Study on process characteristics of friction stir welding based on vortex material flow using 6061-T6 aluminum alloy

In friction stir welding (FSW), many defects (such as kissing bond, incomplete penetration, and weak connection) easily occur at the root of the welded joint. Based on the Levy–Mises yield criterion of the Zener–Hollomon thermoplastic constitutive equation, a 3D thermal–mechanical coupled finite element model was established. The material flow behavior and the stress field at the root area of a 6 mm thick 2024-T3 aluminum alloy FSW joint were studied. The influence of pin length on the root flaw was investigated, and the formation mechanism of the “S line” defects and non-penetration defects were revealed. The research results showed that the “S line” defect forms near the bottom surface of the pin owing to the insufficiently mixed material from the advancing side (AS) and retreating side (RS) near the weld center. The non-penetration defect forms near the bottom surface of the workpiece owing to the insufficient driving force to make the material flow through the weld center. With the continual increase of pin length, the size of the “S line” defect and non-penetration defect reduces, and finally, the defect-free welded joint can be obtained with an optimized suitable length of the pin in this case.

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Effect of Modified Pin Profile and Process Parameters on the Friction Stir Welding of Aluminum Alloy 6061-T6

Advances in Materials Science and Engineering ◽

10.1155/2016/4567940 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

J. C. Verduzco Juárez ◽

G. M. Dominguez Almaraz ◽

R. García Hernández ◽

J. J. Villalón López

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Friction Stir Welding ◽

Material Flow ◽

Flow Behavior ◽

Tensile Tests ◽

Welding Parameters ◽

Friction Stir ◽

Aluminum Alloy 6061 ◽

Alloy 6061

This work deals with the effect of a new “bolt-head” pin profile on the friction stir welding performance of the aluminum alloy 6061-T6, compared to traditional pin profiles. Friction stir welding parameters such as the tool rotation speed and the welding speed were investigated together with the different pin profiles; the results show that the new “bolt-head” pin profile leads to better mechanical properties of welded specimens. The pin profiles used in this work were the straight square (SS), straight hexagon (SH), taper cylindrical (TC), and the straight hexagon “bolt-head” (SHBH). It was found that the last pin profile improves the material flow behavior and the uniform distribution of plastic deformation and reduces the formation of macroscopic defects on the welded zone. Mechanical tensile tests on welded specimens were performed to determine the tensile strength: the specimens welded with the SHBH pin profile have shown the highest mechanical properties. An approach is presented for material flow on this aluminum alloy using the SHBH pin profile, which is related to the improvement on the resulting mechanical properties.

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Mechanical and Microstructural Properties of AA 1030 Aluminum Alloy Plates Joined by Friction Stir Welding

Practical Metallography ◽

10.3139/147.110059 ◽

2010 ◽

Vol 47 (3) ◽

pp. 150-167 ◽

Cited By ~ 1

Author(s):

N. Ozdemir ◽

F. Sarsilmaz ◽

S. Büyükarslan

Keyword(s):

Aluminum Alloy ◽

Friction Stir Welding ◽

Microstructural Properties ◽

Friction Stir ◽

Mechanical And Microstructural Properties

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Defects and tensile properties of 6013 aluminum alloy T-joints by friction stir welding

Materials & Design (1980-2015) ◽

10.1016/j.matdes.2013.12.021 ◽

2014 ◽

Vol 57 ◽

pp. 146-155 ◽

Cited By ~ 47

Author(s):

Yong Zhao ◽

Lilong Zhou ◽

Qingzhao Wang ◽

Keng Yan ◽

Jiasheng Zou

Keyword(s):

Aluminum Alloy ◽

Friction Stir Welding ◽

Tensile Properties ◽

T Joints ◽

Friction Stir

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Study on Quality Prediction of 2219 Aluminum Alloy Friction Stir Welding Based on Real-Time Temperature Signal

Materials ◽

10.3390/ma14133496 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3496

Author(s):

Haijun Wang ◽

Diqiu He ◽

Mingjian Liao ◽

Peng Liu ◽

Ruilin Lai

Keyword(s):

Aluminum Alloy ◽

Friction Stir Welding ◽

Prediction Model ◽

Real Time ◽

Support Vector ◽

Weld Quality ◽

Prediction Ability ◽

Friction Stir ◽

Temperature Signal ◽

2219 Aluminum Alloy

The online prediction of friction stir welding quality is an important part of intelligent welding. In this paper, a new method for the online evaluation of weld quality is proposed, which takes the real-time temperature signal as the main research variable. We conducted a welding experiment with 2219 aluminum alloy of 6 mm thickness. The temperature signal is decomposed into components of different frequency bands by wavelet packet method and the energy of component signals is used as the characteristic parameter to evaluate the weld quality. A prediction model of weld performance based on least squares support vector machine and genetic algorithm was established. The experimental results showed that, when welding defects are caused by a sudden perturbation during welding, the amplitude of the temperature signal near the tool rotation frequency will change significantly. When improper process parameters are used, the frequency band component of the temperature signal in the range of 0~11 Hz increases significantly, and the statistical mean value of the temperature signal will also be different. The accuracy of the prediction model reached 90.6%, and the AUC value was 0.939, which reflects the good prediction ability of the model.

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