Joining of hot-dip coated steel sheets by mechanical clinching

The joinability of hot-dip coated steel sheets using a mechanical clinching was investigated by an experiment. The distributions of the layer thickness of Zn alloy coating of the joined sheets were examined. Although the sheets were joined, the layer of coating on the side wall of the punch was scratched and the layer thickness on the bottom of the die was reduced. In order to increase the layer thickness of coating of the joined sheets, shapes of the punch and die were optimised by controlling of the deforming behaviours of the sheets using means of the finite element simulation. The layer thickness of coating of the joined sheets was improved by the modification of the punch and die shapes.