Experimental and Numerical Analysis on Post Welding Formability of FSWed AZ31 Magnesium Alloy Thin Joints obtained using a “Pinless” Tool Configuration

The post welding formability of friction stir welded AZ31 magnesium alloy thin sheets (1.5 mm thick), obtained using a ???pinless??? tool configuration, was widely investigated by means of the hemispherical punch method at 350°C, with a constant crosshead speed of 0.1 mm/s. The results were compared with those obtained on the base material. It has shown that formability of the joints is lower than the one of the base material. The experimental work was supported by a numerical investigation based on FEM in order to highlight the material flow occurring during the welding process. Additionally, hemispherical punch tests were simulated starting from the calculated conditions, in terms of accumulated strain, derived from the simulation of the welding process. Good agreement was found between the experimental and the numerical results, both for the welding and post welding forming.