Composite ceramic coatings for anti-corrosion protection

Patent metadata

Field	Value
Publication number	US-2018051386-A1
Application number	US-201615555176-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Mar 4, 2015
Publication date	Feb 22, 2018
Grant date	—

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

1 . An anti-corrosive composite ceramic coating comprising:
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.

2 . The coating of claim 1 , wherein the inner metal layer is a zinc or zinc alloy layer.

3 . The coating of claim 1 , wherein the inner metal layer is approximately 4 to 300 μm thick.

4 . The coating of claim 1 , wherein the composite ceramic layer contains zinc and silicon.

5 . The coating of claim 1 , wherein the composite ceramic layer is a hydrous zinc silicate layer.

6 . The coating of claim 5 , wherein the hydrous zinc silicate layer is made of Zn 3 Si 4 O 10 (OH) 2 .

7 . The coating of claim 1 , wherein the composite ceramic layer is approximately 40 to 300 μm thick.

8 . A coated metal object protected by an anti-corrosive composite ceramic coating, the coated metal object comprising:
a steel body having a surface; and an anti-corrosive composite ceramic coating formed on body, the coating including an inner metal layer formed on the surface and an outer composite ceramic layer formed on the inner metal layer.

9 . The object of claim 8 , wherein the inner metal layer is a zinc or zinc alloy layer.

10 . The object of claim 8 , wherein the composite ceramic layer is a hydrous zinc silicate layer.

11 . A method for forming an anti-corrosive coating on a metal object, the method comprising:
electrolytically plating the surface of the object with a metal to form an inner layer; and electrolytically depositing a composite ceramic layer on top of the inner layer.

12 . The method of claim 11 , wherein electrolytically plating the surface of the object comprises electrolytically plating the surface with zinc or a zinc alloy.

13 . The method of claim 11 , wherein electrolytically depositing a composite ceramic layer comprises electrolytically depositing a hydrous zinc silicate layer on top of the inner layer.

14 . The method of claim 13 , wherein electrolytically depositing a composite ceramic layer further comprises mixing a zinc solution with a silicon solution to form a composite plating solution.

15 . The method of claim 14 , wherein the composite plating solution has an Si:Zn ratio of approximately 2:5.

16 . The method of claim 14 , wherein electrolytically depositing a composite ceramic layer further comprises applying a current of approximately 0.5 to 4 amps to the composite plating solution.

17 . The method of claim 16 , wherein electrolytically depositing a composite ceramic layer further comprises heating the composite plating solution to a temperature of approximately 25 to 90° C.

18 . The method of claim 11 , further comprising pre-processing the metal object before electrolytically plating the surface of the object.

19 . The method of claim 18 , wherein pre-processing comprises cleaning and polishing the surface of the object

20 . The method of claim 18 , wherein pre-processing comprises increasing the roughness of the surface of the metal object.

Assignees

• Univ Texas

Inventors

• Rice George Kenneth
• Yacaman Miguel Jose
• Vinogradova Ekaterina

Classifications

• C25D3/22

  of zinc · CPC title

• C25D5/36

  of 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

• C25D9/10 Primary

  on iron or steel · CPC title

• C25D3/565

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