Inertia Friction Welding
The energy for frictional heating is supplied by the kinetic energy of a flywheel
The flywheel is accelerated to the correct speed and disconnected from the drive
Spinning and stationary components are then brought together and an axial force is applied
Friction slows the flywheel and heats the surface - the axial force is then increased
The process is complete when the flywheel comes to a stop