Friction stir welding(FSW) technology is widely used in welding aluminum alloy, magnesium alloy and copper alloy materials because of its lower residual stress and deformation, high strength of welded joints. It has a broad prospect in the fields of aerospace, transportation, shipbuilding, automobile and other industrial manufacturing fields. But friction stir welding technology is still limited by the lifetime of the stir tool in welding materials with high melting point. The tool pin undergoes serious she...