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Open access

M. Skrzyński, R. Dańko and J. Kamińska

Abstract

The results of investigations of the reclamation of spent moulding and core sands, originated from one of the Polish foundry plants, are presented in the paper. Four mixtures consisting of two types of spent sands (spent moulding sand and spent core sand) were subjected to the regeneration process. Each tested mixture consisted of an inorganic type spent moulding sand and of an organic type spent core sand. Proportions of mutual fractions of spent moulding and core sands in mixtures was 70%-30% and was representative for the waste sands from the foundry, from which these sands originated.

Open access

J. Dańko, J. Kamińska and M. Skrzyńsk

Abstract

The results of the reclamation of spent moulding sands with inorganic binder in the prototype vibratory reclaimer REGMAS - are presented in the paper. Spent moulding sands with modified water-glass, burned as well as not burned, present in a form of agglomerates (lumps), were subjected to the reclamation processes.

During individual reclamation cycles the reclaimer efficiency and vibrations amplitudes were determined and physicalchemical and strength investigations were performed for the obtained reclaim materials. The obtained reclaim was used as a component of the matrix of moulding sands with water-glass in the Floster S technology, in which the reclaim constituted 100%, 80% and 50% of the sand matrix - respectively.

Open access

A. Grajcar, M. Różański, M. Kamińska and B. Grzegorczyk

Abstract

The work concerns the studies on non-metallic inclusions occuring in laser-welded Si-Al TRIP steel containing Nb and Ti microadditions. Laser welding tests of 2 mm thick thermomechanically rolled sheets were carried out using keyhole welding and a solid-state laser. The results of laser welding in the air atmosphere for the heat input value of 0.048 kJ/mm are included. The distribution, type and chemical composition of non-metallic inclusions formed in the base metal, heat-affected zone, and fusion zone are analysed in detail. It was found that the base metal contains rare, fine oxysulphides. Their chemical composition was modified by rare earth elements. Numerous oxide inclusions of a various size and a chemical composition occur in the fusion zone. The dependence between a size of particles and their chemical composition was observed. A microstructure of steel was assessed using light microscopy and scanning electron microscopy techniques.

Open access

I. Izdebska-Szanda, J. Kamińska, M. Angrecki, A. Palma and Z. Stefański

Abstract

The aim of the study was to determine the applicability of a new product added to water glass-containing foundry sands hardened with ethylene glycol diacetate. The new additive designated by the symbol “B” is a composition of aqueous solutions of modified polyalcohols, improving the sand knocking out properties. The scope of studies included testing various mechanical and technological properties of foundry sand mixtures, such as permeability, friability, life cycle of cores and knocking out properties. In the technological studies, two types of water glass with different values of the silica modulus and density, designated as R145 and R150, were used. Moulding sands were prepared with the additive “B”. For comparison, reference sands with water glass but without the additive “B” were also made. In Part I of the article, the results of studies of the effect of additive “B” on the properties of foundry sands with water glass hardened by CO2 blowing were discussed.

Open access

I. Izdebska-Szanda, J. Kamińska, M. Angrecki, A. Palma and W. Madej

Abstract

The results of research on the possibility of using a gaseous medium (hot air) as a hardening agent for inorganic binders were discussed, and tests on the reclamation of waste moulding sands were carried out. The research programme also included the use of a modernized test stand for hardening of foundry sands with gaseous agents and a pilot plant for the sand reclamation.

Cores made on the test stand were examined for the basic technological properties and were also used in moulds for the trial knocking out of castings.

Two types of binders were tested, i.e. a modified water glass designated as Binder A and, for comparison, a reference material which was hydrated sodium silicate R145. The hardener for the sand mixtures was hot air (the dehydration of water glass). Trials of the sand reclamation were carried out in a laboratory pilot plant, installed and operating at the Foundry Research Institute. The obtained reclaim was added in different amounts to the sand mixtures subjected to technological tests. The next step included the manufacture of test moulds, pouring them with aluminium alloy, and knocking out of castings to test the collapsibility of moulds and cores.

Open access

J. Kamińska, M. Angrecki, A. Palma, J. Jakubski and E. Wildhirt

Abstract

The results of own studies concerning the application of a new additive to the CO2-hardened sodium water glass foundry sands are presented. The new additive, which is a composition of aqueous solutions of modified polyalcohols, has been designated by the symbol “B” and is used as an agent improving the sand knocking out properties. The scope of studies included various mechanical and technological properties of foundry sand mixtures, such as permeability, friability, life cycle of cores and knocking out properties. Two types of water glass with different values of the silica modulus and density, designated as R145 and R150, were tested. Moulding sands used in the tests were made with the additive “B”. For comparison, a reference sand mixture with water glass but without the additive “B” was also prepared.

Open access

M. Woch, M. Lis, D. Kołacz, M. Kamińska and M. Staszewski

Abstract

The paper presents the study on manufacturing of nickel and cobalt powders by thermal plasma decomposition of the carbonates of these metals. It was shown the dependence of process parameters and grain size of initial powder on the composition of final product which was ether metal powder, collected in the container as well as the nanopowder with crystallite size of 70 - 90 nm, collected on the inner wall of the reaction chamber. The occurrence of metal oxides in the final products was confirmed and discussed.

Open access

S. Księzarek, M. Woch, D. Kołacz, M. Kamińska, P. Borkowski and E. Walczuk

Abstract

The paper outlines technologies currently used for the production of the Ag-Re10 and Ag-SnO2Bi2O3 contact materials in a form of wires and solid and bimetallic rivets. Their characteristic parameters, including physical and mechanical properties and microstructure, are given. It has been found that the level of these parameters, particularly electrical properties (resistance to electric arc erosion), is unsatisfactory considering the present requirements, which applies mainly to the new Ag-Re10 [wt%] alloy, so far not fully technologically mastered. Therefore, under this work a new method for the production of this type of materials has been designed and the related research works were undertaken. The new-generation contact materials in a form of nanostructured composites will be characterised by similar chemical compositions as those specified above but with increased functional properties, including enhanced resistance to arc erosion. In this paper preliminary results of the examination of structure and properties of semi-products obtained by new technology based on powder metallurgy techniques are presented. Conditions for pressure consolidation and plastic consolidation applied for material processing into wires and rivets (solid and bimetallic) have been determined.

Open access

M. Lis, A. Wrona, J. Mazur, C. Dupont, M. Kamińska, D. Kopyto and M. Kwarciński

Abstract

The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4). The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

Open access

Izabela Aspras, Małgorzata Kamińska, Kamil Karzyński, Mateusz Kawka and Małgorzata M. Jaworska

Abstract

Chitin deacetylase is the only known enzyme which is able to deacetylate N-acetyl-D-glucosamine units in chitin or chitosan chains. As chitin can hardly be dissolved in organic/inorganic solvents, new solvents are still searched. Ionic liquids are promising for that application and for homophase enzymatic deacetylation. The aim of the work was to investigate the influence of selected ionic liquids on activity of chitin deacetylase.

It has been shown that [Amim] ionic liquids increase the activity of chitin deacetylase. The highest activity was observed for [Amim][Cl]. Ionic liquids with shorter (ethyl (C2)) and longer side chain (buthyl (C4)) only insignificantly influenced the activity of the enzyme. All tested ionic liquids with [Br] anion increased the activity of chitin deacetylase while the [Emim] and [Bmim] cation in combination with [Cl] anion inhibited the activity of the enzyme.