Influence of Process Parameters on the Vertical Forces Generated during Friction Stir Welding of AA6082-T6 and on the Mechanical Properties of the Joints

Abstract

Abstract:The influence of the process parameters on the vertical force generated during friction stir welding of AA6082-T6 aluminium alloy sheet blanks was studied by performing experiments with constant values of the rotational speed, varying between 1200 and 2500 rpm, and welding speed, ranging between 30 and 100 mm/min. The effect of the tool dwelling was also analysed. The force vs. processing time curve has shown a very complex behaviour during the lowering motion of the pin tool related to the occurrence of both primary and secondary plunging. The tool dwelling produces a quick decrease in the vertical force with growing processing time until reaching a constant value. It was also seen that the tool dwelling does not influence the vertical force in the subsequent stage. As the tool began its welding motion, the vertical force immediately gets to a constant value until tool pulling out takes place. Furthermore, it was shown that the growth in the welding speed and the decrease in the rotational speed lead to an increase in the vertical force. The mechanical properties of the joints were evaluated versus the process parameters and the relationships among the ultimate tensile strength and ultimate elongation and the vertical force were defined. Finally, the microstructure developed during the friction stir welding was investigated and related to the mechanical properties of the joints.

A Study on Microstructure and Mechanical Properties of Micro Friction Stir Welded Ultra-Thin Al-1060 Sheets by the Shoulderless Tool

“…Papahn et al designed and developed a novel fixture for simultaneously measuring axial and transverse forces during friction stir welding process [18]. There are still many researchers who have carried out this measurement work, making significant contributions to understanding the impact of process parameters on the microstructure and mechanical properties of the joint [19][20][21][22][23][24][25][26][27].…”

High-Speed Deformation of Pinless FSWed Thin Sheets in AA6082 Alloy

“…FSW allows for joining blanks without exceeding the melting temperature of workpiece material. The frictional heat developed between tool and workpieces along with that generated by the stirring action of the tool and the adiabatic heating promote a strong plastic deformation of the workpieces and their complex mixing across the weld [5,6].…”

“…Currently, most of researches are focused on the evaluation of the performances of FSWed blanks under quasi-static loading condition. In particular, Casalino et al studied the influence of process parameters on the mechanical properties of FSWed joints in AA6082-T6 and the relationships among the ultimate tensile strength, ultimate elongation and vertical force applied during process [6]. Furthermore, Casalino et al investigated the mechanical properties and formability of FSWed joints in AA5754-H114 after cold rolling performed in order to remove the forging effect, due to the vertical force applied by the tool, in order to ensure a constant thickness of the welded blank [16].…”

Recent Achievements in Rotary, Linear and Friction Stir Welding of Metals Alloys

“…In more detail, the contributions have concerned the following topics.The effect of cold rolling performed after friction stir welding (FSW) on the mechanical properties and formability of joints in AA5754-H114 aluminum alloy [1].The microstructure evolution of the welded joints of AA6082-T6 obtained using the bobbin friction stir welding process with a focus on grain refinement [2].The characteristic features of the entry and exit defects in the weld structure and formation mechanism of them during the BFSW process. The issue was investigated using stacked layers of multi-colored plasticine for the material flow detection [3].The thermo-structural analysis of material behavior, material flow, and defect generation during the friction stir butt-welding of 5083-O sheets [4].The characterization of the dissimilar friction stir weld of Ti-6242 S and Ti-54M in terms of microstructure, microhardness, fracture morphology, and material migrating from the retreating (RET) side to the advancing (ADV) one [5].The characterization of the interface of friction stir lap welding joints of 6082-T6 aluminum alloy and Q235A steel [6].The investigation of the microstructure evolution and properties response of a friction-stir-welded copper-chromium-zirconium alloy [7].The study of the influence of the process parameters on the vertical force generated during friction stir welding of AA6082-T6 aluminum alloy sheet blanks [8].The role of mechanical connection in friction stir keyholeless spot welding of AZ31B Mg alloy, Mg99.50, DP600, and non-zinc-coated DP600 lap welding [9].The application of a fully coupled thermo-mechanical model together with an enhanced friction law for the simulation of an FSW process with a cylindrical threaded pin tool [10].The identification of the chemical composition of etchant reagents for metallographic examination of the friction-stir welded A6082-T6 alloy [11].The study of an advanced meshfree computational framework to be used for the determination of optimal process parameters for the friction stir welding of an AA6061-T6 butt joint [12].The numerical modeling approach to the study of the linear friction welding of 30CrNiMo8 high strength steel Hero chain [13].…”

“…The study of the influence of the process parameters on the vertical force generated during friction stir welding of AA6082-T6 aluminum alloy sheet blanks [8].…”