Laser conduction mode welding of aluminum alloys with cross dual laser beams

Patent metadata

Field	Value
Publication number	US-2016114428-A1
Application number	US-201414521198-A
Country	US
Kind code	A1
Filing date	Oct 22, 2014
Priority date	Oct 22, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A method of laser welding aluminum alloy workpieces with dual laser beams arranged in a cross-beam orientation is disclosed. The method comprises directing dual laser beams, which include a first laser beam and a second laser beam, at and along a weld seam established between the aluminum alloy workpieces together with a filler wire. The first laser beam includes a first longitudinal axis and the second laser beam includes a second longitudinal axis. When arranged in the cross-beam orientation, a plane that intersects the first longitudinal axis and the second longitudinal axis of the first and second laser beams, respectively, forms a line where it meets the aluminum alloy workpieces that is oriented transverse to the weld seam.

First claim

1 . A method of laser welding aluminum alloy workpieces, the method comprising:
providing a first aluminum alloy workpiece and a second aluminum alloy workpiece that are brought together to form a weld seam; directing dual laser beams toward the weld seam established between the aluminum alloy workpieces, the dual laser beams comprising a first laser beam extending along a first longitudinal axis and a second laser beam extending along a second longitudinal axis, and wherein a plane that intersects the first and the second longitudinal axes of the first and second laser beams forms a line where the plane meets the first and second aluminum alloy workpieces that is transverse to the weld seam; moving the dual laser beams along the weld seam together with a filler wire without producing a keyhole that penetrates into the first and second aluminum alloy workpieces, the filler wire having a working end that tracks the weld seam and is impinged by both the first and second laser beams at the weld seam; and melting the working end of the filler wire with the dual laser beams to deposit molten filler material along the weld seam as the dual laser beams and the filler wire are moved along the weld seam, the molten filler material solidifying behind the dual laser beams into a laser weld joint.

2 . The method set forth in claim 1 , wherein the dual laser beams melt portions of the first and second aluminum alloy workpieces adjacent to the weld seam, and wherein the melted portions of the first and second aluminum alloy workpieces harden along with the molten filler wire material and become part of the laser weld joint.

3 . The method set forth in claim 1 , wherein each of the first and second laser beams has a power ranging from 500 W to 10 kW.

4 . The method set forth in claim 1 , wherein a laser optic head directs the dual laser beams towards the first and second aluminum alloy workpieces, and wherein a robot arm carries and moves the laser optic head so that the dual laser beams move along the weld seam.

5 . The method set forth in claim 1 , wherein the filler wire is composed of an aluminum alloy.

6 . The method set forth in claim 1 , wherein the first and second aluminum alloy workpieces together form part of an automobile component part, and wherein the weld seam established between the first and second aluminum alloy workpieces is exposed at a visible exterior surface of the automobile component part.

7 . The method set forth in claim 1 , wherein the laser weld joint formed along the weld seam has a top surface.

8 . The method set forth in claim 7 , further comprising:
painting the first and second aluminum alloy workpieces including the top surface of the laser weld joint, as produced, without having to smooth the top surface of the laser weld joint.

9 . The method set forth in claim 1 , further comprising:
directing a shielding gas at the weld seam where the working end of the filler wire is melted by the dual laser beams.

10 . The method set forth in claim 1 , wherein the first and second laser beams converge towards one another as the first and second laser beams approach the weld seam.

11 . A method of laser welding aluminum alloy workpieces, the method comprising:
directing dual laser beams toward a weld seam established between a first aluminum alloy workpiece and a second aluminum alloy workpiece, the dual laser beams comprising a first laser beam extending along a first longitudinal axis and a second laser beam extending along a second longitudinal axis such that a plane intersecting the first and the second longitudinal axes of the first and second laser beams forms a line where the plane meets the first and second aluminum alloy workpieces that is transverse to the weld seam, the first and second laser beams converging towards one another as the first and second laser beams approach the weld seam; positioning a working end of a filler wire at the weld seam such that the working end of the filler wire is impinged by both the first and second laser beams and melted into molten filler material; moving the dual laser beams and the filler wire along the weld seam to deposit molten filler material at the weld seam without producing a keyhole that penetrates into the first and second aluminum alloy workpieces, the molten filler material solidifying behind the dual laser beams into a laser weld joint having a top surface.

12 . The method set forth in claim 11 , wherein the dual laser beams melt portions of the first and second aluminum alloy workpieces adjacent to the weld seam, and wherein the melted portions of the first and second aluminum alloy workpieces harden along with the molten filler wire material and become part of the laser weld joint.

13 . The method set forth in claim 11 , wherein a laser optic head directs the dual laser beams towards the first and second aluminum alloy workpieces, and wherein a robot arm carries and moves the laser optic head so that the dual laser beams move along the weld seam.

14 . The method set forth in claim 11 , wherein the filler wire is composed of an aluminum alloy.

15 . The method set forth in claim 11 , wherein the first and second aluminum alloy workpieces together form part of an automobile component part, and wherein the weld seam established between the first and second aluminum alloy workpieces is exposed at a visible exterior surface of the automobile component part.

16 . The method set forth in claim 11 , further comprising:
painting the first and second aluminum alloy workpieces including the top surface of the laser weld joint, as produced, without having to smooth the top surface of the laser weld joint.

17 . The method set forth in claim 11 , wherein the working end of the filler wire is impinged by both the first and second laser beams and melted in an oxygen-free environment provided by an inert shielding gas that is directed towards, and moved along the weld seam in conjunction with, the dual laser beams and the filler wire.

Assignees

• Gm Global Tech Operations Inc

Inventors

• Wang hui-ping
• Carlson Blair E
• Poss Michael G
• Gatny David A
• Leggett Perry G

Classifications

• B23K26/0676

  into dependently operating sub-beams, e.g. an array of spots with fixed spatial relationship or for performing simultaneously identical operations · CPC title

• B23K26/0652

  comprising prisms · CPC title

• B23K35/286

  Al as the principal constituent · CPC title

• B23K26/32

  taking account of the properties of the material involved · CPC title

• B23K26/26 Primary

  of rectilinear seams · CPC title