METHOD OF RESISTANCE SPOT WELDING ALUMINUM TO STEEL
First Claim
1. A method of resistance spot welding an aluminum workpiece and an adjacent overlapping steel workpiece, the method comprising:
- locating a source of a reactive metal in a diffusible state along a faying interface of an aluminum workpiece and an adjacent overlapping steel workpiece, the reactive metal being able to react with molten aluminum to form metal aluminide particles;
pressing a weld face of a first welding electrode against an aluminum workpiece surface that provides a first side of the workpiece stack-up;
pressing a weld face of a second welding electrode against a steel workpiece surface that provides a second side of the workpiece stack-up;
passing an electrical current through a workpiece stack-up between the weld faces of the opposed first and second welding electrodes at a weld zone to melt the aluminum workpiece that lies adjacent to the steel workpiece and create a molten aluminum weld pool within the aluminum workpiece that wets a faying surface of the adjacent steel workpiece, and wherein contact between the molten aluminum weld pool and the source of a reactive metal in a diffusible state results in the formation of metal aluminide particles that migrate into the molten aluminum weld pool; and
terminating passage of the electrical current between the weld faces of the opposed first and second welding electrodes to allow the molten aluminum alloy weld pool to solidify into a weld joint.
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Accused Products
Abstract
A method of resistance spot welding an aluminum workpiece and an adjacent overlapping steel workpiece is disclosed in which a source of a reactive metal in a diffusible state is located along a faying interface of an aluminum workpiece and an adjacent overlapping steel workpiece. The source of the reactive metal in a diffusible state may take on a variety of forms including (1) a composite adhesive layer that includes reactive particles dispersed throughout a structural thermosetting adhesive matrix or (1) a reactive alloy layer that confronts and is in proximate contact with a faying surface of the aluminum workpiece. Once the source of a reactive material in a diffusible state is in place and the workpiece stack-up is assembled, an electrical current is passed through the workpiece stack-up and between a set of opposed welding electrodes at a weld zone to ultimately produce a weld joint.
20 Citations
10 Claims
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1. A method of resistance spot welding an aluminum workpiece and an adjacent overlapping steel workpiece, the method comprising:
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locating a source of a reactive metal in a diffusible state along a faying interface of an aluminum workpiece and an adjacent overlapping steel workpiece, the reactive metal being able to react with molten aluminum to form metal aluminide particles; pressing a weld face of a first welding electrode against an aluminum workpiece surface that provides a first side of the workpiece stack-up; pressing a weld face of a second welding electrode against a steel workpiece surface that provides a second side of the workpiece stack-up; passing an electrical current through a workpiece stack-up between the weld faces of the opposed first and second welding electrodes at a weld zone to melt the aluminum workpiece that lies adjacent to the steel workpiece and create a molten aluminum weld pool within the aluminum workpiece that wets a faying surface of the adjacent steel workpiece, and wherein contact between the molten aluminum weld pool and the source of a reactive metal in a diffusible state results in the formation of metal aluminide particles that migrate into the molten aluminum weld pool; and terminating passage of the electrical current between the weld faces of the opposed first and second welding electrodes to allow the molten aluminum alloy weld pool to solidify into a weld joint. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification