Modern metal forming processes of non-ferrous metals, particularly aluminum and its alloys, are increasingly based on integrated technologies combining numerous operations in one process line. The subject of this paper focuses on the possibility of using materials after mould casting (simulating a continuous casting process between cylindrical crystallizers - Twin Roll Casting method) for the direct cold rolling process. As a part of this research a pilotage study on metallurgical synthesis and mould casting process of Al-Mg alloys with the magnesium contents of 5%-10%, testing their mechanical, electrical and structural properties as well as susceptibility to cold plastic deformation. This process was carried out with the measurement of strength parameters and confirmed the possibility of cold rolling alloys with a casting structure without prior hot deformation.
Modern manufacturing methods of non-ferrous metals, especially aluminum and its alloys, are more and more often based on integrated technologies combining multiple operations in a single process. One of the most popular methods for producing flat components by cold working is twin roll casting technology (TRC). It allows to eliminate from manufacturing the extremely expensive hot rolling operation, as the TRC semi-product (strip) can be directly cold rolled. The results of mechanical and electrical properties and structure examination of strips after casting were presented in the paper. The effect of cold rolling parameters on post-process mechanical properties and structure of sheets was investigated too.
Twin Roll Casting technology belongs to modern, integrated method of processing aluminum and its alloys. This method includes preparation of liquid metal and its continuous casting between the rotating cylindrical crystallizers, optional homogenizing treatment, cold rolling and optional interoperation or final heat treatment. Final products of TRC method are strips with a thickness from few to several millimeters, which can be directly subjected to cold rolling process to afford a sheet. Properties of final product are limited by the material’s condition, its chemical composition and also selected path of its processing technology. The paper presents research results of chemical composition and mechanical properties of strips obtained in Twin Roll Casting processing line.
Współczesne technologie przetwórstwa metali nieżelaznych, a w szczególności aluminium i jego stopów w coraz większym stopniu opierają się na technologiach zintegrowanych łączących większą ilość operacji w jednej linii technologicznej. Jednym z coraz częściej stosowanych procesów produkcyjnych wyrobów płaskich zimnowalcowanych jest metoda twin roll casting (TRC). Dzięki niej istnieje możliwość wyeliminowania z procesu walcowania na gorąco. Wsad z linii TRC w postaci taśmy może być bowiem poddany bezpośredniemu procesowi walcowania na zimno. Artykuł przedstawia wyniki parametrów procesowych walcowania na zimno taśm z linii TRC. Dodatkowo przebadano własności mechaniczne blach w stanie po walcowaniu.
EN
Modern metal processing technologies of non-ferrous metals, particularly aluminum and its alloys are increasingly based on integrated technologies, which combine more operations in one technological line. Twin roll casting process (TRC) is one of the most frequently used technologies in flat cold-rolled products manufacturing. TRC method allows to eliminate the hot rolling process. The metal strip produced in TRC process may be subjected directly to cold rolling process. The paper presents parameters of cold rolling process of metal strips obtained in TRC line. Additionally, mechanical properties of sheet after rolling process were tested.
Modern aluminium alloys are more commonly used in various industries. Often the products of such materials operate at elevated temperatures. In addition to standard requirements in terms of mechanical and technological properties, one of the key performance properties becomes the increased resistance to annealing. This paper examines the heat treatment effect on the mechanical properties of sheets made of aluminium with grain refiner additions (Ti + B), Fe, Si and Mn. Tested materials were obtained by cold-rolling strips, manufactured by twin-roll casting – TRCmethod. TRC method is increasingly being used in the manufacture of flat-rolled products. This technology eliminates the hot rolling operations and the strip obtained by TRC method can be subjected to direct cold rolling.
PL
Nowoczesne stopy aluminium znajdują coraz szersze zastosowanie w różnych dziedzinach przemysłu. Niejednokrotnie wyroby z takich materiałów pracują w podwyższonych temperaturach. Obok standardowych wymagań w zakresie własności mechanicznych i technologicznych jedną z kluczowych własności użytkowych staje się podwyższona odporność cieplna. W pracy przebadano wpływ obróbki cieplnej na własności mechaniczne blach z aluminium z dodatkami rozdrabniacza ziarna (Ti + B), Fe, Si oraz Mn. Materiały poddawane badaniom wytworzono przez walcowanie na zimno taśm uzyskanych metodą twin-roll casting – TRC. Metoda TRC jest coraz częściej wykorzystywana w produkcji płaskich wyrobów walcowanych. Eliminuje ona konieczność prowadzenia walcowania na gorąco, a taśma uzyskana metodą TRC może być poddawana bezpośredniemu walcowaniu na zimno.
