Wyniki wyszukiwania - Biblioteka Nauki

1

ECAP methods application on selected non-ferrous metals and alloys

100%

Rusz S. , Čížek L. , Dobrzański L. , Tylšar S. , Kedroň J.

Archives of Materials Science and Engineering

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2010

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tom Vol. 43, nr 2

69-76

EN

Purpose: Paper presents results of investigations mechanical properties and microstructure samples selected nonferrous metals after ECAP. These properties and microstructure are influenced by technological factors during application ECAP method. Design/methodology/approach: The sample bars were plastically deformed during the ECAP process. The methods of the light microscopy and the hardness test for evaluation of mechanical properties and microstructure were used. Findings: Measurement of micro-hardness shows an increase value after application higher number of passes in agreement with ultra high fine grain occurrence. The method determines the dependencies of force on the route during the ECAP process. Research limitations/implications: Achieved hardness and microstructure characteristics will be determined by new research. Practical implications: The results may be utilized for a relation between structure and properties of the investigated materials in future process of manufacturing. Originality/value: These results contribute to complex evaluation of properties new nonferrous metals after application ECAP method. The results of this paper are determined for research workers deal by the process severe plastic deformation.

2

The influence of the heat treatment on structure and properties of copper after DRECE process

100%

Rusz S. , Čížek L. , Dutkiewicz J. , Kedroń J. , Tylšar S.

Hutnik, Wiadomości Hutnicze

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2011

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tom Vol. 78, nr 1

107-109

EN

Several types of SPD technologies serving for production of UFG metals was developed already at the beginning of the nineties. One of them is new type of equipment DRECE (Dual Rolling Equal Channel Extrusion), designated for obtaining UFG structure in strip of sheet. Experiments with use of material Cu 99.5% were made on the DRECE machines in order to achieve grain refinement in the strip of sheet with dimensions 58x2x1000 mm. For orientation information, whether grain was refined preliminary metallographic analysis was made on optical microscope NEOPHOT 2. Structure was analysed on the surface in longitudinal direction in respect to direction of rolling, and also in cross section and longitudinal section. After DRECE machinery the annealing on part of extruded sheets was applied. Two procedure 400 and 450oC/15min/air were selected.

PL

Obecnie rozwinięte kilka technologii SPD przy wytwarzaniu metali UFG. Jedną z nich jest urządzenie DRECE (Dual Rolling Equal Channel Extrusion), opracowane w celu uzyskania struktury UFG w taśmach stalowych. Badania przy zastosowaniu miedzi 99,5% przeprowadzono na maszynie DRECE. Umożliwiło to rozdrobnienie ziarna w taśmach stalowych o wymiarach 58x2x1000 mm. W celu uzyskania informacji czy ziarno zostało rozdrobnione przeprowadzono badania metalograficzne na mikroskopie optycznym NEOPHOT 2. Przeanalizowano strukturę na powierzchni w kierunku wzdłużnym (w kierunku walcowania) a także na przekroju poprzecznym i wzdłużnym. Następnie blachy poddano 15-minutowemu wyżarzaniu w temperaturze 400 i 450 oC.

3

Structure characteristic of modify magnesium alloy MgAl8MnCa

86%

Cížek L. , Kedroň J. , Tylšar S. , Blahož O. , Prażmowski M. , Bański R.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2010

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tom z. 97

13-14

EN

Magnesium alloys has been used for a wide variety of applications, namely from the reason of their low density and high strength-to-weight ratio. Low inertia, which results from its low density, is advantageous in rapidly moving parts, for example automobile wheels and other automobile parts [1-2]. The basic magnesium alloys include ones which contain manganese, aluminium, zinc and other elements which allow obtaining suitable properties. Scope of utilisation of foundry magnesium alloys is continuously being extended, so if we want to operate as competitive producers, it is necessary to investigate very actively properties of individual alloys, optimise their chemical composition, study issues of their metallurgical preparation, verify experimentally their casting properties and conditions of successful casting of castings by individual methods, including heat treatment, forming and others specials methods of processing as are application of new forming method ECAP. Application of this method on aluminium alloys is described by many authors. From the reason low formability metals with hexagonal lattice the application of this method on magnesium alloys is now developed [3]. Paper presents results of investigations in new commercial prepared of modify magnesium alloy MgAl8MnCa with the following chemical composition (wt %): Al - 7,8; Zn - 0.05; Mn - 0.172; Ca - 0.9; rest Mg. Modify magnesium alloy MgAl8MnCa is a competitive cost alloys with aluminum 380. It is a creep resistant alloy with the capability of long-term operation at temperatures up to 150°C under high loads. This alloy exhibits good castability, corrosion resistance and mechanical properties at room temperature, similar or better to AZ91D. The main modifying element is Ca. Comparison the basic mechanical properties are shown in Table 1 [4]. The creep resistance of the alloy is substantially superior to that of commercial magnesium alloys at temperature of 130-150°C under stresses of 50-80MPa. The main applications targeted by this alloy include gearbox housings, valve covers, intake manifolds, oil pans, oil pumps and many under the hood components. For the metallographic analysis of structure magnesium alloy MgAl8MnCa the light microscopy and SEM were used.

