Method for forming binder-free refractory carbide, nitride and boride coatings with a controlled porosity

Patent metadata

Field	Value
Publication number	US-2017335442-A1
Application number	US-201515524632-A
Country	US
Kind code	A1
Filing date	Nov 6, 2015
Priority date	Nov 6, 2014
Publication date	Nov 23, 2017
Grant date	—

Abstract

The present invention is directed to methods for formation of refractory carbide, nitride, and boride coatings without use of a binding agent. The present invention is directed to methods of creating refractory coatings with controlled porosity. Refractory coatings can be formed from refractory metal, metal oxide, or metal/metal oxide composite refractory coating precursor of the 9 refractory metals encompassed by groups 4-6 and periods 4-6 of the periodic table; non-metallic elements (e.g. Si & B) and their oxides (i.e. SiO 2 & B 2 O 3 ) are also pertinent. The conversion of the refractory coating precursor to refractory carbide, nitride or boride is achieved via carburization, nitridization, or boridization in the presence of carbon-containing (e.g. CH 4 ), nitrogen containing (e.g. NH 3 ), and boron-containing (e.g. B 2 H 6 ) gaseous species. Any known technique of applying the refractory coating precursor can be used. The porosity of resultant refractory coatings is controlled through compositional manipulation of composite refractory coating precursors.

First claim

1 . A method of forming a refractory coating comprising:
applying a refractory coating precursor to a surface using any known method such as spray techniques; introducing a gaseous species; and generating thermal decomposition of the gaseous species.

2 . The method of claim 1 further comprising using one of a group consisting of refractory metal, metal oxide, and metal/metal oxide composite as a refractory coating precursor.

3 . The method of claim 1 further comprising using one selected from a group consisting of carbon-containing, nitrogen-containing, and boron containing gaseous species.

4 . The method of claim 1 further comprising using plasma spray.

5 . The method of claim 1 further comprising using cold spray.

6 . The method of claim 1 further comprising forming one of a group consisting of refractory carbide, nitride, and boride coatings or any combination thereof.

7 . A refractory coating with increased hardness and decreased porosity comprising:
a refractory coating precursor applied with spray techniques; and a gaseous species configured to be thermally decomposable such that the refractory coating precursor is converted into a refractory coating with increased hardness and decreased porosity.

8 . The refractory coating of claim 7 wherein the refractory coating precursor is one chosen from a group consisting of refractory metal, metal oxide, and metal/metal oxide composite.

9 . The refractory coating of claim 7 wherein the gaseous species is one selected from a group consisting of carbon-containing, nitrogen-containing, and boron containing gaseous species.

10 . The refractory coating of claim 7 wherein spray techniques comprises plasma spray.

11 . The refractory coating of claim 7 wherein spray techniques comprises cold spray.

12 . The refractory coating of claim 7 wherein the refractory coating is one selected from a group consisting of refractory carbide, nitride, and boride coatings or any combination thereof.

13 . The refractory coating of claim 7 wherein porosity is controlled by compositional manipulation of composite refractory coating precursors.

14 . A method of forming a refractory coating comprising:
applying a refractory coating precursor to a surface using any known technique such as thermal spray; introducing a gaseous species; generating thermal decomposition of the gaseous species resulting in the refractory coating defining a porous refractory matrix; and using the porous refractory matrix as a scaffold for the formation of a multi-functional coating.

15 . The method of claim 14 further comprising using one of a group consisting of refractory metal, metal oxide, and metal/metal oxide composite as a refractory coating precursor.

16 . The method of claim 14 further comprising using plasma spray.

17 . The method of claim 14 further comprising using one or more gaseous species selected from a group consisting of carbon-containing, nitrogen-containing, and boron containing gaseous species.

18 . The method of claim 14 further comprising forming one of a group consisting of refractory carbide, nitride, and boride coatings, or any combination thereof.

19 . The method of claim 14 further comprising creating the multi-functional coating using any known void-filling technique such as ambient-temperature sealing with organic sealants, filling with sol-gel processed inorganic ceramics, and liquid metal infiltration which requires significantly higher temperatures.

20 . A binder-free refractory coating with a controlled porosity comprising:
a refractory coating precursor applied with thermal spray; a gaseous species configured to be thermally decomposable such that the refractory coating precursor is converted into a refractory coating with a controlled porosity; and a porous refractory matrix that serves as a multi-functional coating.

21 . The refractory coating of claim 20 wherein the refractory coating precursor is one chosen from a group consisting of refractory metal, metal oxide, and metal/metal oxide composite.

22 . The refractory coating of claim 20 wherein the gaseous species is one or more selected from a group consisting of carbon-containing, nitrogen-containing, and boron containing gaseous species.

23 . The refractory coating of claim 20 wherein thermal spray comprises plasma spray.

24 . The refractory coating of claim 20 wherein the refractory coating is one selected from a group consisting of refractory carbide, nitride, and boride coatings, or any combination thereof.

25 . The refractory coating of claim 20 wherein porosity is controlled by compositional manipulation of composite refractory coating precursors.

26 . The refractory coating of claim 20 further comprising the porous refractory matrix treated with one or more selected from a group of ambient-temperature sealing with organic sealants, filling with sol-gel processed inorganic ceramics, and liquid metal infiltration which requires significantly higher temperatures.

Assignees

• Univ Johns Hopkins

Inventors

• Brupbacher Michael
• Zhang Dajie
• Nagle Dennis

Classifications

• C23C4/08 Primary

  containing only metal elements (C23C4/073 takes precedence) · CPC title

• C23C4/11

  Oxides · CPC title

• C23C24/04

  Impact or kinetic deposition of particles · CPC title

• C23C18/08

  characterised by the deposition of metallic material · CPC title

• C23C4/134 Primary

  Plasma spraying · CPC title