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Ultrafine Grain Refinement of AlMn1Cu and AZ 31 Alloys by SPD Process

Rusz S., Cizek L., Salajka M., Tylsar S., Kedron J., Michenka V., Donic T., Hadasik E., Klos M.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

359--364

EN

One of the ways to the more effective use of metallic materials is their processing by forming. At present in this the area the use of the process of severe plastic deformation (SPD process), leading to a refinement of the structure (materials with UFG structure) and thus to achievement of higher level of their utility value, is expanding. AlMn1Cu alloy is commercially produced aluminum alloy by the company Al Invest Bridlicna (the cast strip with a mild reduction by rolling up to 10% to the thickness of 10 and 15 mm, which has its uses especially in engineering. AZ31 alloy is commercially produced aluminum alloy after casting and extrusion at 400°C on final rod with 20 mm diameter. For experimental purposes from the belts of alloys the test samples of the underlying dimensions of 10x10 mm length 40 mm (geometry with channel deflection 20°) and 15x15 mm length 60 mm (geometry with helix matrix) in the direction of rolling were made. All three instruments are made of high tool steel - HOTVAR. For compare the influence of geometry ECAP tool on structure refining was used AlMn1Cu and AZ31 alloys were used three specially made tools ECAP, differing mainly in the construction design.

PL

Jednym ze sposobów bardziej efektywnego kształtowania plastycznego metali jest metoda dużych odkształceń plastycznych Aktualnie do tego celu wykorzystywany jest proces SPD. w wyniku którego osiąga się wysokie wartości odkształcenia materiału z ultra drobnoziarnistą strukturą. Prowadzi to do wzrostu właściwości wytrzymałościowych, przy nieznacznym obniże- niu plastyczności. W artykule przedstawiono wyniki badań dwóch stopów - stop aluminium AlMnlCu, który jest produkowany w formie blachy grubości 10 lub 15 mm z zastosowaniem w przemyśle maszynowym oraz stop magnezu AZ31. który po odlaniu jest wyciskany w temperaturze 400°C z pręta o średnicy 60 mm na średnicę 20 mm. Do eksperymentów użyto próbek o rozmiarach 10x10-40 mm z odchyleniem kanału narzędzia ECAP o 20° od kierunku poziomego oraz próbki o rozmiarach 15x15-60 mm z nową geometrią kanału narzędzia ECAP (część kanału w kształcie śruby) dla zwiększenia odkształcenia w poszczególnych przejściach próbki narzędziem ECAP. Uzyskane wyniki twardości oraz struktury, przy użyciu wyżej podanych geometrii narzędzia ECAP. były porównywane oddzielnie u obu stopów.

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

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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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.

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New design of the forming equipment DRECE for obtaining UFG structure in strip of sheet

Rusz S., Malanik K., Dutkiewicz J., Cizek L., Donic T., Kedron J., Tylsar S.

Archives of Materials Science and Engineering

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2010

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Vol. 42, nr 2

111-118

EN

Purpose: of this paper is realisation of engineering design and manufacture of new type of equipment DRECE (Dual Rolling Equal Channel Extrusion), designated for obtaining UFG structure in strip of sheet. Design/methodology/approach: The equipment enables refinement of grain in strip of sheet by extrusion technology without change of cross-section. Special attention is paid to the design of the forming tool in order to prevent upsetting of sheet or its undulation during the forming process. Findings: From the viewpoint of design rate of extrusion has been optimised, range of pressure on pressure rolls has been determined, type of lubricant was optimised. Research limitations/implications: In contradiction to classical ECAP process only “A” and “C” type passes can be used. Due to this no shear planes are created in several grid systems and resulting efficiency of SPD process is therefore lower. It is, however, much higher than at rolling process. Practical implications: This equipment can be successfully used in pilot plant and afterwards in industrial practice. The first verification trials have confirmed functionality of this equipment. Originality/value: Development and manufacture of the DRECE equipment were realised at the Technical University of Mining and Metallurgy in Ostrava (VSB-TU Ostrava) in collaboration with designing and manufacturing company. Very realistic pre-requisite exists for obtaining UFG structure in strip of sheet made of non-ferrous metals and their alloys. The development was realised within the frame of the project MPO No. 2A-1TP1/124.