Wyniki wyszukiwania - Biblioteka Nauki

1

Evaluation of the deep-drawing steel sheets processed by DRECE device

100%

Hilser O. , Rusz S. , Salajka M. , Cizek L.

Archives of Materials Science and Engineering

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2014

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tom Vol. 68, nr 1

31--35

EN

Purpose: The article describes a new developed method for producing fine-grained materials, such as DRECE (DRECE, Dual Rolling Equal Channel Extrusion). Design/methodology/approach: The process of forming of material using the DRECE technique is based on making use of the material’s intensive plastic deformation, i.e. that process is a combination of two known technologies, ECAP and CONFORM. Findings: The article presents the results of both exams, including photographs of cracks. Mechanical properties of the steel grade11 321 before and after extrusion by DRECE tool are described as well. Research limitations/implications: The article describes the process of forming of metal sheets made of steel grade 11 321. It further describes two methods for detection of deep drawing - Erichsen and Fukui. Originality/value: The article describes the process of forming of metal sheets made of steel grade11 321. It further describes two methods for detection of deep drawing - Erichsen and Fukui. These methods were applied to the extruded metal sheet by DRECE tools.

2

Microstructure and Properties of Selected Magnesium-Aluminum Alloys Prepared for SPD Processing Technology

75%

Cizek L. , Rusz S. , Hilser O. , Śliwa R. , Kuc D. , Tański T. , Tkocz M.

Archives of Metallurgy and Materials

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2017

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tom Vol. 62, iss. 4

2365--2370

EN

A growing interest in wrought magnesium alloys has been noticed recently, mainly due to development of various SPD (severe plastic deformation) methods that enable significant refinement of the microstructure and – as a result – improvement of various functional properties of products. However, forming as-cast magnesium alloys with the increased aluminum content at room temperature is almost impossible. Therefore, application of heat treatment before forming or forming at elevated temperature is recommended for these alloys. The paper presents the influence of selected heat treatment conditions on the microstructure and the mechanical properties of the as-cast AZ91 alloy. Deformation behaviour of the as-cast AZ61 alloy at elevated temperatures was analysed as well. The microstructure analysis was performed by means of both light microscopy and SEM. The latter one was used also for fracture analysis. Moreover, the effect of chemical composition modification by lithium addition on the microstructure of the AZ31-based alloy is presented. The test results can be helpful in preparation of the magnesium-aluminum alloys for further processing by means of SPD methods.

3

Microstructure and Texture Changes of MgLiAl Alloys Composed of α or α + β Phases after Twist Channel Angular Pressing TCAP

75%

Dutkiewicz J. , Rusz S. , Kuc D. , Hilser O. , Bobrowski P. , Kania B.

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4

Microstructure and Properties of Selected Magnesium-Aluminum Alloys Prepared for SPD Processing Technology

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Cizek L. , Tański T. , Rusz S. , Hilser O. , Tkocz M. , Śliwa R. , Kuc D.

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nr 4

5

Wpływ geometrii narzędzia na rozdrobnienie ziarna stopu CuZn37 w procesie powtarzalnej obróbki plastycznej

75%

Rusz S. , Salajka M. , Hilser O. , Dutkiewicz J. , Boruta J. , Švec J.

Obróbka Plastyczna Metali

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2016

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tom T. 27, nr 4

301--314

EN

Development of technologies for the production of very fine-grained materials is currently very intensively accelerated. On VSB -Technical University of Ostrava developed a method that uses the principle of severe plastic deformation to refine the structure and enhance mechanical properties of sheet metal strips. The greatest importance in practice represents an increase in proof stress and tensile stress of sheet metal strips. Dual Rolls Equal Channel Extrusion (DRECE) method is a newly developed method. Severe plastic deformation results in a high degree of the material reformation. The method can be used to produce metallic materials with a very fine grain structure (hereinafter referred to as ultrafine grain structure). The forming process is based on extrusion technology with zero removal of the sheet strip thickness with the ultimate aim of achieving a high degree of deformation in the formed material, resulting in a significant improvement of mechanical properties in the input material. The paper analyses the effects of the values of angles of the newly developed forming tools on the achievement of mechanical properties in selected materials Cu and brass in the SPD process. The following types materials were verified experimentally – strip sheet with dimensions 58 (width) x 2 (thickness) x 1000 (length) mm. The paper also evaluates the influence of severe plastic deformation (SPD) on strengthening these materials at different values of the angle in the forming tool. The influence of new geometries of forming tools for improving mechanical properties has been unequivocally demonstrated.

PL

Rozwój technologii produkcji materiałów ultra drobnoziarnistych jest obecnie bardzo intensywnie przyspieszany. Na VŠB – Uniwersytecie Technicznym w Ostravie opracowano metodę, która wykorzystuje zasadę powtarzalnej obróbki plastycznej w celu rozdrobnienia struktury i poprawy właściwości mechanicznych taśm blachy metalowej. Największe praktyczne znaczenie ma wzrost umownej granicy plastyczności oraz granicy wytrzymałości taśm blachy metalowej. Nowo opracowaną metodę stanowi wyciskanie równokanałowe podwójnymi rolkami (DRECE). Powtarzalna obróbka plastyczna (SPD) skutkuje wysokim stopniem przetworzenia materiału. Metodę tę można stosować do produkcji materiałów metalicznych o bardzo drobnoziarnistej strukturze (dalej zwanej strukturą ultradrobnoziarnistą). Proces kształtowania jest oparty na technologii wyciskania z zerową redukcją grubości taśmy blachy z końcowym celem osiągnięcia wysokiego stopnia odkształcenia w formowanym materiale, co skutkuje znaczną poprawą własności mechanicznych materiału wejściowego. W niniejszym artykule przeanalizowano wpływ wartości kątów nowo opracowanych narzędzi kształtujących na osiągnięcie własności mechanicznych w wybranym materiale, mianowicie mosiądzu, w procesie SPD. Sprawdzono doświadczalnie następujące rodzaje materiałów: taśma blachy o wymiarach: 58 mm (szerokość) x 1000 mm (długość) x 2 mm (grubość). W pracy oceniono również wpływ powtarzalnej obróbki plastycznej (SPD) na umocnienie tych materiałów przy różnych wartościach kąta narzędzia kształtującego. Wykazano jednoznacznie wpływ nowych geometrii narzędzi kształtujących na poprawę własności mechanicznych.

