Electron beam welding methods and apparatus

An apparatus for electron beam welding a plurality of secondary components to a primary component, the apparatus comprising:

• an electron beam source configured to generate, in use, an electron beam for electron beam welding;
• a component holder adapted to hold, in use, the secondary components in position for welding to the primary component;
• a beam steering module operable to control the path of the electron beam for welding together the primary and secondary components;
• and
• a controller configured to operate the beam steering module to perform the following steps:
• (a) on a first weld path which defines a respective section of the primary component to be welded to a first secondary component, forming, by electron beam welding, a spot weld which joins the primary component and the first secondary component at a respective spot weld location on the first weld path;
• (b) on a second weld path which defines a respective section of the primary component to be welded to a second secondary component, forming, by electron beam welding, a spot weld which joins together the primary component and the second secondary component at a respective spot weld location on the second weld path;
• and
• repeating each of steps (a) and (b) at least once, in any order, so as to form, on each of the first and second weld paths, a respective set of contiguous spot welds arranged along the respective weld path, wherein each successive spot weld is formed while one or more of the previous spot welds is solidifying and only after any existing spot weld(s) with which it is contiguous has solidified.