Erik Tolf

Abstract

In this study the feasibility of Friction Stir Spot Welding (FSSW) of 1.5 mm zinc coated DP600 thin sheet steel was investigated. A high temperature wear resistant tool made of polycrystalline cubic boron nitride was used for the trials. Static tensile testing and metallographical examinations of the joints were performed and compared to joints welded by resistance spotwelding. As a consequence of the smaller bonding area of the FSSW joints, the cross- and shear-tensile strengths were approximately 50% of the resistance spot weld strengths. Chemical analysis using a Field Emission gun SEM equipped with an Xray detector revealed that a small amount of zinc from the sheet coating was present close the bonding area. This report covers the steel part of a project concerning FSSW of C-Mn thin sheet steel and aluminium alloys. In the second part, are FSSW of 6063 and 5754 aluminium reported.