Since friction welding processes are generally insensitive to the environments in which they are made, and because the processes can be remotely controlled, there is considerable potential for their use in hostile environments. Thus, processes have been considered, and in some cases developed for use in irradiated environments, high vacuum, underwater (even at great depth).
Friction stud welding, for example, has been used successfully in environments which are potentially explosive due to the presence of hydrocarbon substances. It has also been used underwater at both atmospheric and deepwater pressures.
To eliminate the risk of explosion - and, in some cases, to prevent the surrounding medium from adversely affecting the properties of the friction weld - foamed plastics can be used to form a shroud around the weld region to isolate it from the hostile environment.
FAQ: What is friction stud welding?
For further information see Joining Technologies.