Electron Beam Welding is a method which uses a focussed stream
of high energy electrons generated by a filament and directed to
the joint requiring to be welded. The heating is very localised
and the bulk of the assembly therefore remains cold and stable.
This results in a very narrow weld with a minimal heat affected
zone. There is no need to use filler metal as the parent metal
of the assembly is melted. As this is a line of sight method it
is not possible to weld around corners or re-entrant angles.
Weld depths of up to 30mm can be produced and computer controls
ensure minimal operator dependence, thus providing good
reproducibility throughout a batch of components, even though
this is a piece part process. Since the heat input is very
localised it is possible to weld together previously heat
treated components, which is a very economical method for
producing composite gear shafts, with for example a case
hardened gear on a hardened and tempered shaft.