Resistance Spot Brazing Workpiece Stack-Ups Having One Or More Thin-Gauge Steel Workpieces

• US 20190314914A1
• Filed: 04/13/2018
• Published: 10/17/2019
• Est. Priority Date: 04/13/2018
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Wang, Pei-chung, Karagoulis, Michael J., Teng, Zhenke
• Granted Patent: US 11,318,548 B2
• Time in Patent Office: Days
• CPC Class Codes: B23K 1/0004 Resistance soldering
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 11/115 by means of two electrodes placed opposite one another on both sides of the welded parts
• CPC Class Codes: B23K 11/31 Electrode holders and actuating devices therefornot restricted to resistance welding or severing by resistance heating B23K37/02
• CPC Class Codes: B23K 2103/04 Steel or steel alloys

Abstract

A method of resistance spot brazing a workpiece stack-up that includes a first thin-gauge steel workpiece and a second thin-gauge steel workpiece. The method includes several steps. A first step involves applying a filler material to a surface of the first thin-gauge steel workpiece. A second step involves bringing a surface of the second thin-gauge steel workpiece to adjoin the filler material. A third step involves clamping a first welding electrode and a second welding electrode on the first and second thin-gauge steel workpieces and over the filler material. A fourth step involves passing electrical current between the first and second welding electrodes and hence through the filler material. And a fifth step involves terminating passage of the electrical current in order to establish a brazed joint between the first and second thin-gauge steel workpieces.

Claims

1. A method of resistance spot brazing a workpiece stack-up that includes a first thin-gauge steel workpiece and a second thin-gauge steel workpiece, the method comprising:

applying a filler material to a first surface of the first thin-gauge steel workpiece;

bringing the second thin-gauge steel workpiece to the first thin-gauge steel workpiece, a second surface of the second thin-gauge steel workpiece adjoining the filler material;

clamping a first welding electrode and a second welding electrode on the first and second thin-gauge steel workpieces adjacent the filler material;

passing electrical current between the first and second welding electrodes and through the first and second thin-gauge steel workpieces and through the filler material; and

terminating passage of the electrical current to establish a brazed joint between the first and second thin-gauge steel workpieces.

2. The method of claim 1, wherein the first thin-gauge steel workpiece has a thickness dimension that is less than approximately 0.75 millimeters (mm), and the second thin-gauge steel workpiece has a thickness dimension that is less than approximately 0.75 mm.

3. The method of claim 1, wherein applying the filler material involves coating the first surface of the first thin-gauge steel workpiece with the filler material via thermal spraying.

4. The method of claim 1, wherein applying the filler material involves layering the filler material on the first surface of the first thin-gauge steel workpiece via additive manufacturing.

5. The method of claim 4, wherein layering the filler material on the first surface of the first thin-gauge steel workpiece involves 3D printing.

6. The method of claim 1, wherein applying the filler material to the first surface of the first thin-gauge steel workpiece involves applying the filler material in a paste form.

7. The method of claim 1, wherein applying the filler material to the first surface of the first thin-gauge steel workpiece involves applying the filler material in a wire form.

8. The method of claim 1, wherein applying the filler material to the first surface of the first thin-gauge steel workpiece involves providing the filler material in shim form.

9. The method of claim 1, wherein the filler material is composed of a base metal material with a plurality of particles dispersed within the base metal material, the plurality of particles facilitating the application of the filler material to have a retained thickness dimension prior to establishment of the brazed joint.

10. The method of claim 1, wherein the filler material is composed of a base metal material with a plurality of particles dispersed within the base metal material, the plurality of particles facilitating a retained gap dimension between the first and second surfaces at the brazed joint.

11. The method of claim 1, further comprising depositing a plurality of particles into a base metal material of the filler material, wherein the plurality of particles is dispersed within the base metal material.

12. The method of claim 11, wherein the plurality of particles is deposited into the base metal material after the filler material is applied to the first surface of the first thin-gauge steel workpiece and before the second surface of the second thin-gauge steel workpiece is adjoined with the filler material.

13. The method of claim 11, wherein depositing the plurality of particles into the base metal material of the filler material involves thermal spraying of the plurality of particles.

14. The method of claim 1, wherein the first welding electrode, the second welding electrode, or both of the first and second welding electrodes have a weld face with a radius of curvature that ranges between approximately 25 millimeters (mm) and 50 mm.

15. A method of resistance spot brazing a workpiece stack-up, the method comprising:

providing a first thin-gauge steel workpiece and a second thin-gauge steel workpiece;

applying a filler material to a first surface of the first thin-gauge steel workpiece;

depositing a plurality of particles into the applied filler material;

adjoining a second surface of the second thin-gauge steel workpiece to the filler material;

clamping a first welding electrode and a second welding electrode on the first and second thin-gauge steel workpieces adjacent the filler material, the plurality of particles facilitating a retained gap dimension at the filler material between the first and second surfaces as the first and second welding electrodes exert a clamping load thereat;

passing electrical current between the first and second welding electrodes; and

terminating passage of the electrical current to establish a brazed joint between the first and second thin-gauge steel workpieces.

16. The method of claim 15, wherein applying the filler material involves layering the filler material on the first surface of the first thin-gauge steel workpiece via additive manufacturing.

17. The method of claim 15, wherein applying the filler material to the first surface of the first thin-gauge steel workpiece involves applying the filler material in a paste form.

18. The method of claim 15, wherein applying the filler material to the first surface of the first thin-gauge steel workpiece involves applying the filler material in a wire form.

19. The method of claim 15, wherein depositing the plurality of particles into the applied filler material involves thermal spraying.

20. A method of resistance spot brazing a workpiece stack-up, the method comprising:

providing a first thin-gauge steel workpiece and a second thin-gauge steel workpiece, wherein the first thin-gauge steel workpiece has a thickness dimension that is less than approximately 0.75 millimeters (mm), and the second thin-gauge steel workpiece has a thickness dimension that is less than approximately 0.75 mm;

applying a filler material to a first surface of the first thin-gauge steel workpiece via additive manufacturing;

depositing a plurality of particles into the applied filler material via thermal spraying;

adjoining a second surface of the second thin-gauge steel workpiece with the applied filler material having the deposited particles;

clamping a first welding electrode and a second welding electrode on the first and second thin-gauge steel workpieces adjacent the filler material, the plurality of particles facilitating a retained gap dimension at the filler material between the first and second surfaces as the first and second welding electrodes exert a clamping load thereat;

passing electrical current between the first and second welding electrodes; and

terminating passage of the electrical current to establish a brazed joint between the first and second thin-gauge steel workpieces.