KR100753240B1 - Production method for alloy nano powders - Google Patents

Abstract

The present invention relates to a method for producing an alloy nanopowder, in particular to a method for producing an alloy nanopowder characterized in that the production using a wire rod coated with a dissimilar metal on the metal wire.

The present invention provides a method for producing a binary or ternary alloy nanopowder by coating a dissimilar metal on a pure metal wire or an alloy wire by electroplating, electroless plating or other methods and electroexploding the same.

Alloy wire, electroexplosion method, alloy nano powder, electroplating, electroless plating, coating

Description

Production method for alloy nano powders

1 is an electroplating apparatus used in the present invention

Figure 2 is an electric explosion device used in the present invention

Figure 3 is a nickel-copper coated wire picture produced by the present invention

4 is an X-ray diffraction diagram of the nickel-copper alloy nanopowder prepared according to the present invention.

5 is an electron micrograph of the nickel-copper alloy nanopowder prepared according to the present invention

6 is an X-ray diffraction diagram of the aluminum-copper alloy nanopowder prepared according to the present invention.

7 is an electron microscope of the aluminum-copper alloy nano powder prepared by the present invention

       Picture

※ Explanation of code about main part of drawing ※

10 plating bath 20 metal or non-consumable electrode to be plated

30: plating solution 40: plated metal wire

50: DC rectifier 60: plated wire rod support

70: plated wire 80: electric explosion apparatus vacuum chamber

90:-electrode 100: + electrode

110: powder collecting unit

The present invention relates to a method for producing an alloy nanopowder, in particular to a method for producing an alloy nanopowder characterized in that the production using a wire rod coated with a dissimilar metal on the metal wire.

There are various methods of manufacturing metal nanopowders, such as electroexplosion, plasma, liquid phase, laser ablation, and vapor phase. However, methods other than electroexplosion are difficult to produce alloys or multi-component nanopowders or are slow to produce. There are several problems. Electroexplosion is known as an economical method for producing nanopowders of various pure metals, oxides, and nitrides with a relatively high production rate.

Electroexplosion method is a method for producing nanopowder by using a phenomenon that the metal wire is exploded in the form of fine particles or vapor when a high current flows through the metal wire. When a strong impact current is applied to the metal wire located between the two electrodes, the metal wire is first melted by resistance heating and then discharges and vaporizes as the temperature continues to increase.

It is known that the vaporized metal gas is confined inside the wire rod, and when the vapor pressure rises above the threshold value, it expands instantaneously to form a shock wave, and metal particles and gas are ejected at high speed to form fine particles. In current electroexplosion methods, fine wire of less than 1 mm (usually 0.2-0.6 mm wire) is used to produce powder.

In the case of pure metals, most of the wires that can be used in the electric explosion method are produced, so there is no problem in securing raw materials.In contrast to pure metals, alloy or intermetallic wires are technically difficult to wire into wires. There is a problem that cannot be obtained from.

Therefore, in order to expand the field of application of the electroexplosion method to manufacture nanopowders of various alloys and intermetallic compounds, alloy nanopowders can be prepared without using alloy and intermetallic wires as raw material wires. Should be derived. As one of the methods, a method of simultaneously charging a plurality of dissimilar pure metal wires has been attempted, but has not reached the level of practical use.

Known techniques for the equipment for producing alloy nanopowders by the electroexplosive method is Korean Patent No. 10-0394390 (name: method and apparatus for manufacturing metal nanopowder by electroexplosion method, registered on July 30, 2003), 10-0446956 No. (name; feeding device of electroexplosion equipment for manufacturing nano powder, registered on Aug. 24, 2004) and No. 10-0407160 (name: nano powder manufacturing device, registered on Nov. 13, 2003) and domestic patent application No. 10-2004-0105378 ( Name: Electroexplosion equipment for manufacturing nanopowders with thermodynamic and electrical stability, published Dec. 16, 2004).

