(19)
(11) EP 3 978 655 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.05.2022 Bulletin 2022/21

(43) Date of publication A2:
06.04.2022 Bulletin 2022/14

(21) Application number: 21200000.4

(22) Date of filing: 29.09.2021
(51) International Patent Classification (IPC): 
C25D 11/02(2006.01)
C25D 11/04(2006.01)
 C25D 11/30(2006.01)
(52) Cooperative Patent Classification (CPC):
C25D 11/024; C25D 11/30; C25D 11/04
(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: 02.10.2020 JP 2020167803

(71) Applicant: Suzuki Motor Corporation
Shizuoka 432-8611 (JP)

(72) Inventors:
  • MASUHARA, Shinya
    Hamamatsu-shi, 432-8611 (JP)
  • KAWANAKA, Shimpei
    Hamamatsu-shi, 432-8611 (JP)
  • FUJITA, Masahiro
    Hamamatsu-shi, 432-8611 (JP)

(74) Representative: Henkel & Partner mbB 
Patentanwaltskanzlei, Rechtsanwaltskanzlei Maximiliansplatz 21
80333 München
80333 München (DE)

   


(54) METHOD FOR PRODUCING LAYERED FILM STRUCTURE AND PISTON FOR INTERNAL COMBUSTION ENGINE


(57) [Problem to be Solved]
To provide a method for producing a layered film structure wherein a smooth anodized film or chemical conversion film is formed on a surface of an alloy member without being affected by a precipitated phase contained in the alloy member, and a piston for an internal combustion engine.
[Solution]
The production method of the present invention includes the steps of: forming a pure metal layer on a surface of an alloy member; and conducting an anodizing treatment or a chemical conversion treatment on the pure metal layer to obtain a layered film structure having the alloy member and a film formed on the surface thereof. The piston for an internal combustion engine of the present invention has this layered film structure, wherein an interface between the alloy member and the film is linear at a cross section of the layered film structure or a precipitated phase is present in the interface and the interface is linear at the cross-section of the layered film structure except a portion where the precipitated phase is present.







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