Erik Tolf

Abstract

In this project the influence of new tool designs on the FSSW joint properties was examined for 6063-T6 and 5754-H22 aluminium alloys. A study of the effect on the bonding zone was carried out for each of the four developed tools. The joints were evaluated by metallographical examinations and by static shear- and cross-tensile testing. Comparisons with specimens produced with conventional resistance spotwelding have been made. None of the developed tools managed to completely avoid zones with lack of bonding. The size and appearance of these zones was strongly tool specific.

The influence of the tool design on theweld strength was alloy specific. This was caused by insufficient oxide breaking for the 5754-H22 alloy decreasing the weld strength. The axial plunge force, tool rotation, plunge rate and plunge depth were recorded to provide information about the weld cycle time. This report covers the aluminium part of a project concerning FSSW of aluminium alloys and C-Mn thin sheet steel. In the second part of the project, the feasibility of FSSW in thin sheet steel is reported.