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Number of results: 12
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Abstract

One of the purposes of the application of chemically modified inorganic binders is to improve knocking out properties and the related reclamability with previously used in foundry inorganic binder (water glass), which allowing the use of ecological binders for casting nonferrous metals. Good knocking out properties of the sands is directly related to the waste sands reclamability, which is a necessary condition of effective waste management. Reclamation of moulding and core sands is a fundamental and effective way to manage waste on site at the foundry, in accordance with the Environmental Guidelines. Therefore, studies of reclamation of waste moulding and core sands with new types of inorganic binders (developed within the framework of the project) were carried out. These studies allowed to determine the degree of recovery of useful, material, what the reclaimed sand is, and the degree of its use in the production process. The article presents these results of investigation. They are a part of broader research programme executed under the project POIG.01.01.02-00- 015/09 "Advanced materials and technologies".

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Authors and Affiliations

I. Izdebska-Szanda
M. Angrecki
A. Baliński
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Abstract

This paper presents a new perspective on the issue of reclamation of moulding and core sands. Taking as a premise that the reclamation process must remain on the surface of grains some not separated binding materials rests, it should be chosen the proper moulding sand’s composition that will be least harmful for the reclaim quality. There are two different moulding and core sands taken into examinations. The researches prove that a small correction of their compositions (hardener type) improves the quality of the received reclaims. Carried out in this article studies have shown that such an approach to the problem of reclamation of the moulding and core sands is needed and reasonable.

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Authors and Affiliations

S.M. Dobosz
K. Major-Gabryś
M. Hosadyna
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Abstract

The examined material comprised two grades of corrosion-resistant cast steel, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-

3, used for example in elements of systems of wet flue gas desulphurisation in power industry. The operating conditions in media heated

up to 70°C and containing Cl- and SO4 ions and solid particles produce high erosive and corrosive wear.The work proposes an application

of the σ phase as a component of precipitation strengthening mechanism in order to increase the functional properties of the material.

The paper presents the results of examination of the kinetics of σ phase precipitation at a temperature of 800°C and at times ranging from

30 to 180 minutes. Changes in the morphology of precipitates of the σ phase were determined using the value of shape factor R.

Resistance to erosion-corrosion wear of duplex cast steel was correlated with the kinetics of sigma phase precipitating.

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Authors and Affiliations

A. Brodziak-Hyska
Z. Stradomski
C. Kolan
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Abstract

This paper presents the results of research which is part of studies carried out under the project POIG.01.01.02-00-015/09 "Advanced Materials and Technologies", one of the aims of which is to introduce new, environment-friendly, inorganic binders to the production of castings from non-ferrous metals. The paper presents the results of research on the management of waste moulding sands prepared according to the new technology, including their multiple reclamation and management of post-reclamation waste. Studies of multiple reclamation are a continuation of the preliminary research described earlier. The programme of the studies described in this paper also included validation of the results under industrial conditions.
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Authors and Affiliations

I. Izdebska-Szanda
M. Angrecki
A. Palma
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Abstract

This paper presents the impact of microwave penetration depth on the process of heating the moulding sand with sodium silicate. For each material it is affected by: the wavelength in vacuum and the real and imaginary components of the relative complex electrical permittivity εrfor a selected measurement frequency. Since the components are not constant values and they change depending on the electrical parameters of materials and the frequency of the electromagnetic wave, it is indispensable to carry out laboratory measurements to determine them. Moreover, the electrical parameters of materials are also affected by: temperature, packing degree, humidity and conductivity. The measurements of the dielectric properties of moulding sand with sodium silicate was carried out using the perturbation method on a stand of waveguide resonance cavity. The real and imaginary components of the relative complex electrical permittivity was determined for moulding sand at various contents of sodium silicate and at various packing degrees of the samples. On the basis of the results the microwave penetration depth of moulding sand with sodium silicate was established. Relative literature contains no such data that would be essential to predicting an effective process of microwave heating of moulding sand with sodium silicate. Both the packing degree and the amount of sodium silicate in moulding sand turned out to affect the penetration depth, which directly translates into microwave power density distribution in the process of microwave heating of moulding sand with sodium silicate.

