Effect of tool rotational speed on residual stress, microstructure, and tensile properties of friction stir welded 6061-T6 aluminum alloy thick plate

In friction stir welding of heat treatable aluminum alloys, the thermal cycles developed during the joining process result in softening of the joints which adversely affect their mechanical properties. Underwater friction stir welding can be a process of choice to overcome this problem due to low peak temperature and short dwell time involved during the process. Consequently, this article presents a study pertaining to the underwater friction stir welding of aluminum alloy 6082-T6 with an aim to develop a mathematical model to optimize the underwater friction stir welding process parameters for obtaining maximum tensile strength. The results of the study reveal that the tool shoulder diameter (d), tool rotational speed (ω), welding speed (v), and second-order term of rotational speed, that is, ω2, significantly affect the tensile strength of the joint. The maximum tensile strength of 241 MPa which is indeed 79% of the base metal strength and 10.7% higher than that of conventional (air) friction stir welding joint was achieved at an optimal setting of the underwater friction stir welding parameters, that is, tool rotational speed of 900 r/min, the welding speed of 80 mm/min, and a tool shoulder of 17 mm. The article also presents the results of temperature variation, the macrostructural and microstructural investigations, microhardness, and fractography of the joint obtained at the optimal setting for underwater friction stir welded (UFSWed) joint.

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Correlative Analysis Between Tensile Properties and Tool Rotational Speeds of Friction Stir Welded Similar Aluminium Alloy Joints

International Journal of Surface Engineering and Interdisciplinary Materials Science ◽

10.4018/ijseims.2021070104 ◽

2021 ◽

Vol 9 (2) ◽

pp. 58-78

Author(s):

Velaphi Msomi ◽

Busiswa Tracey Jantjies

Keyword(s):

Friction Stir Welding ◽

Tensile Properties ◽

Rotational Speed ◽

Critical Parameter ◽

Welding Parameters ◽

Tool Rotational Speed ◽

Friction Stir ◽

Correlative Analysis ◽

Fsw Parameters ◽

The Impact

Friction stir welding (FSW) is considered as the new joining technique which does not involve fumes like any traditional joining techniques. The attainment of good weld depends on proper combination of FSW parameters, and this combination varies with the materials that are being welded. The tool rotational speed is known as the most critical parameter towards the generation of heat required to produce the weld in friction stir welding. This parameter plays an important role in restructuring the stir zone. The variation of this parameter may yield certain results which are dependent on the type of materials being welded. This paper reports on the impact of the rotational speed variation on the tensile properties of AA6082-T6 joints. The rotational speed was varied while keeping all the other welding parameters constant. The analysis was performed comparatively on the specimens that were sampled from different locations of the joint. The joints produced through the rotational speed of 600 rpm showed good tensile properties compared to joints produced through other rotational speeds.

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FRICTION STIR WELDING OF NYLON -6: EFFECT OF PROCESS PARAMETERS ON MECHANICAL AND MICROSTRUCTURAL PROPERTIES

Jurnal Teknologi ◽

10.11113/jt.v79.10210 ◽

2017 ◽

Vol 79 (6) ◽

Cited By ~ 1

Author(s):

N. Ethiraj ◽

T. Sivabalan ◽

C. Vijaya Raghavan ◽

Shubham Mourya

Keyword(s):

Friction Stir Welding ◽

Tensile Properties ◽

Process Parameters ◽

Welded Joints ◽

Rotational Speed ◽

Nylon 6 ◽

Microstructural Properties ◽

Tool Rotational Speed ◽

Friction Stir ◽

Mechanical And Microstructural Properties

Friction stir welding (FSW) is solid state joining process with more advantages than that of fusion welding. Nylon -6 is one of the engineering plastics used widely in various industrial applications. The main aim of this research work is to investigate the effect of tool rotational speed and tool traversing speed on the mechanical and microstructural properties of the nylon-6 butt welded joints made by FSW. The FSW process was performed in a computer numerically controlled (CNC) vertical milling machine using a cylindrical tool with threaded pin made of heat treated high carbon high chromium (HCHCr) steel. The tensile testing and microscopic examinations were carried out to study the mechanical and microstructural properties of the welded joints. In visual inspection, it is observed that the excessive flashes are observed on either sides of the weld line in all cases. From the results, it is observed that the maximum tensile properties are achieved in a joint made which is approximately 18% and 26% of the parent material’s ultimate tensile strength (UTS) and yield strength (YS) respectively with the tool rotational speed 1200 rpm and the tool traversing speed of 30 mm/min within the experimented process parameters. Overall, the tensile properties of the welded joints made using the experimented process parameters are very much lower than the parent material.

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