Investigation on thermo-mechanical performances of friction stir welding of aluminum alloys (AA6063)

Abstract

In this experimental study, aluminum alloy AA6063 plates are welded with a D2 steel tool shoulder and an HSS tool pin. Three-pin profiles were used to examine the optimum material flow, and three-pin lengths were utilized to determine the best pin length for joining a 6 mm plate. The four parameters, namely rotating tool speed, transverse tool speed, pin length, and pin profile, were analyzed to obtain the optimal bending, elongation%, and ultimate tensile strength (UTS). Mechanical parameters, such as UTS and elongation percentage are evaluated between heat-treated and non-heat-treated joints. It was observed that the cylindrical and threaded pins generated defect-free welding throughout the process. The finding initially produced voids due to excessive material loss upon entering the plate but later had defect-free welding. The temperature during welding is measured at eight separate sites (four on the advancing side and four on the retreating side) using a data logger to compare heat generation in different welding situations. The effect of the annealing process on the UTS (1.97%) and the elongation percentage (40.85%) have been examined for improved weld quality. The scanning electron microscopy (SEM) results revealed that the heat-treated sample possessed superior mechanical strength and a fine surface.

Keywords:

• Aluminum alloy
• friction stir welding
• UTS
• temperature analysis

Acknowledgements

The authors are very thankful to the National Institute of Technical Teachers Training and Research, Kolkata-700106, India, for the experimental setup used in this research work.

Disclosure statement

The authors declared no potential conflicts of interest.