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Authors and Affiliations

D. Nowak
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Abstract

The work deals with the influence of change in the filling conditions of the ceramic moulds with plaster binder on the presence of gaseous

porosity and the microstructure of the achieved test castings with graded wall thickness. Castings made of EN AC-44000 alloy, produced

either by gravity casting, or by gravity casting with negative pressure generated around the mould (according to the Vacumetal

technology), or by counter-gravity casting were compared. The results of examinations concerning the density of the produced castings

indicate that no significant change in porosity was found. The increased size of silicon crystals was found for the increased wall

thicknesses due to the slower cooling and solidification of castings.

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Authors and Affiliations

M. Nadolski
Z. Konopka
M. Łągiewka
A. Zyska
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Abstract

The performed examinations concerning the process of filling the plaster ceramic moulds with aluminium alloys allowed to assess the

influence of various methods of introducing the metal into the mould cavity on the macro- and microstructure of the obtained experimental

castings. The comparison was performed for castings with graded wall thickness made either of EN AC-44000 alloy or of EN AC-46000

alloy, produced either by gravity casting, or by gravity casting with negative pressure generated around the mould (according to the

Vacumetal technology), or by counter-gravity casting. It was found that the silicon crystals grow in size with an increase in wall thickness

due to the slower cooling and solidification of castings.

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Authors and Affiliations

M. Nadolski
Z. Konopka
M. Łągiewka
A. Zyska
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Abstract

The paper presents the results of examination concerning optimization of the σ phase precipitates with respect to the functional properties of ferritic-austenitic cast steel. The examined material comprised two grades of corrosion-resistant cast steel, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-3, used for example in elements of systems of wet flue gas desulphurisation in power industry. The operating conditions in media heated up to 70°C and containing Cl- and SO4 ions and solid particles produce high erosive and corrosive wear. The work proposes an application of the σ phase as a component of precipitation strengthening mechanism in order to increase the functional properties of the material. Morphology and quantities of σ phase precipitates were determined, as well as its influence on the erosion and corrosion wear resistance. It was shown that annealing at 800°C or 900°C significantly improves tribological properties as compared with the supersaturated state, and the best erosion and corrosion wear resistance achieved due to the ferrite decomposition δ → γ’ + σ was exhibited in the case of annealing at the temperature of 800°C for 3 hours.

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Authors and Affiliations

Z. Stradomski
A. Brodziak-Hyska
C. Kolan
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Abstract

One of the factors that contribute to the development of foundry moulding technology is environmental protection. The related challenges are effectively satisfied by a new inorganic binder that has been designed for castings made of non-ferrous metal alloys. This article presents in a concise way the test results, showing the ecological character of the new binder at the stage of making moulds, pouring them with metal and cooling of castings, indicating the possibilities for an economic re-use of waste materials formed during practical application of this technology. The results were compared with the results obtained on the sands with organic binders. Studies were carried out under the project POIG.01.01.02-00-015/09 "Advanced materials and technologies."
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Authors and Affiliations

I. Izdebska-Szanda
M. Angrecki
A. Palma
M. Żmudzińska
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Abstract

The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica. The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined with effective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder. A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The cast iron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.
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Authors and Affiliations

M. Rączka
K. Gandurski
B. Isendorf
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Abstract

In this paper the results of studies of polymeric binders on the example of the new BioCo2 binder, including the problem of its renewability, are presented. The results of structural studies (FT-IR) for the BioCo2 binder before and after crosslinking, and bending strength tests Rg u fresh and renewed cured molding sands with BioCo2 binder are discussed. The cross-linking binder and curring of moulding sand was carried out by physical agents (microwave radiation, temperature). On the basis of obtained results was shown that it is possible to restore the initial properties of the adhesive of BioCo2 binder. The initial properties of moulding sand can be achieved, after the cross-linking binders and after curing in the moulding sands with bioCo2 binder , by supplementing the moulding sand composition by the appropriate amount of water.

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Authors and Affiliations

B. Grabowska
A. Bobrowski
K. Kaczmarska
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Abstract

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.
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Bibliography

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Authors and Affiliations

P.J. Paduchowicz
1
K. Granat
1
P. Biały
1

  1. Department of Foundry Engineering, Plastics and Automation, Wroclaw University of Technology, ul. Smoluchowskiego 25, 50-372 Wrocław, Poland

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