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CDA Awarded U.S. Patent for New Die Casting Technology
21 Claims Cite Applicability to Motor Rotors, Other Cast Products 
On September 7, 2004, the U.S. Patent Office granted patent number 6,786,272 to the Copper Development Association Inc. for the method it developed to permit copper and its alloys to be die cast economically. The method, familiar to readers of Update, is now used commercially to produce copper motor rotors in Europe and India (see Updates for March 10 and October 4, 2004).
Licenses to use the patented technology without fee will be issued to member companies of the CDA-led coalition that developed the new casting technique, according to Hal Stillman, director of technology for the International Copper Association, Ltd., which provided a portion of CDA's R&D funding and will oversee utilization arrangements on a global basis. "Manufacturers who did not participate in the original program and who now wish to utilize the new motor rotor technology will be charged a licensing fee," says Stillman, "and ICA will provide technological support to those companies at cost." The patent discloses the essential elements of CDA's discovery, i.e., even metals with a relatively high melting point can be die cast without risking damage to the dies, if: a) the dies (or strategically placed inserts) are made from a heat-resisting superalloy and b) the temperature of the dies or inserts is maintained at a suitably elevated temperature so as to reduce the thermal stresses induced by repeated casting shots to a level that avoids cracking on the die surface — the well-known heat checking phenomenon. MORE >> |
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