Coating for metal components, method for coating a metal component, piston for internal combustion engines and motor vehicle

Patent metadata

Field	Value
Publication number	US-10458361-B2
Application number	US-201715403556-A
Country	US
Kind code	B2
Filing date	Jan 11, 2017
Priority date	Aug 27, 2014
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

An abrasion-resistant and friction-reduced coating for metal components is provided. The coating includes an inner layer, an intermediate layer and an outer layer. The inner layer is intended to be applied to the metal component and has at least one layer selected from: a metal layer, a metal-carbide layer, a metal-nitride layer, a metalcarbide- nitride layer and a metal-containing hydrocarbon layer. The intermediate layer includes at least one layer of amorphous carbon and the outer layer includes a W—C:H layer or a a-C:H* layer. A maximum layer thickness of the coating is at most 5 μm. The coating is suitable in particular as a piston coating for use in internal combustion engines.

First claim

What is claimed is:

1. A motor vehicle, comprising at least one piston of an internal combustion engine, the piston having a coating comprising:
an inner layer which is applied to the piston;
an intermediate layer; and
a covering layer, wherein
the inner layer comprises at least one layer selected from among: a metal layer, a metal carbide layer, a metal nitride layer, a metal carbonitride layer and a metal-containing hydrocarbon layer,
the intermediate layer comprises an a-C:H layer and an a-C:H* layer, wherein the a-C:H* layer has a higher proportion of graphite-like parts than in the a-C:H layer,
the covering layer comprises a W C:H layer or an a-C:H* layer,
a maximum layer thickness of the coating is not more than 5 μm.

2. The motor vehicle according to claim 1 , wherein in the coating, one of:
the inner layer has a Cr layer, a Cr/WC layer and a W—C:H layer and the Cr layer is provided for application to the piston, or
the inner layer has a CrN layer, a Cr/WC layer and a W—C:H layer and the CrN layer is provided for application to the piston, or
the inner layer has a Cr layer, a CrN layer and a Cr/WC layer and the Cr layer is provided for application to the piston.

3. The motor vehicle according to claim 2 , wherein the intermediate layer comprises an a-C:H layer.

4. The motor vehicle according to claim 1 , wherein in the intermediate layer, the a-C:H layer faces the inner layer and the a-C:H* layer faces the covering layer.

5. The motor vehicle according to claim 1 , wherein
the inner layer is formed by a Cr layer or CrN layer, a Cr/WC layer and a W—C:H layer in this order, where the Cr layer or the CrN layer is provided for application to the piston,
the intermediate layer is an a-C:H layer, and
the covering layer is a W—C:H layer or an a-C:H* layer.

6. The motor vehicle according to claim 1 , wherein
the inner layer is formed by a Cr layer, a Cr/WC layer and a WC/W—C:H layer in this order, where the Cr layer is provided for application to the piston,
the intermediate layer comprises an a C:H layer facing the inner layer and an a-C:H* layer facing the covering layer, and
the covering layer is a W—C:H layer.

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Procopio Andrea
• Stothard Nigel
• Ungar Stefan

Classifications

• C23C16/0272

  Deposition of sub-layers, e.g. to promote the adhesion of the main coating · CPC title

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• C23C28/34

  including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates · CPC title

• C23C28/042 Primary

  including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides · CPC title

• C23C14/0664

  Carbonitrides · CPC title