Composite ceramic coatings for anti-corrosion protection

Patent metadata

Field	Value
Publication number	US-10683582-B2
Application number	US-201615555176-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Mar 4, 2015
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

In some embodiments, an anti-corrosive composite ceramic coating includes an inner metal layer formed on the surface of a metal object to be protected and an outer composite ceramic layer formed on the inner metal layer.

First claim

The invention claimed is:

1. A method for forming an anti-corrosive coating on a metal object, the method comprising:
electrolytically plating a surface of the metal object with a metal to form an inner layer;
mixing zinc and sodium hydroxide together in water to produce a sodium zincate solution having a Zn:NaOH:H 2 O molar ratio of approximately 1:1:6;
separately mixing silicon and sodium hydroxide together in water to produce a sodium silicate solution having an Si:NaOH:H 2 O molar ratio of approximately 6:1:10;
mixing the sodium zincate solution and the sodium silicate solution together to form an Si/Zn composite solution having an Si:Zn molar ratio of approximately 2:5;
depositing the composite solution on top of the inner layer; and
heating the object so that the composite solution forms a composite ceramic layer on top of the inner layer that comprises hydrous zinc silicate having a crystalline structure.

2. The method of claim 1 , wherein heating the object comprises heating the object to a temperature of approximately 25 to 90° C.

3. The method of claim 1 , further comprising pre-processing the metal object before electrolytically plating the surface of the object.

4. The method of claim 3 , wherein pre-processing comprises cleaning and polishing the surface of the object.

5. The method of claim 3 , wherein pre-processing comprises increasing the roughness of the surface of the metal object.

6. The method of claim 1 , wherein the sodium silicate solution has a specific gravity of approximately 1.8 to 2.0.

7. The method of claim 1 , wherein the composite ceramic layer has a thickness of approximately 40 to 300 microns.

8. The method of claim 1 , wherein the composite ceramic layer has a thickness of approximately 260 to 300 microns.

Assignees

• Univ Texas

Inventors

• Rice George Kenneth
• Yacaman Miguel Jose
• Vinogradova Ekaterina

Classifications

• C25D3/22

  of zinc · CPC title

• C25D3/565

  containing more than 50% by weight of zinc · CPC title

• C25D5/36

  of iron or steel · CPC title

• C25D9/10 Primary

  on iron or steel · CPC title

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title