Department of Mechanical Engineering, Indian Institute of Technology (ISM) Dhanbad, Dhanbad-826 004, Jharkhand, India Department of Mechanical Engineering, Birla Institute of Technology, BIT Mesra, Ranchi-835 215, Jharkhand, India E-mail: bhabani.bora11@gmail.com Manuscript received online 10 July 2020, revised and accepted 31 October 2020 Friction Stir Welding (FSW) extends its advantages due to its low energy consumption, reduced material waste and no harm in regards to radiation and hazardous fumes. Also, FSW process does not require any alloying elements, arc and filler wire. This process comes under the category of ‘eco-friendly’ and ‘green’ process, because of its zero pollution, larger efficiency and high productivity. The objectives of this study are: a) to study the aluminium and copper alloy FSW joints, b) to conduct the experiments of aluminium and copper alloy FSW joints using ‘Full Factorial’ Design of Experiment (DOE), c) effects of process variables on power consumption during friction stir welding process. From this study, it can be concluded that FSW can be adopted across industries as it is an eco-friendly and more energy efficient over other fusion welding processes.