Sliding member and piston ring

Patent metadata

Field	Value
Publication number	US-10655208-B2
Application number	US-201615758447-A
Country	US
Kind code	B2
Filing date	Aug 15, 2016
Priority date	Sep 9, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The provided sliding member has both excellent wear resistance and excellent coating adhesion even under harsh sliding conditions. The disclosed sliding member ( 100 ) is used in the presence of a lubricating oil and includes a base member ( 10 ), a metal intermediate layer ( 12 ) formed on the sliding surface ( 10 A) side of the base member, a layered carbon coating ( 18 ) formed on the metal intermediate layer and having a first carbon coating ( 14 ) and a second carbon coating ( 16 ) layered alternately therein, and a hard carbon coating ( 20 ) formed on the layered carbon coating. Under bright-field observation with a transmission electron microscope, an image of the first carbon coating ( 14 ) is brighter than an image of the second carbon coating ( 16 ). Furthermore, 10 nm<T 2 ≤1000 nm and 0.010≤T 1 /T 2 ≤0.60, where T 1 and T 2 are the thicknesses of the first and second carbon coatings ( 14, 16 ).

First claim

The invention claimed is:

1. A sliding member used in the presence of a lubricating oil, the sliding member comprising:
a base member;
a metal intermediate layer formed on a sliding surface side of the base member;
a layered carbon coating formed on the metal intermediate layer and having a first carbon coating and a second carbon coating layered alternately therein; and
a hard carbon coating formed on the layered carbon coating, the hard carbon coating having a Martens hardness of 6 GPa or more and 30 GPa or less;
wherein under bright-field observation with a transmission electron microscope, an image of the first carbon coating is brighter than an image of the second carbon coating;
wherein T 2 is more than 10 nm and 1000 nm or less, and T 1 /T 2 is 0.010 or more and 0.60 or less, where T 1 is a thickness of the first carbon coating, and T 2 is a thickness of the second carbon coating, and
wherein the hard carbon coating is in contact with the second carbon coating.

2. The sliding member of claim 1 , comprising a thin metal coating having a thickness of 100 nm or less between the first carbon coating and the second carbon coating that are adjacent in the layered carbon coating.

3. The sliding member of claim 1 , wherein T 3 is 3 μm or more and 20 μm or less, and T 3 /T 4 is 2 or more and 20 or less, where T 3 is a thickness of the layered carbon coating, and T 4 is a thickness of the hard carbon coating.

4. The sliding member of claim 1 , wherein the first carbon coating, the second carbon coating, and the hard carbon coating are substantially free of hydrogen.

5. The sliding member of claim 1 , wherein the metal intermediate layer comprises one or more elements, or a carbide thereof, selected from the group consisting of Cr, Ti, Co, V, Mo, Si, and W, and a thickness of the metal intermediate layer is 0.1 μm or more and 0.6 μm or less.

6. A piston ring comprising the sliding member of claim 1 , wherein an outer circumferential surface of the piston ring is the sliding surface.

Assignees

• Kk Riken

Inventors

• Shinohara Akio

Classifications

• F16C33/125

  Details of bearing layers, i.e. the lining · CPC title

• F16C2206/04

  Diamond like carbon [DLC] · CPC title

• C23C14/025

  Metallic sublayers · CPC title

• F16C33/24

  with different areas of the sliding surface consisting of different materials · CPC title

• C23C28/44

  characterized by a measurable physical property of the alternating layer or system, e.g. thickness, density, hardness · CPC title