Method of making an electrical aluminum-copper connection

Claim 1

IN A METHOD OF MAKING AN ELECTRICAL CONNECTION BETWEEN AN ALUMINUM BUS BAR AND A COPPER ANODE BAR OF AN ELECTROLYTIC REDUCTION CELL, ARRANGING A COPPER CONTACT MEMBER AND AN ALUMINUM BACKING MEMBER IN END-TOEND ABUTTING RELATION, SAID ALUMINUM BACKING MEMBER BEING MORE DUCTILE THAN SAID COPPER CONTACT MEMBER, FORMING A FLASH WELDED JOINT BETWEEN THE ABUTTING ENDS OF SAID MEMBERS, SAID JOINT HAVING A BRITTLE PHASE AT THE FLASH WELD INTERFACE, AND APPLYING SUFFICIENT PRESSSURE TO THE RESULTTANT COMPOSITE IN A DIRECTION SUBSTANTIALLY NORMAL TO THE FLASH WELD INTERFACE TO THIN OUT SAID BRITTLE PHASE AND EFFECT SUBSTANTIAL LATERAL EXPANSION OF THE SAID MEMBERS IN DIRECTIONS PARALEL TO THE WELD INTERFACE WITH UPSETTING OF SAID ALUMINUM MEMBER OVER SAID COPPER MEMBER TO PRODUCE AT LEAST PARTIAL PERIPHERAL ENCASEMENT OF SAID COPPER MEMBER BY SAID UPSET ALUMINUM MEMBER, AND WELDING SAID BACKING MEMBER TO SAID BUS BAR.