Method for manufacturing metal foam

Abstract

The present application provides a method for manufacturing a metal foam. The present application can provide a method for manufacturing a metal foam, which is capable of forming a metal foam comprising uniformly formed pores and having excellent mechanical properties as well as the desired porosity, and a metal foam having the above characteristics. In addition, the present application can provide a method capable of forming a metal foam in which the above-mentioned physical properties are ensured, while being in the form of a thin film or sheet, within a fast process time, and such a metal foam.

Claims

1. A method for manufacturing a metal foam comprising: preparing a structure using a slurry, applying an electromagnetic field to the structure, wherein the slurry consists of a metal component, an organic binder, and optionally solvent and/or binder, wherein the metal component comprises a conductive metal having a relative magnetic permeability of 90 or more, wherein the metal component comprises, on the basis of weight, 30% by weight or more of the conductive metal, and wherein the metal component to which the electromagnetic field is applied is in the form of powder.

2. The method for manufacturing a metal foam according to claim 1, wherein the conductive metal has a conductivity at 20° C. of 8 MS/m or more.

3. The method for manufacturing a metal foam according to claim 1, wherein the conductive metal is nickel, iron or cobalt.

4. The method for manufacturing a metal foam according to claim 1, wherein the conductive metal has an average particle diameter in a range of 5 μm to 100 μm.

5. The method for manufacturing a metal foam according to claim 1, wherein the organic binder is alkyl cellulose, polyalkylene carbonate, polyvinyl alcohol, polyalkylene oxide or polyvinyl acetate.

6. The method for manufacturing a metal foam according to claim 1, wherein the slurry comprises 10 to 400 parts by weight of the organic binder, relative to 100 parts by weight of the metal component.

7. The method for manufacturing a metal foam according to claim 1, wherein the structure is in a film or sheet shape.

8. The method for manufacturing a metal foam according to claim 7, wherein the film or sheet shape has a thickness of 5,000 μm or less.

9. The method for manufacturing a metal foam according to claim 1, wherein the electromagnetic field is formed by applying a current in a range of 100 A to 1,000 A.

10. The method for manufacturing a metal foam according to claim 1, wherein the electromagnetic field is formed by applying a current at a frequency in a range of 100 kHz to 1,000 kHz.

11. The method for manufacturing a metal foam according to claim 1, wherein the electromagnetic field is applied for a time in a range of 1 minute to 10 hours.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1 and 2 are SEM photographs of metal foams formed in Examples 1 and 2, respectively.

MODE FOR INVENTION

(2) Hereinafter, the present application will be described in detail by way of examples and comparative examples, but the scope of the present application is not limited to the following examples.

Example 1

(3) Nickel powder (having a conductivity of about 14.5 MS/m, a relative magnetic permeability of about 600 or so, and an average particle diameter of about 10 to 20 μm or so) and ethyl cellulose were added in a weight ratio of about 1:1 to methylene chloride and mixed using a planetary mixer to prepare a slurry. The prepared mixture was coated on a quartz plate to a thickness of about 200 μm or so to produce a structure, and the structure was sintered by applying an electromagnetic field thereto with a coil-type induction heater to manufacture a metal foam. At this time, the electromagnetic field was formed by applying a current of about 350 A at a frequency of about 380 kHz, and the application time was about 3 minutes or so. The manufactured metal foam had a porosity of about 65%, and a SEM photograph thereof was shown in FIG. 1.

Example 2

(4) A metal foam was manufactured in the same manner as in Example 1, except that polyethylene carbonate was used instead of ethyl cellulose. The manufactured metal foam had a porosity of about 45%, and a SEM photograph thereof was shown in FIG. 2.

Example 3

(5) A metal foam was manufactured in the same manner as in Example 1, except that polyvinyl alcohol was applied instead of ethyl cellulose and water was applied instead of methylene chloride. The manufactured metal foam had a porosity of about 52%.

Example 4

(6) A metal foam was prepared in the same manner as in Example 1, except that polyethylene oxide was used instead of ethyl cellulose. The manufactured metal foam had a porosity of about 57%.