and proper selection of the generators working cycles guarantee significant speeding-up the process and its full stabilisation. Application of microwave heating for utilization of waste moulds and cores containing synthetic resins as binders ensures significant and measurable economical benefits resulting from shorter process time.

7

New generation of pattern materials for investment casting

Karwiński A., Młodnicki S., Pabiś R., Robak I., Kubosz G.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 1

53-56

EN

Pattern mixtures (so-called soft mixtures) currently used in investment casting are composed of paraffin, stearin, and - to a lesser extent - of ceresin, polyethylene wax and other natural and synthetic waxes. During studies, several types of soft pattern mixtures were developed by modifying the already existing compositions with appropriate additives. Based on the studies of physico-chemical and performance properties, the composition of pattern material was optimised.

8

Acquisition of technology knowledge from online information sources

Kluska-Nawarecka S., Wilk-Kołodziejczyk D., Dziaduś-Rudnicka J., Smolarek-Grzyb A.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 3

107-112

EN

The article discusses problems related with the search of information from open sources, particularly on the Internet. Specific area of concern is searching for technical knowledge in the area of metalcasting. The results of ongoing experiments were given, to serve as a basis in identification of the opportunities to improve the process of searching through determination of own research plans.

9

The influence of copper on the microstructure and selected parameters of duplex cast steel

Stradomska J., Stachura S., Stradomski Z., Soiński M. S.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

87-90

EN

Technological problems related to mastering the production of castings made of ferritic-austenitic cast steel (duplex type), i.e problems related to low carbon content (Cmax 0.03%) and high hot cracking susceptibility due to phenomena taking place during solidification and cooling of castings, cause that this material, although attractive due to its price and improving company prestige, is rarely produced in Poland. The undertaken attempts have mainly dealt with GX2CrNiMoCu25-6-3-3 grade containing copper due to the requirements of power industry which is the main possible customer with respect to the elements made of duplex cast steel. The authors of this paper have thought it reasonable to present selected aspects of microstructural and mechanical properties for the two cast steel grades described in the PN-EN 10283:2002 Standard, which differ only by Cu addition. The examinations concerned mainly the as-cast condition, because it is decisive for the defective production. It has been shown that the weak austenite-forming copper exerts a strong influence on the primary structure of cast steel, resulting in precipitating the [...] austenite within ferrite, where the austenite is crystallographically dependent on the matrix. The GX2CrNiMoCu25-6-3-3 cast steel in supersaturated state is characterised by Charpy V-notch impact energy lower by about 30% than for the cast steel grade without Cu addition.

10

The analysis of solidification process of ferritic-austenitic cast steel

Stradomska J., Stradomski Z., Soiński M. S.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

83-86

EN

One of the most common defects leading to the rejection of faulty castings made of duplex cast steel is hot cracking. Hot cracking - differently from cold cracking which occur on cooling, when the material exhibits already distinct elastic properties - proceeds in the semi-solid state, particularly when the temperature of solidifying casting is close to the equilibrium solidus point. There exist a range of temperatures in the vicinity of the solidus point within which the solidifying metal shows very small deformation ability and small strength. Therefore even little stresses occurring at the solidification stage and caused by density difference between ferrite and austenite, or restricted shrinkage, or various temperature gradients, can be the reason of hot cracking. Copper addition, as it is used in cast steel grades implemented in Polish power industry applications, decreases the temperature of the end of solidification, thus affecting beneficially the surface reproduction quality, but on the other hand it can promote, along with several other elements contained in duplex cast steel, the peritectic transformation during the last stage of solidification. The presence of peritectic solidification, i.e. strictly speaking the structural stresses accompanying that process, is the well-known and significant reason of the increased steel defectiveness in the continuous steel casting (CSC) technology if the steel with carbon content promoting the peritectic transformation is processed. The authors have presented the examination results of the solidification phenomenon for two duplex cast steel grades - one without copper addition, and the other with addition of about 3.0% Cu.

