Electron-beam welding (EBW)
DOI: 10.1063/1.4796874
Leaves the vacuum. The highest-quality welds currently achievable are done using beams of accelerated electrons to melt and join the metal pieces. But because the required electron guns cannot function in normal atmospheric conditions, the welding must take place in a vacuum chamber and is thus possible only for small pieces. Ady Hershcovitch of Brookhaven National Laboratory has now gotten around that limitation with a plasma window that isolates the vacuum of EBW beam sources but allows the electron beams to pass through and weld materials at ambient conditions up to 50 mm away. The window is formed with a plasma 40–50 times hotter than room temperature, confined by electric and magnetic fields. The plasma’s high pressure effectively excludes the ambient atmosphere from the vacuum region that houses the gun. Additionally, the plasma window focuses the electron beams to improve weld quality. With the plasma window and a robot arm, EBW may become a viable option for large manufacturing applications such as cars, airplanes, or ships. Acceleron Inc has licensed the technology from Brookhaven. (
