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(11)

EP 4 081 355 A1

(12)

(43) Date of publication: 02.11.2022 Bulletin 2022/44 (21) Application number: 20904763.8 (22) Date of filing: 22.12.2020

(51) International Patent Classification (IPC):  B21C 23/00(2006.01) C22C 21/02(2006.01) B22D 21/00(2006.01) (52) Cooperative Patent Classification (CPC): C22C 21/02; B21C 23/085; B21C 29/003; B21C 23/002; C22C 21/08; C22F 1/05 (86) International application number: PCT/US2020/066590 (87) International publication number: WO 2021/133792 (01.07.2021 Gazette 2021/26)

(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 Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 23.12.2019 US 201962952614 P (71) Applicant: Alcoa USA Corp. Pittsburgh, PA 15212-5858 (US)	(72) Inventors: YAN, Xinyan Murrysville, PA 15668 (US) CARON, Francis Quebec G0A 2Y0 (CA) (74) Representative: Forresters IP LLP  Skygarden Erika-Mann-Straße 11 80636 München 80636 München (DE)