Wyniki wyszukiwania - Biblioteka Nauki

1

Analiza wyciskania prętów bimetalowych Al-Cu o przekroju okrągłym i kwadratowym

100%

Berski S. , Banaszek G. , Dyja H.

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2010

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tom R. 55, nr 12

861-866

PL

W artykule przedstawiono analizę procesu wyciskania wsadu bimetalowego Al-Cu wstępnie połączonego wybuchem. Zaprezentowano wyniki badań teoretycznych przy użyciu programu komputerowego Forge/R, który umożliwia przeprowadzenie symulacji komputerowej w przestrzennym stanie odkształcenia. Analizie poddano pręt bimetalowy o kompozycji: warstwa zewnętrzna miedź i warstwa wewnętrzna aluminium o określonym udziale warstwy platerującej. Wymiary początkowe wsadu: średnica zewnętrzna 22 mm oraz wysokość 40 mm. Proces wyciskania prowadzono w temperaturze otoczenia dla dwóch schematów wyciskania współbieżnego i przeciwbieżnego. Dla obu schematów wyciskania w celu uzyskania kształtu wyrobu gotowego, zastosowano matryce stożkowe o kącie nachylenia 45 stopni. Analizowano dwa przekroje końcowe: standardowy okrągły oraz kwadratowy. W pracy przedstawiono charakterystyczne etapy procesu oraz poddano analizie charakter płynięcia poszczególnych warstw bimetalu oraz parametry siłowe procesu.

EN

In the article the analysis of extrusion process of bimetallic charge initially joined by explosive cladding was presented. The results of theoretical research with using FEM software Forge/R, which enables to make computer simulations in 3D state of deformation were showed. The analysis concerns bimetallic rods with following composition: copper as a cladded layer and aluminum as a core layer with precise volume fraction of cladded layer. Initial dimensions of charge: outer diameter 22 mm and height 40 mm. The extrusion process was simulated for ambient temperature and for two different schemes of extrusion: direct and indirect. To obtain a shape of final product for both schemes of extrusion the conical matrix with inclination angle 45 degrees were used. Two final shapes of crossection were analyzed: round one and square one. In the paper characteristic stages of the process were presented moreover the analysis of the flow of particular bimetallic layers and force parameters of the process were done.

2

Analiza siły wyciskania wsadu bimetalowego al/cu o wybranej geometrii w procesie ECAE

75%

Berski S. , Dyja H. , Sechman K.

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2013

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tom R. 58, nr 2

80-83

PL

W artykule przedstawiono analizę obciążeń stempli w procesie ECAE. Obliczeń numerycznych dokonano w oparciu o przestrzenny model odkształcenia, dla wsadu o różnych temperaturach początkowych i różnej geometrii komponentów wsadu bimetalowego przy użyciu programu komputerowego Forge2008. Analiza numeryczna pozwoliła na uzyskanie zależności obciążenia stempla w funkcji jego przemieszczenia oraz pozwoliła na identyfikacje maksymalnych wartości sił działających na stempel podczas jednego cyklu procesu. Wymiary początkowe wsadu: średnica zewnętrzna 22 mm oraz wysokość 100 mm. Proces ECAE modelowano dla dwu różnych matryc kątowych. Pierwsza matryca to typowa matryca o równych kanałach (standardowy proces ECAE), natomiast druga matryca, z dodatkową redukcją przekroju w kanale wyjściowym, umożliwia prowadzenie zmodyfikowanego procesu ECAE, w którym występują większe siły wyciskania. Badania miały na celu sprawdzenie wytrzymałości stempla zaprojektowanego do standardowego procesu ECAE prowadzonego w podwyższonej temperaturze i ocenę przydatności tego stempla do prowadzenia procesu "na zimno" oraz w zmodyfikowanej matrycy.

