Effect of Plunging and Dwelling Period on Temperature Profile and Energy Dissipation in FSSW and Its Relevance in FSW

FSW is the welding technique, where filler material for welding is not required resulting into no additional mass being added, which proves very useful in the industry where the addition of small material plays a significant difference on the performance of the working unit. Energy generation and its utilization during welding are crucial in understanding the physics behind the process and further extended to know the effect of process parameters on a way of effective welding to achieve sound weld. FSW experiments are costly as well as tedious where the requirement of the accurate plasticized stage should be reached so that the tool can travel flawlessly in traverse direction to achieve sound weld. Computational modelling and numerical simulation are the solution to the above problem. In this research paper, numerical simulation on FSSW is carried out first for better understanding of energy generation and its utilization at plunge and dwell stage before going further for next step in FSW that is traverse movement of the tool in the direction of the weld line. During the plunging stage, the friction causes the metal around the contiguity area to soften. It transforms the material into the plasticized stage during dwell stage, so the temperature profile obtained during those stages is validated with experimental results for the accuracy of the numerical model. Also, energy generation and its utilizations are confirmed with the experimental values for accurate validation of the numerical model. CEL approach is used for simulation of FSS welding of the aluminium sheet. Plunge speed and dwell time were chosen as different parameters. Simulation results showed that thermal response, along with energy history, varies with simulation parameters used in FSSW. To conclude, this numerical model can be effectively used to predict the FSW process for any other material.