4

Rozdrobnienie ziarna stopu AlMn1Cu przez duże odkształcenie plastyczne (SPD)

72%

Rusz S. , Čížek L. , Dutkiewicz J. , Tylšar S. , Salajka M. , Divin V. , Kedroň J. , Klos M.

Obróbka Plastyczna Metali

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2014

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tom T. 25, nr 2

87--98

PL

Duże odkształcenie plastyczne SPD to technika stosowana w produkcji materiałów o ultradrobnej strukturze (UFG), oparta o intensywne rozdrobnienie ziarna. Dla procesu tego bezwzględnie najważniejsza jest sprawność. Najbardziej znanymi technologiami, które są aktualnie najintensywniej rozwijane są: ECAP, C2S2, CONFORM, HPT, CCDC, ARB oraz CGP. W opracowaniu dokonano analizy technologii ECAP, gdzie istotna poprawa sprawności procesu osiągana jest przez zmianę technologii narzędzia, a przez to zmianę ścieżki deformacji, co znacznie przybliża wizję wdrożenia tej technologii do przemysłu. Wpływ zmiany geometrii wkładki narzędzi ECAP na osiągnięcie wysokiego stopnia odkształcenia, z czym wiąże się wzrost sprawności procesu (tzn. osiągnięcie wymaganej średniej wielkości ziarna przy mniejszej ilości przejść przez narzędzie formujące) przedstawiono na przykładzie stopu AlMn1Cu wyprodukowane przez firmę AL Invest Bridlicna a.s. Dokonano zarówno matematycznej symulacji, jak i fizycznego przeciśnięcia próbek przez narzędzie ECAP. Badanie zostało skoncentrowane na podwyższeniu twardości i średniej wielkości ziarna w klasycznej geometrii kanałów ECAP w porównaniu z narzędziem ECAP o zmodyfikowanej geometrii, gdzie kanał poziomy został odchylony o 20° względem osi „x”, oraz w porównaniu z geometrią, gdzie w kanale poziomym utworzona została linia śrubowa (elektroerozyjnie). Dodatkowo, dla poszczególnych rodzajów geometrii ECAP wykonana została analiza metalograficzna struktury z wykorzystaniem transmisyjnej mikroskopii elektronowej (TEM) oraz przez pozyskanie obrazów dyfrakcyjnych w wybranych obszarach próbki (SAED). Sprawność nowego projektu została jednoznacznie potwierdzona.

EN

Severe plastic deformation is basic process used in technologies for production of ultra-fine grained materials (UFG), using the principle of high disintegration of grain. Efficiency of the given process is therefore of utmost importance. The best known technologies that are currently being intensively developed are the following ones: ECAP, C2S2, CONFORM, HPT, CCDC, ARB and CGP. The paper analyses the ECAP technology, where substantial enhancement of the process efficiency is achieved by change of tool geometry and therefore by change of deformation route, which significantly approaches implementation of this technology into industrial practice. Influence of change of geometry of the ECAP tool insert on achievement of high degree of deformation and thus on the increased efficiency of the process (i.e. achievement of the required mean grain size at significantly lower number of passes through the forming tool) has been demonstrated on the alloy AlMn1Cu manufactured by the company AL Invest Bridlicna a.s. Both mathematical simulation and practical extrusion of samples through the ECAP tool have been performed. Research was focused on the resulting magnitude of hardness and mean grain size in classical geometry of ECAP channels in comparison with modified geometry of the ECAP tool, where horizontal channel was deflected in respect to the axis “x“ by 20°, and in comparison with geometry, when helical line was created (by sparking) into part of horizontal channel. Moreover, metallographic analysis of structure realised on TEM and SAED was applied to individual types of ECAP channel geometry. Efficiency of new design has been confirmed unequivocally.