Joined body and method for producing the same

Patent metadata

Field	Value
Publication number	US-10167235-B2
Application number	US-201514848938-A
Country	US
Kind code	B2
Filing date	Sep 9, 2015
Priority date	Mar 19, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A joined body 20 includes a porous ceramic 22 made of porous ceramic, a metal member 24 made of a metal, and a joint 30 formed of an oxide ceramic that penetrates into pores 23 of the porous ceramic 22 and joins the porous ceramic 22 to the metal member 24 . The penetration depth of the oxide ceramic into the pores of the porous ceramic is preferably 10 μm or more, and more preferably 15 to 50 μm. The joined body 20 may be produced through a joining step of forming a joint by placing a metal raw material between a porous ceramic and a metal member and firing the metal raw material in the air at a temperature in the range of 400° C. to 900° C., where an oxide ceramic produced by oxidation of the metal raw material penetrates into the pores of the porous ceramic in the joint.

First claim

What is claimed is:

1. A joined body, comprising:
a porous ceramic;
a metal member; and
a joint of an oxide ceramic that penetrates into pores of the porous ceramic and joins the porous ceramic to the metal member,
wherein a penetration depth of the oxide ceramic into the ores of the porous ceramic is 10 μm or more.

2. The joined body according to claim 1 , wherein a penetration depth of the oxide ceramic in the pores of the porous ceramic is in the range of 15 to 50 μm.

3. The joined body according to claim 1 , wherein the average pore size of the porous ceramic is A (μm), the average particle size of a raw material powder of the oxide ceramic is B (μm), and B/A is in the range of 0.1 to 5.0.

4. The joined body according to claim 1 , wherein the thickness of a reaction layer at an interface between the porous ceramic and the oxide ceramic is 0.1 μm or less.

5. The joined body according to claim 1 , wherein the porosity of the oxide ceramic penetrating into the porous ceramic is in the range of 0% to 50% by volume.

6. The joined body according to claim 1 , wherein the joint includes a penetrating portion in which the oxide ceramic penetrates into the pores and a non-penetrating portion other than the penetrating portion, and the porosity of the non-penetrating portion is in the range of 0% to 60% by volume.

7. The joined body according to claim 1 , wherein the oxide ceramic contains at least one selected from Fe, Ni, Mn, Cu, Ti, V, Mg, and Al.

8. The joined body according to claim 1 , wherein the oxide ceramic contains, in addition to a primary component being a main component and a metallic component, a secondary component being at least one of Li, Na, K, Ga, Si, Zr, Ti, Sn, Nb, Sb, and Ta.

9. The joined body according to claim 1 , wherein the porous ceramic is a composite material containing SiC and Si bonding SiC, and the SiC and the Si form the pores.

10. The joined body according to claim 1 , wherein the porous ceramic has a honeycomb structure comprising partition walls forming a plurality of cells serving as a flow path of a fluid.

11. The joined body according to claim 1 , wherein the metal member is an alloy containing at least Fe and Cr.

12. The joined body according to claim 1 , wherein the metal member is an alloy in which Fe constitutes 70% or more by mass and less than 90% by mass and Cr constitutes 10% or more by mass and less than 30% by mass.

13. The joined body according to claim 1 , wherein the joint is the oxide ceramic formed by placing a metal raw material between the porous ceramic and the metal member and firing the metal raw material in an oxidizing atmosphere at a temperature in the range of 400° C. to 900° C.

14. The joined body according to claim 1 , wherein the electrical conductivity of the joined body is 10 −6 S/cm or more.

15. A method for producing a joined body of a porous ceramic and a metal member joined together, comprising:
a joining step of forming a joint by placing a metal raw material between the porous ceramic and the metal member and firing the metal raw material in an oxidizing atmosphere at a temperature in the range of 400° C. to 900° C., wherein an oxide ceramic produced by oxidation of the metal raw material penetrates into pores of the porous ceramic,
wherein a penetration depth of the oxide ceramic into the pores of the porous ceramic is 10 μm or more.

16. The method for producing a joined body according to claim 15 , wherein the average particle size of the metal raw material in the joining step is in the range of 1 to 40 μm.

17. The method for producing a joined body according to claim 15 , wherein raw materials satisfying B/A in the range of 0.1 to 5.0 are used in the joining step, wherein the average pore size of the porous ceramic is A (μm), and the average particle size of the raw material powder of the oxide ceramic is B (μm).

18. The method for producing a joined body according to claim 15 , wherein the metal raw material is fired in the joining step while the metal member is restricted in its movements.

19. The method for producing a joined body according to claim 15 , wherein the metal raw material having a volume change ratio of 0.7 or more is used in the joining step, the volume change ratio being a ratio of a volume after oxidation to a volume before the oxidation.

20. The method for producing a joined body according to claim 15 , wherein the metal raw material having a volume change ratio of 1.3 or more is used in the joining step, the volume change ratio being a ratio of a volume after oxidation to a volume before the oxidation.

21. The method for producing a joined body according to claim 15 , wherein a raw material containing, in addition to a primary component being a main component and a metallic component, a secondary component being at least one of Li, Na, K, Ga, Si, Zr, Ti, Sn, Nb, Sb, and Ta is placed between the porous ceramic and the metal member in the joining step.

Assignees

• Ngk Insulators Ltd

Inventors

• Izumi Yunie
• Kobayashi Yoshimasa
• Morimoto Kenji
• Kawasaki Shinji

Classifications

• C04B2237/123

  based on iron group metals, e.g. steel · CPC title

• B23K35/325

  Ti as the principal constituent · CPC title

• C04B2237/343

  Alumina or aluminates · CPC title

• C04B35/45

  based on copper oxide or solid solutions thereof with other oxides · CPC title

• C04B2237/61

  Joining two substrates of which at least one is porous by infiltrating the porous substrate with a liquid, such as a molten metal, causing bonding of the two substrates, e.g. joining two porous carbon substrates by infiltrating with molten silicon · CPC title