US 12,392,367 B2
Method for laser microwelding
Daniel Anthony Capostagno, Santa Clara, CA (US); Jacek Tadeusz Gabzdyl, East Boldre (GB); Malcolm Paul Vamham, Alresford (GB); Paul Martin Harrison, Salisbury (GB); Stephen Roy Norman, Romsey (GB); Adam Piotr Rosowski, Southampton (GB); and Tara Murphy, Portsmouth (GB)
Assigned to Trumpf Laser UK Limited, Hedge End (GB)
Appl. No. 15/549,715
Filed by Trumpf Laser UK Limited, Hedge End (GB)
PCT Filed Feb. 8, 2016, PCT No. PCT/GB2016/000028
§ 371(c)(1), (2) Date Aug. 9, 2017,
PCT Pub. No. WO2016/128704, PCT Pub. Date Aug. 18, 2016.
Claims priority of application No. 1502149 (GB), filed on Feb. 9, 2015; application No. 1509504 (GB), filed on Jun. 1, 2015; and application No. 1517768 (GB), filed on Oct. 7, 2015.
Prior Publication US 2018/0045232 A1, Feb. 15, 2018
This patent is subject to a terminal disclaimer.
Int. Cl. B23K 26/22 (2006.01); B23K 26/00 (2014.01); B23K 26/06 (2014.01); B23K 26/0622 (2014.01); B23K 26/082 (2014.01); B23K 26/10 (2006.01); B23K 26/244 (2014.01); B23K 26/323 (2014.01); B23K 26/352 (2014.01); F16B 5/08 (2006.01)
CPC F16B 5/08 (2013.01) [B23K 26/0006 (2013.01); B23K 26/0608 (2013.01); B23K 26/0622 (2015.10); B23K 26/082 (2015.10); B23K 26/10 (2013.01); B23K 26/22 (2013.01); B23K 26/244 (2015.10); B23K 26/323 (2015.10); B23K 26/355 (2018.08)] 24 Claims
OG exemplary drawing
 
1. A method for laser microwelding a first material to a second material, which method comprises:
placing a first metal part comprising the first material on a second metal part comprising the second material;” providing a laser for emitting a laser beam in the form of laser pulses;
providing a scanner for scanning the laser beam with respect to a surface of the first metal part;
providing an objective lens for focusing the laser pulses onto the surface; and
providing a controller that is adapted to control the scanner such that the scanner moves the laser beam with respect to the surface,
characterized by
moving the laser beam with respect to the surface;
focusing the laser pulses with a spot size and a pulse fluence that cause the formation of a weld comprising at least one microweld in the form of a welding pattern defined parallel to the surface; and
operating the controller to form the microweld by selecting a first laser signal comprising a plurality of the laser pulses during a first time period to create a melt pool on the surface, then selecting a second laser signal comprising a plurality of the laser pulses during a second time period to initiate welding of the first metal part to the second metal part, and then selecting a third laser signal comprising either the laser pulses or a continuous wave laser beam during a third time period to weld the first metal part to the second metal-part;
wherein the method is one that forms a key hole, the method further includes providing a fourth laser signal which is selected to close the key hole;
wherein the microweld has a characteristic feature size of between 20 μm and 400 μm;
the laser pulses have pulse widths between 1 ns and 3000 ns; “the first material is a first metal;” the second material is a second metal which is different from the first metal;
the weld is autogenous; and
wherein the laser pulses have a pulse energy of 10 mJ or less, the laser pulses have a pulse repetition frequency greater than 10 kHz, and the spot size is less than 100 μm.