On the joining of steel and aluminium by means of a new friction melt bonding process

A new lap welding process for dissimilar materials has been developed and tested for steel-to-aluminium joints. A simple cylindrical tool is rotated and translated over the top steel plate, leading to a transient partial melting of the bottom aluminium plate and the formation of intermetallic reaction layers of FeAl3 and Fe2Al5 as thin as 2.5 μm. Lap shear tests of the welds show very good resistance with fracture mostly in the base materials.