Friction bonding process
An induction heater equipped with a high radio frequency
module is typically used to increase the workpiece
temperature for friction bonding process. The rate of heating
depends on the applied frequency, electric current, specific
heat of work material, magnetic permeability of work material
and electrical resistance of work material [7]. In order to bond
the hot metal sheets, a screw press machine can be used to
provide a mechanical force for enabling the bonding action
[8]. In this step, the bonding process can be done along with
the typical metal forming process, where a set of forming die
is setup inside the screw press machine. In addition, a spot
welding process can be applied before the step of friction
bonding process to enhance the bonding ability. Fig. 1 shows
the schematic of spot welding, induction heating and friction
bonding process in a typical sequence found in the most metal
forming industries.