PREPARATION METHOD FOR METAL FOAM

Abstract

The present application provides a method for preparing a metal foam. The present application provides a method which can freely control characteristics, such as pore size and porosity, of the metal foam, prepare the metal foam in the form of films or sheets which have conventionally been difficult to produce, particularly the form of thin films or sheets as well, and prepare a metal foam having excellent other physical properties such as mechanical strength. According to one example of the present application, it is possible to efficiently form a structure in which such a metal foam is integrated on a metal base material with good adhesive force.

Claims

1. A method for preparing a metal foam, the method comprising: forming a metal foam precursor using a slurry that comprises metal powder, a dispersant and a binder; and sintering the metal foam precursor.

2. The method for preparing the metal foam according to claim 1, wherein the slurry comprises 1 to 500 parts by weight of the binder, relative to 100 parts by weight of the metal powder and 10 to 2,000 parts by weight of the dispersant relative to 100 parts by weight of the binder.

3. The method for preparing the metal foam according to claim 1, wherein the metal powder comprises copper powder.

4. The method for preparing the metal foam according to claim 1, wherein the metal powder has an average particle diameter in a range of 0.1 μm to 200 μm.

5. The method for preparing the metal foam according to claim 1, wherein the binder is alkyl cellulose, polyalkylene carbonate or a polyvinyl alcohol-based binder.

6. The method for preparing the metal foam according to claim 1, wherein the dispersant is an alcohol.

7. The method for preparing the metal foam according to claim 1, wherein the slurry further comprises a solvent.

8. The method for preparing the metal foam according to claim 1, wherein the metal foam precursor is formed in the form of a film or sheet.

9. The method for preparing the metal foam according to claim 1, wherein forming the metal foam precursor comprises forming the metal foam precursor on a metal base material.

10. The method for preparing the metal foam according to claim 9, wherein forming the metal foam precursor on the metal base material comprises coating the slurry on the metal base material.

11. The method for preparing the metal foam according to claim 9, wherein the metal base material is a base material of any one metal selected from the group consisting of copper, molybdenum, silver, platinum, gold, aluminum, chromium, indium, tin, magnesium, zinc, nickel, iron, cobalt and manganese, or a base material of a mixture or alloy of two or more selected from these metals.

12. The method for preparing the metal foam according to claim 1, wherein the sintering is performed at a temperature in a range of 500° C. to 2000° C.

13. The method for preparing the metal foam according to claim 12, wherein the sintering is performed in an atmosphere including hydrogen and argon.

14. The method for preparing the metal foam according to claim 10, wherein forming the metal foam precursor further comprises drying the slurry coated on the metal base material before sintering the metal foam precursor.

15. The method for preparing the metal foam according to claim 14, wherein drying the slurry is performed at a temperature in a range of 50° C. to 250° C.

16. The method for preparing the metal foam according to claim 9, wherein the metal powder comprises copper powder, and the metal base material comprises copper.

17. The method for preparing the metal foam according to claim 7, wherein the solvent comprises water, an alcohol, DMSO (dimethyl sulfoxide), DMF (dimethyl formamide) or NMP (N-methylpyrrolidinone).

18. The method for preparing the metal foam according to claim 1, wherein sintering is performed by induction heating.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0051] FIG. 1 is a diagram showing the form of an exemplary metal foam of the present application.

[0052] FIG. 2 is a SEM photograph of the metal foam formed in an example.

MODE FOR INVENTION

[0053] 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

[0054] Copper (Cu) powder having an average particle diameter (D50 particle diameter) of about 10 to 20 μm was used as a metal component. The copper powder was mixed with a mixture in which ethylene glycol (EG) as a dispersant and ethyl cellulose (EC) as a binder were mixed in a weight ratio (EG:EC) of 4:5, so that the weight ratio (Cu:EC) of the copper powder to the binder was about 10:1, thereby preparing a slurry. The slurry was coated in the form of a film and dried at about 120° C. for about 1 hour to form a metal foam precursor. At this time, the thickness of the coated metal foam precursor was about 300 The sintering was performed to prepare copper foam by applying an external heat source in an electric furnace so that the precursor was maintained at a temperature of about 1000° C. in a hydrogen/argon gas atmosphere for 2 hours. The porosity of the prepared sheet-shaped copper foam was about 65%.

Example 2

[0055] Copper (Cu) powder having an average particle diameter (D50 particle diameter) of about 10 to 20 μm was used as a metal component. The copper powder was mixed with a mixture in which Texanol as a dispersant and ethyl cellulose (EC) as a binder were mixed in a weight ratio (Texanol:EC) of 4:5, so that the weight ratio (Cu:EC) of the copper powder to the binder was about 10:1, thereby preparing a slurry. The slurry was coated in the form of a film and dried at about 120° C. for about 1 hour to form a metal foam precursor. At this time, the thickness of the coated metal foam precursor was about 300 μm. The sintering was performed to prepare copper foam by applying an external heat source in an electric furnace so that the precursor was maintained at a temperature of about 1000° C. in a hydrogen/argon gas atmosphere for 2 hours. The porosity of the prepared sheet-shaped copper foam was about 62%.

Example 3

[0056] A slurry was prepared in the same manner as in Example 1, except that terpineol was used instead of ethylene glycol as a dispersant and polyvinyl acetate (PVAc) was used instead of ethyl cellulose (EC) as a binder. Upon preparing the slurry, the formulation ratio of the copper powder, the dispersant and the polyvinyl acetate was 1:1:0.1 (Cu: terpineol: PVAc) on the basis of weight. The slurry was coated on a copper base material to a thickness of about 30 μm in a film shape and dried in the same manner as in Example 1 to form a metal foam precursor on the copper base material. Subsequently, the sintering was performed under the same conditions as in Example 1 to form the copper foam integrated with the copper base material. The porosity of the prepared copper foam was about 68%, which was integrated with the copper substrate with excellent adhesion. FIG. 2 is a SEM photograph of the structure thus formed.