Patent ID: 9321131
Filing Date: 2016-04-26
CPC Classification: B23K

Claim Text:
1. A method for the laser butt welding of one or more metal parts positioned against one another along a junction plane, in which: a) a laser beam is generated using a CO b) a nozzle is fed with a gas or a gas mixture and said nozzle is used to send a jet of protective gas formed from said gas or gas mixture toward a junction plane, c) a laser beam is used to melt or vaporize the metal of the metal parts, leading to the formation of a metal vapor capillary in the thickness of the part or parts and at said junction plane, with the simultaneous formation of a metal plasma which, by propagating outside the metal vapor capillary, forms a metal plasma plume above the junction plane, characterized in that the protective gas jet delivered by the nozzle is directed or sent toward the metal plasma plume being formed above the junction plane, wherein the protective gas jet is flush with the top of the metal plasma plume and impinges on a part or the parts at a place where the metal of the parts has not been melted by the beam, wherein the gas jet is directed so that the distance between the axis of said gas jet and the axis of the laser beam, measured between the impact points of said gas jet and said laser beam on the upper surface of the parts to be welded, is equal to or higher than 1.5 times the inside diameter of the nozzle delivering the gas jet.