Patent ID: 6144006
Filing Date: 2000-11-07
Classification: B22F,B23K,C22C

Abstract:
A method of making and using copper-based electrodes to spot-weld aluminum workpieces comprising:(a) dissolving copper and one or more alloying elements X to yield an alloy that increases the liquidus of Al when dissolved in molten Al, said copper and X being super heated to an elevated temperature at which X is soluble in copper, X being selected from the group of tungsten and vanadium elements, said elements forming phases with copper and aluminum devoid of an eutectic, when X is present in said copper in an amount of 4-15% by weight of the copper;(b) rapidly cooling said alloy to room temperature while trapping X in solid solution within said copper;(c) either concurrently with or subsequent to step (b), forming said alloy as an electrode shape; and(d) passing current through said electrode shape to effect spot-welding of said aluminum workpieces when pressed thereagainst while suppressing formation of low melting Al/Cu eutectics and thereby extend the welding life of the electrode.