Editing Electron-beam technology (section)

===Surface treatments===
Modern electron-beam welders are usually designed with a computer-controlled deflection system that can traverse the beam rapidly and accurately over a selected area of the work piece. Thanks to the rapid heating, only a thin surface layer of the material is heated. Applications include [[hardening (metallurgy)|hardening]], [[annealing (metallurgy)|annealing]], [[tempering (metallurgy)|tempering]], texturing, and polishing (with argon gas present). If the electron beam is used to cut a shallow trough in the surface, repeatedly moving it horizontally along the trough at high speeds creates a small pile of ejected melted metal. With repetition, spike structures of up to a millimeter in height can be created. These structures can aid bonding between different materials and modify the surface roughness of the metal.