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

1. A method 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 using a welding method, the method comprising the following steps:

activating a laser beam ( 27 ) having a maximum power of 2000 W,

directing the laser beam ( 27 ) to that position on a surface of the work piece ( 14 ) on which the structure is produced,

igniting an electric arc ( 13 ) between a welding wire ( 9 ) guided in a welding torch ( 7 ) and the work piece ( 14 ),

producing the three dimensional structure with the welding wire, and

severing the welding wire ( 9 ) by directing the laser beam ( 27 ) onto the welding wire ( 9 ) at a predetermined height (Δx) from the surface of the work piece ( 14 ) and activating the laser beam there;

wherein the laser beam ( 27 ) is ignited prior to the ignition of the electric arc ( 13 ) and stabilizes the electric arc during welding.

2. The method according to claim 1 , wherein the laser beam ( 27 ) is activated based on an increase in a welding current (IW).

3. The method according to claim 1 , wherein the laser beam ( 27 ) is activated a predetermined period of time (Δt) prior to the ignition of the electric arc ( 13 ), and during the ignition of the electric arc ( 13 ).

4. The method according to claim 1 , wherein the electric arc is extinguished during the step of deflecting the laser beam.

5. The method according to claim 1 , further comprising adjusting a point of impact of the laser beam ( 27 ).

6. The method according to claim 1 , wherein the welding process used is a CMT (cold metal transfer) welding process with a forward/backward movement of the welding wire ( 9 ).

7. The method according to claim 1 , wherein the laser beam ( 27 ) is an infrared laser beam.

8. The method according to claim 1 , wherein argon is used as shielding gas ( 5 ).

9. A method for the production of a three-dimensional structure ( 26 ) on a surface of a metallic work piece ( 14 ) using a welding process, comprising the following steps:

igniting an electric arc ( 13 ) between a welding wire ( 9 ) guided in a welding torch ( 7 ) and the work piece ( 14 ),

melting a tip of the welding wire ( 9 ) and moving the welding wire so that the welding wire is connected to the workpiece ( 14 ), and

directing the laser beam ( 27 ) in a direction of the welding wire so that the laser beam severs the welding wire ( 9 ) in a predetermined height (Δx) from the surface of the work piece ( 14 ).

10. The method according to claim 9 , wherein the electric arc is extinguished during the step of directing the laser beam.

11. The method according to claim 9 , further comprising adjusting a point of impact of the laser beam ( 27 ).

12. The method according to claim 9 , wherein the welding process used is a CMT (cold metal transfer) welding process with a forward/backward movement of the welding wire ( 9 ).

13. The method according to claim 9 , wherein the laser beam ( 27 ) is an infrared laser beam.

14. The method according to claim 9 , wherein argon is used as shielding gas ( 5 ).

15. 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 ).

16. The apparatus ( 1 ) according to claim 15 , wherein the control means ( 28 ) is adapted to activate the laser beam ( 27 ) in a period of time (Δt) of 30 ms to 60 ms prior to the ignition of the electric arc ( 13 ), and during the ignition of the electric arc ( 13 ).

17. The apparatus ( 1 ) according to claim 15 , further comprising an adjusting means ( 29 ) for adjusting a point of impact of the laser beam ( 27 ).

18. The apparatus ( 1 ) according to claim 15 , further comprising an adjusting means ( 30 ) for adjusting the point of impact of the laser beam ( 27 ) in a direction perpendicular to the surface of the work piece ( 14 ).

19. The apparatus according to claim 18 , wherein the adjusting means ( 30 ) comprises a controlled deflecting mirror ( 31 ).

20. The apparatus ( 1 ) according to claim 15 , wherein the laser ( 27 ′) is an infrared laser for emitting an infrared laser beam.

21. The apparatus ( 1 ) according to claim 15 , wherein the welding torch ( 7 ) is connected to a line ( 32 ) for the supply of argon as shielding gas ( 5 ).