AL-STEEL WELD JOINT

• US 20170291247A1
• Filed: 04/04/2017
• Published: 10/12/2017
• Est. Priority Date: 04/08/2016
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company), Huami, Inc.
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Sigler, David, Carlson, Blair, Maddela, Surender
• Granted Patent: US 10,675,703 B2
• Time in Patent Office: Days
• 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 11/185 of aluminium or aluminium alloys
• CPC Class Codes: B23K 11/20 of different metals
• CPC Class Codes: B23K 2103/20 Ferrous alloys and aluminium or alloys thereof
• CPC Class Codes: F16B 5/08 by means of welds or the like welding B23K

Abstract

A weld joint is disclosed that weld bonds together an aluminum workpiece and a steel workpiece. The weld joint includes an aluminum weld nugget, an intermetallic layer, and an annular ring of aluminide particles that is selected from the group consisting of nickel aluminide particles, iron aluminide particles, and a combination thereof. The annular ring of aluminide particles extends upwards from a weld bond surface of the weld joint such that the annular ring of aluminide particles extends radially inwardly into the aluminum weld nugget and protects the weld bond surface of the weld joint against crack propagation that may originate from a notch root of the weld joint.

Claims

1. A weld joint that weld bonds together an aluminum workpiece and a steel workpiece, the weld joint comprising:

an aluminum weld nugget contained within an aluminum workpiece;

an intermetallic layer located between the aluminum weld nugget and a faying surface of the steel workpiece, the intermetallic layer providing a weld bond surface of the weld joint that is adjacent to and bonded with the faying surface of the steel workpiece; and

an annular ring of aluminide particles that extends upwards from the weld bond surface of the weld joint and radially inwardly into the aluminum weld nugget, wherein the annular ring of aluminide particles comprises at least one of nickel aluminide particles or iron aluminide particles.

2. The weld joint set forth in claim 1, wherein the annular ring of aluminide particles comprises nickel aluminide particles and iron aluminide particles.

3. The weld joint set forth in claim 1, wherein the annular ring of aluminide particles comprises at least one of nickel aluminide particles having 20 at % to 50 at % nickel or iron aluminide particles having 20 at % to 50 at % iron.

4. The weld joint set forth in claim 3, wherein the annular ring of aluminide particles comprises at least one of NiAl₃ particles, NiMnAl particles, FeAl₃ particles, Fe₂Al₅ particles, or FeMnAl particles.

5. The weld joint set forth in claim 1, wherein the aluminum weld nugget of the weld joint tapers radially inwardly as the aluminum weld nugget extends away from the weld bond surface of the weld joint.

6. The weld joint set forth in claim 1, wherein the weld bond surface has a surface area that ranges from 4π

t to 20π

t, in which “

t”

is a thickness of the aluminum workpiece within a weld zone that contains the weld joint prior to formation of the weld joint.

7. The weld joint set forth in claim 1, wherein the intermetallic layer comprises iron-aluminum intermetallic compounds and has a thickness across the weld bond surface that ranges from 1 μ

m to 5 μ

m.

8. A weld joint that bonds an aluminum workpiece and a steel workpiece together, the weld joint having a weld bond surface adjacent to and bonded with a faying surface of the steel workpieces, the weld joint comprising:

an aluminum weld nugget contained within the aluminum workpiece, the aluminum weld nugget tapering radially inward as the aluminum weld nugget extends away from the weld bond surface of the weld joint;

an intermetallic layer located between the aluminum weld nugget and the faying surface of the steel workpiece, the intermetallic layer providing the weld bond surface of the weld joint and comprising iron-aluminum intermetallic compounds; and

an annular ring of aluminide particles that extends upwards from the weld bond surface of the weld joint and radially inwardly into the aluminum weld nugget from a notch root that surrounds the weld joint at a faying interface of the aluminum and steel workpieces, wherein the annular ring of aluminide particles comprises at least one of nickel aluminide particles or iron aluminide particles.

9. The weld joint set forth in claim 8, wherein the annular ring of aluminide particles comprises at least one of nickel aluminide particles having 20 at % to 50 at % nickel or iron aluminide particles having 20 at % to 50 at % iron.

10. The weld joint set forth in claim 8, wherein the aluminum workpiece includes a base aluminum substrate composed of an aluminum alloy that includes at least 85 wt % aluminum.

11. The weld joint set forth in claim 8, wherein the annular ring of aluminide particles comprises at least one of NiAl₃ particles, NiMnAl particles, FeAl₃ particles, Fe₂Al₅ particles, or FeMnAl particles.

12. The weld joint set forth in claim 8, wherein the intermetallic layer has a thickness across the weld bond surface that ranges from 1 μ

m to 5 μ

m.