Multi-objective Optimization of FSW Process Parameters of Aluminium Alloy Using Taguchi-Based Grey Relational Analysis

The advantages of friction stir welding (FSW) of aluminium alloys have promoted research in the area of FSW of aluminium. The recent developments in FSW are focused on optimisation of process parameters for multi-response characteristics. Experiments were conducted using the tool shoulder diameter, rotational speed, welding speed and the axial load as typical process parameters for multi-objective optimisation in FSW of AA 8011. The grey analysis was adopted to obtain grey relational grade for FSW process with multiple-characteristics, namely, tensile strength, microhardness and power consumption. Analysis of variance was used to study significance of process variables on grey relational grade which showed rotational speed and welding speed to be most significant parameters. Other than rotational speed and welding speed, tool shoulder diameter and axial load were also found to be significant. To validate the study, confirmation experiments were carried out at optimum set of parameters and predicted results were found to be in good agreement with experimental findings.