Abstract: A method is disclosed for controlling a process in which a component 4 is moved relative to another component 6 such that at least one of the components 4, 6 experiences a reduction in magnitude in at least one dimension. Such processes may include for example friction welding. The method comprises monitoring energy input to the process and adjusting an input parameter for the process based on the monitored energy input. The monitoring of energy input is performed before any reduction in component magnitude has begun to take place.

Abstract: A method is disclosed for controlling a process in which a component 4 is moved relative to another component 6 such that at least one of the components 4, 6 experiences a reduction in magnitude in at least one dimension. Such processes may include for example friction welding. The method comprises monitoring energy input to the process and adjusting an input parameter for the process based on the monitored energy input. The monitoring of energy input is performed before any reduction in component magnitude has begun to take place.

Abstract: A method of friction welding comprising providing a first workpiece (24) having a first weld surface (38) and a second workpiece (26) having a second weld surface (40). In a first region (42) adjacent the first weld surface (38) the first workpiece (24) is arranged at an angle (?) of substantially 90° to the first weld surface (38) and in a second region (44) adjacent to the first region (42) the first workpiece (24) tapers away from the first weld surface (38). The first workpiece (24) is arranged such that in the second region (44) the first workpiece (24) is arranged at an angle (?) greater than 90° and less than 180° to the first weld surface (38). The first and second workpieces (24, 26) are arranged such that first weld surface (38) of the first workpiece (24) abuts the second weld surface (40) of the second workpiece (26).

Abstract: A method of friction welding comprising providing a first workpiece (24) having a first weld surface (38) and a second workpiece (26) having a second weld surface (40). In a first region (42) adjacent the first weld surface (38) the first workpiece (24) is arranged at an angle (?) of substantially 90° to the first weld surface (38) and in a second region (44) adjacent to the first region (42) the first workpiece (24) tapers away from the first weld surface (38). The first workpiece (24) is arranged such that in the second region (44) the first workpiece (24) is arranged at an angle (?) greater than 90° and less than 180° to the first weld surface (38). The first and second workpieces (24, 26) are arranged such that first weld surface (38) of the first workpiece (24) abuts the second weld surface (40) of the second workpiece (26).