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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

New original method and device for testing aluminum alloys susceptibility for extrusion welding

Leśniak D.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1491--1505

EN

Common methods of weldability assessment of aluminium alloys do not fully reflect the welding conditions occurring during extrusion through the porthole dies, hence the obtained results are not much good for practical use. There are no weldability tests in which the temperature, unit pressure, welding time and deformations in the welding zone can be simultaneously controlled. It is necessary in the correct bonding test to provide the welding conditions without contact of air, which could oxidise of the metal streams. The paper presents the original device for the research of aluminium alloy weldability, reflecting the conditions of metal bonding (without air access), which occur in the welding chamber of porthole dies. This device is a modification of a previously patented device carried out in order to determine more precise basic welding parameters. The operation principle as well as the methodology for determination of susceptibility to welding of aluminum alloys has been presented, using the AlMgSi alloy as an example in the type of EN AW-6082. The welding conditions of the 6082 alloy were determined, which allowed for high quality bonding. A parameter describing the welding conditions was defined as the relationship of the normal welding stress to the yield stress (σn/k) and its values were determined at different temperatures. The obtained values of welding stress are the basis for the proper design of porthole dies.

3

Study of welding of poly(ether-ester) elastomers. Part I. Influence of contents of flexible segments on morphology and mechanical properties

Kwiatkowski K., Rosłaniec Z.

Polimery

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2004

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T. 49, nr 4

268-274

EN

Weldability of poly(ether-ester) (PEE) multiblock elastomers, which belong to the group of the thermoplastic elastomers (TPE), was investigated. Investigated PEE consisted of soft polyoxytetramethylene (FS) blocks and hard poly(butylene terephthalate) (RS) blocks; with the FS:RS ratio variable. Welds were prepared using the wire (rod) welding technique and extrusion welding. Optical and scanning electron microscopy were used to characterize weld morphology and their mechanical properties (elongation, bending, impact strength). Materials for the seams were not dried prior to welding, so hydrolytic degradation took place during welding (250-300 °C), visible particularly in PEEs with higher RS content, as shown by results of flow rate measurements (MFR). The investigations demonstrate that the PEE elastomers containing predominantly the PTMO rich soft phase are well weldable using the applied techniques, even when non-dried material is used for the welds.

PL

Przedstawiono wyniki badań spawania multiblokowych elastomerów poli(eterowo-estrowych) (PEE) zaliczanych do grupy elastomerów termoplastycznych (TPE). Badane PEE [wzór (I)] składały się z miękkich bloków polioksytrametylenowych (FS) i twardych bloków poli(tereftalanu butylenu) (RS); różniły się one wzajemnym stosunkiem FS:RS. Do wykonania połączeń zastosowano technikę spawania drutem (prętem) (wire welding, rys. 1) oraz spawania wytłocznego (extrusion welding, rys. 2). Metodami mikroskopii optycznej i skaningowej mikroskopii elektronowej scharakteryzowano morfologię spoin (rys. 4-7) oraz ich właściwości mechaniczne (rozciąganie, zginanie, udarność, tabela 1, rys. 8, 9). Materiały spoin nie były suszone przed użyciem i dlatego podczas spawania (temp. 250-300 °C) zachodziła degradacja hydrolityczna, zwłaszcza widoczna w PEE o większej zawartości RS, co stwierdzono na podstawie pomiarów wskaźnika szybkości płynięcia (MFR, rys. 10). Wykazano, że PEE o przewadze miękkiej fazy polioksytetrametylenowej (FS) są spawalne zastosowanymi technikami spawania, nawet przy użyciu niesuszonych materiałów na spoiny.

4

Wpływ parametrów technologicznych ekstruzyjnego spawania tworzyw sztucznych na jakość złączy doczołowych.

Boroń S.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2000

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R. 44, nr 6

58-58

PL

Stosując metodę planowania eksperymentu, badano wpływ czynników technologicznych na właściwości wytrzymałościowe i plastyczne spawanych ekstruzyjnie złączy doczołowych z polietylenu o grubości 10 mm. W oparciu o wyniki badań wizualnych, makroskopowych i próbę zginania stwierdzono dobrą jakość połączeń. Analiza matematyczna uzyskanych wyników badań wykazała, że spośród parametrów spawania ekstruzyjnego decydujący wpływ na wartość kąta zginania ma temperatura uplastycznienia spoiwa.

EN

With use of experimental design, it was tested the influence of technological factors on mechanical and plastic properties of extrusion welded polyethylene butt joints, 10 mm in thickness. On the bassis of visual examination, macroscopy and bending test results, it was found that the quality of the joints was good. Mathematical analysis of the test results showed that, among extrusion welding parameters, the vital influence on the bending angle value had the temperature of filter material plasticization.

5

Technologia spawania ekstruzyjnego złączy doczołowych i teowych z polietylenu i polipropylenu.

Dziuba S., Boroń S.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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1999

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R. 43, nr 6

42-45

PL

Omówiono zasadę spawania ekstruzyjnego, przygotowanie brzegów do spawania w zależności od grubości łączonego materiału, kształt i wymiary nakładki formującej lico spoiny oraz opisano przeprowadzone badania technologiczne i wytrzymałościowe, których celem było ustalenie optymalnych parametrów spawania PEHD i PPH. Parametrami tymi są: temperatura uplastycznienia materiału dodatkowego, temperatura powietrza podgrzewającego brzegi rowka spawalniczego oraz prędkość podawania 'drutu'.

EN

It has been presented the pronciple of extrusion welding and the edge preparation means according to the thickness of material to be welded as well as the shape and dimensions of cover plate for forming weld face. It has been described also the technological and mechanical tests aimed at finding the optimum welding parameters for PEHD and PPH. The essential extrusion welding parameters are: temperature of plasticizing of filter material, temperature of air to plasticize welding groove and filter material feed rate.