KR20100113828A - Manufacture device of metal-complex-powder using for gas atomization - Google Patents

Abstract

PURPOSE: A manufacturing device of the metallic composite powder using a gas injecting process is provided to enable the metallic composite powder to be mass-produced at a low cost and to enhance the abrasion-resistance and the stiffness through the sintering and the compression of the manufactured metallic composite powder. CONSTITUTION: A manufacturing device(100) of the metallic composite powder using a gas injecting process is composed of a housing(10), a crucible(20), an induction coil(30), an injection nozzle(40), a melting chamber(50), a gas emitter(60), and a lower chamber(70). The induction coil is installed on the outer circumferential surface of the crucible. The injection nozzle is connected to the crucible. The injection nozzle sprays the molten metal which is formed from the metal in the crucible. The melting chamber accepts the material sprayed form the injection nozzle. The gas emitter sprays the argon gas to the melting chamber. The lower chamber is communicated with the melting chamber. The lower chamber collects the metallic composite powder.

Description

Manufacture device of metal-complex-powder using for gas atomization

The present invention relates to an apparatus for producing a metal composite powder using a gas spraying process, and more particularly, a ceramic reinforcement phase (TiC) is in-situ reaction in an aluminum-silicon (Al-Si) matrix phase. The produced metal composite powder can be produced, and by using the above process, the metal composite powder can be mass-produced at low cost, and the manufactured metal composite powder is manufactured by sintering and extruding to produce mechanical structural parts having excellent wear resistance and strength. The present invention relates to an apparatus for producing a metal composite powder using a gas spraying process, which can replace iron-based powder parts.

In the mechanical parts industry represented by automobiles, attempts to use lightweight metals such as aluminum instead of heavy steel materials have been made since the 1990s.

In the past, there was a preference for lightweight metals in terms of lower energy consumption. However, in the 1990s, concerns about environmental pollution and energy depletion have increased, and interest in lightweight metals has increased.

The proportion of aluminum in automobile parts (mass ratio) has increased dramatically since the 1990s, and the manufacturing method of metal composite powders using the two-gas spraying process in the early 0s, 7 percent (%) for the same as in the United States, and 30 percent for Japan %, And about 5 percent of domestic cars.

Among the various automotive aluminum parts, the area occupied by powder metallurgy parts is related to friction or wear.

In the early days when aluminum was applied to automobiles, rolled materials and cast materials, which were not expensive due to the simple manufacturing process, were mainly used for car bodies or chassis.

However, the heavy parts of a car are driving parts that repeat high-speed translation and rotational movements such as engines, transmissions, and brakes.

Unlike other parts, they require high strength and wear resistance, and have complex shapes. Rolled materials and cast materials have lower strength and wear resistance than steel and require a plurality of processing to form complex shapes. Holding it.

Therefore, powder metallurgy materials, which have high raw material prices but do not require a lot of processing, can make complex shapes, and have high strength and excellent wear resistance through alloying and compounding with a wide composition, have been considered as materials to replace steel. .

In fact, when aluminum powder metallurgy parts were first applied to automobiles, Camshaft Bearing Cap manufactured by Metal Powder Product (MPP) of the United States was applied to GM's Northstar engine. It was 1993.

Since then, diesel engine pistons (Toyoda), cylinder liners (Honda), drive shafts (GM trucks), brake parts (GM) and the like were made of aluminum powder metallurgy.

Then, there is an aluminum powder cam cap manufactured by the US Metal Powder Products (MPP) Co., Ltd. for 6 years.

These parts require high strength and good abrasion resistance. Aluminum powder materials solve this problem through alloying and compounding.

Representative examples include over-processed aluminum-silicon (Al-Si) alloy powder materials that maximize strength and wear resistance through alloying, and aluminum-silicon carbide (Al-SiC) composite powder materials that maximize wear resistance through complexation.

Both materials have been studied in earnest from the 1990s and can be manufactured only through powder metallurgy.

When over-processed aluminum-silicon (Al-Si) alloy is manufactured by casting process, silicon particles precipitated beyond the solubility limit become coarse due to the slow cooling rate, resulting in low strength and fracture. .

In addition, the casting material has to go through a machining process for dimensional correction, the composite material is a relatively soft metal base and hard ceramic particles are mixed is not easy to cut, has excellent wear resistance and difficult to polish.

Therefore, the powder metallurgy process, which does not require dimensional correction, is a very suitable process for manufacturing a composite material part, and also has an advantage of easier microstructure control than the casting process. The advantage of easy control of the microstructure is that the uniform distribution of ceramic particles, prevention of coarsening of ceramic particles, and prevention of reaction of metal base-ceramic particles.

