A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process uniformly preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process uniformly preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A manufacturing method for joined bodies that allows galvanic corrosion to be reduced is provided. The method is for manufacturing a joined body obtained by joining together a mating member made of ferrous metal and a non-ferrous metal material. The method includes: a press fit step of press-fitting a joining element made of ferrous metal into a predetermined surface of the non-ferrous metal material; and a welding step of forming a melted portion between an exposed portion of the joining element press-fitted into the non-ferrous metal material and the mating member. After the press fit step, a part of the joining element is exposed from the predetermined surface and the remaining part of the joining element is not exposed and is buried in the non-ferrous metal material. The remaining part of the joining element includes a lodging portion having a surface facing to the predetermined surface.

A manufacturing method for joined bodies that allows galvanic corrosion to be reduced is provided. The method is for manufacturing a joined body obtained by joining together a mating member made of ferrous metal and a non-ferrous metal material. The method includes: a press fit step of press-fitting a joining element made of ferrous metal into a predetermined surface of the non-ferrous metal material; and a welding step of forming a melted portion between an exposed portion of the joining element press-fitted into the non-ferrous metal material and the mating member. After the press fit step, a part of the joining element is exposed from the predetermined surface and the remaining part of the joining element is not exposed and is buried in the non-ferrous metal material. The remaining part of the joining element includes a lodging portion having a surface facing to the predetermined surface.

A welded assembly includes a first object, a second object, and an interlayer. The interlayer is an ESD coating deposited on the first object, and the second object is welded to the coating. The second object may be a material that has thermally sensitive properties, such as a shape-memory material. The second weld may also be made by ESD. The interlayer may be made of more than one layer. The layer or layers may be deposited of a material chosen for its compatibility with one, the other, or both of the material of the first object and the material of the second object.

A resistance spot welding method includes sandwiching metal plates put on top of one another between a pair of electrodes and performing resistance spot welding sequentially on a plurality of welding points close to each other on the metal plates by performing a current application between the electrodes so as to join the metal plates to each other. A welding current value to form a welding nugget at a welding point to be subjected to the resistance spot welding second or later among the welding points is set to be higher than a first welding current value to form a first welding nugget at a first welding point to be subjected to the resistance spot welding first among the welding points.

A resistance spot welding method may involve spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece. A pair of opposed welding electrodes are pressed against opposite sides of the workpiece stack-up with one welding electrode contacting the aluminum alloy workpiece and the other welding electrode contacting the steel workpiece. The welding electrodes are constructed so that, when an electrical current is passed between the electrodes and through the workpiece stack-up, the electrical current has a greater current density in the steel workpiece than in the aluminum alloy workpiece to thereby concentrate heat within a smaller zone in the steel workpiece. Concentrating heat within a smaller zone in the steel workpiece is believed to modify the solidification behavior of the resultant molten aluminum alloy weld pool in a desirable way.

A resistance spot welding method may involve spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece. A pair of opposed welding electrodes are pressed against opposite sides of the workpiece stack-up with one welding electrode contacting the aluminum alloy workpiece and the other welding electrode contacting the steel workpiece. The welding electrodes are constructed so that, when an electrical current is passed between the electrodes and through the workpiece stack-up, the electrical current has a greater current density in the steel workpiece than in the aluminum alloy workpiece to thereby concentrate heat within a smaller zone in the steel workpiece. Concentrating heat within a smaller zone in the steel workpiece is believed to modify the solidification behavior of the resultant molten aluminum alloy weld pool in a desirable way.