However, the only method for producing alloy nanopowder is Korean Patent No. 10-0551547 (name: a method of manufacturing metal, alloy or ceramic nanopowder by electroexplosion method which simultaneously inputs a plurality of wires, registered on Feb. 06, 2006), This patent invention proposes a method of simultaneously exploding several heterogeneous single metal wires, but this has not yet reached practical level.

In particular, as described above, there is no simple and inexpensive method for producing an alloy or intermetallic wire, which is difficult to obtain in the market, or a technique for manufacturing an alloy nanopowder without using an alloy or intermetallic wire.

Accordingly, an object of the present invention is to propose a method for producing an alloy nanopowder without using an alloy or intermetallic wire.

The present invention proposes a method of using a wire rod coated with a dissimilar metal on the metal wire rod as a raw material wire rod in order to solve the problems associated with such raw wire rod. Here, the metal wire is a pure metal wire, an alloy wire or an intermetallic wire, and the dissimilar metal to be coated may be one metal or two or more different metals.

Coating of other metals or alloys on the metal wire includes physical methods such as electroplating, electroless plating, sputtering, and evaporation, chemical vapor deposition, molten metal immersion, and the like. Among them, coating of various metals with electroplating and electroless plating This is possible and most economical. In addition, electroplating is a simple facility that can be continuous plating on the wire rod has the advantage that can be automated by connecting the plating process and the electric explosion process.

Therefore, by producing a wire coated with a dissimilar metal on the metal wire by the method of electroplating, it can be used as a raw material of the electroexplosive method to produce an alloy nano powder, the thickness of the base metal, coating metal, coating layer Etc., the type, composition, etc. of the alloy of the alloy nanopowder can be adjusted.

Hereinafter, in the preparation of alloy nanopowders, copper plating is performed on nickel or aluminum wires to prepare raw material wires, and electro-explosion method is applied to the method of manufacturing Ni-Cu and Al-Cu alloy nanopowders. It explains in detail.

FIG. 1 schematically illustrates a plating apparatus used for manufacturing a coated wire rod according to the present invention. Referring to the example of copper plating on a nickel wire rod, the base material wire 40 is formed in the plating bath 10 into which the copper plating solution 30 is injected. ) Is connected to the wire support 60 and connected to the cathode of the DC rectifier 50, and the copper plate 20 attached to the inner wall of the plating tank is connected to the anode, and when a DC voltage of about 1 to 2 Volt is applied, the plating solution Copper ions in the surface adhere to the surface of the nickel wire to form a copper layer. At this time, the thickness of the copper layer is proportional to the plating time, and the increase rate of the thickness of the copper layer is proportional to the applied voltage (or current). In this case, it is necessary to mechanically reciprocate the wire rod support 60 to prevent stirring of the plating solution and adhesion between the nickel base material 40.

Figure 2 is a schematic diagram of the electric explosion apparatus used in the production of nanopowder of the present invention. After the nickel / copper wire 70 manufactured by the method described above is positioned between the two electrodes 90 and 100 positioned in the chamber 80 through a roller, the air in the chamber 80 is evacuated and vacuumed. Pressurized with argon (Ar) gas. Then, when a high pressure and a strong impact current is instantaneously applied, the nickel / copper wire 70 is alloyed and nanopowdered through a process of melting, discharging, and vaporizing by heat of resistance. The powder generated by the electric explosion is completed is collected in the glass bottle attached through the powder collecting unit 110. The alloy nanopowder thus produced has a particle size of 100 nm or less.

<Example 1>

In this embodiment, a nickel / copper wire is manufactured by plating copper on a nickel wire base material using a plating apparatus as shown in FIG. 1, and a nickel-copper alloy nanopowder is manufactured in an electric explosion apparatus as shown in FIG. 2 using this wire. One embodiment.

