Method for coating a piston

Patent metadata

Field	Value
Publication number	US-2022010141-A1
Application number	US-202117368800-A
Country	US
Kind code	A1
Filing date	Jul 6, 2021
Priority date	Jul 7, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A method for coating a piston of an internal combustion engine may include providing the piston, which may include a piston skirt and a piston crown with a fire land. The method may also include producing a ceramic suspension, which may include a solvent, a binder dissolved in the solvent, a plurality of hollow glass spheres distributed in the binder, and a plurality of ceramic particles distributed in the binder. The method may further include applying the ceramic suspension onto the piston and producing a coating on the piston via removing the solvent from the applied ceramic suspension. The coating may have a matrix formed by the binder in which the plurality of hollow glass spheres and the plurality of ceramic particles are arranged in a distributed manner.

First claim

1 . A method for coating a piston of an internal combustion engine, comprising:
providing the piston, which includes a piston skirt and a piston crown with a fire land; producing a ceramic suspension including:
a solvent
a binder dissolved in the solvent;
a plurality of hollow glass spheres distributed in the binder; and
a plurality of ceramic particles distributed in the binder;
applying the ceramic suspension onto the piston; and producing a coating on the piston via removing the solvent from the applied ceramic suspension, the coating having a matrix formed by the binder in which the plurality of hollow glass spheres and the plurality of ceramic particles are arranged in a distributed manner.

2 . The method according to claim 1 , wherein the coating has a proportion of at least 50%-mass formed by the plurality of ceramic particles.

3 . The method according to claim 1 , wherein the binder is an inorganic binder.

4 . The method according to claim 3 , wherein the binder includes at least one of:
a salt; and water glass.

5 . The method according to claim 1 , wherein the solvent is at least one of:
an aqueous solvent; a polar solvent for dissolving salts; and a short-chain alcohol solvent.

6 . The method according to claim 1 , wherein the coating has a proportion of less than 5%-mass formed by the matrix.

7 . The method according to claim 1 , wherein the plurality of ceramic particles includes at least one of oxides, nitrides, and carbides.

8 . The method according to claim 1 , the plurality of ceramic particles in the coating have a size distribution with a d50 of 0.5 μm to 1.0 μm.

9 . The method according to claim 1 , wherein the plurality of hollow glass spheres are composed of silicon dioxide.

10 . The method according to claim 1 , wherein the plurality of hollow glass spheres in the coating have a size distribution with a d50 of 20 μm to 65 μm.

11 . The method according to claim 1 , wherein the coating has a proportion of 25%-mass to 35%-mass formed by the plurality of hollow glass spheres.

12 . A piston of an internal combustion engine, comprising a piston skirt, a piston crown, and a coating, wherein the coating is provided in accordance with the method according to claim 1 .

13 . The method according to claim 1 , wherein:
applying the suspension onto the piston includes applying the suspension onto the piston crown and the fire land; and producing the coating on the piston includes producing the coating on the piston crown and the fire land.

14 . The method according to claim 1 , wherein the coating has a layer thickness of 50 μm to 100 μm.

15 . The method according to claim 1 , wherein removing the solvent is performed in a manner that does not destroy the plurality of hollow glass spheres.

16 . The method according to claim 1 , wherein the binder includes monoaluminium phosphate.

17 . The method according to claim 1 , wherein a first mass fraction of the coating formed by the plurality of hollow glass spheres is (i) less than a second mass fraction of the coating formed by the plurality of ceramic particles and (ii) greater than a third mass fraction of the coating formed by the matrix.

18 . The method according to claim 1 , wherein:
the plurality of ceramic particles form 69%-mass of the coating; the matrix forms less than 3%-mass of the coating; and the plurality of hollow glass spheres form 28%-mass of the coating

19 . A method for coating a piston of an internal combustion engine, comprising:
providing the piston, which includes a piston skirt and a piston crown with a fire land; producing a ceramic suspension including:
a polar solvent;
an ionic inorganic binder dissolved in the solvent;
a plurality of hollow glass spheres distributed in the binder; and
a plurality of ceramic particles distributed in the binder, the plurality of ceramic particles including at least one of oxides, nitrides, and carbides;
applying the ceramic suspension onto the piston; and producing a coating on the piston via removing the solvent from the applied ceramic suspension, the coating having a matrix formed by the binder in which the plurality of hollow glass spheres and the plurality of ceramic particles are arranged in a distributed manner.

20 . A method for coating a piston of an internal combustion engine, comprising:
providing the piston, which includes a piston skirt and a piston crown with a fire land; producing a ceramic suspension including:
a solvent;
a binder dissolved in the solvent;
a plurality of hollow glass spheres distributed in the binder; and
a plurality of ceramic particles distributed in the binder;
applying the ceramic suspension onto the piston; producing a coating on the piston via removing the solvent from the applied ceramic suspension, the coating having a matrix formed by the binder in which the plurality of hollow glass spheres and the plurality of ceramic particles are arranged in a distributed manner; wherein the plurality of ceramic particles form at least 50%-mass of the coating; wherein the matrix forms less than 5%-mass of the coating; and wherein the plurality of hollow glass spheres form 25 to 35%-mass of the coating.

Assignees

• Mahle Int Gmbh

Inventors

• Koerner Stephan
• Lecker Alois
• Lopez Daniel
• Rose Reinhard

Classifications

• C09D1/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances · CPC title

• C09D7/61

  inorganic · CPC title

• F02F3/10 Primary

  having surface coverings (F02F3/02 takes precedence) · CPC title

• C09D7/70

  characterised by shape, e.g. fibres, flakes or microspheres · CPC title

• C23C28/04

  only coatings of inorganic non-metallic material · CPC title