Sliding member and coating film

Patent metadata

Field	Value
Publication number	US-11293548-B2
Application number	US-201816624781-A
Country	US
Kind code	B2
Filing date	Jun 15, 2018
Priority date	Jun 20, 2017
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A sliding member (10) including a coating film (1) composed of a hard carbon layer on a sliding surface (16) of a base material (11). The coating film has, when a cross section thereof is observed by a bright-field TEM image, a thickness within a range of 1 μm to 50 μm, and is configured by repeating units including black hard carbon layers (B), relatively shown in black, and white hard carbon layers (W), relatively shown in white, and laminated in a thickness direction, and comprise an inclined region, provided on a base material side, where thicknesses of white hard carbon layers (W) of the repeating units gradually increase in a thickness direction, and a homogeneous region\, provided on a surface side of the sliding member, where thicknesses of the white hard carbon layers (W) of the repeating units are the same or substantially the same in the thickness direction.

First claim

What is claimed is:

1. A sliding member comprising:
a coating film composed of a hard carbon layer on a sliding surface,
the coating film having, when a cross section thereof is observed by a bright-field TEM image, a thickness within a range of 1 μm to 50 μm, and configured by repeating units including black hard carbon layers, relatively shown in black, and white hard carbon layers, relatively shown in white, and laminated in a thickness direction, and
the coating film including
an inclined region, provided on a base material side, where thicknesses of the white hard carbon layers of the repeating units gradually increase in a thickness direction, and
a homogeneous region, provided on a surface side, where thicknesses of the white hard carbon layers of the repeating units are the same or substantially the same in the thickness direction,
the inclined region having a form grown into a V-shape or a radial pattern in the thickness direction, and
the homogeneous region not having a form grown into a V-shape or a radial pattern in the thickness direction.

2. The sliding member according to claim 1 , wherein
a thickness ratio of the black hard carbon layer to the white hard carbon layer (black thickness/white thickness) in the homogeneous region is 0.01 to 0.3.

3. The sliding member according to claim 1 , wherein
the white hard carbon layer has an sp 2 /sp 3 ratio of 0.2 to 0.7, and the black hard carbon layer has an sp 2 /sp 3 ratio lower than the sp 2 /sp 3 ratio of the white hard carbon layer and the sp 2 /sp 3 ratio is 0.05 to 0.3.

4. The sliding member according to claim 1 , wherein,
when a cross section thereof is observed by a bright-field TEM image, a hard carbon base film relatively shown in white is provided between the base material or a base film provided on the base material, and the coating film.

5. The sliding member according to claim 1 , wherein,
when a cross section thereof is observed by a bright-field TEM image, a hard carbon surface film relatively shown in white is provided on the coating film.

6. The sliding member according to claim 1 , wherein
the sliding member is a piston ring.

7. A coating film having, when a cross section thereof is observed by a bright-field TEM image, a thickness within a range of 1 μm to 50 μm, and configured by repeating units including black hard carbon layers, relatively shown in black, and white hard carbon layers, relatively shown in white, and laminated in a thickness direction, the coating film comprising:
an inclined region where thicknesses of the white hard carbon layers of the repeating units gradually increase in a thickness direction; and
a homogeneous region, provided on the inclined region, where thicknesses of the white hard carbon layers of the repeating units are the same or substantially the same in the thickness direction,
the inclined region having a form grown into a V-shape or a radial pattern in the thickness direction, and
the homogeneous region not having a form grown into a V-shape or a radial pattern in the thickness direction.

Assignees

• Nippon Piston Ring Co Ltd
• Nippon Itf Inc

Inventors

• Okazaki Takahiro
• Ito Yoshihiro
• Sugiura Hiroyuki
• Kanazawa Shinya
• Moriguchi Hideki
• Shibata Akinori
• Ooshiro Takehiko

Classifications

• F16C33/12

  Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing · CPC title

• C23C14/16

  on metallic substrates or on substrates of boron or silicon · CPC title

• C23C28/048

  with layers graded in composition or physical properties · CPC title

• C23C14/024

  Deposition of sublayers, e.g. to promote adhesion of the coating (C23C14/027 takes precedence) · CPC title

• C23C14/325

  Electric arc evaporation · CPC title