On the Use of High Density Electron Beams for Welding

The use of the electron beam for welding, melting and evaporating was visualised by Marcells von Pirrani as early as 1907 when he patented a workable electron beam furnace in the United States. The use of the technique in those days was however limited to small objects and slow heating rates due to electrical discharges caused by the out-gassing of the metal heated and poor vacuum conditions.