Analysis and Comparison of Friction Stir Welding and Laser Assisted Friction Stir Welding of Aluminum Alloy

Abstract

Friction Stir Welding (FSW) is a solid-state joining process; i.e., no melting occurs. The welding process is promoted by the rotation and translation of an axis-symmetric non-consumable tool along the weld centerline. Thus, the FSW process is performed at much lower temperatures than conventional fusion welding, nevertheless it has some disadvantages. Laser Assisted Friction Stir Welding (LAFSW) is a combination in which the FSW is the dominant welding process and the laser pre-heats the weld. In this work FSW and LAFSW tests were conducted on 6 mm thick 5754H111 aluminum alloy plates in butt joint configuration. LAFSW is studied firstly to demonstrate the weldability of aluminum alloy using that technique. Secondly, process parameters, such as laser power and temperature gradient are investigated in order to evaluate changes in microstructure, micro-hardness, residual stress, and tensile properties. Once the possibility to achieve sound weld using LAFSW is demonstrated, it will be possible to explore the benefits for tool wear, higher welding speeds, and lower clamping force.

Use of High-Power Diode Laser Arrays for Pre- and Post-Weld Heating during Friction Stir Welding of Steels

“…These methods are often referred to as hybrid FSW techniques and include: electrically assisted FSW [6], vibration assisted FSW [7], conduction assisted FSW [8], gas tungsten arc assisted FSW [9][10][11], ultrasonic assisted FSW [12], high frequency induction assisted FSW [13], plasma assisted FSW [14], and laser assisted friction stir welding (LAFSW) [15][16][17][18][19][20][21]. Several of these methods (electrically assisted, vibration assisted, conduction assisted, and ultrasonic assisted) require an additional physical contact with the workpiece and rely on transfer of energy through the workpiece to the weld area.…”

Analysis of Thermo-Elastic Fracture Problem during Aluminium Alloy MIG Welding Using the Extended Finite Element Method

“…The effective heating radius of the Gauss heat source is determined by an infrared thermal imaging temperature measurement experiment [9,19]. The appropriate radius is 4.0 mm corresponding to the welding parameters of I = 160 A, voltage U = 20 V and speed v = 2 mm/s.…”

“…In order to validate the effectiveness of the proposed method, the real-time temperature curve of the weldment surface is measured by the infrared thermal imager in the welding experiment [9,19], which is shown in Figure 9. In order to validate the effectiveness of the proposed method, the real-time temperature curve of the weldment surface is measured by the infrared thermal imager in the welding experiment [9,21], which is shown in Figure 9.…”

“…The enriched FE approximation of the displacement (19) and temperature (20) can be symbolically written in the following form.…”

“…The effective heating radius of the Gauss heat source is determined by an infrared thermal imaging temperature measurement experiment [9,19] …”