IP Library Granted Patent US 7,267,736
Granted Patent B2
US 7,267,736 · App. 10/739,356 · Granted Sep 11, 2007

Method of joining dissimilar materials

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,267,736
App. No.
10/739,356
Granted
Sep 11, 2007
Kind
B2
Abstract

The present invention provides a method of joining dissimilar materials, particularly a non-ferrous component to a ferrous component to form an assembly. In an overlapping configuration, the parts are held together under a clamping force while a self-piercing rivet is driven through the assembly by a welding electrode. The rivet pierces and passes through the non-ferrous component and then at least into contact with the ferrous component to thereby form a mechanical interlock. An electrical current is then applied to this mechanical retention to melt a portion of the rivet as well as a portion of the ferrous metal in the joining region. The flow of electrical current is then stopped after several welding cycles where the now melted material is allowed to solidify upon cooling, thereby forming a weld.

Claims (27)

1. A method of joining dissimilar materials, said method comprising the steps of:

placing a first component against a second component at a predetermined joining location, wherein the first and second components are composed of dissimilar materials;

driving a self-piercing rivet through said first component and into said second component to mechanically attach said first component to said second component at said joining location, the self-piercing rivet comprising a head attached to a hollow cylindrical shank with a tapered end so that the shank penetrates through said first component and into said second component and encloses material of said first component in the hollow of said shank;

passing an electrical current through said self-piercing rivet and said second component at said joining location to fuse material at an interface of at least the shank of said rivet and said second component; and

stopping the flow of electrical current to solidify the fused material and form a welded bond between at least said rivet and said second component.

2. The method as recited in claim 1 comprising passing said electrical current by contacting said rivet with a first electrode and contacting said second component with a second electrode at a second surface opposite said joining location and using said electrodes to pass said current through said rivet and second component.

3. The method as recited in claim 1 comprising engaging said first component at said joining location with an electrode assembly comprising a first electrode and a hollow cylindrical electrode tool, said tool being adapted to encompass said rivet and said first electrode and to exert a clamping force on said first component;

engaging said second component at a second surface with a second electrode adapted to conform to said second surface for clamping and electrical contact; and

using said electrodes to pass said current through said rivet and second component, said current flowing around or through said second component from said second surface to said joining location and said interface.

4. The method as recited in claim 1 comprising engaging said first component at said joining location with an electrode assembly comprising a first electrode and a hollow cylindrical electrode tool, said tool being adapted to encompass said rivet and said first electrode and to exert a clamping force on said first component;

engaging said second component at a second surface with a second electrode adapted to conform to said second surface for clamping and electrical contact;

placing said rivet in said electrode tool and driving said rivet through said first component and into said second component with said first electrode; and

using said electrodes to pass said current through said rivet and said second component.

5. A method of joining a non-ferrous component to a ferrous component, said method comprising the steps of:

pressing said non-ferrous component against one surface of said ferrous component at a predetermined joining location using a first electrode assembly to press against said non-ferrous component and a second electrode against another surface of said ferrous component;

driving a self-piercing ferrous rivet through said non-ferrous component using said first electrode and at least into contact with a wall of said ferrous component at said joining location to mechanically attach said non-ferrous component to said ferrous component, the self-piercing ferrous rivet comprising a head attached to a hollow cylindrical shank with a tapered end so that the shank penetrates through said first component and into said second component and encloses material of said first component in the hollow of said shank; and

passing an electrical current through said electrodes, said ferrous rivet, and said ferrous component at said joining location to fuse at least said ferrous rivet to said ferrous component; and

stopping the flow of electrical current to form a welded bond between at least said rivet and said ferrous component.

6. A method of joining a non-ferrous component to a ferrous component as recited in claim 5 in which the non-ferrous component comprises a metal alloy.

7. A method of joining a non-ferrous component to a ferrous component as recited in claim 5 in which the non-ferrous component comprises a polymer composition.

8. A method of joining a sheet portion of a non-ferrous component to a ferrous tube having a first surface and a second surface opposing the first surface, said method comprising the steps of:

pressing the sheet portion of the non-ferrous component against the first surface of the ferrous tube at a predetermined joining location using a first electrode assembly to press against said non-ferrous component and a second electrode against the second surface of the ferrous tube;

driving a self-piercing ferrous rivet through the sheet portion of the non-ferrous component and at least into contact with the first surface of the ferrous tube at said joining location to mechanically attach said non-ferrous component to said ferrous tube, the self-piercing ferrous rivet comprising a head attached to a hollow cylindrical shank with a tapered end so that the shank penetrates through the sheet portion of the non-ferrous first component and into the ferrous tube and encloses material of the first component in the hollow of the shank; and

passing an electrical current through the electrodes, the ferrous rivet, and the ferrous component at said joining location to fuse at least the ferrous rivet to the ferrous component; and

stopping the flow of electrical current to form a welded bond between at least the rivet and the ferrous component.

9. A method of joining a non-ferrous component to a ferrous tube as recited in claim 8 in which the non-ferrous component comprises a metal alloy.

10. A method of joining a non-ferrous component to a ferrous tube as recited in claim 8 in which the non-ferrous component comprises a polymer composition.

Assignments (13)
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2014
From: WILMINGTON TRUST COMPANY
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 034192/0299 →
CHANGE OF NAME Recorded Feb 10, 2011
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 025780/0902 →
SECURITY AGREEMENT Recorded Nov 8, 2010
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: WILMINGTON TRUST COMPANY
Reel/Frame 025327/0262 →
RELEASE OF SECURITY INTEREST Recorded Nov 4, 2010
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025245/0347 →
RELEASE OF SECURITY INTEREST Recorded Nov 4, 2010
From: UAW RETIREE MEDICAL BENEFITS TRUST
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025311/0725 →
SECURITY AGREEMENT Recorded Aug 28, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UAW RETIREE MEDICAL BENEFITS TRUST
Reel/Frame 023161/0911 →
SECURITY AGREEMENT Recorded Aug 27, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 023156/0001 →
RELEASE OF SECURITY INTEREST Recorded Aug 21, 2009
From: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023127/0468 →
RELEASE OF SECURITY INTEREST Recorded Aug 20, 2009
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023124/0429 →
SECURITY AGREEMENT Recorded Apr 16, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
Reel/Frame 022553/0446 →
SECURITY AGREEMENT Recorded Feb 4, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 022201/0547 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 14, 2009
From: GENERAL MOTORS CORPORATION
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 022102/0533 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 2, 2004
From: WANG, PEI-CHUNG; HOU, WENKAO; HU, SHIXIN JACK
To: GENERAL MOTORS CORPORATION; UNIVERSITY OF MICHIGAN
Reel/Frame 014390/0567 →