Patent ID: 7997473

Claim:
A method of friction welding comprising: providing a first workpiece having a first weld surface and a second workpiece having a second weld surface; arranging the first workpiece such that in a first region adjacent the first weld surface the first workpiece is arranged at an angle of substantially 90° to the first weld surface; arranging the first workpiece such that in a second region adjacent to the first region the first workpiece tapers away from the first weld surface, the first workpiece converging in a direction away from the first weld surface in the second region; arranging the first workpiece such that in the second region the first workpiece is arranged at an angle greater than 90° and less than 180° to the first weld surface; arranging the second workpiece such that in a first region adjacent the second weld surface the second workpiece is arranged at an angle of substantially 90° to the second weld surface; arranging the second workpiece such that in a second region adjacent to the first region the second workpiece tapers away from the second weld surface, the second workpiece converging in a direction away from the second weld surface in the second region; arranging the second workpiece such that in the second region the second workpiece is arranged at an angle greater than 90° and less than 180° to the second weld surface; positioning the first and second workpieces such that the first weld surface of the first workpiece abuts the second weld surface of the second workpiece; moving the first and second workpieces relative to each other such that at least one of the weld surfaces of at least one of the workpieces moves relative to the other weld surface of the other workpiece such that the temperature increases at the weld surfaces to create a weld interface; and stopping the movement and allowing the first and second workpieces to cool to weld the first and second workpieces together.