Method for making a bimetal resistance welding electrode
AssigneeThe Nippert Company
InventorRussell A. Nippert
Life of this patent
Estimating the term…
Abstract
A bi-metal resistance welding electrode has a dispersion strengthened copper tip and a high conductivity copper shank. The electrode is made by forming a tip member in two successive upsetting operations to produce a tip member having a coating of high conductivity copper covering substantially all of one end thereof. A solid, high conductivity copper, cylindrical billet is formed and brazed to the tip member at its coated end to form an extrusion blank. The extrusion blank is back extruded with the high conductivity copper material being worked substantially, while only partially back extruding the tip portion of the extrusion blank.
Claims6
A method of making a bimetal resistance welding electrode having a dispersion strengthened copper tip and a high conductivity copper shank, comprising:
- (a) cutting a cylindrical rod of the desired quantity of dispersion strengthened copper material for the electrode tip, said rod including a cylindrical coating of high conductivity copper extending circumferentially therearound,
- (b) upsetting said cylindrical rod along the axis thereof to form a generally cylindrical billet having a coating of high conductivity copper extending circumferentially therearound,
- (c) upsetting said generally cylindrical billet in a direction perpendicular to the axis thereof to form an electrode tip member of extrusion diameter having a negative locator recess positioned in one end thereof and a coating of high conductivity copper covering substantially all of said one end of said tip member,
- (d) forming a solid, high conductivity copper, cylindrical billet of extrusion diameter having a positive locator protrusion which is centrally positioned on one end thereof, said billet formed of the desired quantity of high conductivity copper for the shank of the electrode,
- (e) placing together said electrode tip member and said high conductivity copper cylindrical billet with brazing compound therebetween, such that said protrusion and said recess mate,
- (f) heating said electrode tip member, said high conductivity copper cylindrical billet, and said brazing compound such that said tip member and said high conductivity copper cylindrical billet are brazed together into a single extrusion blank having a tip portion formed of dispersion strengthened copper and a shank portion formed of annealed high conductivity copper, and
- (g) back extruding said shank portion of said extrusion blank such that a high conductivity shank is formed while only partially back extruding said tip portion of extrusion blank, thereby forming a full-hard bimetal electrode, whereby said coating of high conductivity copper prevents depletion of said brazing compound from the brazed joint between said tip member and said high conductivity copper cylindrical billet, and reduces the stress experienced by the brazed joint during extruding.
A method of making a bimetal resistive welding electrode of unitary construction having a tip portion formed of a dispersion strengthened copper and a shank portion formed of a high conductivity copper, comprising the steps of:
- forming a tip member of dispersion strengthened copper having a high conductivity copper coating across a first end thereof,
- forming a cylindrical billet of high conductivity copper,
- brazing said cylindrical billet to said first end of said tip member using a brazing compound, at a temperature which does not anneal said dispersion strengthened copper, to form a bimetal extrusion blank having a tip portion formed of dispersion strengthened copper and a shank portion formed of annealed high conductivity copper, and
- extruding said shank portion of said bimetal extrusion blank into a hardened electrode shank while only partially extruding said tip portion of said bimetal extrusion blank, thereby forming a full-hard bimetal electrode, whereby said high conductivity copper coating prevents depletion of said brazing compound from the brazed joint between said tip member and said cylindrical billet of high conductivity copper, and reduces the stress experienced by the brazed joint during extruding.
Dependencies are inferred from the claim text.