A linear friction welding system in one embodiment includes a welding control system operably connected to a hydraulic press and a ram, the welding control system including a processing circuit operably connected to a memory and configured to execute program instructions stored in the memory to bring a shaped charge portion of a first component to be welded into contact with a second component to be welded, and establish an initial scrub load pressure between the two components based upon a ratio between initial surface area of a contact initiation portion of the shaped charge portion and a final surface area of the first component. The processing circuit increases pressure between the components from the initial scrub load pressure to a target scrub load pressure before terminating oscillation of the ram and establishing or maintaining a weld load pressure.

Systems and methods for calculating efficiency of a rotary friction welding process are described herein. An example method can include measuring kinetic energy transferred from a welding machine to an interface of a welded joint, and calculating an efficiency of a rotary friction welding process based on the measured kinetic energy. For example, a workpiece torque experienced by a sample can be measured, and an energy associated with the workpiece torque can be calculated. The efficiency of the rotary friction welding process can then be calculated using the energy associated with the workpiece torque.

A brake disc to be mounted on an axle hub, including sliding surfaces with which friction members respectively come into a sliding contact and which face in mutually opposite directions, wherein the brake disc includes: a first member having a disc-like shape and including a mount portion through which the brake disc is mounted on an axle hub and a radially outer portion located radially outward of the mount portion, one of the sliding surfaces being formed on the radially outer portion; and a second member having a doughnut plate shape, the other of the sliding surfaces being formed on the second member, and wherein the first member and the second member are bonded through a protruding portion formed on one of the radially outer portion of the first member and the second member and protruding toward the other of the radially outer portion and the second member.

A linear friction welding machine comprising a compression unit and an oscillator unit, each having a clamping holder for a workpiece. Both clamping holders are configured such that workpieces are held with the surfaces thereof to be welded, aligned and facing each other. The clamping holder of the compression unit is linearly movable relative to the clamping holder of the oscillator unit, and the latter is movable in an oscillating manner at right angles transversely with respect to the direction of travel of the compression unit and fixed to ends of vertical and horizontal supports which can be deflected laterally in a sprung manner in the oscillation direction, the other ends of which are anchored rigidly on supporting bodies. The supports are flexible under deflection in the oscillation direction but are designed to resist buckling when the clamping holders are loaded in the direction of travel of the compression unit.

An apparatus for forming a friction weld, the apparatus comprising: a support arrangement; a holding member, which is supported by the supporting arrangement, and which may be driven to rotate with respect thereto, or move with respect thereto along an arcuate path; a consumable element having a first joining face, the consumable element being mounted in a mounting location on the holding member so that the first joining face is exposed, wherein the consumable element is rotatable with respect to the holding member about a first centre of rotation, and wherein when the holding member is driven to rotate or move with respect to the support arrangement, the first centre of rotation travels in an orbital motion with respect to the support arrangement; and at least a first alignment arrangement, positioned to hold a first workpiece in place so that an attachment face of the first workpiece is aligned with the first joining face of the consumable element.

A linear friction welding system in one embodiment includes a welding control system operably connected to a hydraulic press and a ram, the welding control system including a processing circuit operably connected to a memory and configured to execute program instructions stored in the memory to bring a shaped charge portion of a first component to be welded into contact with a second component to be welded, and establish an initial scrub load pressure between the two components based upon a ratio between initial surface area of a contact initiation portion of the shaped charge portion and a final surface area of the first component. The processing circuit increases pressure between the components from the initial scrub load pressure to a target scrub load pressure before terminating oscillation of the ram and establishing or maintaining a weld load pressure.

A pressure welding method and a pressure welding device (1) are provided. The pressure welding device (1) includes a plastification device (7), an upsetting device (8) and component mountings (34,35,36,37) for the components (2,3,3,4) to be welded together and a machine frame (12). The pressure welding device (1) further includes a plurality of machine heads (13,14), each having a component mount (34,35), which machine heads are movably arranged on the machine frame and are connected to respective upsetting drives (22). The machine heads (13,14) and respective upsetting drives (22) can be independently driven. An upsetting head or support head (27), which is preferably secured on the frame, is arranged between the machine heads (13,14).

The present invention provides a friction welding method capable of reducing the welding temperature and a friction welding method capable of obtaining a welded portion free of defects regardless the type of material. A frictional welding method in which one member is brought into contact with the other member and slides while a load is applied substantially perpendicularly to the interface to be welded, the frictional welding method comprising: a first step in which frictional welding is carried out by setting a pressure calculated from the area and the load of the interface to be welded to be equal to or higher than the yield stress and the tensile strength of one member and/or the other member at a desired welding temperature; and a second step in which frictional welding is carried out by lowering the load, wherein the first step and the second step are continuously carried out.

A friction welding method includes: applying axial force to first and second metallic components so as to force the components against each other at an interface therebetween, while oscillating the two components relative to each other in a cyclic motion, so as to generate friction and heat at the interface; rapidly stopping the cyclic motion; and applying a spike in the axial force to complete a weld between the first and second components.

The present disclosure provides a linear friction joining device which includes: a pressing device for pressing a second member onto a first member in a pressing direction; a vibrator for relatively vibrating the first member and the second member; a controller which is configured to bring the second member into contact with the first member by a position control, which depends on a measurement result of position sensors, to change the position control to a load control, which depends on a measurement result of load sensors, and to increase a pressing load toward a joining load; and a joining load reaching time adjuster which is configured to adjust a length of a joining load reaching time which is between the time when the position control is changed to the load control and the time when the pressing load reaches the joining load.