Comparative Analysis of Non-Uniformity of Mechanical Properties of Welded Joints of Al – Mg – Si Alloys During Friction Stir Welding and Laser Welding

Abstract

The properties of the welded joints of 6082-T6 alloy produced by friction stir welding (FSW) and laser welding (LW) were studied. The maximum temperature and microhardness fields in the friction stir-welded joints were shown to be asymmetrical. The concentrated energy input during laser welding yields a narrow heat-affected zone (HAZ) with sharp changes in mechanical properties. The strength of the FSW joint constitutes 72% and that of the LWjoint—67% of the base metal strength. In case of LW, the minimum hardness of the joint corresponds to the metal of the welded joint, while in case of FSW, it corresponds to the heat-affected zone. At the same maximum heating temperature, the hardness of the heat-affected zone of the friction stir-welded joint is lower compared to laser welding due to substantially lower rates of heating and cooling.