Thermal Spray for Durable and Large-Area Hydrophobic and Superhydrophobic/Icephobic Coatings

Patent metadata

Field	Value
Publication number	US-2016096972-A1
Application number	US-201414508846-A
Country	US
Kind code	A1
Filing date	Oct 7, 2014
Priority date	Oct 7, 2014
Publication date	Apr 7, 2016
Grant date	—

Abstract

A method for forming a hydrophobic coating on a substrate by a thermal spray deposition process is described. The method may comprise feeding a thermal spray apparatus with a coating precursor consisting of particles having an initial particle morphology, and heating the particles with the thermal spray apparatus to cause the particle to at least partially melt. The method may further comprise accelerating the particles towards the substrate, and forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the particles is retained.

First claim

What is claimed is:

1 . A method for forming a hydrophobic coating on a substrate by a thermal spray deposition process, comprising:
feeding a thermal spray apparatus with a coating precursor, the coating precursor including particles having an initial particle morphology; heating the particles with the thermal spray apparatus to cause the particles to at least partially melt; accelerating the particles towards the substrate using the thermal spray apparatus; and forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the particles is retained.

2 . The method of claim 1 , wherein the hydrophobic coating exhibits an average roughness of between about 1 nanometer and about 100 micrometers.

3 . The method of claim 1 , wherein the coating precursor comprises a powder having an average particle size of between about 10 nanometers and about 100 micrometers.

4 . The method of claim 1 , wherein heating the particles with the thermal spray apparatus to cause the particles to at least partially melt comprises controlling a temperature of a gas stream of the thermal spray apparatus by adjusting an oxygen feed rate and a fuel feed rate of the thermal spray apparatus.

5 . The method of claim 1 , wherein forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state comprises adjusting a stand-off distance between the thermal spray apparatus and the substrate.

6 . The method of claim 1 , further comprising heating the hydrophobic coating to enhance an oxide content of the hydrophobic coating.

7 . The method of claim 1 , wherein the coating precursor consists of a single component having a single chemical identity with a single particle size and single particle morphology.

8 . The method of claim 1 , wherein the coating precursor consists of a primary component and a secondary component having a smaller thermal mass than the primary component, wherein the primary component and the secondary component have the same chemical identity but a different particle size and a different particle morphology, and wherein coating precursor consists of more than 50 weight percent of the primary component.

9 . The method of claim 1 , wherein the coating precursor consists of a primary component and a secondary component, wherein the primary component and the secondary component have a different chemical identity and a same particle size and a same particle morphology, and wherein the coating precursor consists of more than 50 weight percent of the primary component.

10 . The method of claim 1 , wherein the coating precursor consists of a primary component and a secondary component, wherein the primary component and the secondary component have a different chemical identity and a different particle size and a different particle morphology, and wherein the coating precursor consists of more than 50 weight percent of the primary component.

11 . The method of claim 1 , further comprising applying an additional layer on the hydrophobic coating by a thermal spray deposition process comprising:
feeding the thermal spray apparatus with secondary particles having an initial particle morphology, the secondary particles having at least one of a lower surface energy and a smaller particle size than the particles of the coating precursor; heating the secondary particles with the thermal spray apparatus to cause the secondary particles to at least partially melt; accelerating the secondary particles towards the substrate using the thermal spray apparatus; and forming the additional layer on the hydrophobic coating by allowing the secondary particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the secondary particles is retained.

12 . The method of claim 11 , wherein the additional layer is a monolayer that covers between about 70% and about 150% of a surface of the hydrophobic coating.

13 . The method of claim 11 , wherein the secondary particles have a particle size that is at least one order of magnitude smaller than the particles of the coating precursor.

14 . The method of claim 11 , wherein the hydrophobic coating includes the additional layer, and wherein the hydrophobic coating exhibits multi-length scale surface roughness.

15 . An article including a substrate and a hydrophobic coating applied to a surface of the substrate, the hydrophobic coating being applied to the surface of the substrate by a thermal spray deposition process comprising:
feeding a thermal spray apparatus with a coating precursor, the coating precursor including particles having an initial particle morphology; heating the particles with the thermal spray apparatus to cause the particles to at least partially melt; accelerating the particles towards the substrate using the thermal spray apparatus; and forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the particles is retained.

16 . The article of claim 15 , wherein the hydrophobic coating exhibits an average roughness of between about 1 nanometer and about 100 micrometers.

17 . The article of claim 15 , wherein the coating precursor comprises a powder having an average particle size of between about 10 nanometers and about 100 micrometers.

18 . The article of claim 17 , wherein the powder is a polymer powder.

19 . The article of claim 15 , further comprising applying an additional layer on the hydrophobic coating by a thermal spray deposition process comprising:
feeding the thermal spray apparatus with secondary particles having an initial particle morphology, the secondary particles having at least one of a lower surface energy and a smaller particle size than the particles of the coating precursor; heating the secondary particles with the thermal spray apparatus to cause the secondary particles to at least partially melt; accelerating the secondary particles toward the substrate using the thermal spray apparatus; and forming the additional layer on the hydrophobic coating by allowing the secondary particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the secondary particles is retained.

20 . An article, comprising:
a substrate having a surface; and a hydrophobic coating applied to the surface of the substrate, the hydrophobic coating having an average roughness of between about 1 nanometer and about 100 micrometers, the hydrophobic coating produced by depositing partially melted particles on the surface of the substrate by a thermal spray deposition process.

Assignees

• Boeing Co

Inventors

• Newbloom Gregory M
• Thompson William A
• Froning Marc J
• Ghabchi Arash

Classifications

• B05D1/10 Primary

  Applying particulate materials · CPC title

• C23C4/105

  Chemistry & Metallurgy · mapped topic

• C23C4/122

  Chemistry & Metallurgy · mapped topic

• C09D161/02 Primary

  Condensation polymers of aldehydes or ketones only · CPC title

• C23C4/005

  Chemistry & Metallurgy · mapped topic