EN

In the work the analysis of punch load during ECAE process was presented. The numerical analysis was conducted on the base of 3-dimmensional model of deformation for billets with various temperatures and various bimetal components geometry with help of computer programme Forge2008 based on FEM. The numerical analysis enabled to obtain the dependence between the punch load and punch road and also enabled the identification of the maximum extrusion force imposed on punch during one pass of ECAE process. Dimensions of the billet were: outer diameter 22 mm and height 100 mm. Process ECAE was simulated for two different "angle" dies. The first one is a standard tool with two equal channels while the second one, with additional reduction of the billet cross-section into second channel, enables to realize modified ECAE process which consums greater extrusion forces. The force analysis was carried out for the purpose of verification of punch strength designed for standard ECAE process in higher temperatures and also for an assessment of the punch usability for cold processes and for processes in modified die.

3

Explosion welding of titanium - copper bimetals

71%

Maronek M. , Gatial M. , Szulc Z. , Turna M.

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2007

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tom Vol. 7, nr 4(14)

89-94

EN

The paper deals with explosion welding of titanium and copper in order to produce bimetals suitable for making targets used in sputtering process. Paper describes materials frequently used for target fabrication and technologies often used for their production. There are also brief characteristics of welded materials, their mechanical and other properties as well as need for their purity. A key part of the paper is devoted to explosion welding process, its description, including welding parameters, used explosives and welding procedure itself. The last part of paper deals with quality control examination of final bimetal, i. e. ultrasonic testing, mechanical testing and microstructure analysis.

4

Spatial bimetallic castings manufactured from iron alloys

63%

Cholewa M. , Tenerowicz S. , Suchoń J.

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2007

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tom Vol. 7, iss. 3

33-38

EN

In this paper a conception for manufacturing method of skeleton castings with composite features was shown. Main application of such castings are the working organs of machines subjected to intensive abrasive and erosive wear. Skeleton geometry was based on three-dimensional cubic net consisting of circular connectors and nodes joining 6 connectors according to Cartesian coordinate system. Dimension of an elementary cell was equal to 10 mm and diameter of single connector was equal to 5 mm. For bimetallic castings preparation two Fe based alloys were used: L25SHMN cast steel for skeleton substrate and ZlCr15NiMo cast iron for working part of the casting. In presented work obtained structure was analyzed with indication of characteristic regions. Authors described phenomena occurring at the alloys interface and phases in transition zone. A thesis was formulated concerning localization of transition zone at the cast iron matrix - cast steel reinforcement interface. Direction of further studies were indicated.

5

Analiza teoretyczna procesu przetwarzania bimetalu Al-Cu i AlMgSi-Cu na druty przeznaczone na przewody.

63%

Knych T. , Nowak S.

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2003

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tom R. 48, nr 9

431-434

PL

Przedstawiono prostą analizę teoretyczną przetwarzania bimetalu Al(AlMgSi)-Cu metodą ciągnienia na druty przeznaczone na przewody o podwyższonej oporności właściwej, wytrzymałości na rozciąganie i atrakcyjnych cechach eksploatacyjnych (pełzanie, zmęczenie etc). Druty takie mogą stanowić w niektórych przypadkach materiał wyjściowy do produkcji samonośnych przewodów zastępujących tradycyjne przewody aluminiowo-stalowe. W szczególności przedstawiono formuły umożliwiające określenie rezystancji i wytrzymałości na rozciąganie drutu bimetalowego oraz grubości powłoki miedzianej.

EN

Simple theoretical analysis of processing Al(AlMgSi)-Cu bimetal by drawing wires designed for conductors with increased resistivity and tensile strength and attractive operational properties (creep, fatigue, etc.) has been presented. In some cases these wires can be an input material for the production of self-supporting conductors replacing traditional aluminium-steel wiring. In particular, the formulae enabling determination of resistance and tensile strength of bimetallic wire and the thickness of a copper coating have been included.

6

Quality of bimetal Al-Cu joint after explosive cladding

63%

Berski S. , Stradomski Z. , Dyja H.