W ostatnich latach zauważalny jest wyraźny rozwój technologii wytwarzania różnych produktów na bazie aluminium i jego stopów do różnych zastosowań. Wiele jednostek naukowych oraz przedsiębiorstw pracuje nad nowymi materiałami, które sprostałyby coraz to bardziej rygorystycznym wymaganiom stawianym przez odbiorców. Z punktu widzenia zarówno producentów jak i odbiorców, niezwykle ważne jest otrzymanie wyrobu wysokiej jakości po jak najniższej cenie. Możliwość taką daje zastosowanie technologii twin roll casting, a więc procesu jednoczesnego odlewania połączonego z częściową przeróbką plastyczną materiału na gorąco. Dzięki temu możliwe jest wyeliminowanie z procesu produkcji walcowania na gorąco. W ramach niniejszej pracy przedstawiono wyniki badań własności mechaniczno-elektrycznych oraz analiz strukturalnych dwóch wybranych stopów aluminium otrzymanych metodą twin roll casting.
EN
In recent years, it is clearly noticeable continuous development of manufacturing technology of various products based on aluminum and its alloys for different applications. Many scientific institutions and companies works on new materials to cope the increasingly stringent requirements of the customers. From the point of view of both, producers and consumers, it is essential to obtain a high quality product at the lowest price. The possibility of this gives the twin roll casting (TRC) method. Application of TRC technology allows to eliminate hot-rolling process from the manufacturing process. The paper presents influence of alloying elements on the structure and mechanical properties of two different aluminum alloy from twin roll casting process.
Technologia twin roll casting (TRC) staje się coraz popularniejsza ze względu na możliwość otrzymywania przy jej wykorzystaniu taśm aluminiowych mogących służyć, jako wsad do bezpośredniego procesu walcowania na zimno. Dodatkowo taśmy te charakteryzują się korzystnym połączeniem własności mechanicznych i elektrycznych oraz tolerancji wymiarowych. Określenie własności materiałów otrzymywanych przy zastosowaniu metody TRC jest ważnym z użytkowego punktu widzenia problemem badawczym. W ramach niniejszego artykułu przedstawiono badania nad laboratoryjną technologią wytwarzania taśm metodą TRC oraz badania wpływu parametrów procesowych, ilości i rodzaju dodatków stopowych charakterystycznych dla grupy stopów 1XXX, 3XXX i 8XXX na strukturę oraz własności mechaniczne i elektryczne otrzymanych materiałów.
EN
Twin-roll casting technology of (TRC) is currently very popular due to the as cast strips manufacturing possibility for cold rolling process. In addition, these strips are characterised by a favourable combination of mechanical and electrical properties and dimension tolerances. Identification of the TRC cast material properties is an important practical and technological issue. The paper describes research on TRC laboratory technology of strip manufacturing. Process parameters, the quantity and type of alloying additives to aluminium (typical for 1XXX, 3XXX and 8XXX aluminium alloy series) were investigated and its effect on the macrostructure and the mechanical and electrical properties were analysed.
W pracy przedstawiono wyniki badań mikrostruktury i właściwości mechanicznych taśm ze stopu magnezu AZ31 po procesie walcowania na gorąco. Procesowi walcowania poddano pasma odlewane o grubości 5 mm. Walcowanie prowadzono w zakresie temperatury od 450˚C do 300˚C na grubość końcową od 2,8 do 0,9 mm. Na podstawie badań strukturalnych stwierdzono, że zastosowanie gniotów powyżej 45% i temperatury końca walcowania około 300˚C umożliwia otrzymanie taśm bez pęknięć i zawalcowań. Stop AZ31 po walcowaniu wykazuje korzystne właściwości mechaniczne oraz charakteryzuje się drobnoziarnistą strukturą, bez widocznych obszarów ziarn pierwotnych.
EN
The paper presents the results of microstructure and mechanical properties tests of bands made of magnesium alloy AZ31 after the process of hot rolling. Rolling was conducted on bands casted in thickness of 5mm. Rolling was conducted in temperature range from 450˚C to 300˚C to achieve final thickness from 2,8 to 0,9 mm. It was concluded on the basis of structural tests that the application of drafts above 45% and temperature of rolling end of 300˚C makes it possible to keep the band without crackings and cold shuts. Alloy AZ31 after rolling shows beneficial mechanical properties and is characterised with fine-grained structure without visible areas of primary grains.
Magnesium alloys have great potential in the area of lightweight production especially in the automotive industry due to their favorable combination of mechanical properties and low density. The Institute for Metal Forming at the Freiberg University of Mining and Technology (TUBAF) and MgF Magnesium Flachprodukte GmbH have developed an energy efficient and therefore eco-friendly technology for the production of magnesium sheets to enhance the availability of magnesium sheets. For this purpose a pilot plant has been constructed in Freiberg. The twin roll casting facility with a downstream rolling mill is described in the following. The state of the technology is shown regarding the twin roll casting product and the properties of rolled and annealed sheets and bands respectively. Furthermore examples from the automotive and electronic industry are shown.
