High temperature oxidation protection for composites

Patent metadata

Field	Value
Publication number	US-11046619-B2
Application number	US-201816102100-A
Country	US
Kind code	B2
Filing date	Aug 13, 2018
Priority date	Aug 13, 2018
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.

First claim

What is claimed is:

1. A method for forming an oxidation protection system on a composite structure, comprising:
forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, wherein the first pre-slurry composition comprises a first phosphate glass composition;
applying the first slurry to the composite structure;
heating the composite structure to a temperature sufficient to form a base layer on the composite structure;
forming a second slurry by combining a second pre-slurry composition with a second carrier fluid, wherein the second pre-slurry composition comprises a second phosphate glass composition and a strengthening compound comprising boron nitride;
applying the second slurry to the composite structure; and
heating the composite structure to a temperature sufficient to form a sealing layer on the composite structure.

2. The method of claim 1 , wherein the strengthening compound further comprises at least one of a metal oxide or silicon carbide.

3. The method of claim 2 , wherein the metal oxide comprises at least one of aluminum oxide, silicon dioxide, and titanium oxide.

4. The method of claim 1 , wherein the second slurry comprises between 0.1 and 6 weight percent boron nitride.

5. The method of claim 1 , wherein the second slurry comprises between 2 and 5 weight percent boron nitride.

6. The method of claim 1 , wherein the second phosphate glass composition comprises a glass frit, and wherein a weight ratio of boron nitride to the glass frit in the second slurry is between 5:100 to 15:100.

7. The method of claim 1 , wherein the second phosphate glass composition comprises a glass frit, and wherein a weight ratio of boron nitride to the glass frit in the second slurry is between 10:100 to 12:100.

8. The method of claim 1 , wherein the first pre-slurry composition further comprises a silica compound comprising at least one of silica and a silica former.

9. The method of claim 8 , wherein the silica former comprises at least one of a metal silicide, silicon, fumed silica, silicon carbide, and silicon carbonitride.

10. The method of claim 1 , wherein the first pre-slurry composition of the base layer comprises between about 15 weight percent and about 30 weight percent boron nitride.

11. The method of claim 1 , wherein the first pre-slurry composition comprises a first acid aluminum phosphate wherein a first molar ratio of aluminum to phosphate is between 1 to 2 and 1 to 3.

12. The method of claim 1 , further comprising applying a pretreating composition, wherein the applying comprises:
applying a first pretreating composition to an outer surface of the composite structure before the applying the first slurry, wherein the first pretreating composition comprises aluminum oxide and water;
heating the pretreating composition; and
applying a second pretreating composition comprising at least one of a phosphoric acid or an acid phosphate salt, and an aluminum salt on the first pretreating composition, wherein the composite structure is porous and the second pretreating composition penetrates at least a portion of a plurality of pores of the composite structure.

13. The method of claim 1 , wherein at least one of the first phosphate glass composition or the second phosphate glass composition is represented by the formula
a (A′ 2 O) x (P 2 O 5 ) y1 b (G f O) y2 c (A″O) z :

A′ is selected from: lithium, sodium, potassium, rubidium, cesium, and mixtures thereof;
G f is selected from: boron, silicon, sulfur, germanium, arsenic, antimony, and mixtures thereof;
A″ is selected from: vanadium, aluminum, tin, titanium, chromium, manganese, iron, cobalt, nickel, copper, mercury, zinc, thulium, lead, zirconium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, actinium, thorium, uranium, yttrium, gallium, magnesium, calcium, strontium, barium, tin, bismuth, cadmium, and mixtures thereof;
a is a number in the range from 1 to about 5;
b is a number in the range from 0 to about 10;
c is a number in the range from 0 to about 30;
x is a number in the range from about 0.050 to about 0.500;
y 1 is a number in the range from about 0.100 to about 0.950;
y 2 is a number in the range from 0 to about 0.20; and
z is a number in the range from about 0.01 to about 0.5;
(x+y 1 +y 2 +z)=1; and
x<(y 1 +y 2 ).

Assignees

• Goodrich Corp

Inventors

• Poteet Steven A

Classifications

• C04B35/83 Primary

  Carbon fibres in a carbon matrix · CPC title

• C03C8/08

  containing phosphorus · CPC title

• C04B41/5041

  Titanium oxide or titanates · CPC title

• C04B2235/9684

  Oxidation resistance · CPC title

• C03C1/008

  for the production of films or coatings · CPC title