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2007

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tom Vol. 22, nr 1

73-76

EN

Purpose: An analysis of quality of bimetallic joint between aluminium and copper layers of billet for extrusion process is the subject of the work. Design/methodology/approach: For preparing the quality analysis of particular layer of bimetal, the shearing test were done. During the tests the maximal stress for particular sets of the bimetal was established. For chosen cases the metallographic research of Al-Cu joint were done. Findings: The geometry of the cylindrical set and explosive cladding process parameters which allow to obtain the cylindrical bimetallic billets without cracks and delaminations and also with uniform cladded layer along and across the billet. Research limitations/implications: The analysis is concerning the explosive joint of pure aluminium A1995 and electrolytic copper M1E 99,97 in cylindrical sets. In the future research the analysis of this kind of joints after direct extrusion process is planning. Practical implications: The analysis could be helpful for more effective designing of the bimetal billets trough the explosive cladding process and next for the plastic working processes. Originality/value: During the extrusion process with high value of extrusion ratio the delamination of the billet layers especially on the boundary of the layers is observed, this fact causes that joint after the metal working processes has lower strength even than components of the bimetal billet. So very important task is establishing the geometry set and explosive parameters to obtain the best quality of the joint.

7

Quality of the joint between cast steel and cast iron in bimetallic castings

63%

Cholewa M. , Tenerowicz S. , Wróbel T.

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2008

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tom Vol. 8, iss. 3

37-40

EN

The paper presents conception and production method of skeleton composite castings with use of cast steel G35CrSiMnMoNi skeleton casting and chromium cast iron EN-GJN-XCr15 filling. Working elements in winning machines and devices, which work in intensive aberasive wear i.e. liner of exhausters, percussive and ram hammers, are destination of bimetallic castings. Skeleton geometry was based on three-dimensional symmetrical cubic net consisting of circular connectors and nodes joining 6 connectors according to Cartesian coordinate system. Dimension of an elementary cell was equal to 10 mm and diameter of single connector was equal to 5 mm. In range of studies were casted cast steel skeletons with chromium cast iron filling and based on metallographic research on light and scanning electron microscope was made quality assessment of joint in bimetallic castings. Moreover in range of studies was used microanalysis of chemical composition in transition zone of cast steel-cast iron joint.

8

Modelowanie wyciskania przeciwbieżnego bimetali.

63%

Sińczak J. , Łukaszek A. , Skubisz P.

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2002

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tom R. 47, nr 1

7-10

PL

Analizowano, na podstawie obliczeń numerycznych, mechanizm odkształcania dwóch warstw materiałów o różnych własnościach mechanicznych w procesie wyciskania przeciwbieżnego. Stwierdzono, że ułożenie warstw ma wpływ nie tylko na rozkład odkształceń, lecz również na rozkład nacisków jednostkowych na powierzchni styku odkształconego bimetalu i narzędzi.

EN

Basing on numerical calculations, the analysis of deformation of two layers of materials, with different mechanical properties, in the indirect extrusion process, was carried out. It was found that packing of layers influenced both strains distribution and also unit pressures distribution on contact surface of deformed bimetal and tools.

9

A modified flow field in the extrusion of bimetallic systems

54%

Śliwa R. E. , Mishuris G. S.

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1999

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tom Vol. 47, iss. 2

203-215

EN

The aim of the paper is to propose a new kinematically admissible velocity field corresponding to experimental results of the co-extrusion of various materials. A modified mathematical description of the plastic flow in the extrusion of the bi-metallic composite including boundaries of the plastic zone described by appropriate function has been proposed. Velocities, grid distortion and strain rate distribution have been calculated by taking into account information on the plastic zone boundaries and their forms. Excellent agreement between the analytical and the experimental results of the plastic flow of longitudially oriented metal composite has been established.

10

Examples of material solutions in bimetallic layered castings

51%

Wróbel T. , Cholewa M. , Tenerowicz S.

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2011

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tom Vol. 11, iss. 3

11-16

EN

In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer). The bearing part of bimetallic layered casting is typical foundry material i.e. pearlitic grey cast iron, whereas working part (layer) is depending on accepted variant plates of alloy steels sort X6Cr13, X12Cr13, X10CrNi18-8 and X2CrNiMoN22-5-3. The ratio of thickness between bearing and working part is 8:1. The verification of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing), structure and macro- and microhardness researches.

