Method Of Laser Beam Localized-Coating

A process for joining together metallic parts, comprising:

• joining together a first metallic part and a second metallic part at a joining region, at least one of the first metallic part and the second metallic part having an anti-corrosion surface layer pre-coat, and wherein the surface layer pre-coat is disrupted within the joining region during the joining;
• and
• forming a localized anti-corrosion surface layer within a target area that is at least one of within the joining region and adjacent to the joining region, comprising:
• scanning a laser beam having a predetermined beam spot-size through the target area;
• and
• during the scanning, providing a flow of a powdered anti-corrosion surface layer material toward a portion of the target area that is being irradiated by the laser beam,
• wherein the powdered anti-corrosion surface layer material is melted by the laser beam and forms a layer adhering to surfaces within the joining region.

A system for laser-welding together pre-coated sheet metal plates, comprising:

• a support for holding a first pre-coated sheet metal plate in a predetermined orientation relative to a second pre-coated sheet metal plate, such that an edge of the first plate and an edge of the second plate are disposed adjacent to one another and define an interface therebetween;
• a laser optic assembly in optical communication with a laser source and operable in a first mode for scanning a laser beam having a first beam spot-size along the interface and in a second mode for scanning a laser beam having a second beam spot-size larger than the first beam spot-size along the interface;
• a powder delivery conduit in communication with a source of a powdered anti-corrosion surface layer material and having an outlet end disposed for directing a flow of the powdered anti-corrosion surface layer material toward the interface;
• and
• at least one actuator for relatively moving the laser optic assembly and the outlet end of the powder delivery conduit relative to the support,
• wherein the laser beam having the first beam spot-size is scanned along the interface in a first pass to form a laser weld joint between the first and second plates, and
• wherein the laser beam having the second beam spot-size is scanned along the laser weld joint, and at the same time the powdered anti-corrosion surface layer material is fed via the powder delivery conduit toward a currently irradiated portion of the laser weld joint, to form a localized anti-corrosion surface layer at least on the laser weld joint.