Wyniki wyszukiwania - Biblioteka Nauki

1

Odlewanie tiksotropowe żeliwa

100%

Wierzchowski W. , Białobrzeski A.

Archiwum Odlewnictwa

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2006

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tom R. 6, nr 19

409-412

PL

W oparciu o literaturę przedstawiono w dużym skrócie zagadnienie krystalizacji stopów metali podeutektycznych w warunkach sprzyjających fragmentaryzacji i sferoidyzacji fazy pierwotnej, a zatem w warunkach sprzyjających powstawaniu struktury tiksotropowej. Wykonano także przegląd literatury na temat technik semi-solid w zastosowaniu do stopów metali, w tym również przedstawiono dane dotyczące możliwości uzyskiwania struktury tiksotropowej w żeliwie.

EN

Basing on data given in literature, the problems related with solidification of hypoeutectic metal alloys under the conditions promoting fragmentation and spheroidisation of the primary phase, and hence under the conditions favouring the formation of thixotropic structure, were outlined. A review of technical literature on the semi-solid techniques applied to metal alloys was presented, including information on the possibilities of obtaining thixotropic structure in cast iron.

2

Semi-solid processing method for cast iron

100%

Wierzchowski W. , Grochal T.

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tom T. 49, z. 4

27-37

EN

A device for the fabrication of ingots from cast iron of globular non-dendritic structure of the primary phase was designed and made, using the principle of overflow on the Slope Cooling Plate, known as the SCP method. Trials were made on hypoeutectic grey cast iron and high-chromium cast iron. Even during the first trials the intended effect has been achieved, which means that a fragmentation and globularization of the primary austenite was obtained. A simultaneous effect of the applied SCP technique on the shape of graphite in grey cast iron was observed.

PL

Zaprojektowano i skonstruowano urządzenie do wytwarzania wlewków z żeliwa o globularnej - niedendrytycznej strukturze fazy pierwotnej. W tym celu wykorzystano zasadę przepływu po płycie pochyłej, tj. metodę SCP (Slope Cooling Plate). Wykonano próby z zastosowaniem żeliwa szarego podeutektycznego i żeliwa wysokochromowego. Już w trakcie pierwszych prób osiągnięto zamierzony efekt, co oznacza, że doprowadzono do fragmentaryzacji i globularyzacji austenitu pierwotnego. Zaobserwowano równoczesny wpływ zastosowanej techniki SCP na postać grafitu w żeliwie szarym.

3

Semi-solid processing method for cast iron

100%

Wierzchowski W. , Grochal T.

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2010

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tom Vol. 10, iss. 3

149--154

EN

A device for the fabrication of ingots from cast iron of globular non-dendritic structure of the primary phase was designed and made, using the principle of overflow on the Slope Cooling Plate, known as the SCP method. Trials were made on hypoeutectic grey cast iron and high-chromium cast iron. Even during the first trials the intended effect has been achieved, which means that a fragmentation and globularization of the primary austenite was obtained. A simultaneous effect of the applied SCP technique on the shape of graphite in grey cast iron was observed.

4

Challenges in Producing Reliable Tensile Properties by SIMA 7075

80%

Erzi E. , Gursoy O. , Yüksel Ç. O. K. , Kirtay S. , Dispinar D.

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tom Vol. 18, iss. 3

71--75

EN

Aluminium alloys are one of the preferred materials especially for land and air transportation because of their high strength and low-density properties. Although production using casting method is economical yet it has some disadvantages. Shrinkage which is occurred due to the density difference between the solid and liquid metal is prevented by feeders which need to be calculated. Liquid metal should be transferred to the mould without any turbulence. As a result, sprues are needed to be designed precisely. On the other hand, aluminium alloys can also be shaped by forging at semi-solid temperatures. There are some advantages compared to the traditional forging methods of improving die life due to the lower tonnage values. In this study, semi-solid produced 7075 aluminium alloy die filling capabilities were investigated. To achieve semisolid structure strain induced melt activated method (SIMA) was used. The desired structure was achieved at 635°C and 30 minutes of duration of heat treatment. After determining the optimum parameters, metallographic analysis, density calculations, porosity distribution and tensile tests were carried out. It was found that the reproducibility of SIMA produced 7075 alloy was quite low. A proper tensile test result was achieved only 7 of the total 15 tests and the mean value was 386 MPa. The main reason for this scattered in mechanical properties could be the chemical composition of the alloy and the rapid solidification of the liquid eutectic phases. It is important to define the best fitting process parameters and controlling them precisely will be the most important factors for future studies.