Friction welding is a method of welding by using the heat generated by friction between the contact surfaces of the workpieces as a heat source to produce plastic deformation of the workpieces under pressure.
Under pressure, is under the action of constant or incremental pressure and torque, the use of welding contact between the relative motion of the end face in the friction surface and the surrounding area to produce frictional heat and plastic deformation heat, so that the temperature of the area and its vicinity to close to the melting point of the temperature range but generally lower than the melting point of the material to reduce the resistance to deformation, plasticity, the interface of the oxide film is broken in the top of the forging pressure, accompanied by the material to produce Plastic deformation and flow, through the interface of the molecular diffusion and recrystallisation to achieve the welding of the solid state welding method.
Friction welding usually consists of the following four steps:
(1) Mechanical energy is converted into thermal energy;
(2) Plastic deformation of the material;
(3) Forging pressure under thermoplasticity;
(4) Intermolecular diffusion and recrystallisation.
