Fiber-reinforced ceramic matrix composite for electronic devices

Patent metadata

Field	Value
Publication number	US-2016347674-A1
Application number	US-201615146545-A
Country	US
Kind code	A1
Filing date	May 4, 2016
Priority date	May 25, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A method of forming a ceramic component is disclosed. A ceramic matrix material is combined with a binder material. The ceramic matrix material and the binder material are mixed to create an intermediate slurry. After mixing the ceramic matrix material and the binder material, reinforcing fibers are added to the intermediate slurry to create a final slurry. The final slurry is introduced into a mold cavity having a shape corresponding to the ceramic component. The final slurry is at least partially cured within the mold cavity to form an intermediate casting. The intermediate casting is sintered to produce the ceramic component from the intermediate casting.

First claim

What is claimed is:

1 . A method of forming a ceramic component, comprising:
introducing a slurry into a mold cavity having a shape corresponding to the ceramic component, wherein the slurry comprises a ceramic matrix material, a binder material, and reinforcing fibers; at least partially curing the slurry within the mold cavity to form an intermediate casting; and sintering the intermediate casting to produce the ceramic component.

2 . The method of claim 1 , further comprising forming the slurry, wherein forming the slurry comprises:
combining the ceramic matrix material and the binder material; mixing the ceramic matrix material and the binder material to create an intermediate slurry; after mixing the ceramic matrix material and the binder material, adding the reinforcing fibers to the intermediate slurry; and mixing the reinforcing fibers with the intermediate slurry to form the slurry.

3 . The method of claim 2 , wherein mixing the ceramic matrix material and the binder material comprises:
at least partially submerging an agitator in the ceramic matrix material and the binder material; and mixing the ceramic matrix material and the binder material with the agitator.

4 . The method of claim 1 , wherein introducing the slurry into the mold cavity comprises passing the slurry through a gate having a minimum opening size that is a predetermined factor larger than an average length of the reinforcing fibers.

5 . The method of claim 4 , wherein the minimum opening size is about ten times larger than the average length of the reinforcing fibers.

6 . The method of claim 1 , further comprising aligning the reinforcing fibers in a direction that is parallel to a direction of flow of the slurry through the mold cavity, prior to introducing the slurry into the mold cavity.

7 . The method of claim 1 , wherein:
the reinforcing fibers include carbon fibers encased in silicon carbide sheaths; the sintering comprises heating at least a portion of the intermediate casting to an elevated temperature that is below a liquefaction temperature of the ceramic matrix material, and above a temperature at which the carbon fibers decompose due to heat; and the silicon carbide sheaths prevent at least a portion of the carbon fibers encased therein from reaching the temperature at which the carbon fibers decompose due to heat.

8 . A method of forming a ceramic component, comprising:
forming a slurry by:
combining a ceramic matrix material and a binder material; and
substantially evenly distributing reinforcing fibers throughout the slurry;
introducing the slurry into a mold cavity having a shape corresponding to the ceramic component; aligning the reinforcing fibers substantially unidirectionally within the mold cavity; at least partially curing the slurry within the mold cavity to form an intermediate casting; and sintering the intermediate casting to produce the ceramic component.

9 . The method of claim 8 , wherein:
the reinforcing fibers include carbon fibers encased in silicon carbide sheaths; the sintering comprises heating at least a portion of the intermediate casting to an elevated temperature that is below a liquefaction temperature of the ceramic matrix material, and above a temperature at which the carbon fibers decompose due to heat; and the silicon carbide sheaths prevent at least a portion of the carbon fibers encased therein from reaching the temperature at which the carbon fibers decompose due to heat.

10 . The method of claim 8 , wherein introducing the slurry into the mold cavity comprises gravity casting the slurry.

11 . The method of claim 8 , wherein the reinforcing fibers are substantially aligned within the ceramic component radially outward from a particular area.

12 . The method of claim 8 , wherein the reinforcing fibers are substantially parallel with a major axis of the ceramic component.

13 . The method of claim 8 , wherein forming the slurry comprises:
combining the ceramic matrix material and the binder material; mixing the ceramic matrix material and the binder material to create an intermediate slurry; after mixing the ceramic matrix material and the binder material, adding the reinforcing fibers to the intermediate slurry; and mixing the reinforcing fibers with the intermediate slurry to form the slurry.

14 . A ceramic housing component for an electronic device, comprising:
a ceramic matrix material; and reinforcing fibers distributed substantially evenly throughout the ceramic matrix material and oriented substantially unidirectionally within the ceramic housing component; wherein the housing component is formed from a slurry comprising the ceramic matrix material and the reinforcing fibers.

15 . The ceramic housing component of claim 14 , wherein the ceramic matrix material is selected from the group consisting of porcelain, alumina, beryllia, ceria, zirconia, carbide, boride, nitride, and silicide.

16 . The ceramic housing component of claim 14 , wherein the reinforcing fibers have an average length of about 150 microns.

17 . The ceramic housing component of claim 14 , wherein the ceramic matrix material is zirconia powder, and the reinforcing fibers are zirconia fibers.

18 . The ceramic housing component of claim 14 , wherein the reinforcing fibers are substantially aligned within the ceramic component radially outward from a particular area.

19 . The ceramic housing component of claim 14 , wherein the reinforcing fibers are substantially parallel with a major axis of the ceramic component.

20 . The ceramic housing component of claim 14 , wherein the reinforcing fibers are substantially aligned within the ceramic component in a direction that is parallel to a direction of flow of the slurry when the slurry is introduced into a mold cavity.

Assignees

• Apple Inc

Inventors

• Meschke Andrew J
• Matsuyuki Naoto

Classifications

• C04B35/58085

  based on silicides · CPC title

• C04B2235/6027

  Slip casting · CPC title

• C04B35/638

  Removal thereof · CPC title

• C04B35/58

  based on borides, nitrides, {i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides} or silicides {(containing free binder metal C22C29/00)} · CPC title

• C04B35/56

  based on carbides {or oxycarbides (containing free metal binder C22C29/00)} · CPC title