KR101080926B1 - The preparation method of ceramic/metal composite powders for metal materials to enhance the mechanical properties - Google Patents

Abstract

The present invention relates to a method for producing a ceramic / metal composite powder reinforcement and to a ceramic / metal composite powder reinforcement for improving the mechanical properties produced thereby, and more specifically, mechanically milling TiC powder and Cu powder (step 1). ; And a step of preparing a ceramic / metal composite powder reinforcing material by mixing a surfactant metal to the TiC / Cu composite powder prepared in step 1 (step 2). The ceramic / metal composite powder reinforcement according to the present invention improves mechanical properties (strength and hardness, etc.) by adding to the metal material to make the internal structure of the metal material uniform and fine, and there is no limitation on the added metal material. It can be usefully used for metal materials.

Mechanical milling, surfactants, mechanical properties, ceramic / metal composite powder reinforcements

Description

The preparation method of ceramic / metal composite powders for metal materials to enhance the mechanical properties

The present invention relates to a method for producing a ceramic / metal composite powder reinforcement and to a ceramic / metal composite powder reinforcement for improving the mechanical properties produced thereby.

Recently, as the industrial development is accelerated, researches on the complexation of dissimilar materials for the development of high strength / high toughness mechanical parts materials are being conducted, and the results are applied throughout the industry. However, in the case of a composite material made of a metal material and a nonmetallic material such as a ceramic, the compounding is very difficult due to the fundamental heterogeneity between the ceramic and the metal. Until now, research has been conducted to apply powder metallurgy technology, which mainly depends on physical methods, that is, mechanical alloying technology that combines metal powder and ceramic powder by mechanical / physical grinding and mixing. . Korean Patent Laid-Open Publication No. 2006-0123881 describes a method of manufacturing a high strength semi-crystalline reinforced aluminum composite material after mechanically / alloying a mixed powder of a semi-crystalline powder and an aluminum powder or an alloying element, followed by a hot forming process. In addition, Korean Patent Laid-Open No. 2008-0057544 discloses a method for producing a composite powder by mechanical alloying by mixing aluminum powder and silicon carbide powder by ball milling.

However, the mechanical alloying technique as described above has a problem that the manufacturing method is limited because the process is very complicated and the productivity is low.

In addition, US Patent No. 5296301 describes a method of manufacturing a ceramic matrix of a polycrystalline ceramic in which a metal phase is dispersed in order to improve mechanical strength, and Korean Patent Publication No. 1996-0017578 discloses an alumina silica based addition of zirconia. A method for producing a ceramic fiber-reinforced metal composite material is described by press-casting a preform made of fiber with a molten metal selected from aluminum and magnesium alloys, followed by heat treatment. Further, Japanese Laid-Open Patent Publication No. 2006-016296 discloses a method for producing a ceramic powder including metal nanoparticles by adding metal nanoparticles, which are nano-sized metal particles, to particles of ceramic powder.

In recent years, researches have been made on a method of manufacturing a component having a complex and sophisticated shape, and a method of manufacturing a composite material by casting has been studied, but heterogeneity between ceramic powder and metal, that is, ceramic powder reinforcement and molten metal Due to the difference in specific gravity, wettability and dispersibility are very low, and casting of a composite is very difficult. In addition, in the case of composites using mechanical alloying, the mechanical properties of the composites are remarkably improved when the size of the ceramic powder becomes nanoscale, but when applied to liquid casting, the dispersibility becomes very poor due to the aggregation phenomenon of the nanoceramic. There is a problem that it is impossible to manufacture a composite using a liquid casting.

Therefore, the inventors of the present invention while studying the reinforcing material to improve the mechanical properties of the metal, using a ceramic powder, metal powder and surfactant metal to develop a ceramic / metal composite powder reinforcement to improve the mechanical properties of the metal material, the present invention Was completed.

It is an object of the present invention to provide a method for producing a ceramic / metal composite powder reinforcement.

It is another object of the present invention to provide a ceramic / metal composite powder reinforcement for improving mechanical properties.

In order to achieve the above object, the present invention comprises the steps of mechanical milling the TiC powder and Cu powder (step 1); And it provides a method for producing a ceramic / metal composite powder reinforcement comprising the step (step 2) of preparing a ceramic / metal composite powder reinforcement by mixing a surfactant metal to the TiC / Cu composite powder prepared in step 1.

The present invention also provides a ceramic / metal composite powder reinforcing material for improving mechanical properties.

The ceramic / metal composite powder reinforcement according to the present invention improves mechanical properties (strength and hardness, etc.) by adding to the metal material to make the internal structure of the metal material uniform and fine, and there is no limitation on the added metal material. It can be usefully used for metal materials.

The present invention provides a ceramic / metal composite powder reinforcement in which a mechanically milled TiC and Cu powder and a surfactant metal are mixed in a weight ratio of 0.5: 0.5 to 1.

