On the field variables influence on bonding phenomena during FSW processes: experimental and numerical study

Solid state bonding recurs in several manufacturing processes, as Friction Stir Welding(FSW), Linear Friction Welding (LFW), extrusion of hollow profiles and Accumulative RollBonding (ARB). The former processes are nowadays of particular industrial interest because of thespecific advantages with respect to the classic welding technologies. In FSW the solid state bondingis obtained between an undeformed “cold” material, already placed in the advancing side of thejoint, and the “hot” material flow incoming from the retreating side. Proper conditions of pressure,temperature, strain and strain rate are needed in order to get the final effective bonding. In the paperexperimental tests on butt joints made out of AA6061-T6 aluminum alloys are used to identify thesets of process parameters resulting either in sound or poor joints. The same process conditions havebeen simulated used an already developed model in order to highlight the actual bonding line andthe values of the main field variables determining the soundness of the joints. Finally a correlationbetween process parameters values, field variables values and joint effectiveness is made.