11

Effect of additives promoting the formation of lustrous carbon on the knocking out properties of foundry sands with new inorganic binders

Izdebska-Szanda I., Stefański Z., Pezarski F., Szolc M.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

17-20

EN

The article presents the results of investigations, which make a fragment of the broad-scale studies carried out as a part of the statutory activity on optimising the foundry sand technology using new, modified, inorganic binders. The results of investigations regarding the effect of lustrous carbon carriers on the technological properties of foundry sands with inorganic binders were presented in a concise manner. The selected additives were introduced to moulding sands prepared with the new, modified, inorganic binders bonded by the chemical reaction or by blowing with gaseous CO2. Attention was focussed on the effect of selected additives promoting the formation of lustrous carbon on the knocking out properties of moulds and cores prepared from sands with the new types of inorganic binders. The quality of the test castings was also evaluated along with the tendency to the formation of lustrous carbon at the metal - mould interface, basing on the results of microscopic examinations and analysis of the chemical composition using an X-ray microanalyser.

12

Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 2

Granat K., Nowak D., Pigiel M., Stachowicz M., Wikiera R.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

51-56

EN

This article, constituting continuation of the subject discussed in the first part, presents results of the experimental trial of water glass molding sands' curing method modification with application of fluid esters and innovative microwave heating. The research objective was to determine possibilities of microwave application for curing of water glass molding sands prepared with addition of hardening agents sold under the trade name of Mach. After initial chemical curing molding sands, prepared with addition of the above mentioned hardeners, have been heated with microwaves in order to determine their influence on changes of basic technological and strength parameters of the sands, and indirectly on the quality of quartz grains binding. Studies aimed at determination of water content changes in the sands have also been undertaken. As our studies demonstrated, microwave heating allows for quick reduction of water content, thus resulting in improvement of strength parameters such as bending and tensile strength. Application of the combined methods of ester curing and innovative microwave heating facilitates production of high quality foundry moulds and cores, while simultaneously improving mould and core preparation procedures at the foundries and as a result reduces their time to an indispensable minimum.

13

Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 1

Granat K., Nowak D., Pigiel M., Stachowicz M., Wikiera R.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

45-50

EN

This article presents results of the experimental trial of combination of the chemical method of water glass molding sands' curing, used in foundry industry, with an innovative microwave heating. The research objective was to indicate at new areas of microwave energy application. The sands prepared, according to recommendations for curing technology, with the use of ethylene glycol diacetate, have been subject to microwave influence. The attempt at determination of microwave influence on qualitative changes of the binding bridges created during the curing process concerned such parameters as: bending and tensile strength, permeability as well as wear resistance. Moreover, we also determined the influence of microwave curing on the phenomena accompanying the process as well as bond stability (storage time of the prepared molding and core sands). It has been found, basing on the result analysis, that the innovative microwave heating might constitute a very good supplementation of the ester curing method. The advantages of the combined chemical and microwave gelation process include, among others, improvement of the described resistance and technological parameters as well as significant decrease of preparation time of foundry moulds and cores. The subject discussed in this article will be continued in its second part.

14

Numerical model of the solidification of alloys with natural convection of the liquid

Węgrzyn-Skrzypczak E., Skrzypczak T.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 1

109-112

EN

The paper deals with comparison of numerical analysis results obtained for binary alloys solidification process in the sand and permanent mould with motion of the fluid in the liquid and mushy zone. The partial differential equations describing mathematical model of the phenomena are presented. Finite Element Method is used for modeling process. Characteristic Based Split (CBS) method is used for solving momentum equation. Such approach allows to uncouple velocities and pressure. Petrov-Galerkin formulation is employed to stabilize heat conductivity equation with convective term. The results of the numerical simulations in the 2D region are discussed. Velocity fields, cooling rates and positions of the liquid, solid-liquid and solid regions are compared.

