Abstract: The present invention provides a method and apparatus for die-casting copper and other metals that are cost-effective and practical for production use in die-casting, for example, copper motor rotors. In motor rotors, the incorporation of die-cast copper for conductor bars and end rings in place of aluminum is known to result in improvements in motor energy efficiency. Previous attempts to die-cast copper motor rotors in a commercially feasible manner have failed because copper's high melting point places too great a stress on the die material, resulting in cracking and fracturing of the molds. High temperature die materials such as nickel, tungsten and molybdenum based alloys with a high melting point are employed, and a die casting apparatus is provided to pre-heat the molds prior to injection of the molten copper. Pre-heating and high operating temperatures provide extended die life.

Abstract: A method of joining metal surfaces is provided which comprises contacting the metal surfaces with a zinc-based composition and joining the metal surfaces, the zinc-based composition comprising, by weight:from about 0.1 to about 4 percent copper;from about 0.1 to about 1 percent nickel;from about 0.01 to less than 0.5 percent aluminum;0 to about 0.5 percent chromium;0 to about 0.5 percent titanium; and the remainder being zinc is also provided. The composition is useful for coating metal surfaces, particularly metals formed of or containing copper.The above composition and method may be used with or without a flux. Particularly beneficial results are obtained when a flux having a composition comprising, by weight:from about 5 to about 70 percent ZnCl.sub.2 ;from about 1 to about 28 percent NH.sub.4 Cl;from about 0.1 to about 10 percent SnCl.sub.2 ;from about 0 to about 10 percent HCl;from about 0 to about 10 percent Li.sub.2 B.sub.4 O.sub.7 ;from about 0 to about 5 percent MgBr.sub.

Abstract: A zinc-based composition comprising, by weight:from about 0.1 to 4 percent copper;from about 0.1 to about 1 percent nickel;from about 0.01 to less than 0.5 percent aluminum;0 to about 0.5 percent chromium;0 to about 0.5 percent titanium; and the remainder being zinc is provided. The composition is useful for coating or joining metal surfaces, particularly metals formed of or containing copper.The above composition may be used with or without a flux. Particularly beneficial results are obtained when a flux having a composition comprising, by weight:from about 5 to about 70 percent ZnCl.sub.2 ;from about 1 to about 28 percent NH.sub.4 Cl;from about 0.1 to about 10 percent SnCl.sub.2 ;from about 0 to about 10 percent HCl;from about 0 to about 10 percent Li.sub.2 B.sub.4 O.sub.7 ;from about 0 to about 5 percent MgBr.sub.2 ;from about 0 to about 5 percent ZnBr.sub.2 ; and about 0 to about 94 percent water is used.

Abstract: A zinc-based composition comprising from 0.01 to 5 percent lead and 0.01 to 20 percent tin, preferably minor amounts of chromium and/or titanium and/or nickel and with the balance being zinc is provided. A minor amount of copper may also be present. The composition is particularly useful for joining copper and copper alloys because it will wet and readily flow on the copper or copper alloy surfaces. It can be used with or without a flux. It has reduced dissolving action on the copper and copper alloys due to its reduced reactivity with them. It also has improved conductivity vis-a-vis conventional lead-tin and lead-tin-silver solders.