Effect of the gap width in AZ31 magnesium alloy joints obtained by friction stir welding

Thin AZ31 magnesium alloy sheets, i.e., 2 mm thick, are welded by Friction Stir Welding (FSW) in butt joint configuration using gap width up to 1.15 mm. All welds present good surface finishing and no internal defects, except for the weld produced maximum width. A reduction of thickness within Zone is seen with increase width, leading a 8.5%. Microstructure Vickers hardness investigations reveal influence on these properties. Up 0.51 mm, slight decrease Ultimate Tensile Strength (UTS) observed increasing For larger widths, UTS, as well fracture strain, constant. To keep metallurgical integrity, 1 seems acceptable joints thin sheets FSW.