Numerical Modelling of Laser Material Deposition Method of AA1100 Billet for In-Situ Repair of an Exit Hole in Friction Stir Welding

The Friction stir welding process has found immense use in many industrial sectors like ship building, railways, automotive and so on. The advantages of this process over other conventional welding processes have made this process to grow faster compared to many other processes. The use of this process is extensive, however, is limited by one of the major limitations. This welding process results in end hole at the end of the joining path. This restricts the joined material use and brings aesthetic challenges to the product. This hole if present in the job may also work as a point of failure due to stress accumulation under various applications. Usually, this hole is trimmed off from the parent material that result in material loss and disintegration of the joining line. Thus, it would have been interesting to have techniques developed for filling up this hole without disturbing the joining characteristics. The goal of the current effort is to identify the ideal range of laser heating parameters for fusing a billet to an exit hole. A three-dimensional (3D) axis-symmetric model was developed in order to perform a numerical analysis in order to analyse the impact of laser heating process factors on the thermal behaviour of aluminium alloy AA1100.In accordance with the temperature distribution and thermal stress of the material, the optimal parameters were ascertained by adjusting process factors such as laser power, scanning speed and beam spot radius. The parameters opting for from the computational investigation to effectively repair the exit hole were the pancake coil format, 1 mm/s scanning speed, 80 W to 200 W laser power range and a 0.25 mm beam spot radius. The findings show that a sound joint may be achieved between the billet and exit hole surface under laser material deposition method using laser power of 90 W, 100 W, 110 W and 200 W for 1mm, 2 mm, 3 mm and 4 mm billet height. This study will bring the FSW process to a new level of acceptance among different application based industrial uses.