Methods for producing aluminum powder have been developed in a variety of ways, such as gas spray, rotary spray, ball milling. However, for economical and mass production, the gas atomization process is known as the most suitable powder production method to date.

Basically, the gas spraying process is a method of manufacturing a metal powder by injecting a gas jet of high pressure and high speed into the molten metal, separating the molten metal into a fine solution, and simultaneously solidifying it.

When the over-process aluminum-silicon (Al-Si) alloy is prepared by a gas spraying process, it is possible to control the particle size of the powder and to prepare a spherical uniform powder. However, over-processed aluminum-silicon (Al-Si) alloys typically exhibit lower mechanical properties than conventional iron-based components due to the weak strength and abrasion resistance of aluminum bases.

In addition, in the ex-situ process of mechanically mixing a ceramic reinforcement phase after manufacturing an overprocessed aluminum-silicon (Al-Si) alloy by a gas spray method, the ceramic reinforcement phase is overprocessed during the sintering process. Located at the interface of the silicon (Al-Si) alloy, it is not uniformly dispersed due to the aggregation phenomenon, there is a disadvantage that the mechanical properties do not improve as fracture occurs first at the interface where the ceramic reinforcement phase is located.

Therefore, it is indispensable to develop a process for producing a metal composite powder in an in-situ process in which a ceramic reinforcement phase is formed in an aluminum (Al) matrix by using a gas spray method that can control the particle size of powder. to be.

The present invention has been proposed to solve the above-mentioned problems, and an object thereof is that a ceramic reinforcement phase (TiC) is produced by an in-situ reaction in an aluminum-silicon (Al-Si) matrix phase. The metal composite powder can be prepared, and by using the above process, the metal composite powder can be mass-produced at low cost, and the manufactured metal composite powder can be manufactured by sintering and extruding to produce mechanical structural parts having excellent wear resistance and strength. It is an object of the present invention to provide an apparatus for producing a metal composite powder using a gas spraying process that can replace the iron-based powder parts.

Apparatus for producing a metal composite powder using a gas spraying process according to the present invention for achieving the above object, a crucible for accommodating a housing, a molten metal contained in the housing, dissolved metal, the crucible Induction coil installed on the outer periphery of the, and connected to the crucible, the spray nozzle for injecting molten metal dissolved in the crucible, a dissolution chamber for receiving the spray injected from the spray nozzle, and the argon in the melting chamber And (Ar) a gas discharge system for injecting gas, and a lower chamber in communication with the dissolution chamber and collecting the metal composite powder.

In addition, in the apparatus for producing a metal composite powder using the gas spraying process according to the present invention, the temperature of the molten metal is 700 ° C. to 1000 ° C.

In addition, in the manufacturing apparatus of the metal composite powder using the gas spraying process according to the present invention, the vacuum pressure provided in the housing is characterized in that 1 × 10 ^-4 Torr to 1 × 10 ^-6 Torr It is done.

In addition, in the apparatus for producing a metal composite powder using the gas spraying process according to the present invention, the nozzle is characterized in that the diameter of 0.5 mm (mm), length 2.5 mm (mm).

In addition, the argon (Ar) gas is injected from the gas discharge system of the metal composite powder manufacturing apparatus using the gas spraying process according to the present invention is characterized in that the spraying at a pressure of 18 bar (22) to 22 bar (bar) It is done.

According to the apparatus for producing a metal composite powder using the gas spraying process according to the present invention, a ceramic composite phase (TiC) is a metal composite produced by the in-situ reaction in the aluminum-silicon (Al-Si) matrix phase Powder can be prepared, and by using the above process, metal composite powder can be mass-produced at low cost, and the manufactured metal composite powder can be manufactured by sintering and extruding to produce mechanical structural parts with excellent wear resistance and strength. It has the effect of replacing powder parts.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

Hereinafter, an apparatus for manufacturing a metal composite powder using a gas spraying process according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 6 show an apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention, Figure 1 is an apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention Figure 2 is a schematic diagram showing an example of, Figure 2 is a flow chart showing a method for producing a metal composite powder using the apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention, Figure 3 is a gas spraying Figure 4 shows the observation of an aluminum composite powder containing titanium carbide (TiC) prepared by using a scanning electron microscope. FIG. 4 shows an energy dispersive X-ray micro analyzer of a cross section of the manufactured composite powder. , EDX), Figure 5 is a cross-sectional view of the prepared composite powder (Energy Dispersive X-ray Micro Analyzer, EDX) Figure (Mapping) Figure (Figure 6) The composite powder of the figure shows the one measured by the hot press (Hot press) to the surface X (X)-ray photoelectron spectroscopy (X-ray Photoelecron Spectroscopy, XPS) by sintering through each.