11

Bimetallic layered castings alloy steel - carbon cast steel

51%

Wróbel T. , Cholewa M. , Tenerowicz S.

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2011

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tom Vol. 11, iss. 1

105-108

EN

In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer). The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic carbon cast steel, whereas working part (layer) is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing), structure and macro- and microhardness researches.

12

Diffusion phenomena between alloy steel and gray cast iron in layered bimetallic casting

51%

Cholewa M. , Wróbel T. , Tenerowicz S. , Szuter T.

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2010

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tom Vol. 55, iss. 3

771-777

EN

The work presents bimetallic layered casting technology in configuration: the upper layer of high chromium steel or chrome-nickel steel with layer made of cast iron casting. In presented technology of layered bimetallic castings steel elements with a thickness of 1.5 and 5mm. It was used a process of overlay of a surface layer, directly during casting process so-called mould cavity preparation method. Steel elements were placed in sand mould just before pouring the liquid gray cast iron. Verification of bimetallic castings was based on ultrasonic non-destructive testing and examination of the structure and selected utility properties.

PL

W pracy przedstawiono technologie bimetalicznych odlewów warstwowych w konfiguracji: warstwa wierzchnia na bazie stali wysokochromowej lub chromowo-niklowej z podłożem w postaci odlewu z żeliwa szarego. W przedstawionej technologii bimetalicznych odlewów warstwowych użyto do uszlachetnienia warstwy wierzchniej elementów stalowych o grubości 1,5 i 5mm, które w wyniku zastosowania metody nakładania warstw bezpośrednio w procesie odlewania tzw. metodą preparowania wnęki formy, zostały umieszczone w formach piaskowych bezpośrednio przed zalaniem ciekłym żeliwem szarym. Weryfikacje wykonanych bimetalicznych odlewów warstwowych przeprowadzono w oparciu o nieniszczace badania ultradźwiękowe oraz badania struktury i wybranych własności użytkowych.

13

Microstructure of a composite padded layer of metal powders and its resistance to penetration with a hard core bullet

32%

Starczewski L.

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2008

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tom Vol. 53, iss. 1

247-251

EN

The article presents the followin g, thesis: an armour material with hardness gradient shall successfully withstand the impact of a bullet with a hard core (65HRC) if the hardness of the surface layer is higher than the hardness of the bullet core and the layer is deposited on a soft substrate. A ballistic experiment was conducted to examine the ability of a hard (72HRC) composite padded layer — made of metal powders deposited by the plasma technique on soft steel (180HB) — to withstand the impact of bullets with a hard core. The microstructure of the padding weld was identified and its chemical composition was analysed. The examined material system with hardness gradient was found to be able to withstand successfully the impact of bullets with a hard core, while core defragmentation was the dominant mechanism. The examination of microstructure demonstrated an interrelation between the mechanism and the structure of the padded material.

PL

W artykule postawiono tezę, że materiał na pancerz o właściwościach gradientu twardości skutecznie zatrzyma pocisk z twardym rdzeniem (65HRC), jeżeli twardość warstwy powierzchniowej będzie powyżej twardości rdzenia pocisku i będzie utworzona na miękkim podłożu. W eksperymencie balistycznym zbadano zdolność twardej (72HRC) kornpozytowej warstwy napawanej, utworzonej z proszków metali techniką plazmową na miękkiej stali (180HB), do zatrzymania pocisków z twardym rdzeniem. Przeprowadzono identyfikacje mikrostruktury i analizę składu chemicznego napoiny. Badany układ materiałowy o gradiencie twardości, potwierdził swoją skuteczność w zatrzymaniu pocisków. W procesie tym dominującym mechanizmem jest fragmentacja twardego rdzenia. Badania mikrostruktury ujawniły związek pomiędzy tym mechanizmem a budową strukturalną napawanego materiału.