The copper plating solution used was prepared using distilled water, the composition was 195 g / l copper sulfate powder (CuSO ₄ 5H ₂ O) and sulfuric acid (H ₂ SO ₄ ) 30g / l. Copper plating was carried out at room temperature, the current density during plating was about 10 ~ 50mA / cm2, the nickel wire used as the base material was used having a diameter of 0.2 mm. 3 is an appearance of the manufactured nickel / copper wire.

The plated nickel-copper wire was mounted on an electroexplosion apparatus and subjected to nano powder manufacturing experiments. The electroexplosion apparatus was a model (NTI 10P) manufactured by Nanotechnology. The length of the wire rod for electric explosion was 10 mm. In order to prevent oxidation of the nanopowder, the electroexplosion experiment was performed while argon gas was pressurized to about 3 atm in the chamber. After the electroexplosion experiment, the chamber lid was opened slightly to passivation treatment to prevent ignition due to rapid oxidation of the powder, and then the crystal structure, composition, size and shape of the prepared powder were analyzed.

The shape, size and crystal form of the particles produced through the above experiments were investigated. As a result, the average particle size of the powder was determined by electron microscopic analysis, and the values were in the range of 50-100 nanometers. appear.

4 shows the results of X-ray diffraction analysis of the prepared nickel-copper alloy powder, and the diffraction angles of peaks 111, 200 and 220 show a single phase with values between copper and nickel. It was found that the fully dissolved nickel-copper alloy powder was prepared. Figure 5 shows an electron micrograph of the prepared nickel-copper alloy nanopowder, the average particle size is 50 nanometers, it can be seen that the particle shape is almost spherical.

       <Example 2>

In this embodiment, aluminum / copper wire is manufactured by electroplating copper on an aluminum wire in the same manner as in <Example 1>, and an aluminum-copper alloy nanopowder is manufactured by electroexplosion using this as a raw material.

The aluminum wire was 0.2 mm in diameter. The copper plating solution consisted of 195 g / l copper sulfate powder (CuSO ₄ 5H ₂ O) and 30 g / l sulfuric acid (H ₂ SO ₄ ). Plating was performed at room temperature and the current density was about 10 ~ 50mA / cm2. The plated aluminum-copper wire was mounted on the electric wire explosion apparatus of FIG. 2 and subjected to a powder manufacturing experiment under the same conditions as in <Example 1>.

Figure 6 shows the X-ray diffraction analysis of the aluminum-copper alloy powder prepared by the present method, it can be seen that the alloy powder of aluminum-copper. Most of the powder prepared as shown in Figure 6 is in the CuAl ₂ phase, Cu ₉ Al ₁₄ It can be seen that Al and some are mixed. 7 is an electron micrograph of the prepared aluminum-copper alloy nanopowder, the average particle size is about 58 nanometers, it can be seen that the particle shape is almost perfect spherical shape.

Unlike the above embodiment, when the present invention is actually applied, the electroplating may be performed by a continuous plating method and connected to the electroexplosion process to automate the entire process.

Although the present invention has been described in detail by way of examples, the present invention is not limited to these examples and is not limited to the electroexplosion method.

The present invention does not require the use of expensive or expensive alloy or intermetallic wire, which is difficult to obtain by using a dissimilar metal coated wire in the production of alloy nano powder, and can produce alloy nanopowders of various compositions. And there is an effect that can easily control the composition.

In addition, the present invention is a simple manufacturing method, low manufacturing cost, mass production is easy to commercialize, as well as the electroplating continuous plating method and connected to the electro-explosion process has the advantage of automating the whole process There is this.

Claims (2)

In the method of manufacturing alloy nano powder, a plating process of plating dissimilar metals different from the metal wires on a metal wire, and an explosion to explode a metal wire plated with dissimilar metal by the plating process in an electric explosion device. Process for producing an alloy nano powder, characterized in that it comprises a step '' The method of claim 1, wherein the plating of the dissimilar metal on the metal wire is a continuous plating process.

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