As shown in the figure, the apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention, the housing 10, the crucible 20, the induction coil 30, the spray nozzle 40 ), A dissolution chamber 50, a gas release system 60, and a lower chamber 70.

The housing 10 has a space therein.

The crucible 20 is accommodated in the housing 10 and accommodates a molten metal containing dissolved metal.

The induction coil 30 is installed on the outer circumference of the crucible 20 to transfer heat to the crucible 20.

The spray nozzle 40 is connected to the end of the crucible 20, to spray the molten metal in the crucible 20.

The dissolution chamber 50 is to accommodate the injection sprayed from the spray nozzle (40).

The gas emission system 60 injects argon (Ar) gas into the dissolution chamber 50.

The lower chamber 70 communicates with the dissolution chamber 50 and collects the metal composite powder.

On the other hand, it is preferable that the temperature of the said molten metal is 700 degrees C (degreeC)-1000 degrees C (degreeC).

In addition, the vacuum pressure provided in the housing 10 may be 1 × 10 ⁻⁴ Torr to 1 × 10 ⁻⁶ Tor.

The nozzle is preferably 0.5 mm (mm) in diameter and 2.5 mm (mm) in length.

In addition, the argon (Ar) gas is injected from the gas discharge system is preferably injected at a pressure of 18 bar (22) to 22 bar (bar).

It will be described in more detail a method for producing a metal composite powder using the apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention having the above configuration.

The over-process aluminum-silicon (Al-Si) alloy system is selected for the design of the aluminum (Al) matrix alloy for in-situ reaction. This is because the over-process aluminum-silicon (Al-Si) alloy has excellent mechanical properties to weight, excellent high temperature properties, excellent tensile strength (> 450 MPa), hardness (> 90 HRB) and rigidity, and a coefficient of thermal expansion. This is because it is low and suitable for manufacturing into parts using powder metallurgy.

In addition, aluminum-silicon (Al-Si) casting material has a limitation of silicon (Si) content to increase the mechanical properties of the material due to the coarsening of precipitates, but coarsening of silicon (Si) precipitate during manufacturing by powder metallurgy process It is possible to increase to about 30% by weight (wt%) while suppressing.

Meanwhile, in order to obtain an aluminum composite powder in which titanium carbide (TiC) is formed by in-situ reaction in a matrix, first, a work for forming a ceramic reinforcing agent (TiC) in an aluminum matrix is performed.

In this operation, carbon (C) is introduced into aluminum (Al) and titanium (Ti) molten metal to form an intermediate phase of aluminum carbide and Al ₃ Ti, and then reacted again to form a titanium carbide (TiC) reinforced phase.

The reaction formula at this time is as follows.

Al + Ti + C → Create Al ₃ Ti or Al ₄ C ₃

Al ₄ C ₃ + 3Al ₃ Ti → 3TiC + 13Al

Meanwhile, separately prepared aluminum-silicon (AlSi) ingots are prepared, and titanium carbide (TiC) formed through the above process is prepared in the form of ingots.

Subsequently, the aluminum-silicon (AlSi) ingot and the titanium carbide (TiC) ingot are immersed in the crucible 20.

Subsequently, a cylindrical heating induction coil 30 installed around the crucible heats the ingot, and at this time, molten metal is formed by a high frequency induction heating method.

When the molten metal is made by the high frequency induction heating method, the molten metal in the crucible 20 is obtained with a homogeneous molten metal by the residual stirring force. This is more economical than manufacturing a molten metal by heating with a conventional heater and stirring with a stirrer.

In addition, when producing a mixed melt by the high frequency induction heating method, there is little unbalance in the melt temperature distribution, and the adjustment of the components is easy.

When the temperature of the mixed melt in the crucible 20 is 700 degrees Celsius or less, the viscosity of the mixed melt is increased, and thus the fluidity of the mixed melt is reduced to the spray nozzle 40. When the temperature of the mixed melt is higher than 1000 degrees C, the fluidity of the mixed melt is increased. Since the rapid flow to the nozzle 40 is faster than the gas injection rate, it is impossible to produce a composite powder of uniform size, so the temperature of the molten metal should be controlled to 700 ° C. to 1000 ° C.

