KR20150069470A - Cvd surface processed tools - Google Patents

Abstract

The present invention relates to an extruding tool processed using a CVD surface processing method. The extruding tool comprises an upper mold and a lower mold. A core shaping an extruded object is formed between the upper and lower molds. The core and the upper and lower molds are coated in a position predetermined by a vapor deposition process with a carbide, a nitride, an oxide, and a mixture of those substances; and a substance selected from a group comprising a titanium carbide, a titanium nitride, a titanium boride, a vanadium carbide, a chrome carbide, an aluminum oxide, a silicon nitride, titanium, an aluminum oxide, a titanium aluminum nitride, and an aluminum chrome nitride, and a substance selected from a group comprising a nitride and a carbide of those substances.

Description

CVD SURFACE PROCESSED TOOLS < RTI ID = 0.0 >

The present invention relates to an extrusion tool that has been processed using a CVD surface treatment method.

The present invention relates to an extrusion tool that has been processed using a CVD surface treatment method. Extrusion is a kind of plastic working method for metal, which means extrusion molding in a die by placing a metal ingot in a container and applying pressure to it. Many products are currently being manufactured by extrusion molding.

Since the conventional extrusion mold core is generally constructed as a one-piece structure, if a part of the formed holes are damaged in accordance with the product shape of the product to be extruded, there is a problem that the whole core mold needs to be replaced, The two parts were assembled and assembled by fastening the upper and lower parts with bolts. However, there was a problem that the eccentricity occurred. To solve this problem, a method of preventing the eccentricity due to the connection by the taper pin was also introduced.

However, as shown in FIG. 1, when the upper mold and the lower mold are brought into contact with each other and the upper and lower molds are forcedly fitted and extruded, the mandrel and the die are expanded due to the pressure and thermal expansion, and eccentricity occurs little by little (the direction of extrusion of the fluid is from top to bottom). However, such eccentricity can lead to a fatal error in a mold product which needs to maintain a fine precision.

In addition, since the core shim of the conventional mold core has only a straight line combination of the outline and the inner line, the flow rate of the extruded material in the semi-molten state is not constant, so that the load applied to the outer wall of the core core or the mold In addition, dead zones are formed at the angled sites, which may result in the deposition of foreign matter, resulting in deterioration of the quality of final products and causes and results of defects.

In addition, the mold used in the extrusion of FIG. 1 must be able to withstand the conditions of high temperature and high pressure during the flow and extrusion of the extrudate, while it is easy to separate and fasten the molds corresponding to the upper mold and the lower mold. Was difficult.

Korean Patent No. 10-622632 'Extrusion die for die' has a forced fit to prevent the die from being separated at the time of high-temperature processing, but it is not a method for metal forming die.

Conventionally, various coating methods have been used in order to maintain abrasion resistance of metals and to reduce the damage caused by extruded products. Such coatings are often damaged by friction with subsequent extrudates.

In order to overcome the problems described above, it is an object of the present invention to provide an extrusion tool having a high density of extruded products with less damage due to friction with extruded products.

In order to achieve the above object, the present invention provides an extrusion tool that is processed using a CVD surface treatment method, wherein the extrusion tool comprises an upper mold and a lower mold, The core, the upper mold, and the lower mold are formed by depositing a carbide, a nitride, an oxide and a mixture thereof, and a titanium carbide, a titanium nitride, a titanium boride, a vanadium carbide, a chromium carbide, an aluminum oxide , A material selected from the group consisting of silicon nitride, titanium, aluminum oxide, titanium aluminum nitride, and aluminum chromium nitride, and nitrides and carbides of these materials.

 The coating may be made in three steps.

The first stage coating may be roughened and may allow discharge processing to occur prior to coating so that the coating is better deposited on the metal surface.

The second stage coating may be one comprising an adhesive.

 The third step coating may be to include a gas such as C, H to allow deposition to increase the content of C on the coated surface.

The gas consisting of C and H may be C ₆ H ₆ .

The extrusion tool may have a width to height ratio of 1: 1.1 to 1.2 when the die and mandrel are defective.

The jaw portion is protruded on both sides of the extrusion tool. The jaw portion may have a triangular shape with the lower side protruding outward and the lower side being rounded and the both sides inserted into the inside.