15

Dilatometric studies of plaster sandmix in raw and heat treated state

Pawlak M., Niedźwiedzki Z.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 3

145-148

EN

Results of dilatometric studies of bounded plaster sandmix applied in precision pressure below atmospheric casting, are presented in this paper. Sandmix composed of half-hydrate alpha-CaSO4ź2H2O with different parts of silica SiO2 was a subject of investigations. Silica is a factor weakening the influence of phase transformations on total distortion of the mould during heating and thus influences the accuracy of prepared cast. Experimental moulders of dimensions 735 made of plaster sandmix with silica fraction equal 30; 40; 50; 60 and 70% were used during studies. Sandmix was tested in raw state and after heat treatment changing the alpha-half hydrate into anhydrite II (CaSO4). It was demonstrated that addition of the silica at level about 50% influences most advantageously on dimension changes of heated sandmix by lowering dilatations 3 times in comparison with sandmix composed of pure alpha-half hydrate. The transformation of plaster structure into anhydrite II is also important - the shrinkability phase disappears and expansion similar to linear-like appears. It was determined that it is possible to obtain sandmix of small, stabile distortion on the way of appropriate selection of components and heat treatment parameters what improves dimensional and shape accuracy limits of the cast and significantly limits internal stresses in the mould eliminating risk of its cracking.

16

Kierunki rozwoju wybranych technologii odlewniczych

Smoluchowska E., Izdebska-Szanda I.

Przegląd Odlewnictwa

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2001

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Vol. 51, nr 11

392-396

PL

W artykule opisano kierunki niektórych technologii odlewniczych, które w obecnym czasie są wykorzystywane w odlewnictwie. Oprócz zapewnienia wysokiej jakości odlewów powinny one maksymalnie zmniejszać energo- i materiałochłonność, po-wyższać właściwości odlewów, umożliwiać odzysk ciepła z odlewów i urządzeń, a także zapewniać automatyczne sterowanie jakością odlewów przez system komputerowej kontroli produkcji. Ponadto technologie te powinny zapewniać hermetyzację procesów i utylizację odpadów w celu ochrony środowiska i oszczędności surowców. Podano przykłady wybranych technologii odlewniczych, których stosowanie spełnia w dużym stopniu wymagane żądania.

EN

In the article the trends of some foundry technologies which are now used in foundry practice are described. Apart from ensuring high quality of castings, these technologies should to the highest degree reduce the energy- and material consumption indices, increase the castings properties, enable the heat recovery from the castings and installations due to the computer control system of the production. Moreover, these technologies ought to guarantee air-tight sealing of processes and utilization of waste in order to protect the environment and to save raw materials. Examples of the chosen foundry technologies, the application of which fulfil to a high degree the demanded requirements, are given.

17

Przyszłość technologii odlewniczej

Eigenfeld F.

Przegląd Odlewnictwa

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2000

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Vol. 50, z. 2

62-65

PL

W wyniku wprowadzenia nowej techniki między innymi w środkach transportu, również odlewnictwo weszło na nowe drogi rozwoju. Proekologiczna orientacja, a także związane oszczędności w zużyciu energii oraz tworzyw metalowych, dyktują rozwinięcie nowych technologii odlewniczych. W pierwszym rzędzie dotyczą one zwiększenia udziałów stopów metali lekkich oraz ograniczenia zakresu obróbki mechanicznej części do budowy samochodów. Na kilku wybranych przykładach przedstawiono wymagania stawiane odlewom w budowie samochodów w najbliższej przyszłości. W tym światowym współzawodnictwie istotne jest wprowadzanie nowych konstrukcji odlewów ze stopów aluminium, magnezu, a także z żeliwa wysokojakościowego. Użytkownicy, producenci i dostawcy powinni w jednakowym stopniu zastosować się do tych wymagań stawianych przez producentów samochodów reprezentujących światowe współzawodnictwo. Odlewy nam pomogą w uzyskaniu znaczących osiągnięć.

EN

As a result of introducing new technologies, among others, in transport facilities, the foundry industry has entered new ways of development. Proecological orientation and savings connected with energy as well as metal material consumption dictate the development of new foundry technologies. In the first place they concern an increase in the production of light metal alloys and limitation in the range of mechanical working for car building parts. Requirements imposed on castings for car building in the nearest future have been presented on some chosen examples. In this world competition the introduction of new designs for castings made of aluminium, magnesium and also of high-duty cast iron is essential. Users, producers and suppliers should equally comply with these requirements imposed by car producers who represent world competition. Casting will help us in gaining important achievements.