PL
Ze względu na korzystną kombinację własności mechanicznych ze znikomą gęstością stopy magnezu mają wiele możliwości zastosowania w konstrukcjach lekkich, a w szczególności w przemyśle motoryzacyjnym. Aby zwiększyć dostęp do blach z magnezu, Instytut fur Metalformung Uniwersytetu TU-Bergakademie Freiberg wraz z firmą MgF Magnesium Flachprodukte GmbH opracował nową energowydajną i przyjazną środowisku technologię produkcji blach magnezowych. W tym celu zostało również wykonane na terenie Instytutu fur Metalformung urządzenie pilotażowe. W pracy przedstawiono urządzenie do odlewnia blach między walcami ze stopów magnezu zaopatrzone w jednostkę do przerobu plastycznego. Pokazano: stan aktualny rozwoju technologii, dostępne odlane półprodukty, właściwości przewalcowanych i wyżarzonych blach oraz taśm. Na zakończenie zaprezentowano możliwości zastosowania produktów magnezowych do budowy pojazdów oraz w sprzęcie elektronicznym.
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In this paper, Anand's model, a uni?ed visco-plasticity constitutive model, was employed to simulate the highly nonlinear behavior in the twin-roll casting process. Anand model's parameters were regressed based on compression tests at various temperatures and strain rates for magnesium alloy AZ31. To calculate the thermal mechanical stresses, the thermal ?ow of twin-roll casting process was simulated ?rstly; then the stresses were calculated by the imposed thermal ?ow as the body load, and a small displacement load along roller's tangential direction was imposed simultaneously in order to simulate the rolling action. The stresses and deformation results were compared with experimental data. Based on the stresses analysis and experimental tests, it reveals that separating force should be strictly controlled in the twin roll casting process in order to avoid cracks caused by thermal and deformation stresses.
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Purpose: of this paper is to clear the possibility of high speed roll casting of aluminium alloy strip. In the body of the automobiles, a sheet of 6016 aluminium alloy is adopted for the outer panel. Therefore, casting of 6016 was tried in this study. Characteristics of roll cast 6016 were investigated. Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designed to overcome the low castability of the twin roll caster. Findings: are as below. 6016 alloy could be cast into the strip continuously at the speed of 60 m/min. The thickness of the strip was 3.4 mm. The microstructure at as-cast and after T4 heat treatment was shown. The microstructure was very fine. The mechanical properties were investigated by the tensile test and 180 degrees vending test. The as-cast strip could be cold rolled without homogenization to 1 mm. Result of tensile test was tensile strength was 230MPa, 0.2% proof stress was 118MPa and elongation was 33%. 6016 strip of T4 heat treatment could be bent 180 degrees without occurrence of crack at the outer surface or breaking. Research limitations/implications: is the width of the strip was 100 mm. It is necesarry to test twin roll caster equipped wide rolls. Practical implications: are as below. The mechanical properites of the roll-cast 6016 were enough for the sheet metal for the automobile. The low productivity of the twin roller caster could be improved. Originality/value: is that 6016 strip could be cast continuously at speed 60 m/min and this strip had good mechanical properties.
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Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated. Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metallography, a tension test, and a bending test. Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe. Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip. Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.
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Purpose: The purpose of the work is to development of a strip casting technology for manufacturing magnesium alloy sheets. The aim of the work is to establish a manufacturing process and technology to facilitate the economical manufacture of high-strength magnesium sheet alloys. Design/methodology/approach: A horizontal type twin roll caster was used to manufacture magnesium alloy sheets. Pair of copper alloy roll, pure copper roll and steel roll was used for the horizontal type twin roll caster. The diameter of the rolls was 300 mm and the width of rolls was 100 and 150 mm. Findings: The magnesium alloy sheets could be successfuly manufactured by the horizontal twin roll caster. The product sheet thickness in the present experiment was 2.0 to 5.0 mm. The equiaxed microstructure was observed in cast magnesium alloys when a pair of copper and copper alloy rolls were used. The mean grain size of the cast magnesium alloys strip was from 30 to 60 micrometers. After hot rolling process, the grain size was reduced to about 10 micrometers. The obtained magnesium alloy sheet indicated a good plastic formability by a warm-drawing test. Research limitations/implications: The superheat in the experiment was between 15 and 30 degrees centigrade, also an appropriate hot rolling temperature was 250 degrees centigrade for AZ31, AZ61 and AM60, 300 degrees centigrade for AZ91. Practical implications: The proposed manufacturing process was effective from the view point of economical manufacturing process as well as of formation of rapid solidification microstructures. Introducing the twin roll casting technology enable to manufacture magnesium sheet alloys with high aluminium contents, such as AZ61, AM60 and AZ91. Originality/value: AZ31, AM60, AZ61 and AZ91 wrought magnesium alloy sheets can be manufactured economically by twin roll casting. These cast sheet can be hot rolled and the proposed manufacturing process enables manufacturer to manufacture thin magnesium alloy sheets with high aluminium contents such as AM60, AZ61 and AZ91.
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