Insulating ceramic panels and methods of forming insulating ceramic panels

Patent metadata

Field	Value
Publication number	US-12509403-B2
Application number	US-202217665337-A
Country	US
Kind code	B2
Filing date	Feb 4, 2022
Priority date	Feb 25, 2021
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

Insulating ceramic panels and methods of forming insulating ceramic panels are disclosed herein. The insulating ceramic panels include a plurality of hollow particles and an oxide binder. The plurality of hollow particles are formed from a hollow particle material that includes a metal oxide. The plurality of hollow particles defines an average equivalent particle diameter of at least 10 micrometers (μm) and at most 500 μm. In addition, the plurality of hollow particles defines an average wall thickness that is at least 3% and at most 30% of the average equivalent particle diameter. The oxide binder material attaches each hollow particle to at least one other hollow particle and differs from the hollow particle material. The insulating ceramic panels define a particle-enclosed void volume fraction, which is enclosed within the plurality of hollow particles, and an interstitial void volume fraction, which is defined within an interstitial space among the plurality of hollow particles.

First claim

The invention claimed is:

1 . A method of forming an insulating ceramic panel, the method comprising:
binder jet printing a printed panel that includes a plurality of hollow particles and a binder jet binder material that attaches each hollow particle of the plurality of hollow particles to at least one other hollow particle of the plurality of hollow particles; infusing an interstitial void volume fraction of the printed panel with an oxide binder material solution, which includes an oxide binder material and a solvent, to define a solution-infused panel; and heating the solution-infused panel to generate the insulating ceramic panel, wherein the heating includes: (i) evaporating the solvent; (ii) degrading the binder jet binder material; (iii) depositing the oxide binder material on the plurality of hollow particles such that the oxide binder material attaches each hollow particle of the plurality of hollow particles to at least one other hollow particle of the plurality of hollow particles; and (iv) fusing the plurality of hollow particles to one another to define the insulating ceramic panel.

2 . The method of claim 1 , wherein, prior to the binder jet printing, the method further includes purifying a hollow particle supply to separate the plurality of hollow particles from a remainder of the hollow particle supply, wherein the purifying includes at least one of:
(i) selectively separating a fines fraction of the hollow particle supply from the hollow particle supply to generate the plurality of hollow particles, wherein the fines fraction of the hollow particle supply has an average equivalent fines diameter that is less than 10 micrometers (μm); and (ii) selectively separating a coarse fraction of the hollow particle supply from the hollow particle supply to generate the plurality of hollow particles, wherein the coarse fraction of the hollow particle supply has an average equivalent coarse diameter that is greater than 500 μm.

3 . The method of claim 1 , wherein, prior to the binder jet printing, the method further includes purifying a hollow particle supply to separate the plurality of hollow particles from a remainder of the hollow particle supply, wherein the purifying includes selectively separating broken hollow particles from the hollow particle supply to generate the plurality of hollow particles.

4 . The method of claim 1 , wherein, subsequent to the binder jet printing and prior to the infusing, the method further includes curing the printed panel.

5 . The method of claim 1 , wherein, subsequent to the binder jet printing and prior to the infusing, the method further includes cleaning the printed panel.

6 . The method of claim 1 , wherein the infusing includes positioning the oxide binder material solution within the interstitial void volume fraction of the printed panel.

7 . The method of claim 1 , wherein the infusing is performed subsequent to the binder jet printing and prior to the heating the solution-infused panel.

8 . The method of claim 1 , wherein the heating includes heating to a threshold fusing temperature of at least 900 Celsius.

9 . The method of claim 1 , wherein the degrading the binder jet binder material includes at least one of:
(i) evaporating the binder jet binder material; (ii) oxidizing the binder jet binder material; (iii) decomposing the binder jet binder material; and (iv) melting the binder jet binder material.

10 . The method of claim 1 , wherein the depositing the oxide binder material on the plurality of hollow particles includes depositing metal oxide crystals within interface regions between adjacent hollow particles of the plurality of hollow particles.

11 . The method of claim 1 , wherein the fusing the plurality of hollow particles to one another includes forming a plurality of adhesions within corresponding interface regions between adjacent hollow particles of the plurality of hollow particles.

12 . The method of claim 1 , wherein:
the plurality of hollow particles is formed from a hollow particle material that includes a metal oxide; the plurality of hollow particles: (i) defines an average equivalent particle diameter of at least 10 micrometers (μm) and at most 500 μm; and (ii) defines an average wall thickness of at least 3% and at most 30% of the average equivalent particle diameter; and the insulating ceramic panel defines: (i) a particle-enclosed void volume fraction that is enclosed within the plurality of hollow particles; and (ii) the interstitial void volume fraction is defined within an interstitial space among the plurality of hollow particles.

13 . The method of claim 12 , wherein the hollow particle material is a ceramic hollow particle material.

14 . The method of claim 1 , wherein:
(i) the plurality of hollow particles defines a threshold particle mass fraction of the insulating ceramic panel, wherein the threshold particle mass fraction is at least 60% and at most 99%; and (ii) the oxide binder material defines a threshold binder material mass fraction of the insulating ceramic panel, wherein the threshold binder material mass fraction is at least 1% and at most 25%.

15 . The method of claim 12 , wherein:
(i) the interstitial void volume fraction of the insulating ceramic panel is at least 10% and at most 75%; and (ii) the particle-enclosed void volume fraction of the insulating ceramic panel is at least 5% and at most 85%.

16 . The method of claim 1 , wherein the oxide binder material consists essentially of at least one of:
(i) a metal oxide hydroxide; (ii) a metal oxide hydrate; (iii) an alumina hydrate; (iv) an aluminum oxide hydroxide; and (v) an alumina boehmite.

17 . The method of claim 1 , wherein the oxide binder material consists essentially of at least one of an aluminum oxide and a crystalline aluminum oxide.

18 . The method of claim 1 , wherein the binder jet binder material differs from both the oxide binder material and a hollow particle material of the plurality of hollow particles.

19 . The method of claim 1 , wherein the insulating ceramic panel defines a first major surface and a second major surface that is opposed to the first major surface, wherein the insulating ceramic panel includes a plurality of cooling holes, wherein each cooling hole of the plurality of cooling holes extends between the first major surface and the second major surface, and further wherein at least one cooling hole of the plurality of cooling holes extends along an arcuate trajectory between the first major surface and the second major surface.

20 . The method of claim 1 , wherein the insulating ceramic panel is an exhaust insulation panel of an afterburner of a craft.

Assignees

• Boeing Co

Inventors

• Lehman Stephen E
• Porter Kayleigh
• Schaedler Tobias A

Classifications

• B29C67/242

  Moulding mineral aggregates bonded with resin, e.g. resin concrete (shaping ceramic compositions without binder or water-setting cementitious material B28B; compositions per se C04B) · CPC title

• C04B2111/00181

  Mixtures specially adapted for three-dimensional printing (3DP), stereo-lithography or prototyping · CPC title

• B28B1/001

  Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material (selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00) · CPC title

• C04B2235/52

  Constituents or additives characterised by their shapes · CPC title

• C04B2111/28

  Fire resistance, i.e. materials resistant to accidental fires or high temperatures · CPC title