公开(公告)号：US10946479B2

公开(公告)日：2021-03-16

申请号：US16089038

申请日：2016-04-14

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/22 ,  B23K26/32 ,  B23K26/082 ,  B23K103/10

Abstract: A method of laser welding a workpiece stack-up (10) that includes at least two overlapping aluminum workpieces comprises advancing a laser beam (24) relative to a plane of a top surface (20) of the workpiece stack-up (10) and along a beam travel pattern (74) that lies within an annular weld area (82) defined by an inner diameter boundary (86) and an outer diameter boundary (84) on the plane of the top surface (20). The beam travel pattern (74) of the laser beam (24) surrounds a center area encircled by the annular weld area (82) on the plane of the top surface (20) so as to force entrained porosity inwards into a region of the weld joint (72) beneath the center area on the plane of the top surface (20) of the workpiece stack-up (10).

公开(公告)号：US20200171603A1

公开(公告)日：2020-06-04

申请号：US16614561

申请日：2017-06-13

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/244 ,  B23K26/082 ,  B23K26/08 ,  B23K26/06 ,  B23K26/322 ,  B23K26/354

Abstract: A method of laser welding together two or more overlapping metal workpieces (12, 14, or 12, 150, 14) included in a welding region (16) of a workpiece stack-up (10) involves advancing a beam spot (44) of a laser beam (24) relative to a top surface (20) of the workpiece stack-up along a first weld path (72) in a first direction (74) to form an elongated melt puddle (76) and, then, advancing the beam spot (44) of the laser beam (24) along a second weld path (78) in a second direction (80) that is opposite of the first direction while the elongated melt puddle is still in a molten state. The first weld path and the second weld path overlap so that the beam spot of the laser beam is conveyed through the elongated melt puddle when the beam spot is advanced along the second weld path.

公开(公告)号：US10195689B2

公开(公告)日：2019-02-05

申请号：US15206856

申请日：2016-07-11

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/06 ,  B23K26/322 ,  B23K26/21 ,  B23K26/08 ,  B23K26/32 ,  B23K26/082 ,  B23K26/244 ,  B23K103/04 ,  B23K103/10 ,  B23K103/08 ,  B23K103/16 ,  B23K101/00 ,  B23K101/18 ,  B23K101/34 ,  B23K103/20

Abstract: A method of laser welding a workpiece stack-up that includes at least two overlapping metal workpieces is disclosed. The method includes advancing a beam spot of a laser beam relative to a top surface of the workpiece stack-up and along a beam travel pattern to form a laser weld joint, which is comprised of resolodified composite metal workpiece material, that fusion welds the metal workpieces together. And, while the beam spot is being advanced along the beam travel pattern, between a first point and a second point, which may or may not encompass the entire beam travel pattern, at least one of the following laser beam parameters is repeatedly varied: (1) the power level of the laser beam; (2) the travel speed of the laser beam; or (3) the focal position of the laser beam relative to the top surface of the workpiece stack-up.

公开(公告)号：US11235422B2

公开(公告)日：2022-02-01

申请号：US16484010

申请日：2017-02-09

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Yu Pan ,  David Yang ,  Wu Tao ,  Paolo Novelletto

IPC: B23K26/22 ,  B23K26/082 ,  B23K26/244 ,  B23K26/08 ,  B23K103/08 ,  B23K103/10 ,  B23K103/04

Abstract: A method for joining together metal workpiece (12,14 or 12,150, 14) includes forming a laser weld joint (66) in a workpiece stack-up (10) that fusion welds two or more overlapping metal workpiece (12,14 or 12,150 or 14) together. The laser weld joint (66) has an initial top surface (76). Once the laser weld joint (66) is formed, the method calls for impinging the laser weld joint (66) with a laser beam (24) and moving the laser beam (24) along the initial joint (66) including the initial top surface (76). The laser beam (24) is eventually removed from the laser weld joint (66) to allow the melted upper portion (78) of the joint (66) to resolidify and provide the laser weld joint (66) with a modified top surface (84) that is smoother than the initial top surface (76). By providing the laser weld joint with a smoother modified top surface, residual stress concentration points are removed and the laser weld joint is less liable to damage seal strips.

