In aerospace applications, Friction Stir Welding (FSW) has emerged as a good choice for joining aluminum. This solid-state process relies on a rotating cylindrical tool to generate enough localized heat and pressure to create a continuous weld as the tool translates through the joint. In his paper at Great Designs In Steel, Tsung-Yu Pan and co-authors from two of our national laboratories detailed a FSW variant that shows promise for AHSS. Friction Stir Spot Welding (FSSW) creates spot welds rather than a linear weld line. It has successfully been in production on aluminum components since 2003. Pan's presentation shows that it may be a good fit for AHSS too. Studies on an increasingly popular AHSS, DP 780, showed that the FSSW produced spot welds with 8-12 kN strengths, comparable with JIS standards. The bonding region showed similar microstructure and hardness to the base material. And all this comes without any attempt to optimize the materials or process.
Download Pan's presentation