US 12,330,235 B2
Laser welding of metal pin pairs with time-dependent scan pattern and energy input
Peter Kallage, Hamburg (DE); Oliver Forster, Güster (DE); Oliver Kraus, Jork (DE); Falk Nagel, Bad Oldesloe (DE); and Stefan Schulz, Güster (DE)
Assigned to Corelase Oy, Tampere (FI)
Filed by Corelase Oy, Tampere (FI)
Filed on Aug. 14, 2020, as Appl. No. 16/994,439.
Prior Publication US 2022/0048137 A1, Feb. 17, 2022
Int. Cl. B23K 26/28 (2014.01); B23K 26/082 (2014.01); B23K 101/36 (2006.01); B23K 103/12 (2006.01)
CPC B23K 26/28 (2013.01) [B23K 26/082 (2015.10); B23K 2101/36 (2018.08); B23K 2103/12 (2018.08)] 21 Claims
OG exemplary drawing
 
1. A method for laser welding a pair of metal pins, comprising steps of:
delivering a laser beam to a work-side, of the pair of metal pins, formed by a respective pair of exposed surfaces of the metal pins adjacent to each other and facing in the same direction;
tracing a first path on the work-side with the laser beam at a first delivered rate of energy per unit path length to form a melt pool by keyhole welding, wherein the first path crosses an interface between the metal pins, and the laser beam is incident on (a) the exposed surface of one of the metal pins during one portion of the first path and (b) the exposed surface of the other one of the metal pins during another portion of the first path; and
before a keyhole, formed by the keyhole welding in the step of tracing the first path, reaches a location on the first path that is occupied by the melt pool, switching from the step of tracing the first path to a step of tracing a second path on the work-side with the laser beam at a second delivered rate of energy per unit path length that is at most ⅔ of the first delivered rate of energy per unit path length, wherein the second path crosses the interface and wherein the entire second path is entirely within the first path, and the laser beam is incident on (a) the exposed surface of one of the metal pins during one portion of the second path and (b) the exposed surface of the other one of the metal pins during another portion of the second path.