公开(公告)号：US20200316713A1

公开(公告)日：2020-10-08

申请号：US15779743

申请日：2016-01-18

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao ,  Li Sun

IPC: B23K26/22 ,  B23K26/073 ,  B23K26/322

Abstract: A method of laser spot welding a workpiece stack-up (10) that includes at least two overlapping steel workpieces (12,14), at least one of which includes a surface coating (40), is disclosed. The method includes directing a laser beam (24) at the top surface (20) of the workpiece stack-up (10) to create a molten steel weld pool (90) that penetrates into the stack-up (10). The molten steel weld pool (90) is then grown to penetrate further into the stack-up (10) by increasing an irradiance of the laser beam (24) while reducing the projected sectional area (86) of the laser beam (24) at a plane of the top surface (20) of the workpiece stack-up (10). Increasing the irradiance of the laser beam (24) may be accomplished by moving a focal point (62) of the laser beam (24) closer to the top surface (20) or by reducing an angle of incidence (82) of the laser beam (24) so as to reduce the eccentricity of the projected sectional area (86) of the laser beam (24).

公开(公告)号：US10688595B2

公开(公告)日：2020-06-23

申请号：US15575170

申请日：2015-06-02

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David S. Yang ,  Justin Allen Wolsker ,  Jing Zhang ,  Wu Tao ,  Dalong Gao

IPC: B23K26/244 ,  B23K101/34 ,  B23K103/04 ,  B23K103/08

Abstract: A method of laser welding a workpiece stack-up (10) that includes at least two overlapping steel workpieces (12, 14) comprises directing a laser beam (40) at a top surface (26) of the workpiece stack-up to form a keyhole (56) surrounded by a molten steel weld pool (58). The laser beam is conveyed along a predefined weld pattern that includes one or more nonlinear inner weld paths (66) and an enclosed outer peripheral weld path (68) surrounding the one or more nonlinear inner weld paths. During conveyance of the laser beam along the one or more nonlinear inner weld paths, the keyhole fully penetrates through the workpiece stack-up from the top surface of the stack-up to the bottom surface (28) of the stack-up. The method produces weld joints between the steel workpieces that do not have an intentionally imposed gap formed between their faying surfaces.

公开(公告)号：US20190040487A1

公开(公告)日：2019-02-07

申请号：US15668751

申请日：2017-08-04

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Charles Enloe ,  Curt D. Horvath ,  David Yang ,  Qi Lu ,  Wu Tao

IPC: C21D9/46 ,  C21D8/02 ,  C21D3/04 ,  C23C2/06 ,  B32B15/01 ,  B23K11/11 ,  B23K11/16 ,  B23K26/22 ,  B23K26/322

CPC classification number: C21D9/46 ,  B23K11/11 ,  B23K11/115 ,  B23K11/166 ,  B23K26/22 ,  B23K26/322 ,  B23K2103/166 ,  B32B15/013 ,  C21D3/04 ,  C21D8/0205 ,  C21D8/0236 ,  C21D8/0257 ,  C21D2211/005 ,  C23C2/02 ,  C23C2/06 ,  C23C2/26 ,  C23C2/28 ,  C23C2/40 ,  C23C8/18 ,  C23C28/02 ,  C23C28/025 ,  C23C30/00 ,  C23C30/005 ,  Y10T428/12458 ,  Y10T428/12799 ,  Y10T428/12958 ,  Y10T428/12965 ,  Y10T428/12972 ,  Y10T428/2495 ,  Y10T428/24967 ,  Y10T428/24975 ,  Y10T428/263 ,  Y10T428/264 ,  Y10T428/265