At this time, it is preferable that the vacuum formed inside the housing 10 is 1 × 10 ⁻⁴ Torr to 1 × 10 ⁻⁶ Tor. This is because the vacuum pressure is also related to the flowability of the molten metal, so that the fluidity of the molten metal falls below the reference value, and the fluidity of the molten metal becomes too high above the reference value, so that a desired result cannot be obtained.

When the molten metal is formed by the high frequency induction heating method through the above-described process, it flows into the spray nozzle 40 having a diameter of 0.5 mm and a length of 2.5 mm.

In addition, high-purity argon (Ar) gas is injected into the spray nozzle 40 through the gas discharge system 60 at a pressure of about 20 bar.

This will form a fine composite powder of 20 micrometers (μm) or less containing titanium carbide (TiC).

The aluminum composite powder containing titanium carbide (TiC) formed through the above-described process is recovered in the lower chamber 70 of FIG. 1 and received separately.

3 through 6 illustrate an aluminum composite powder containing titanium carbide (TiC) formed through the above process.

Figure 3 shows the observation of the Al-20Si + 3vol% TiC composite powder prepared by using a gas spraying process with a scanning electron microscope, the shape of the composite powder was prepared in a spherical shape, the particle size distribution of the powder is about 500 nanometers Meters (nm) to 25 micrometers (μm).

Figure 4 shows the cross-sectional view of the prepared composite powder through an energy dispersive X-ray microanalyzer (EDX), it can be confirmed the titanium carbide (TiC) precipitated in the composite powder.

FIG. 5 is a diagram illustrating a cross-section of the manufactured composite powder through an energy dispersive X-ray microanalyzer (EDX). FIG. 5 shows titanium (Ti) and carbon (C) in the composite powder. It is confirmed that titanium carbide (TiC) is found to correspond to a large number of points.

FIG. 6 is a diagram showing the surface of the prepared composite powder by sintering through a hot press and measuring the surface by X-ray photoelecron spectroscopy (XPS). It can be seen that (Si) and titanium carbide (TiC) are present.

1 is a schematic view showing an example of an apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention.

Figure 2 is a flow chart showing a method of manufacturing a metal composite powder using the apparatus for producing a metal composite powder using a gas spraying process according to an embodiment of the present invention

FIG. 3 is a photograph of an aluminum composite powder containing titanium carbide (TiC) prepared by using a gas spraying process, using a scanning electron microscope

4 is a cross-sectional view of a manufactured composite powder through an energy dispersive X-ray micro analyzer (EDX).

FIG. 5 is a diagram in which the cross-sections of the manufactured composite powders are mapped by an energy dispersive X-ray micro analyzer (EDX). FIG.

FIG. 6 is a sintered composite powder prepared by hot press, and the surface thereof is measured by X-ray photoelecron spectroscopy (XPS).

<Description of Symbols for Main Parts of Drawings>

10. Housing 20. Crucible

30. Induction coil 40. Spray nozzle

50. Dissolution chamber 60. Gas emission meter

70. Lower chamber

Claims (5)

housing; A crucible accommodated in the housing and containing a molten metal containing dissolved metal; An induction coil installed at an outer circumference of the crucible; A spray nozzle connected to the crucible and spraying molten metal in which the metal in the crucible is dissolved; Dissolution chamber for receiving the spray injected from the spray nozzle; A gas emission system for injecting argon (Ar) gas into the dissolution chamber; The lower chamber is in communication with the melting chamber, the lower chamber for collecting the metal composite powder; apparatus for producing a metal composite powder using a gas spraying process comprising a. The method of claim 1, Temperature of the molten metal is 700 ℃ (℃) to 1000 ℃ (℃) characterized in that the apparatus for producing a metal composite powder using a gas spraying process. The method of claim 1, The vacuum pressure provided in the housing is 1 × 10 ^-4 Torr (Torr) to 1 × 10 ^-6 Torr (torr) characterized in that the apparatus for producing a metal composite powder using a gas spraying process. The method of claim 1, The nozzle is 0.5 mm (mm) in diameter, 2.5 mm (mm) in length of the metal composite powder manufacturing apparatus using a gas spraying process, characterized in that. The method of claim 1, Argon (Ar) gas is injected from the gas discharge system is a method of manufacturing a metal composite powder using a gas spraying process, characterized in that the spraying at a pressure of 18 bar (22) to 22 bar (bar).

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