Method and apparatus for the production of a welding seam or a three-dimensional structure on a surface of a metallic work piece

An apparatus (1) for the production of a three-dimensional structure (26) on a surface of a metallic work piece (14) made of titanium or a titanium alloy, comprising:

• a welding torch (7) configured for carrying out a welding process with a welding wire (9) guided in the welding torch (7), whereby an electric arc (13) is ignited between the welding wire (9) and the work piece (14), and
• a laser for stabilizing the electric arc (13), the laser (27′) emitting a laser beam (27) having a maximum power of 2000 W, and being positionable on the work piece (14) such that the laser beam contacts that position on the surface of the work piece (14) where the structure (26) is produced, and
• a control means (28) connected to the laser (27′) for controlling the laser beam (27), said control means (28) being configured for activating the laser beam (27) prior to the ignition of the electric arc (13),
• wherein the laser is configured for severing the welding wire (9) at a predetermined height (Δx), by directing the laser beam (27) to the welding wire (9) at a predetermined height (Δx) from the surface of the work piece (14) and activating the laser beam (27) there, and deactivating a current source for forming the electric arc (13).