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The Influence of Inorganic Binder Type on Properties of Self-Hardening Moulding Sands Intended for the Ablation Casting Process

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Puzio S. , Kamińska J. , Angrecki M. , Major-Gabryś K.

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tom Vol. 60, iss. 4

99--108

EN

The aim of the present work is to compare the properties of self-hardening moulding sands based on inorganic binders based on sodium silicate of different modules, geopolymer binders and phosphate binders and to prove they can be used in the ablation casting process. Ablation casting is a process in which, directly after pouring the liquid alloy, the mould is sprayed with water until it is completely eroded and a finished, cooled casting is obtained. The use of proecological water-dilutable binder makes it possible to recover the sand matrix after drying the suspension that remains after the process. Moulding sands were prepared on the basis of four inorganic binders available on the market. For each of the moulding sands the bending strength was tested after 1, 2, 4 and 24 h of hardening. Then, the masses with optimum bending strength were selected and subjected to gas emissivity tests. A thermal analysis of moulding sands selected for testing was also carried out in order to determine the loss of mass during annealing. The susceptibility of moulds to erosion under the influence of ablative medium was also assessed by measuring the time of mould erosion. Tests showed the possibility of using self-hardening moulding sands based on inorganic binders for the ablation casting process of aluminium-silicon alloys.

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Determination of Mass Loss in Samples of Post-Regeneration Dust from Moulding Sands with and without PCL Subjected to Biodegradation Processes in a Water Environment

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Major-Gabryś K. , Hosadyna-Kondracka M. , Stachurek I.

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tom Vol. 60, iss. 4

121--129

EN

In recent years, the demand for products made of biodegradable or partially biodegradable materials has been increasing. This is mainly due to the ever-increasing amount of waste in landfills, but also to the problem of post-production waste management. This problem also concerns waste from the casting process of sands made on the basis of furfuryl resin, as well as residues from the regeneration process of these sands. The article presents the issues related to the methodology of research on the biodegradation process both in the natural environment and methods conducted in laboratory conditions. The preliminary results of the research on the biodegradation process in the aquatic environment, to which the dusts from mechanical regeneration of moulding sand were subjected, indicate the directions of further research and work in the field of selection of components of moulding sand with biodegradable properties. These tests should be carried out primarily in terms of determining the minimum and maximum amount of the addition of a biodegradable component to the moulding sand.

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The influence of biomaterial in the binder composition on the quality of reclaim from furan no-bake sands

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Major-Gabryś K. , Hosadyna-Kondracka M. , Skrzyński M. , Stachurek I.

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tom Vol. 68, nr 4

163--177

EN

The aim of this paper is to determine the influence of biomaterial in the binder composition on the quality of reclaim from furan no-bake sands. The biomaterial is introduced into the moulding sand in order to accelerate the biodegradation of post-regeneration dust and thus to reduce the amount of harmful waste from foundries in landfills. This addition, however, can’t deteriorate the technological properties of the moulding sand, including its ability to mechanical regeneration. Chemically bonded moulding sands are characterized by high ability to mechanical regeneration, which reduces the consumption of the raw material and costs related to their transport and storage. A side effect of the regeneration process is the formation of a large amount of post-regeneration dusts. According to the tendencies observed in recent years, moulding processes must meet high requirements connected to environmental protection including problems related to the disposal of generated wastes. A partial replacement of synthetic binding materials with biomaterials may be one of scientific research directions on the production of innovative foundry moulding and core sands. The conducted regeneration tests presented in this paper initially proved that biomaterial slightly decreases the quality of reclaim from moulding sand with its addition. However, its ability to regeneration increases with time of the process. In previous research authors tested biodegradability of the dust remaining after the regeneration process. The tests proved that moulding sand with biomaterial added at the stage of the production process is characterized by about three times better biodegradability than the same moulding sand without additive.

