Abstract: A method for producing a bipolar plate strand comprises: providing of the unipolar plate strands; moving of the unipolar plate strands in the direction of a roll gap of a roll pair provided with roll structures of a rolling device; sending of a laser beam of a laser device onto a rotating mirrored polygon wheel, so that the laser beam is directed at a plurality of individual positions of a surface of one or both of the unipolar plate strands and the individual positions are thus heated to a joining temperature immediately before or upon entry of the unipolar plate strands in the roll gap; and joining of the unipolar plate strands at least at one of the individual positions of the surface to form a bipolar plate strand upon transporting of the unipolar plate strands through the roll gap under the action of pressure. A method for production of a bipolar plate as well as a device to implement the method are also provided.

Abstract: A method for laser beam welding at least two joint partners which are placed one above the other in a lap joint. The two joint partners are welded to one another by a linear seam to form a preferably closed-surface connection zone. In order to form the connection zone, the laser beam is guided along a target welding track in the welding process according to any path planning strategy, in particular while forming a weld seam path, the adjacent path sections of which build up the preferably closed-surface connection zone.

Abstract: A method for laser-based deep welding of at least two parts to be joined, in which a laser beam device generates a laser beam with a deep welding laser beam component, which is moved at a feed rate along a joint. The deep welding laser beam component generates a vapor capillary in the material of the parts to be joined, which capillary is surrounded by a melt pool and which moves with the laser beam in the welding direction through the material of the parts to be joined, forming a capillary flow, in which a metal melt located at the capillary front flows via melt pool channels formed on both sides of the vapor capillary in the direction of the capillary rear side and solidifies there.

Abstract: A method for producing a bipolar plate strand comprises: providing of the unipolar plate strands; moving of the unipolar plate strands in the direction of a roll gap of a roll pair provided with roll structures of a rolling device; sending of a laser beam of a laser device onto a rotating mirrored polygon wheel, so that the laser beam is directed at a plurality of individual positions of a surface of one or both of the unipolar plate strands and the individual positions are thus heated to a joining temperature immediately before or upon entry of the unipolar plate strands in the roll gap; and joining of the unipolar plate strands at least at one of the individual positions of the surface to form a bipolar plate strand upon transporting of the unipolar plate strands through the roll gap under the action of pressure. A method for production of a bipolar plate as well as a device to implement the method are also provided.

Abstract: A method for joining at least two components of a fuel cell, especially for joining two single plates of a fuel cell to make a bipolar plate, comprises: providing a first component of the fuel cell and providing at least one second component of the fuel cell; and directing a pulsed laser beam of a laser apparatus onto a rotating mirrored polygon wheel, by which the laser beam forms a joint line consisting of a plurality of overlapping pointlike and/or line-shaped joining locations on the components. A device for carrying out the method is also provided.