(19)

(11)

EP 2 758 557 A2

(12)

(88) Date of publication A3: 27.06.2013 (43) Date of publication: 30.07.2014 Bulletin 2014/31 (21) Application number: 12762575.4 (22) Date of filing: 19.09.2012

(51) International Patent Classification (IPC):  C22C 21/02(2006.01) C22C 21/04(2006.01) (86) International application number: PCT/EP2012/068465 (87) International publication number: WO 2013/041584 (28.03.2013 Gazette 2013/13)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 19.09.2011 US 201161536451 P (71) Applicant: Alcoa GmbH 72636 Frickenhausen (DE)	(72) Inventors: MÜLLER, Claus, Michael 35423 Lich (DE) SCHEID, Ralf 52078 Aachen (DE) VOS, Martijn CH-8113 Boppelsen (CH) (74) Representative: LENZING GERBER  Patentanwälte Bahnstrasse 9 40212 Düsseldorf 40212 Düsseldorf (DE)