Porous metal body and method for producing porous metal body

Patent metadata

Field	Value
Publication number	US-10128513-B2
Application number	US-201515123333-A
Country	US
Kind code	B2
Filing date	Feb 20, 2015
Priority date	Mar 6, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An object of the present invention is to provide, at a low cost, a porous metal body that can be used in an electrode of a fuel cell and that has better corrosion resistance. The porous metal body has a three-dimensional mesh-like structure and contains nickel (Ni), tin (Sn), and chromium (Cr). A content ratio of the tin is 10% by mass or more and 25% by mass or less, and a content ratio of the chromium is 1% by mass or more and 10% by mass or less. On a cross section of a skeleton of the porous metal body, the porous metal body contains a solid solution phase of chromium, nickel, and tin. The solid solution phase contains a solid solution phase of chromium and trinickel tin (Ni 3 Sn), the solid solution phase having a chromium content ratio of 2% by mass or less, and does not contain a solid solution phase that is other than a solid solution phase of chromium and trinickel tin (Ni 3 Sn) and that has a chromium content ratio of less than 1.5% by mass.

First claim

The invention claimed is:

1. A porous metal body having a three-dimensional mesh-like structure, the porous metal body comprising nickel (Ni), tin (Sn), and chromium (Cr),
wherein a content ratio of the tin is 10% by mass or more and 25% by mass or less,
a content ratio of the chromium is 1% by mass or more and 10% by mass or less,
on a cross section of a skeleton of the porous metal body, the porous metal body contains a solid solution phase of chromium, nickel, and tin, and the solid solution phase
contains a solid solution phase of chromium and trinickel tin (Ni 3 Sn), the solid solution phase having a chromium content ratio of 2% by mass or less, and
does not contain a solid solution phase that is other than a solid solution phase of chromium and trinickel tin (Ni 3 Sn) and that has a chromium content ratio of less than 1.5% by mass.

2. The porous metal body according to claim 1 , wherein, on the cross section of the skeleton of the porous metal body, an area ratio of the solid solution phase of chromium and trinickel tin (Ni 3 Sn), the solid solution phase having a chromium content ratio of 2% by mass or less, is 7% or more and 60% or less of a total area of the cross section of the skeleton.

3. The porous metal body according to claim 1 , wherein, on the cross section of the skeleton of the porous metal body, an area ratio of the solid solution phase of chromium and trinickel tin (Ni 3 Sn), the solid solution phase having a chromium content ratio of 2% by mass or less, is less than 7% of a total area of the cross section of the skeleton.

4. A method for producing a porous metal body having a three-dimensional mesh-like structure and containing nickel (Ni), tin (Sn), and chromium (Cr), the method comprising:
a step of subjecting a surface of a resin formed body having a three-dimensional mesh-like structure to an electrical conduction treatment by applying a conductivity-imparting material containing a chromium powder or a chromium oxide powder onto the surface of the resin formed body so that a content ratio of chromium in the porous metal body becomes 1% by mass or more and 10% by mass or less;
a step of forming a resin structure by forming a nickel plating layer and a tin plating layer on the resin formed body so that a content ratio of tin in the porous metal body becomes 10% by mass or more and 25% by mass or less;
a step of diffusing the chromium, the nickel, and the tin by heat-treating the resin structure at 1,100° C. or more for 5 minutes or more; and
a step of performing cooling at a rate of higher than 30° C./min until a temperature of the porous metal body after the heat treatment becomes at least 550° C. or less.

5. A method for producing a porous metal body having a three-dimensional mesh-like structure and containing nickel (Ni), tin (Sn), and chromium (Cr), the method comprising:
a step of subjecting a surface of a resin formed body having a three-dimensional mesh-like structure to an electrical conduction treatment;
a step of forming a resin structure by forming a nickel plating layer, a tin plating layer, and a chromium plating layer on the resin formed body so that a content ratio of tin in the porous metal body becomes 10% by mass or more and 25% by mass or less and a content ratio of chromium in the porous metal body becomes 1% by mass or more and 10% by mass or less;
a step of diffusing the nickel, the tin, and the chromium by heat-treating the resin structure at 1,100° C. or more for 5 minutes or more; and
a step of performing cooling at a rate of higher than 30° C./min until a temperature of the porous metal body after the heat treatment becomes at least 550° C. or less.

6. The method for producing a porous metal body according to claim 4 , wherein, in the formation of the tin plating layer, the tin plating layer is formed so that a content ratio of tin in the porous metal body becomes 17% by mass or more.

7. The method for producing a porous metal body according to claim 4 , wherein, in the formation of the tin plating layer, the tin plating layer is formed so that a content ratio of tin in the porous metal body becomes less than 17% by mass.

8. The method for producing a porous metal body according to claim 5 , wherein, in the formation of the tin plating layer, the tin plating layer is formed so that a content ratio of tin in the porous metal body becomes 17% by mass or more.

9. The method for producing a porous metal body according to claim 5 , wherein, in the formation of the tin plating layer, the tin plating layer is formed so that a content ratio of tin in the porous metal body becomes less than 17% by mass.

Assignees

• Sumitomo Electric Industries
• Sumitomo Electric Toyama Co

Inventors

• Okuno Kazuki
• Kato Masahiro
• Awazu Tomoyuki
• Majima Masatoshi
• Tsukamoto Kengo
• Tsuchida Hitoshi
• Saito Hidetoshi

Classifications

• C23C18/36

  using hypophosphites · CPC title

• C22C21/08

  with silicon · CPC title

• C22C19/058

  without Mo and W · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• C25D5/54

  Electroplating of non-metallic surfaces (C25D7/12 takes precedence) · CPC title