TWI has recommissioned a rotary friction welding (RFW) machine for use on future projects. The machine had previously been used to join thin-walled tube casings as well as for demonstrations.
Although it is connected to a Harms and Wende unit and head, the bespoke machine was built in-house at TWI and recommissioned by friction and forge processes apprentice, Oliver Watts.
The RFW machine is currently ready for use on projects requiring the rotary friction joining of small parts. Examples of the projects that the recommissioned machine would be suitable for include trial runs for small projects, feasibility studies, and demonstrations.
Rotary friction welding is a solid-state joining process which works by rotating one part to be joined against another while subjected to a compressive axial force. The friction between the two parts creates heat which plasticizes the interface material, expelling any surface oxide layers and contaminants and joining the workpieces together. Once the rotational movement is finished the forging force is maintained or increased to help consolidate the weld.