The ceramic / metal composite powder reinforcement according to the present invention improves Brinell hardness and tensile strength by adding a ceramic / metal composite powder reinforcement to uniform and refine the internal structure of the metal material.

In addition, when the ceramic / metal composite powder reinforcing agent according to the present invention is mechanically milled TiC powder and Cu powder, the shape of the metal Cu matrix surrounding the fine TiC ceramic particles is preferable.

Furthermore, it is preferable to use tin (Sn), calcium (Ca), magnesium (Mg), lithium (Li), etc., and it is more preferable to use tin (Sn).

In the ceramic / metal composite powder reinforcing material according to the present invention, it is preferable to mix the TiC / Cu composite powder and the surfactant metal in a weight ratio of 0.5: 0.5 to 1. If out of the weight ratio, there is a problem that the injection of the powder in the molten metal is limited.

Furthermore, the present invention comprises the steps of mechanical milling the TiC powder and Cu powder (step 1); And

It provides a method for producing a ceramic / metal composite powder reinforcement comprising the step (step 2) of preparing a ceramic / metal composite powder reinforcement by mixing a surfactant metal to the TiC / Cu composite powder prepared in step 1.

Hereinafter, a method of manufacturing a ceramic / metal composite powder reinforcing material according to the present invention will be described in detail.

First, step 1 according to the present invention is a step of mechanical milling TiC powder and Cu powder.

Mechanical milling of step 1 may be performed by a high speed ball mill process, but is not limited thereto.

In addition, the mixing of the Cu powder with respect to the TiC powder of step 1 is preferably 50: 50% by weight. If out of the mixing ratio, there is a problem that the injection of the powder in the molten metal is limited.

Further, the mechanical milling of step 1 is preferably carried out at 900-1100 rpm for 6-10 minutes. If mechanical milling is performed at less than 900 rpm, there is a problem that the ceramic is not finely pulverized to a nano size, and if it is performed at more than 1100 rpm, the recovery rate is lowered when manufacturing the composite powder reinforcement, thereby reducing productivity. have. In addition, when less than 6 minutes, there is a problem that the ceramic is not finely pulverized to a nano-size and the ceramic is not evenly distributed in the metal base, if more than 10 minutes, the recovery rate in the production of composite powder reinforcement is lowered and productivity There is a decreasing problem.

Next, step 2 according to the present invention is a step of preparing a ceramic / metal composite powder reinforcing material by mixing a surfactant metal to the composite powder prepared in step 1.

The surfactant metal of step 2 may be tin (Sn), calcium (Ca), magnesium (Mg), lithium (Li) and the like, it is preferable to use tin (Sn).

In addition, the mixing of step 2 is preferably performed at 60-80 rpm for 50-70 minutes. If mechanical milling is performed at less than 60 rpm, there is a problem that the surfactant metal and the composite powder prepared in step 1 do not mix uniformly, and when the mechanical milling is performed at more than 80 rpm, the surfactant metal powders aggregate. There is. In addition, if it is carried out in less than 50 minutes, there is a problem that the composite metal prepared in step 1 and the surfactant metal is not mixed uniformly, and when carried out for more than 70 minutes, there is a problem that the surfactant metal powder is aggregated.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are merely to illustrate the present invention, but the content of the present invention is not limited by the following examples.

Example 1 Preparation of Carbon Steel Added Ceramic / Metal Composite Powder Reinforcement

Step 1: mechanically milling TiC powder and Cu powder

TiC powder and Cu powder were mechanically milled at 50 rpm for 50 minutes at 1000 rpm.

Step 2: preparing a ceramic / metal composite powder reinforcing material by mixing a surfactant metal to the composite powder prepared in step 1

Tin (Sn), which is a surfactant metal, was added to the TiC / Cu composite powder prepared in Step 1 and mixed at 70 rpm for 1 hour.

The ceramic / metal composite powder reinforcement prepared in the above manufacturing method was charged and solidified in the molten metal to prepare carbon steel to which the ceramic / metal composite powder reinforcement was added (see FIG. 1).

Comparative Example 1 Carbon Steel Without Addition of Ceramic / Metal Composite Powder Reinforcement

Carbon steel (S45C, Hyundai Special Steel) was used as Comparative Example 1.

Analysis 1. Particle Analysis of Ceramic Powder and Metal Powder

In order to analyze the particles of the TiC powder and the Cu powder were observed by scanning electron microscope (SEM, JAPAN, SIRION), the results are shown in FIG.

As shown in FIG. 2, it was found that the particles of the Cu powder (FIG. 2A) and the TiC powder (FIG. 2B) are in a relatively uniform state.

Analysis 2. Aspect analysis of mechanically milled composite powder, surfactant metal powder, ceramic / metal composite powder reinforcement

Powder photographs were taken to investigate the mechanically milled TiC / Cu composite powder, surfactant metal Sn powder, and simple mixed TiC / Cu composite powder and Sn powder.

