Friction stir welding of similar and dissimilar thin–gauge aluminum alloys was investigated. A variety of tools was designed for monitoring and optimizing the welding parameters. The principal welding parameters: Tool geometry, Rotating speed, Linear velocity and Temperature, where monitored for a variety of plate thicknesses. A further attempt to optimize the welding parameters and tool geometry has been carried out for welding dissimilar Aluminum alloys plate of thickness less then one millimeter.
The Microstructure of the dissimilar μFSW welds reveals a slightly different nugget morphology as compared to the well established FSW.   SEM and EDX were used to follow the welded metal morphology and chemistry, monitoring the Cu and the  Mg distribution of the dissimilar alloys weldment. 
By optimizing process parameters such as pin rotation speed and weld travel speed, the welding process developed sufficient heat to produce defect-free welds within the stir zone and minimize the softening effects in the adjacent TMAZ and HAZ.