Metallurgical Studies on the Friction Stir Welding of Dissimilar A356 and A413 Alloys

2012 ◽  
Vol 488-489 ◽  
pp. 345-349
Author(s):  
G. Elatharasan ◽  
V.S. Senthil Kumar

Friction stir welding is a technique useful for joining aluminum alloys that are difficult to weld. In recent years, however the focuses has been on welding dissimilar aluminum alloys, and analyze their mechanical properties and micro-structural characteristics. In the present study, the less investigated welding of cast aluminum alloys is considered. Cast aluminum alloys, A356 and A413, commonly used in automotive and aerospace industries, were friction-stir welded and their mechanical properties and micro-structural characteristics were analyzed. On testing their welded region, no welding defects were observed. The welded region exhibited a maximum tensile strength of 90 N/mm2 and Vickers micro-hardness of 56.8. The micro-structural observations at the nugget region revealed a refined grain structure.

2014 ◽  
Vol 39 (8) ◽  
pp. 6363-6373 ◽  
Author(s):  
A. Karam ◽  
T. S. Mahmoud ◽  
H. M. Zakaria ◽  
T. A. Khalifa

Author(s):  
Morteza Ghaffarpour ◽  
Mohammad Kazemi ◽  
Mohammad Javad Mohammadi Sefat ◽  
Ahmad Aziz ◽  
Kamran Dehghani

In the present study, friction stir welding (FSW) and tungsten inert gas (TIG) techniques were used to join the dissimilar aluminum alloys of 5083-H12 and 6061-T6. The laboratory tests were designed using design of experiment (DOE) method. Variables for the FSW process were the rotational speed, traverse speed, shoulder diameter, and pin diameter. They changed in ranges of 700–2500 r/min, 25–400 mm/min, 10–14 mm, and 2–4 mm, respectively. In the case of TIG process, the variables were current intensity, traverse speed, and tilt angle. These parameters varied from 80 to 90 A, 200 to 400 mm/min, and 3° to 12°, respectively. The optimum amounts of parameters were obtained using response surface methodology (RSM). The RSM-based model was developed to predict ultimate tensile strength (UTS) of the welds produced. In FSW, the difference between predicted and measured UTS was about 1.28% and in TIG it was 1.78%. The good agreement between experimental and predicted results indicates the high accuracy of the developed model. Mechanical properties and also the microstructure of the welds were compared after optimizing both welding processes using RSM. The results showed that the welds produced by FSW indicated a considerably higher quality and also improved mechanical properties compared to TIG. Properties of the joints obtained by FSW in single-sided joints were more desirable. In the double-sided welds obtained by FSW these differences were of an even higher significance.


Author(s):  
Nataliya Kalinina ◽  
Tetyana Nosova ◽  
Stella Mamchur ◽  
Nataliya Tsokur ◽  
Nikita Komarov

The effect of modification with dispersed compositions on the grain structure and mechanical properties of industrial aluminum alloys has been studied. Aluminum alloys of the Al-Si, Al-Mg-Sc, Al-Cu-Mn systems were modified with dispersed Mg2Si powder with a particle size of up to 200 nm. The amount of modifier to be added to the melt is calculated. The physicochemical properties of dispersed Mg2Si have been studied. Melting of the AMg6, 1570, 2219, AK9ch alloys in the initial state and with the treatment of Mg2Si melts have been carried out. The action of insoluble applications, isomorphic to aluminum, the similarity of the influence of soluble elements holds only when the amount of insoluble addition exceeds the number of crystals formed arbitrarily under the same conditions. Thus, with an increase in the amount of insoluble addition, in particular silicon carbide particles, the grain size first decreases and then remains constant. The mechanism of the influence of dispersed particles of magnesium silicide on the formation of the structure of hypoeutectic aluminum alloys during crystallization is that their bulk is pushed out by the crystallization front into the liquid phase and participates in the refinement of the structural components of the alloy. To determine the optimal amount of silicon carbide modifier, industrial melting and testing were performed on specimens that underwent heat treatment according to the T6 mode (quenching and artificial aging). The quality of cast aluminum alloys during modification depends on many factors: the nature of the dispersed phase, the temperature of the melt, and the modes of its mixing with the introduction of particles. Dependences of the particle size and the amount of the modifier on the mechanical properties of the alloys have been established. The mechanism of interaction of the modifier with aluminum melt during crystallization has been established. In industrial experiments, the most effective size of SiC particles for increasing the σm of the AK9ch alloy from 115 to 260 MPa in the as-cast state has been established. The optimal content of Mg2Si (0.10 %) for increasing the σm of aluminum alloys has been determined.


2016 ◽  
Vol 710 ◽  
pp. 137-142 ◽  
Author(s):  
Jean Pierre Bergmann ◽  
Michael Grätzel ◽  
René Schürer ◽  
Anna Regensburg ◽  
Markus Weigl

Within the last decade, Friction Stir Welding (FSW) has increasingly been gaining relevance for joining nonferrous metals, especially aluminum alloys. Possible applications range from the aerospace and automotive sector up to manufacturing electrical components. Compared to conventional fusion welding processes, FSW offers numerous advantages, as it for example does not require shielding gas or filler material. However, FSW is still not applied or taken into account during the product development process in proportion to its potential. This is mainly caused by the lack of data in order to evaluate the process economically and differentiate it to other processes like arc and laser welding, also regarding technological factors. Therefore, this investigation focusses on the possibilities and limits when joining wrought and cast aluminum alloys, like EN AW-6082 T6, EN AW-7075 T651 and AlSi11Mg0,3, respectively, by FSW compared to MIG. The weld quality of the samples is characterized by tensile testing, hardness measurements and microstructure analysis. Furthermore, an approach to reduce the process forces by using FSW tools with reduced diameters and respectively adjusted process parameters is presented.


2018 ◽  
Vol 22 (Suppl. 1) ◽  
pp. 55-66 ◽  
Author(s):  
Furkan Sarsilmaz

Friction stir welding can be applied to weld dissimilar aluminum alloys which have different chemical and mechanical properties without causing any weld defects under a wide range of welding conditions. In this study, AA2024-T3 and AA6063-T6 aluminum alloys were selected and successfully welded in butt position together using by friction stir welding. The welding trials were conducted using different rotational speed and traverse speed conditions also investigating their effect on mechanical and micro-structural behavior of friction stir welding joints. The micro-structural evolution of the material was analyzed by optical observations and scanning electron microscopy inspections of the weld cross-sections. Tension and fatigue studies were also employed to the study. On the other hand, the fracture characterizations of samples were examined by scanning electron microscopy. Fatigue tests were performed by using a resonant electro-mechanical fatigue testing machine by axial bending fatigue test procedure. The fatigue strength has been analyzed drawing S-N curves. Experimental results indicate that micro-structural and mechanical properties are significantly affected by changing welding parameters within the chosen range of welding conditions.


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