Eva Sjöström

Abstract

The idea of hybrid FSW is to reduce the stresses of the tool which can be used to improve the productivity or to increase the range of applications. Various possibilities to combine conventional FSW with an adjacent heat source are reported in the literature. FSW in combination with laser, ultrasonic vibrations, resistance heating and plasma arc heating is reviewed in this work.

Advantages such as increased productivity, reduced tool wear and improved weldability have been reported. Benefits with hybrid FSW have been described for applications where conventional FSW is used limitedly such as welding of materials with high melting point or for joining of dissimilar material combinations.

The complexity of the equipment for hybrid FSW and the interaction between process parameters increase considerably.

Heat sources integrated with the FSW tool are far more complex as compared to the use of external heat sources. External heating is also beneficial for dissimilar material combinations since the heat can be applied individually to one of the parts being joined together.

A majority of the literature reviewed concern hybrid process realization. Potential benefits with hybrid FSW needs to be further explored for specific applications. Also the interaction between the extra heat input and the FSW process parameters needs further optimization.

It is believed that hybrid FSW concepts should have potential to open up new application areas. Also hybrid FSW should facilitate robotization since the heavy work load and the related robot stiffness requirements may be reduced by the extra heat input.