Damping behaviour of submerged friction stir welded AA6061-T6 alloy with addition of brass interlayer

The effect of brass interlayer and water cooling on the damping behavior of friction stir welded AA6061 was investigated in the present work. The results revealed that weld samples showed better damping capacity than base metal attributed to the grain refinement. Moreover, the damping capacity of weld with the addition of interlayer is enhanced due to more grain refinement, formation of hard intermetallics, and high inherent damping capacity of brass. The reduced intermetallics and formation of smooth interface obtained for water-cooled weld attributed to the faster cooling rate improved the mobility of grain boundaries which enhanced the damping capacity than natural cooling. The water-cooled weld with interlayer showed better damping at high temperatures than other weld joints due to the increased grain boundary area.