Mechanical and Microstructural Evolution of Friction Stir Welded Joint of AA2014 Alloys

The solidification cracking phenomenon restricts the use of fusion welding process to join aluminum and its alloy. Friction stir welding (FSW) process can be used in joining of aluminium alloys which is not or less susceptible to form welded voids, induced distortions, solidification cracking. In the present work an investigation of mechanical and microstructural changes after FSW is presented during the similar joining of AA2014 aluminium alloys. The influences of tool geometry during FSW is analysed and compared among the joint made by triangular, pedal and pentagonal pin. Based on the obtained mechanical properties of the joint metallurgical investigation is performed. Optical micrographs are used to reveal the phases present in the fusion zone. EBSD investigation of the selected sample is done to analyse the mis-orientaion angle and grain size etc. Pedal pin profile tool exhibit better mechanical properties in comparison to pentagonal pin and triangular pin. Obtained ultimate tensile strength and percentage elongation are 345MPa and 13.5 % respectively. Micro-hardness and impact energy are obtained as 125HV0.2 and 4.6 J of F_pedalsample. Obtained joint efficiency of Fpedal sample is 74%, which is higher among joint efficiency of Fpentagonal and Ftringular samples.