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(11)

EP 0 851 943 A1

(12)

(43) Date of publication: 08.07.1998 Bulletin 1998/28 (21) Application number: 96935838.0 (22) Date of filing: 17.09.1996

(51) International Patent Classification (IPC):  B22D 11/ 06( . ) C22F 1/ 04( . ) C22C 21/ 06( . ) C22F 1/ 047( . ) (86) International application number: PCT/US1996/014877 (87) International publication number: WO 1997/011205 (27.03.1997 Gazette 1997/14)

(84) Designated Contracting States: BE DE ES FR GB GR IT LU NL SE (30) Priority: 18.09.1995 US 19950529522 18.09.1995 US 19950529644 18.09.1995 US 19950531554 02.10.1995 US 19950538415 01.11.1995 US 19950548337 (71) Applicant: KAISER ALUMINUM & CHEMICAL CORPORATION Pleasanton, California 94566 (US)

(72) Inventors: SUN, Tyzh-Chiang Danville, CA 94526 (US) BETTS, William Pleasanton, CA 94566 (US) HARRINGTON, Donald, G. Danville, CA 94549 (US) SMITH, Ian Pleasanton, CA 94566 (US) WESTERMAN, Edwin, J. San Ramone, CA 94583 (US) WYATT-MAIR, Gavin, F. Lafayette, CA 94549 (US) (74) Representative: W.P. THOMPSON & CO.  Eastcheap House Central Approach Letchworth, Hertfordshire SG6 3DS Letchworth, Hertfordshire SG6 3DS (GB)