(19)

(11)

EP 0 937 162 A1

(12)

(43) Date of publication: 25.08.1999 Bulletin 1999/34 (21) Application number: 98934292.0 (22) Date of filing: 10.07.1998

(51) International Patent Classification (IPC):  C22F 1/ 043( . ) (86) International application number: PCT/US1998/014031 (87) International publication number: WO 1999/002749 (21.01.1999 Gazette 1999/03)

(84) Designated Contracting States: DE FR GB IT SE (30) Priority: 11.07.1997 US 19970052275P 10.10.1997 US 19970062956P (71) Applicant: Alcoa Inc. Pittsburgh, PA 15212-5858 (US)	(72) Inventor: BENEDYK, Joseph, C. Lake Zurich, IL 60047 (US) (74) Representative: Flynn, Michael Joseph, et al  William Jones, Willow Lane House, Willow Lane Norwich NR2 1EU Norwich NR2 1EU (GB)