Resistance spot welding manufacture and method of forming same

Abstract

A method of forming a resistance spot welding manufacture includes sandwiching a third metal layer between first and second metal layers to form a workpiece. The second layer has a surface defining an embossed region. The first layer has a first thickness, the third layer has a third thickness, and the second layer has a second thickness that is less than the first and third thicknesses so that a ratio of the first thickness to the second thickness is greater than about 2:1. The method includes positioning the workpiece between a first and second electrode so that the workpiece is disposed in electrically-conductive relationship with the first and the second electrodes, and applying an electrical current through the first electrode to concurrently melt the first and third layers and the surface at the embossed region to join the first and second layers to the third layer and form the manufacture.

1 . A method of forming a resistance spot welding manufacture, the method comprising:
 sandwiching a third metal layer between a first metal layer and a second metal layer to thereby form a workpiece;   wherein the second metal layer has a faying surface defining an embossed region and disposed adjacent the third metal layer;   wherein the first metal layer has a first thickness, the third metal layer has a third thickness, and the second metal layer has a second thickness that is less than each of the first thickness and the third thickness so that a ratio of the first thickness to the second thickness is greater than about 2:1;   positioning the workpiece between a first electrode and a second electrode so that the workpiece is disposed in electrically-conductive relationship with each of the first electrode and the second electrode; and   applying an electrical current through the first electrode to concurrently melt each of the first metal layer, the third metal layer, and the faying surface at the embossed region to join each of the first metal layer and the second metal layer to the third metal layer and thereby form the resistance spot welding manufacture.   
     
     
         2 . The method of  claim 1 , wherein said positioning aligns the first electrode and the second electrode with the embossed region. 
     
     
         3 . The method of  claim 1 , wherein said positioning aligns the workpiece between the first electrode and the second electrode along an axis perpendicular to the faying surface through the embossed region. 
     
     
         4 . The method of  claim 3 , wherein said positioning disposes the workpiece adjacent and in contact with each of the first electrode and the second electrode. 
     
     
         5 . The method of  claim 3 , wherein said positioning includes disposing the first metal layer adjacent and in contact with the first electrode and disposing the second metal layer adjacent and in contact with the second electrode. 
     
     
         6 . The method of  claim 1 , wherein said sandwiching disposes the third metal layer adjacent and in contact with each of the first metal layer and the faying surface. 
     
     
         7 . The method of  claim 1 , wherein said sandwiching includes disposing the third metal layer between the first metal layer and the embossed region such that the third metal layer is disposed adjacent and in contact with each of the first metal layer and the second metal layer. 
     
     
         8 . The method of  claim 1 , wherein the second metal layer has a second surface spaced opposite the faying surface and defining an imprint aligned with the embossed region, and further wherein said sandwiching includes disposing the third metal layer between the first metal layer and the embossed region such that the imprint is spaced opposite the third metal layer. 
     
     
         9 . The method of  claim 1 , wherein said applying forms a weld joint between the first metal layer, the third metal layer, and the faying surface at the embossed region. 
     
     
         10 . The method of  claim 9 , further including penetrating the faying surface at the embossed region with the weld joint. 
     
     
         11 . The method of  claim 1 , wherein said applying includes increasing resistance heating at the faying surface. 
     
     
         12 . The method of  claim 1 , wherein said applying includes resisting flow of the electrical current at the embossed region. 
     
     
         13 . The method of  claim 1 , further including defining a ratio of the third thickness to at least one of the first thickness and the second thickness to be greater than about 3:1. 
     
     
         14 . The method of  claim 1 , further including selecting the first electrode to have a shape and size that is substantially the same as a shape and size of the second electrode. 
     
     
         15 . The method of  claim 14 , wherein the first electrode and the second electrode are each formed from substantially the same material. 
     
     
         16 . A method of forming a resistance spot welding manufacture, the method comprising:
 sandwiching a third metal layer between a first metal layer and a second metal layer to thereby form a workpiece;   wherein the second metal layer has a faying surface defining an embossed region and disposed adjacent the third metal layer;   wherein the first metal layer has a first thickness, the third metal layer has a third thickness, and the second metal layer has a second thickness that is less than each of the first thickness and the third thickness so that a ratio of the first thickness to the second thickness is greater than about 2:1;   wherein said sandwiching disposes the third metal layer adjacent and in contact with each of the first metal layer and the faying surface;   positioning the workpiece between a first electrode and a second electrode so that the workpiece is disposed in electrically-conductive relationship with each of the first electrode and the second electrode;   wherein said positioning aligns the workpiece between the first electrode and the second electrode along an axis perpendicular to the faying surface through the embossed region; and   applying an electrical current through the first electrode to concurrently melt each of the first metal layer, the third metal layer, and the faying surface at the embossed region to join each of the first metal layer and the second metal layer to the third metal layer and thereby form the resistance spot welding manufacture;   wherein said applying forms a weld joint between the first metal layer, the third metal layer, and the faying surface at the embossed region.   
     
     
         17 . The method of  claim 16 , wherein said sandwiching includes disposing the third metal layer between the first metal layer and the embossed region such that the third metal layer is disposed adjacent and in contact with each of the first metal layer and the second metal layer. 
     
     
         18 . The method of  claim 16 , further including penetrating the faying surface at the embossed region with the weld joint. 
     
     
         19 . A method of forming a resistance spot welding manufacture, the method comprising:
 sandwiching a third metal layer between a first metal layer and a second metal layer to thereby form a workpiece;   wherein the second metal layer has a faying surface disposed adjacent the third metal layer and defining a plurality of embossed regions each spaced apart from one another;   wherein the first metal layer has a first thickness, the third metal layer has a third thickness, and the second metal layer has a second thickness that is less than each of the first thickness and the third thickness so that a ratio of the first thickness to the second thickness is greater than about 2:1;   positioning the workpiece between a first electrode and a second electrode so that the workpiece is disposed in electrically-conductive relationship with each of the first electrode and the second electrode; and   applying an electrical current through the first electrode to concurrently melt each of the first metal layer, the third metal layer, and the faying surface at each of the plurality of embossed regions to join each of the first metal layer and the second metal layer to the third metal layer and thereby form the resistance spot welding manufacture.   
     
     
         20 . The method of  claim 19 , wherein said applying includes resisting flow of the electrical current at each of the plurality of embossed regions.