Method for fabricating silicon carbide assemblies

Patent metadata

Field	Value
Publication number	US-10032527-B2
Application number	US-201615176942-A
Country	US
Kind code	B2
Filing date	Jun 8, 2016
Priority date	Sep 23, 2011
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A method for fabricating assemblies includes providing first and second components that include ceramic, metal, or composite; positioning a multiphase joining interlayer between the first and second components, wherein the joining interlayer includes a first phase that melts at a first temperature and a second phase interspersed throughout the first phase, and wherein the second phase melts at a second temperature that is lower than the melting temperature of the first phase; and heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time to soften the first phase and melt the second phase, wherein the first phase remains in a solid or a semi-solid state, and wherein the second phase segregates to the boundaries of the first phase and transforms the joining interlayer into a substantially porosity-free adherent material that joins the first component to the second component.

First claim

What is claimed:

1. A method for fabricating assemblies, comprising:
(a) providing a first component, wherein the first component includes ceramic, metal, or composite;
(b) providing a second component, wherein the second component includes ceramic, metal, or composite;
(c) positioning a multiphase joining interlayer between the first and second components, wherein the joining interlayer includes:
(i) a first phase that includes niobium silicide or titanium silicide and that melts at a first temperature, and
(ii) a second phase interspersed throughout the first phase, and wherein the second phase melts at a second temperature that is lower than the melting temperature of the first phase; and

(d) heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time, wherein heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time softens the first phase and melts the second phase, wherein the first phase remains in a solid or a semi-solid state, and wherein the second phase segregates to the boundaries of the first phase and transforms the joining interlayer into a substantially porosity-free adherent material that joins the first component to the second component.

2. The method of claim 1 , wherein the first component is a silicon carbide ceramic-matrix composite.

3. The method of claim 1 , wherein the second component is a silicon carbide ceramic-matrix composite.

4. The method of claim 1 , wherein the first phase of the multiphase joining interlayer includes silicon and the second phase of the multiphase joining interlayer includes aluminum.

5. The method of claim 1 , wherein the substantially porosity-free adherent material includes silicon nitride.

6. The method of claim 5 , wherein the silicon nitride is formed by heating the multiphase joining interlayer to a temperature in the range of about 1100° C. to 1450° C. in high-purity nitrogen for a period of at least five minutes to several hours.

7. The method of claim 1 , wherein the transformed joining interlayer has a shear strength in excess of 125 MPa.

8. A method for fabricating assemblies, comprising:
(a) providing a first component, wherein the first component includes ceramic, metal, or composite;
(b) providing a second component, wherein the second component includes ceramic, metal, or composite;
(c) positioning a multiphase joining interlayer between the first and second components, wherein the multiphase joining interlayer includes three distinct layers, wherein the first and third layers are multiphase Al-80 wt % Si alloys and the second layer, which is sandwiched between the first and third layers, is a metal selected from the group consisting of titanium, zirconium, molybdenum, niobium, and combinations thereof, and wherein the first and third layers each include a first phase that melts at a first temperature and a second phase interspersed throughout the first phase, and wherein the second phase melts at a second temperature that is lower than the melting temperature of the first phase; and
(d) heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time, wherein heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time softens the first phase and melts the second phase, wherein the first phase remains in a solid or a semi-solid state, and wherein the second phase segregates to the boundaries of the first phase to form a substantially porosity-free adherent material.

9. A method for fabricating assemblies for use in nuclear reactors, comprising:
(a) providing a first silicon carbide component;
(b) providing a second silicon carbide component;
(c) positioning a multiphase joining interlayer between the first and second components, wherein the multiphase joining interlayer
includes three distinct layers, wherein the first and third layers are multiphase Al-80 wt % Si alloys and the second layer, which is sandwiched between the first and third layers, is a metal selected from the group consisting of titanium, zirconium, molybdenum, niobium, and combinations thereof, and wherein the first and third layers each include a first phase that melts at a first temperature and a second phase interspersed throughout the first phase, and wherein the second phase melts at a second temperature that is lower than the melting temperature of the first phase; and
(d) heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time, wherein heating the joining interlayer to a temperature in the range of 725° C. to 1450° C. for a predetermined period of time softens the first phase and melts the second phase, wherein the first phase remains in a solid or a semi-solid state, and wherein the second phase segregates to the boundaries of the first phase to form a substantially porosity-free adherent material.

10. The method of claim 9 , wherein the substantially porosity-free adherent material includes silicon nitride that is formed by heating the multiphase joining interlayer to a temperature in the range of about 1100° C. to 1450° C. in high-purity nitrogen for a period of at least five minutes to several hours.

11. The method of claim 9 , wherein the first and third layers are hypereutectic Al-80 wt % Si alloys.

Assignees

• Edison Welding Inst Inc

Inventors

• Herderick Edward D
• Cooper Kirk E
• Ames Nathan D

Classifications

• B32B37/06

  characterised by the heating method · CPC title

• C22C21/02

  with silicon as the next major constituent · CPC title

• C04B2237/40

  Metallic · CPC title

• C04B37/006

  consisting of metals or metal salts · CPC title

• B23K1/0056

  soldering by means of beams, e.g. lasers, electron beams [EB] · CPC title