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Susceptibility for extrusion welding of AlMg alloys

Leśniak Dariusz, Wassermann Alicja, Dziki Mateusz, Zaborowski Krzysztof, Jurczak Henryk

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 1

20--31

EN

The extrusion of hollow profiles from high strength aluminium alloys through porthole dies causes serious problem in practice. Mainly, this is due to low weldability of these alloys and high extrusion force. The present paper discusses the investigations undertaken to determine the weldability of hard AlMg alloys using the original method and device. Main advantage of the proposed method is that it allows for the reflection of real welding conditions occurring in a welding chamber of the porthole die. Weldability tests were performed for alloys: 5754 (3.5% Mg), 5083 (4.5% Mg), 5019 (5.6% Mg) and 5xxx (7.1% Mg) in a wide range of temperature, unit pressure (normal compressive stress) and duration of welding. Microstructure and strength properties of the welds were examined. Most favourable welding conditions for the tested alloys, allowing for obtaining high strength welds were defined. To validate the laboratory experiments the extrusion trials were performed in the industrial conditions, in which the round tubes from 5754 alloy were produced using the porthole dies. The tensile strength of the welds in the extruded tubes is comparable to that for the solid material. Strength of the welds as well as of the solid material strongly increases with magnesium content in the alloy.

2

Numerical analysis and experimental validation of conjunction gear via hot forging-upsetting finishing-radial extrusion

Li Shilin, Ji Hongchao, Wang Baoyu, Mu Yanhong

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 2

391--404

EN

Numerical analysis and experimental validation of conjunction gear via hot forging-upsetting finishing-radial extrusion

3

Design of extrusion die for plastic profile using ansys polyflow software

Pepliński K., Mozer A.

Journal of Polish CIMAC

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2011

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Vol. 6, no 3

221-226

EN

Extrusion is one of the most widely used processes for polymer processing. Example: extrusion is a technique for producing film, pipe, sheet, profiles, cable and coatings in coextrusion process. The main tool used in this process for the manufacturing final shape product is die. The task of this article is to design the last part of extrusion die (die land) for plastic profile, using numerical simulation. In this paper was presented methodology of numerical simulation for the die design. A commercial computer fluid dynamics program Ansys Polyflow was used to design the die passage. The objective of the simulation is to determine the die passage that results in a balanced mass flow exiting the die that closely matches the target profile. The die land shape modification with using optimization algorithm is very helpful to obtain geometry and dimension of extrudate desired profile.

4

3D finite element analysis of metal flow in hot aluminium extrusion of T-shaped profile with various offset pockets

Carmai S. J. J., Pitakthapanaphong S., Sechjarern S.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

463-468

EN

Purpose: The present paper has therefore investigated influence of offset pocket design on metal flow behaviour in hot aluminium extrusion of a T-shaped profile. Design/methodology/approach: A series of finite element simulations have been carried out by offsetting the centre of pocket cross-section and examining exit velocity distributions of the profile cross-section for each case. Findings: That the offset pocket has influence on the metal flow during extrusion process. Small distance between the edge of the pocket and the edge of the die leads to slow flow velocity but if the distance is large the metal can flow through easily, hence higher velocity. With the information from the analyses, the new pocket was proposed. The velocity difference across the cross-section of the extrude was smaller compared to the original pocket. The extrudate is straight and not bent. Offsetting pocket can therefore be used to control metal flow to the die. Practical implications: The appropriate design of pocket will help in regulating the metal flow and lead to a single bearing length or even zero length bearings. This is more favorable than a flat die with varying bearing lengths as a pocket die could be more easy to machine or correct especially extrusion of a thin walled profile. The pocket is usually required for extrusion of complex geometries. The fundamental understandings of pocket design are currently inadequate. It depends heavily on the experience of the die designer. Limited work has been done towards systematically examining influences of the pocket geometries and offsets on metal flow. Originality/value: The present paper has therefore investigated influence of offset pocket design on metal flow behaviour in hot aluminium extrusion of a T-shaped profile of which its cross-sectional width varies. Its shape factor is 6.76. The thermal effect has also been incorporate. An appropriate pocket die design for a T-shaped profile has later been proposed.