Experimental study on the effect of welding speed and tool pin profiles on AA6082-O aluminium friction stir welded butt joints

Abstract

Friction stir welding (FSW) is a novel solid state welding process for joining metallic alloys and has emerged as an alternative technology used in high strength alloys that are difficult to join with conventional techniques. The applications of FSW process are found in several industries such as aerospace, rail, automotive and marine industries for joining aluminium, magnesium and copper alloys. The FSW process parameters such as rotational speed, welding speed, axial force and attack angle play vital roles in the analysis of weld quality. The aim of this research study is to investigate the effects of different welding speeds and tool pin profiles on the weld quality of AA6082-O aluminium. This material has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio. Tri-flutes and taper screw thread pin are used as tool pin profiles in this research. The appearance of the weld is well and no obvious defect is found using these tools. Consequently, the obtained results explain the variation of stress as a function of strain and the effect of different welding speed and pin profiles on yield strength ultimate tensile strength and elongation. The friction stir welded plates of AA6082-O by using the taper screw thread pin profile reaches the ultimate tensile strength of 92.30% of the base metal ultimate strength and % elongation of 27.58%.

Keywords: Friction stir welding, AA6082-O aluminium alloy, welding speed, mechanical properties