Abstract: A method for laser welding a stack of metal foils to a metal substrate includes first interconnecting the metal foils with a first laser-weld joint by serially tracing a plurality of paths on the side of the stack, and then connecting the stack of interconnected metal foils to the metal substrate by oscillating-beam welding. The oscillating-beam welding includes modulating the travel speed of the laser beam, and optionally also the laser beam power, along the path of the oscillation pattern. This method allows for the oscillation pattern to span across the entire height of the foil stack and onto the substrate, while depositing energy at a rate that is commensurate with the structural properties of the material irradiated by the laser beam at any given time during the oscillating-beam welding process. The method thereby forms a strong and robust connection between the foil stack and the substrate.

Abstract: A method for laser welding a pair of metal pins delivers a laser beam to a work-side of the pair of metal pins where a respective pair of surfaces of the metal pins are adjacent to each other and face in the same direction. The laser beam first traces a first path on the work-side to form a melt pool by keyhole welding. The first path crosses an interface between the metal pins. After tracing the first path, the laser beam is switched to trace a second path on the work-side with the laser beam at a delivered rate of energy per unit path length that is less than the one used for the first path. The second path crosses the interface and is within the first path. The method is well-suited for welding of hairpin and I-pin stators.

Abstract: A method for laser welding a stack of metal foils to a metal substrate includes securing the stack of metal foils between a surface of the metal substrate and a removable clamp such that a side of the stack, formed by edges of the foils, is located on an interior portion of the surface, and the clamp is set back from the side of the stack. A first laser welding step interconnects the foils with an initial laser-weld joint by serially tracing a plurality of lateral paths along the foil edges with a laser beam. A second laser welding step connects the stack of interconnected foils to the substrate by tracing, with a laser beam, a path along the interface between the initial laser-weld joint and the substrate surface. This two-step laser welding process circumvents the difficulties of welding together materials with highly disparate thicknesses in a single laser-welding operation.

Abstract: A method for laser welding a pair of metal pins delivers a laser beam to a work-side of the pair of metal pins where a respective pair of surfaces of the metal pins are adjacent to each other and face in the same direction. The laser beam first traces a first path on the work-side to form a melt pool by keyhole welding. The first path crosses an interface between the metal pins. After tracing the first path, the laser beam is switched to trace a second path on the work-side with the laser beam at a delivered rate of energy per unit path length that is less than the one used for the first path. The second path crosses the interface and is within the first path. The method is well-suited for welding of hairpin and I-pin stators.

Abstract: The invention relates to a method for laser welding workpieces (W), a laser beam (L) directed onto a workpiece surface having such a radiation intensity that the workpiece material of the at least one workpiece (W) to be welded is melted in the region of the laser focus (F), a vapor capillary (D) which is at least partly surrounded by a molten bath (S) forming in the region of the laser focus (F). The laser beam (L) is moved relative to the workpiece surface in a direction of advance (V) in order to produce a weld seam. According to the invention, the molten bath (S) is subjected to mechanical stress by directing a gas stream (G) onto the workpiece surface for the purpose of stabilization during welding. The invention further relates to a device (1) designed for carrying out said method.