Figure 3 (a) is a mechanically milled TiC / Cu composite powder (Fig. 3 (a)) is a picture, Figure 3 (b) is a surfactant metal Sn powder picture, Figure 3 (c) is TiC Powder photograph after mixing / Cu composite powder and Sn powder.

Analysis 3. Particle Analysis of Mechanically Milled Ceramic / Metal Composite Powders

In order to analyze the particles of the TiC / Cu composite powder prepared in step 1 of Example 1 was observed by a runner electron microscope (SEM), the results are shown in FIG.

As shown in FIG. 4, it can be seen that the surface after mechanical milling shows a relatively uniform particle distribution, and that black TiC ceramic particles are uniformly distributed in the bright Cu particles (FIG. 4). (A)). In addition, it can be seen that the fine TiC ceramic particles are made of a shape wrapped around the metal Cu base (see FIG. 4B).

Analysis 4. Microstructure analysis of cast carbon steel with and without ceramic / metal composite powder reinforcement

In order to analyze the microstructure of the cast carbon steel with the addition of the ceramic / metal composite powder reinforcement and the cast carbon steel without the addition of the reinforcing material, the optical microscope was observed and the results are shown in FIG. 5.

As shown in FIG. 5, it can be seen that the carbon steel of Example 1 has a smaller grain size than the carbon steel of Comparative Example 1.

Experimental Example 1 Analysis of tensile fracture surface of carbon steel cast by adding ceramic / metal composite powder reinforcement and carbon steel cast without reinforcing material

In order to analyze the tensile fracture surface of the cast carbon steel with the addition of the ceramic / metal composite powder reinforcement and the cast carbon steel without the reinforcing material, it was analyzed by a scanning electron microscope, and the results are shown in FIG. 6.

As shown in FIG. 6, it can be seen that the carbon steel fracture surface (FIG. 6A) of Comparative Example 1 has a larger grain size than the carbon steel fracture surface (FIG. 6B) of Example 1, and fractured. Even in the case of behavior, carbon steel added with ceramic / metal composite powder reinforcement shows that ductile fracture is dominant. Therefore, it can be seen that the tensile strength is improved by dispersing the ceramic / metal composite powder reinforcement in carbon steel.

Experimental Example 2 Analysis of Brinell Hardness and Tensile Strength of Carbon Steel Cast by Addition of Ceramic / Metal Composite Powder Reinforcement and Carbon Steel Cast without Addition of Reinforcement

Brinell hardness and tensile strength were measured to analyze the Brinell hardness and tensile strength of the cast carbon steel with the addition of ceramic / metal composite powder reinforcement and the cast carbon steel without the reinforcement, and the results are shown in Table 1 and Table 2. It was.

matter Brinell Hardness (HB) Tensile Strength (MPa) Example 1 215 506.1 Comparative Example 1 169 402.9

Referring to Table 1, it can be seen that the carbon steel of Example 1 is 27% improved Brinell hardness compared to the carbon steel of Comparative Example 1, the tensile strength is also improved 25%. Therefore, it can be seen that by adding the ceramic / metal composite powder reinforcement to the carbon steel, the grains are refined and mechanical properties are improved due to the properties of the TiC particles themselves.

1 is a schematic view showing a manufacturing process of a ceramic / metal composite powder reinforcement according to the present invention;

2 is a scanning electron micrograph of a TiC ceramic powder and a Cu metal powder;

3 is a photograph of a mechanically milled TiC / Cu composite powder, a surfactant metal Sn powder, and a powder mixed with a TiC / Cu composite powder and a Sn powder;

4 is a scanning electron micrograph of the TiC / Cu composite powder prepared in Example 1;

5 is an optical micrograph of the carbon steel of Example 1 and the carbon steel of Comparative Example 1;

6 is a scanning electron micrograph of the tensile fracture surface of the carbon steel of Example 1 and the carbon steel of Comparative Example 1.

Claims (9)

delete delete delete Mechanically milling the TiC powder and the Cu powder at 900-1100 rpm for 6-10 minutes (step 1); And Method for producing a ceramic / metal composite powder reinforcement comprising the step (step 2) of preparing a ceramic / metal composite powder reinforcement by mixing a surfactant metal to the TiC / Cu composite powder prepared in step 1. The method of claim 4, wherein the mechanical milling of step 1 is performed by a high speed ball mill process. 5. The method of claim 4, wherein the mixing of the TiC powder and the Cu powder in Step 1 is 50: 50 wt%. delete 5. The method of claim 4, wherein the surfactant metal of step 2 is selected from the group consisting of tin, calcium, magnesium and lithium. The method of claim 4, wherein the mixing of step 2 is performed for 60 to 80 rpm for 50 to 70 minutes.

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