Wyniki wyszukiwania - Biblioteka Nauki

1

Miejsce organu stanowiącego w systemie zarządzania jakością w urzędzie administracji publicznej

100%

Rączka M.

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2006

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tom R. 38, nr 3

28-29

PL

Głos w dyskusji do artykułu K. Lisieckiej i T. Papaja: Zarządzanie jakością w urzędach terytorialnej administracji publicznej.

2

Studies of Binding Kinetics and Choice of Self-Hardening Moulding and Core Sands Used for Casting Massive Parts for Wind Power Industry under the Conditions of Krakodlew Foundry

63%

Rączka M. , Isendorf B.

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tom Vol. 17, iss. 2

222--226

EN

In highly developed countries, a significant progress in the use of alternative and clean energy sources has recently been observed. The European Union has implemented a programme to build wind turbines. It is estimated that in the coming years, thanks to the support in tax and credit, the global energy will develop very intensively. Many components of the wind turbines are castings. The basic material used for these castings is ductile iron, which in this particular case must meet high requirements imposed by the operating conditions of wind turbines. Anticipating an increase in customer demand for this type of castings, Krakodlew SA has decided to modernize its foundry using the ability to obtain external financing. The ductile iron manufacturing technology is now being developed and adapted to the specific conditions of the foundry plant, including the melting process yielding cast material with the required chemical composition, the technology of moulding, and the conditions for possible secondary metallurgy, spheroidizing treatment and graphitizing inoculation. The fulfilment of the imposed conditions for the casting production demands the use of advanced casting technologies introduced to the manufacturing process. The development of technology to launch the production of ductile iron castings for the wind power industry was supported by The National Centre for Research and Development (NCBiR). This article presents part of research on the binding kinetics of furan resin sands and choice of their composition for moulds and cores to make heavy castings used as components of equipment for the wind power industry.

3

Analiza mikrostruktury spieków SiC o zmiennej zawartości węgla dodawanego jako aktywatora spiekania.

51%

Rączka M. , Górny G. , Stobierski L.

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1999

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tom R. 50, nr 1

26-28

4

Casting ductile iron in layer moulds made from ecological sands

51%

Rączka M. , Gandurski K. , Isendorf B.

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tom Vol. 12, iss. 3

99-104

EN

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%.

5

Wpływ rozdrobnienia proszku fazy osnowy na mikrostrukturę i właściwości mechaniczne kompozytu ziarnistego SiC-TiB2

51%

Górny G. , Rączka M. , Rutkowski P. , Stobierski L.

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2014

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tom Vol. 35, nr 3

245--251

PL

Badania nad ceramicznymi kompozytami ziarnistymi o osnowie z węglika krzemu zawierającej cząstki borku tytanu TiB2 są prowadzone ze względu na potrzebę uzyskania materiałów, które, dysponując zaletami ceramiki z węglika krzemu, równocześnie mają większą odporność na kruche pękanie. W pracy przeprowadzono analizę wpływu wielkości ziaren użytego proszku SiC na mikrostrukturę i właściwości mechaniczne kompozytu SiC-TiB2. Kompozyty otrzymano z mieszaniny proszków SiC i TiB2 metodą prasowania na gorąco pod ciśnieniem 25 MPa w temperaturze 2150°C przez 60 minut w atmosferze argonu. Jako osnowy kompozytu użyto dwa rodzaje proszku SiC (H.C. Starck: UF-15 i UF-25), a udział objętościowy fazy TiB2 ustalono na poziomie 10 lub 20 %. Obserwacje mikrostruktury prowadzono na obrazach powierzchni zgładów kompozytów uzyskanych za pomocą elektronowego mikroskopu skaningowego. Komputerowo wspomaganą ilościową analizę mikrostruktury kompozytów przeprowadzono z wykorzystaniem programu Aphelion. W celu ilościowego opisu mikrostruktury kompozytów wyznaczono wartości wybranych parametrów stereologicznych. Badania właściwości mechanicznych otrzymanych kompozytów obejmowały wyznaczenie ich modułu Younga, twardości Vickersa, wytrzymałości na zginanie oraz odporności na kruche pękanie. Uzyskane wyniki wskazały na istotny wpływ wielkości ziaren użytego proszku SiC oraz udziału objętościowego fazy TiB2 na morfologię fazy zdyspergowanej oraz wytrzymałość na zginanie i odporność na kruche pękanie kompozytu.

EN

Research on silicon carbide matrix composites containing titanium boride particles is conducted in the aim of obtaining materials joining the advantages of silicon carbide ceramics with a higher fracture toughness. The paper analyzes the influence of the particle size of SiC powder on the microstructure and mechanical properties of a SiC-TiB2 composite. The composites were obtained from a mixture of SiC and TiB2 powders by hotpressing at a pressure of 25 MPa and at a temperature of 2150°C for 60 minutes in an argon environment. Two types of SiC powders (HC Starck UF-15 and UF-25) were used as the composite matrix, the volume fraction of the TiB2 phase was fixed at 10 or 20%. Microstructure observations were performed on composite cross-section surface images obtained by scanning electron microscopy (SEM). Computer- aided quantitative analysis of the composites microstructure were carried out using the Aphelion program. In order to quantitatively describe the microstructure of the composites, the stereological values of selected parameters were determined. Testing the mechanical properties of the composites included designation of the Young's modulus, Vickers hardness, flexural strength and fracture toughness. The results showed a significant effect of the particle size of SiC powder used and the volume fraction of the TiB2 phase on the dispersed phase morphology and mechanical properties of the SiC-TiB2 composite. The SiC-TiB2 composites obtained in this research show a significantly higher fracture toughness than silicon carbide sinters.