Lap Joints of 6061 Al Alloys by Friction Stir Welding

In this paper, the effect of water cooling on mechanical properties and microstructure of AA5086 aluminum joints during friction stir welding is investigated. For doing so, the mechanical and microstructural behavior of samples welded both in air and in water was analyzed. Tests were performed involving both butt and lap welds and the results were compared. The effect of rotational speed at constant feed rate of 50 mm/min and changing rotational speed ranging from 250 to 1250 r/min was investigated. The results showed a significant change in the tensile behavior of the butt-welded specimens due to water cooling. In addition, welding was performed at constant spindle speed of 800 r/min and various traverse speeds (25 mm/min to 80 mm/min) to determine the effect of feed rate. The strength increases at first, but then decreases dramatically along with the feed rate which is due to the occurrence of a groove defect. Results showed some generally positive impacts of water cooling which are discussed in terms of tensile results, hardness distributions and microstructure analysis.

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Friction stir welding of dissimilar Al alloys: effect of process parameters on mechanical properties

Engineering Solid Mechanics ◽

10.5267/j.esm.2016.2.001 ◽

2016 ◽

pp. 125-132 ◽

Cited By ~ 18

Author(s):

Jitender Kundu ◽

Hari Singh

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Process Parameters ◽

Al Alloys ◽

Friction Stir

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Effect of double-sided friction stir welding on the mechanical and microstructural characteristics of AA5754 aluminium alloy

Materials Testing ◽

10.1515/mt-2021-0009 ◽

2021 ◽

Vol 63 (9) ◽

pp. 829-835

Author(s):

Sare Çelik ◽

Fatmagül Tolun

Keyword(s):

Friction Stir Welding ◽

Al Alloys ◽

Fusion Welding ◽

Welding Parameters ◽

Al Alloy ◽

Test Results ◽

Feeding Rates ◽

Microstructural Characteristics ◽

Friction Stir ◽

Tool Tilt Angle

Abstract AA5754Al alloy is widely used in industry. However, as in the case of all Al alloys, the 5xxx series Al alloys cannot be easily joined through fusion welding techniques. To address this problem, in this study, the effect of double-sided friction stir welding at various tool rotational speeds (450, 710, and 900 rpm), feeding rates (40, 50, and 80 mm × min-1), and tool tilt angles (0°, 1°, 2°) on the welding parameters and mechanical and microstructural characteristics of AA5754 Al alloy was determined. Tensile strength tests and microhardness tests were performed to examine the mechanical properties of the welded specimens. The microstructures of the welded zone were examined by obtaining optical microscopy and scanning electron microscopy images. The tensile test results indicated that the specimens exhibited the highest welding performance of 95.17 % at a tool rotational speed, feed rate, and tool tilt angle of 450 rpm, 50 mm × min-1 and 1°, respectively.

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Friction Stir Welding Parameters: Impact of Abnormal Grain Growth during Post-Weld Heat Treatment on Mechanical Properties of Al–Mg–Si Welded Joints

Metals ◽

10.3390/met10121607 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1607

Author(s):

Amir Hossein Baghdadi ◽

Zainuddin Sajuri ◽

Mohd Zaidi Omar ◽

Armin Rajabi

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Friction Stir Welding ◽

Grain Growth ◽

Precipitation Hardening ◽

Al Alloys ◽

Abnormal Grain Growth ◽

Post Weld Heat Treatment ◽

Welding Parameters ◽

Friction Stir

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.

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