Method for fabricating silicon carbide assemblies

Patent metadata

Field	Value
Publication number	US-2016284427-A1
Application number	US-201615176942-A
Country	US
Kind code	A1
Filing date	Jun 8, 2016
Priority date	Sep 23, 2011
Publication date	Sep 29, 2016
Grant date	—

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 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 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 first phase of the multiphase joining interlayer includes niobium silicide or titanium silicide.

6 ) The method of claim 1 , wherein the multiphase joining interlayer is a silicon nitride joining interlayer.

7 ) The method of claim 6 , wherein the silicon nitride joining interlayer is formed by heating an Al—Si alloy 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.

8 ) The method of claim 1 , wherein the multiphase joining interlayer is a hypereutectic Al-80 wt % Si alloy.

9 ) The method of claim 8 , wherein the hypereutectic Al-80 wt % Si alloy joining interlayer is heated in a vacuum at about 1330° C. for about 13 minutes.

10 ) The method of claim 1 , wherein the multiphase joining interlayer includes three distinct layers, wherein the first and third layers are multiphase alloys, and wherein the second layer is a metal sandwiched between the first and third layers,

11 ) The method of claim 10 , wherein the first and third layers are Al-12 wt % Si alloy and the second layer is Al-70 wt % Si alloy.

12 ) The method of claim 10 , wherein the first and third layers are Al-80 wt % Si alloy and the second layer is a metal selected from the group consisting of titanium, zirconium, molybdenum, niobium, and combinations thereof.

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

14 ) 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 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 (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.

15 ) The method of claim 14 , wherein the first phase of the multiphase joining interlayer includes silicon and the second phase of the multiphase joining interlayer includes aluminum.

16 ) The method of claim 14 , wherein the multiphase joining interlayer is a silicon nitride joining interlayer formed by heating an Al—Si alloy 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.

17 ) The method of claim 14 , wherein the multiphase joining interlayer is a hypereutectic Al-80 wt % Si alloy.

18 ) The method of claim 14 , wherein the multiphase joining interlayer includes three distinct layers, wherein the first and third layers are multiphase alloys, and wherein the second layer is a metal sandwiched between the first and third layers,

19 ) The method of claim 18 , wherein the first and third layers are Al-12 wt % Si alloy and the second layer is Al-70 wt % Si alloy.

20 ) The method of claim 18 , wherein the first and third layers are Al-80 wt % Si alloy and the second layer is a metal selected from the group consisting of titanium, zirconium, molybdenum, niobium, and combinations thereof.

Assignees

• Herderick Edward D
• Cooper Kirk E
• Ames Nathan D
• Edison Welding Inst Inc

Inventors

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

Classifications

• C04B2237/595

  whereby the interlayer is continuous, but heterogeneous on macro-scale, e.g. one part of the interlayer being a joining material, another part being an electrode material · CPC title

• B32B37/06

  characterised by the heating method · CPC title

• C04B2237/365

  Silicon carbide · CPC title

• C04B37/006

  consisting of metals or metal salts · CPC title

• C04B37/026

  consisting of metals or metal salts · CPC title