PL

Tematem niniejszej pracy jest określenie wpływu dodatku biomateriału (PCL) do spoiwa na jakość regeneratu z samoutwardzalnych mas furanowych. Zadaniem biomateriału jest przyspieszenie biodegradacji pyłów poregeneracyjnych i tym samym doprowadzenie do zredukowania na składowiskach ilości szkodliwych odpadów pochodzących z odlewni. Dodatek ten nie może jednak pogarszać właściwości technologicznych masy, w tym jej zdolności do regeneracji mechanicznej. Autorzy przeprowadzili proces regeneracji mechanicznej, a następnie badaniom poddali regeneraty z mas formierskich utwardzanych chemicznie przeznaczonych do produkcji wielkogabarytowych odlewów żeliwnych. Odlewy żeliwne znajdują szerokie zastosowanie w motoryzacji, transporcie morskim i kolejowym, w energetyce, rolnictwie oraz budownictwie. Produkcja odlewu wielkogabarytowego o złożonym kształcie, charakteryzującego się wysoką jakością przy zachowaniu wymaganych właściwości użytkowych, obejmuje wiele etapów procesu produkcyjnego. Jednym z nich jest odpowiedni dobór technologii mas formierskich i rdzeniowych. Masy formierskie i rdzeniowe wykorzystywane są do produkcji odlewów w około 80% wszystkich odlewni. Największą ilość odpadów wytwarzanych w odlewniach stanowi zużyta masa formierska / rdzeniowa i sięga ona czasem nawet 90%. Przyjmuje się, że średnio z 1 Mg odlewów powstaje 0,6-1,0 Mg zużytej masy [4, 5], a według [2] do wyprodukowania 1 kg odlewu potrzeba około 4 kg masy formierskiej. Światowa produkcja odlewów wynosi około 100 mln Mg [2, 6], w tym odlewy żeliwne w masach formierskich utwardzanych chemicznie w ilości 30 mln Mg, co przy założeniu stopnia regeneracji na poziomie 40-50% daje 15-18 mln Mg zużytego piasku [4]. Prezentowany w pracy temat poświęcony jest materiałom pochodzącym z procesu odlewania do form piaskowych wykonanych z piasku kwarcowego ze spoiwem organicznym na bazie żywicy modyfikowanej alkoholem furfurylowym, utwardzanej mieszaniną kwasów zawierających siarkę.

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Quality Assessment of Castings Manufactured in the Technology of Moulding Sand with Furfuryl-Resole Resin Modified with PCL Additive

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Hosadyna-Kondracka M. , Major-Gabryś K. , Warmuzek M. , Brůna M.

Archives of Metallurgy and Materials

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2022

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tom Vol. 67, iss. 2

753--758

EN

This paper deals with the issue of using moulding sands with a new two-component binder: furfuryl-resole resin - PCL polycaprolactone for the production of ductile iron heavy castings. The previous laboratory studies showed the possibility of using biodegradable materials as binders or parts of binders’ compositions for foundry moulding and core sands. The research proved that addition of new biodegradable PCL in the amount of 5% to the furfuryl-resole resin does not cause significant changes in moulding sand’s properties. The article presents research related to the production of ductile iron castings with the use of moulds with a modified composition, i.e. sands with furfuryl resole resin with and without PCL. Mechanical properties and microstructure of the casting surface layer at the metal/ mould interface are presented. The obtained test results indicate that the use of a biodegradable additive for making foundry moulds from moulding sand with a two-component binder does not deteriorate the properties of ductile iron castings.

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Computer modelling of the ablation casting process and prediction of the strength properties of AC-42000 castings

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Małysza M. , Puzio S. , Major-Gabryś K. , Głowacki M. , Wilk-Kołodziejczyk D. , Kamińska J.

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tom Vol. 22, No. 2

79--88

EN

The demand for castings with superior properties has compelled the development and optimization of manufacturing technologies. By further developing already known techniques, we are able to contribute to the introduction of new research possibilities. The article presents the methodology of conducting simulation tests of the gravity casting process into sand moulds with the use of ablation. The ablation technique consists in spraying water through evenly spaced nozzles onto a mould into which the liquid casting alloy has been poured. The conducted research focuses on an alloy from the group of Al-Si alloys. In order to compare the effects of different techniques, additional tests were carried out for gravity casting into sand and metal die moulds. At the same time, virtual experiments were conducted to develop a simulation methodology for ablation casting technology, taking into account mould degradation. Additionally, the possibility of predicting the final mechanical properties of various manufacturing technologies was tested. Destructive tests were carried out to determine the mechanical properties in the cast samples, as well as microstructure tests and secondary dendrite spacing. The results of the mechanical tests are compared with the predicted simulation properties.