A method of forming an assembly in which a metal extension element is connected with a metal stub element, by an intermediate element. The intermediate element extends between first and second ends. The intermediate element is positioned to locate its first end spaced apart from the stub element. An inner end of the extension element is spaced apart from the second end of the intermediate element. Heating elements are located between the elements, to heat the proximal portions of the elements to a hot working temperature, at which the heated portions are subject to plastic deformation. The heating elements are removed, and while the intermediate element is rotating, the first end is urged against the stub element to bond the intermediate element with the stub element. While the extension element is rotating, the inner end is urged against the second end to bond the extension element and the intermediate element.

A manufacturing method for manufacturing a cylinder tube includes a joining step of joining a tube main body and a head member by friction welding by abutting an end surface of the tube main body and a flange portion of the head member in a state in which a through hole of the tube main body and a projecting portion of the head member are fitted to each other so as to form a predetermined clearance. In the joining step, a non-contact portion of the flange portion of the head member facing the clearance is joined to the tube main body by heating the non-contact portion with friction heat generated by relative rotation between the tube main body and the head member.

The invention concerns a method for joining a metal component and a polymer component, and a structure comprising said components. In the method, an extrusion die plate with a through hole is placed between the metal component and the polymer component. A probe is rotated and plunged across the thickness of the metal component and eventually through said through hole of the extrusion die plate, thereby extruding a part of the metal component through said through hole of the extrusion die plate into the polymer component. The probe has a rotation axis having an offset to the centre of the through hole during the rotating and plunging action.

A method for joining dissimilar materials is provided. The method includes a solid-state joining process in which a rivet is plunged into a predrilled hole in a top workpiece. When the rivet contacts the bottom workpiece, ultrasonic vibration by oscillatory motion of a sonotrode, such as horizontal, vertical, or rotational motion, creates frictional heat at the interface between the rivet and the lower workpiece. With the aid of frictional heat and axial compression, metallurgical bonding is achieved at the interface between the rivet and the bottom sheet, while being below the melting temperature of the bottom workpiece. The sonotrode is retracted while the rivet remains.

A non-weldable workpiece may be affixed to a weldable workpiece by friction stirring the weldable workpiece to plasticize and extrude at least a portion thereof into a recess in the non-weldable workpiece. The weldable workpiece may then be welded to a body of a downhole tool to enable the welding of a non-weldable workpiece onto a body to increase the wear-resistance of the body.

Methods and devices for controlling a mechanical joining or forming process, in particular friction drilling in thin-walled materials, apply several reverse pulses acting on a process parameter to bring the course of an actual curve of the parameter more into line with the course of a predetermined nominal curve of the process parameter. The number and length of the reverse pulses and the length of the intervals between the pulses are determined as a function of at least one immediately detectable variable associated with the process parameter.

A method and apparatus (20) provide light-safe heating of advanced high strength steel metallic sheet(s) (28 and/or 30) for securement of metallic sheets by flow fasteners (31).

The invention concerns a method for joining a metal component and a polymer component, and a structure comprising said components. In the method, an extrusion die plate with a through hole is placed between the metal component and the polymer component. A probe is rotated and plunged across the thickness of the metal component and eventually through said through hole of the extrusion die plate, thereby extruding a part of the metal component through said through hole of the extrusion die plate into the polymer component. The probe has a rotation axis having an offset to the centre of the through hole during the rotating and plunging action.

A method for joining dissimilar materials is provided. The method includes a solid-state joining process in which a rivet is plunged into a predrilled hole in a top workpiece. When the rivet contacts the bottom workpiece, ultrasonic vibration by oscillatory motion of a sonotrode, such as horizontal, vertical, or rotational motion, creates frictional heat at the interface between the rivet and the lower workpiece. With the aid of frictional heat and axial compression, metallurgical bonding is achieved at the interface between the rivet and the bottom sheet, while being below the melting temperature of the bottom workpiece. The sonotrode is retracted while the rivet remains.

Methods and devices for controlling a mechanical joining or forming process, in particular friction drilling in thin-walled materials, apply several reverse pulses acting on a process parameter to bring the course of an actual curve of the parameter more into line with the course of a predetermined nominal curve of the process parameter. The number and length of the reverse pulses and the length of the intervals between the pulses are determined as a function of at least one immediately detectable variable associated with the process parameter.