Fused silica tooling for high temperatures ceramic matrix composite sintering

Patent metadata

Field	Value
Publication number	US-12330335-B2
Application number	US-202217984781-A
Country	US
Kind code	B2
Filing date	Nov 10, 2022
Priority date	Nov 10, 2022
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A method of manufacturing a ceramic matrix composite component includes casting a tool and placing a ceramic matrix composite layup on the tool. The method further includes sintering the ceramic matrix composite layup at a predetermined sintering temperature at atmospheric pressure while the ceramic matrix composite layup is supported on the tool.

First claim

What is claimed is:

1. A method of manufacturing a ceramic matrix composite component, the method comprising
casting a tool comprising fused silica materials,
placing a ceramic matrix composite layup on the tool, and
performing pressureless sintering to the ceramic matrix composite layup at a predetermined sintering temperature at atmospheric pressure while the ceramic matrix composite layup is supported on the tool so that heat applied to the ceramic matrix composite layup is evenly distributed across the ceramic matrix composite layup during the pressureless sintering.

2. The method of claim 1 , wherein the predetermined sintering temperature is about 1300 degrees Celsius.

3. The method of claim 1 , wherein the step of casting the tool comprises:
adding a silica slurry to a mold of the tool,
allowing the silica slurry to set for a predetermined cast period to form a silica casting of the tool,
demolding the silica casting from the mold after the predetermined cast period, and
curing the silica casting to form the tool.

4. The method of claim 3 , wherein the step of casting the tool further includes vibrating the mold for a predetermined vibration period after adding the silica slurry to the mold.

5. The method of claim 3 , further comprising preparing the mold of the tool before casting the tool, wherein the step of preparing the mold of the tool includes assembling and securing inserts on bottom edges of the mold.

6. The method of claim 5 , wherein the step of demolding the silica casting from the mold includes removing the inserts and placing prybars in areas created by the inserts to assist in removing the silica casting from the mold.

7. The method of claim 3 , wherein the step of casting the tool further includes machining the silica casting to remove excess material after demolding the silica casting.

8. The method of claim 3 , wherein the step of curing the silica casting to form the tool comprises:
drying the silica casting at room temperature for two days,
applying heat at a first predetermined drying temperature to the silica casting for three days after drying the silica casting at room temperature,
increasing the temperature of the heat applied to the silica casting to a second predetermined drying temperature for a predetermined heating period after applying heat at the first predetermined drying temperature, and
applying heat at the second predetermined drying temperature for fifty hours after increasing the temperature to fully cure the silica casting.

9. The method of claim 8 , further comprising preparing the mold of the tool before casting the tool, wherein the step of preparing the mold of the tool includes assembling and securing inserts on bottom edges of the mold.

10. The method of claim 9 , wherein the step of preparing the mold of the tool further includes treating the mold and the inserts with a release agent.

11. The method of claim 1 , wherein the tool is formed to include a first side that contacts the ceramic matrix composite layup and a second side opposite the first side that faces away from the ceramic matrix composite layup, and wherein the tool is formed to include truncated pyramids on the first side of the tool to provide ventilation to the ceramic matrix composite layup to evenly distribute the heat applied to the ceramic matrix composite layup.

12. The method of claim 11 , wherein the tool is formed to include features on the second side of the tool configured to increase the surface area of the tool to match the specific heat capacity and thermal conductivity of the tool with the ceramic matrix composite layup.

13. The method of claim 12 , wherein the fused silica tool has a volume to surface area ratio of about 1.5 times larger than that of the ceramic matrix composite layup so that the fused silica tool dissipates heat at the same rate as the ceramic matrix composite layup.

14. The method of claim 1 , wherein the fused silica tool has a volume to surface area ratio of about 1.5 times larger than that of the ceramic matrix composite layup so that the fused silica tool dissipates heat at the same rate as the ceramic matrix composite layup.

15. A method comprising
treating a mold with a release agent,
casting a tool comprising fused silica in the mold,
placing a ceramic matrix composite layup on the tool, and
sintering the ceramic matrix composite layup at a predetermined sintering temperature while the ceramic matrix composite layup is supported on the fused silica tool so that heat applied to the ceramic matrix composite layup is evenly distributed across the ceramic matrix composite layup.

16. The method of claim 15 , wherein the predetermined sintering temperature is greater than or equal to about 1200 degrees Celsius.

17. The method of claim 15 , wherein the step of casting the tool comprises:
adding a silica slurry to a mold of the tool,
vibrating the mold for a predetermined vibration period after adding the silica slurry to the mold,
allowing the silica slurry to set for a predetermined cast period to form a silica casting of the tool,
demolding the silica casting from the mold after the predetermined cast period, and
curing the silica casting to form the tool.

18. The method of claim 17 , wherein curing the silica casting to form the tool comprises:
drying the silica casting at room temperature for two days,
applying heat at a first predetermined drying temperature to the silica casting for three days after drying the silica casting at room temperature,
increasing the temperature of the heat applied to the silica casting to a second predetermined drying temperature for a predetermined heating period after applying heat at the first predetermined drying temperature, and
applying heat at the second predetermined drying temperature for fifty hours after increasing the temperature to fully cure the silica casting.

19. The method of claim 15 , wherein the tool has a volume to surface area ratio of about 1.5 times larger than that of the ceramic matrix composite layup so that the tool dissipates heat at the same rate as the ceramic matrix composite layup.

20. The method of claim 15 , wherein the tool is formed to include truncated pyramids on a side of the tool that contacts the ceramic matrix composite layup.

Assignees

• Rolls Royce Plc

Inventors

• Healey Adam C

Classifications

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• C01B33/12 Primary

  Silica; Hydrates thereof, e.g. lepidoic silicic acid · CPC title

• C04B2235/656

  characterised by specific heating conditions during heat treatment · CPC title

• C04B35/80

  Fibres, filaments, whiskers, platelets, or the like · CPC title

• C04B2235/945

  Products containing grooves, cuts, recesses or protusions · CPC title