Hybrid metal extrusion and bonding

In this chapter, a new and novel solid-state joining method for metals and alloys is presented, where the best features of gas metal arc welding, friction stir welding and cold pressure welding are combined. The invention, which is known as the Hybrid Metal Extrusion & Bonding (HYB) process, utilizes continuous extrusion as a technique to squeeze the aluminium filler material into the groove between the two plates to be joined under high pressure to achieve metallic bonding. The PinPoint extruder is the core of the HYB technology. This is because the different tool parts constituting the extruder head are both interchangeable and replaceable so that their geometry can be tailor-made to handle a wide range of different applications, ranging from butt, lap, slot, fillet and multi-pass welding to plate surfacing and additive manufacturing. Originally, the idea was to use the HYB process only for welding of aluminium alloys. But over the years the method has evolved into a multi-material joining process capable of handling a wide range of base metal combinations (Al, Fe, Ti and Cu). At present, up to four different metals can be joined together in one pass using the HYB PinPoint extruder and AA6082 as filler wire. In the future the advantages of customising the filler wire composition for specific welding applications will be further explored.