Abstract: A multilayer steel includes a core formed of transformation-induced plasticity (TRIP) steel. A decarburized layer is exterior to the core on at least one side thereof. The decarburized layer has reduced carbon content relative to the core. A zinc-based layer is exterior to the decarburized layer. The decarburized layer may have a composition of at least 80 percent ferrite, such that LME is reduced or mitigated. In some configurations, the decarburized layer is between 10-50 microns thick. A method of creating a coated advanced high-strength steel component is also provided. An apparatus for forming a coated advanced high-strength steel is also provided. The core of the multilayer steel may have a carbon weight-percent of less than or equal to 0.4. The decarburized layer of the multilayer steel may have a carbon weight-percent of less than or equal to 50 percent of the carbon weight-percent of the core.

公开(公告)号：US11203085B2

公开(公告)日：2021-12-21

申请号：US16141142

申请日：2018-09-25

Applicant: GM Global Technology Operations LLC

Inventor： Wu Tao

IPC: B23K26/00 ,  B23K26/06 ,  B23K26/32 ,  B23K26/26

Abstract: A device and associated method for joining, via a laser welder, a first workpiece to a second workpiece is described. This includes arranging the first and second workpieces in a stack, including overlapping a portion of the first workpiece with a portion of the second workpiece. The laser welder generates a first laser beam and coincidentally controls the laser welder to traverse a desired weld path that is disposed on the top surface of the first workpiece. The laser devices generates a second laser beam and coincidentally controls the laser welder to traverse the desired weld path. Generating, via the laser welder, the first laser beam includes operating the laser welder at a pulsed operation and at a first power level. Generating, via the laser welder, the second laser beam includes operating the laser welder at a continuous operation and at a second power level.

公开(公告)号：US10953494B2

公开(公告)日：2021-03-23

申请号：US16073536

申请日：2016-03-16

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/24 ,  B23K26/244 ,  B23K26/073 ,  B23K26/22 ,  B23K26/322 ,  B23K26/082 ,  B23K26/00 ,  B23K101/00 ,  B23K101/18 ,  B23K101/34 ,  B23K103/04 ,  B23K103/10 ,  B23K103/18

Abstract: A method of laser welding a workpiece stack-up (10) that includes at least two overlapping metal workpieces (12, 14) comprises advancing a laser beam (24) relative to a plane of a top surface (20) of the workpiece stack-up (10) from a start point (84) to an end point (86) along a beam travel pattern (78) at a high laser beam travel speed of greater than 8 meters per minute. The two or more overlapping metal workpieces (12, 14) may be steel workpieces or they may be aluminum workpieces, and at least one of the metal workpieces (12, 14) includes a surface coating (40). Advancing the laser beam (24) along the beam travel pattern (78) forms a weld joint (76), which includes resolidified composite workpiece material derived from each of the metal workpieces (12, 14) penetrated by a molten weld pool (80), that fusion welds the metal workpieces (12, 14) together. The relatively high laser beam travel speed contributes to improve strength properties of the weld joint (76).

公开(公告)号：US10675713B2

公开(公告)日：2020-06-09

申请号：US15659092

申请日：2017-07-25

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao ,  Paolo A. Novelletto ,  Yu Pan ,  Justin Wolsker

IPC: B23K26/244 ,  B23K26/082 ,  B23K26/322 ,  B23K26/08 ,  B23K101/34 ,  B23K103/16

Abstract: A method of laser welding a workpiece stack-up that includes two or more overlapping metal workpieces is disclosed. The disclosed method includes directing a laser beam at a top surface of the workpiece stack-up to create a molten metal weld pool and, optionally, a keyhole, and further gyrating the laser beam to move a focal point of the laser beam along a helical path having a central helix axis oriented transverse to the top and bottom surfaces of the workpiece stack-up. The gyration of the laser beam may even be practiced to move the focal point of the laser beam along a plurality of helical paths so as to alternately convey the focal point back-and-forth in a first overall axial direction and a second overall axial direction while advancing the laser beam relative to the top surface of the workpiece stack-up along a beam travel pattern.