6

Possibilities of Application Methods Drece in Forming of Non-Ferrous Metals / Możliwości Aplikacyjne Metody Drece Dotyczące Odkształcania Metali Nieżelaznych

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Kłyszewski A. , Rusz S. , Hilser O. , Salajka M. , Cizek L. , Klos M.

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nr 4

7

Possibilities of Application Methods Drece in Forming of Non-Ferrous Metals

75%

Rusz S. , Kłyszewski A. , Salajka M. , Hilser O. , Cizek L. , Klos M.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 4

3011--3016

EN

Device “DRECE - Dual Rolls Equal Channel Extrusion” is used for production of metallic materials with very fine grain size (UFG). During the actual forming process the principle of severe plastic deformation is used. Metallic strip with dimensions 57×2×1000 mm is inserted into the device. During the forming process the main cylinder in synergy with the pressure roller extrude the material through the forming tool without any change of cross section of the strip. In this way a significant refinement of grain is achieved by severe plastic deformation. This method is used for various types of metallic materials, non-ferrous metals and their alloys. The DRECE device is also being verified from the viewpoint of achievement of a UFG structure in a blank of circular cross-section (wire) with diameter of ϕ 8 mm × 1000 mm.

PL

Urządzenie „DRECE - Dual Rolls Equal Channel Extrusion” znajduje swoje zastosowanie do wytwarzania metali o strukturze ultradrobnoziarnistej (UFG). W trakcie procesu wytwarzania stosuje się metodę wielokrotnej deformacji. W urządzeniu założona jest metalowa taśma o wymiarach 57×2×1000 mm. Podczas procesu formowania, główny cylinder we współdziałaniu z dociskowym wałkiem wytłaczającym odkształca materiał bez zmiany wymiaru przekroju poprzecznego taśmy. W ten sposób uzyskuje się znaczne rozdrobnienie ziarna przez wielokrotne odkształcenie plastyczne. Metoda ta jest wykorzystywana do różnego rodzaju materiałów metalowych, metali nieżelaznych i ich stopów. Urządzenie DRE CE jest również testowane pod kątem osiągnięcia struktury UFG w materiale o przekroju okrągłym (drut) o średnicy ϕ8 mm i długości 1000 mm.

8

Microstructure and Texture Changes of MgLiAl Alloys Composed of α or α + β Phases after Twist Channel Angular Pressing TCAP

75%

Dutkiewicz J. , Rusz S. , Kuc D. , Hilser O. , Bobrowski P. , Kania B.

Archives of Metallurgy and Materials

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2018

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tom Vol. 63, iss. 4

1827--1835

EN

Two MgLiAl alloys of composition 4.5% Li and 1.5% Al (in wt.%) composed of α phase and of 9% Li, 1.5% Al composed of α (hcp) + β (bcc) phases were subjected to twist channel angular pressing (TCAP) deformation. Such deformation of α + β alloys caused less effective grain refinement than that of single α phase alloy. However, with increasing number of passes, grain size of single α phase alloy increased and that of β phase in two phase α + β alloy also grew, which suggested the effect of dynamic recrystallization. TEM studies allowed identifying particles of Li2MgAl phase of size of few μm. {001}<100> texture was observed in extruded alloy. Texture studies of extruded and TCAPed single phase hcp alloy indicated texture with {1010} plane perpendicular to the extrusion direction and {0002} plane parallel to the extrusion direction. Duplex α + β alloys showed poor texture development.

9

New type of device for achievement of grain refinement in metal strip

63%

Rusz S. , Cizek L. , Michenka V. , Dutkiewicz J. , Salajka M. , Hilser O. , Tylsar S. , Kedron J. , Klos M.

Archives of Materials Science and Engineering

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2014

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tom Vol. 69, nr 1

38--44

EN

Purpose: The main goal of the paper is a review of current achieved results obtained by processing of Cu based materials by DRECE technology, the prototype equipment of which was put in service towards the end of 2008 at the Department of mechanical technology, Faculty of Mechanical Engineering, VSB - Technical University of Ostrava. Design/methodology/approach: Device „DRECE - Dual Rolls Equal Channel Extrusion” (dual rolls pressure combined with equal channel extrusion) is used for production of metallic materials with very fine grain size (hereinafter referred to as UFG structure - Ultrafine Grain Size). Findings: The results reached after heat treatment show the necessity of next experiments with changing conditions of heat treatment parameters. Research limitations/implications: This method is used for various types of metallic materials, non-ferrous metals and their alloys. Forming process is based on extrusion technology with zero reduction of thickness of the sheet metal with the ultimate aim - achieving a high degree of deformation in the formed material. The DRECE device is also being verified from the viewpoint of achievement of a UFG structure in a blank of circular cross-section (wire) with diameter of ø 7 mm × 1000 mm (length).Originality/value: Article shows new type of device for achievement of grain refinement in metal strip.