摘要：Abstract Friction stir welding (FSW) is a promising welding process that can join age hardenable aluminium alloys with high joint efficiency. However, the thermal cycles experienced by the material to be joined during {FSW} resulted in the deterioration of mechanical properties due to the coarsening and dissolution of strengthening precipitates in the thermo-mechanical affected zone (TMAZ) and heat affected zone (HAZ). Under water friction stir welding (UWFSW) is a variant of {FSW} process which can maintain low heat input as well as constant heat input along the weld line. The heat conduction and dissipation during {UWFSW} controls the width of {TMAZ} and {HAZ} and also improves the joint properties. In this investigation, an attempt has been made to evaluate the mechanical properties and microstructural characteristics of AA2519-T87 aluminium alloy joints made by {FSW} and {UWFSW} processes. Finite element analysis has been used to estimate the temperature distribution and width of {TMAZ} region in both the joints and the results have been compared with experimental results and subsequently correlated with mechanical properties.
