Solid state spot joining of sheet materials using consumable bit

Abstract

A new spot joining technology relying on a consumable joining bit has been developed and evaluated on dual phase (DP) 980 steel and a dissimilar combination of aluminium alloy 5754-O and DP 980. This new process, called friction bit joining (FBJ), uses a consumable bit to create a solid state joint in sheet materials by the action of cutting and frictional bonding. FBJ lap shear fracture loads were 14˙7 kN for 1˙4 mm DP 980 compared to 16˙6 kN for RSW, for the same spot diameters. FBJ of a dissimilar combination of aluminium alloy 5754-O and DP 980 produced joints with average lap shear fracture load of 6˙3 kN. This strength is greater than lap shear fracture load obtained by self-piercing riveting (SPR) in HSLA 350 bonded to AA 5754-O.

Keywords:

• SPOT JOINING
• UHSS
• ALUMINIUM