Effect of Cooling on Mechanical Properties and Residual Stresses in Aluminium AA2017 Friction Stir Welds

Abstract

Friction stir welding (FSW) is a relatively new joining technique particularly for aluminium alloys that are difficult to fusion weld. The most common applications are aircraft structures where the cost and weight can be reduced by using new joining techniques instead of riveting.The paper has investigated the effect of cooling on the distribution of residual stresses in friction stir welding of AA2017 aluminium alloy. An attempt has been made to examines the possibility to modify the residual stress state in the joint by applying cooling fluid during FSW processes. The results show that the magnitude of the tensile stress can be reduced significantly in the weld region and we can produce compressive stresses which can be beneficial e.g. for reducing crack propagation speed.