The jaw portion may be formed by protruding outward from the inlet. A sloping guide may be formed between the jaw portions so as to be substantially straight at the entrance and thicker toward the inside.

The present invention also provides a method of processing an extruded tool that has been processed using a CVD surface treatment method, wherein the extrusion tool is provided with a carbide, a nitride, an oxide and a mixture thereof, and a mixture of titanium carbide, titanium nitride, titanium boride, vanadium carbide, , A material selected from the group consisting of a material selected from the group consisting of silicon nitride, titanium, aluminum oxide, titanium aluminum nitride, aluminum chromium nitride, and nitride and carbide of these materials in a gaseous form and in a first step And a second step of depositing the provided material by CVD process at 700 degrees Celsius and 1000 degrees Celsius

The second step may be a three-step deposition process.

 The first deposition process of the second step may be performed after the step of machining the metal surface by electric discharge machining.

The second deposition process of the second step may include an adhesive material.

The third deposition process of the second step may further include a step of providing a gaseous compound consisting of C and H, followed by deposition.

The present invention has the effect of providing an extrusion tool and a coating method which have excellent adhesion but are less damaged by extrusion and have a high extrusion density.

1 is a view showing the prior art
2 to 5 are views showing an embodiment according to the present invention

Hereinafter, the present invention will be described in detail.

The present invention processes the surface of an extrusion tool using a CVD process to reduce damage by extrusion. In the present invention, in the machining of a tool, a machining process of a heat treatment-> a grinding-> arc machining process is replaced with a machining process using a high-speed machining machine, thereby reducing a change in the surface properties caused by arc machining.

However, simultaneous machining with high speed machining can result in less consistent surface properties, but when using aluminum (especially at extrusion temperatures of 450 ° C, aluminum), the cumulative tolerance .

These disadvantages can be solved by adding a deposition process using a deposition method to reduce the cumulative tolerance. Also, before the deposition process, the surface is smoothly and softly processed by electric discharge machining, so that the coating liquid is well impregnated and the adhesion strength is enhanced.

Also, in the deposition process, the deposition was performed several times rather than one time, thereby increasing the strength of the coating.

In the present invention, the coating completed by the vapor deposition method is made of a coating material formed by bonding titanium, aluminum, chromium and carbon, nitrogen, and boron

Titanium nitride, titanium carbide, titanium nitride, boron titanium, vanadium carbide, chromium carbide, aluminum oxide, silicon nitride, titanium aluminum nitride, aluminum chromium nitride and two or more materials selected therefrom.

In the case of a chemical vapor deposition (CVD) process, a solid or liquid raw material must be injected into the reaction chamber in a gaseous state, so that an apparatus capable of gasifying the raw material is additionally required and before the vaporized raw material reacts in the reaction chamber An additional device is required to prevent condensation again.

According to the present invention, when a CVD process is carried out, the metal to be treated is first processed to form a gas in the form of carbide or nitride, thereby transferring an injection gas (such as TiCl ₄ ) to the surface of the metal. Gas or hydrogen gas is injected together to heat the metal to be processed to 700 degrees Celsius or 1000 degrees Celsius. At this time, the temperature may be more than 1000 degrees centigrade.

In this process, a nitride such as TiN (s) is formed on the surface of the metal and is grown. Quenching and tempering can then be performed on the surface to achieve high hardness.

This is summarized in the following process.

1) providing a metal to be treated;

2) a step of making a coating material by primarily processing the metal forming the thin film including the curing process; and

3) coating the metal at a predetermined location by a CVD process with the coating material

4) Additional hardening steps

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In addition, this deposition step can be done in several steps.

That is, the deposition step can be divided into three steps. In order to make the deposition of the first step to be rough on the surface of the tool, the surface of the metal is discharged before the deposition step, The surface of the coating liquid is smoothly and smoothly processed so that the coating liquid can penetrate well, thereby enhancing the adhesion.

In addition, although the deposition of the second step is performed in the same manner, the adhesive force may be increased by increasing the adhesive force to increase the adhesive strength.

The deposition of the third step may be performed in the same manner as described above, and the carbon and hydrogen compounds may be supplied together in a gas form in order to enhance the strength of the coating.

For example, the C2H6 gas can be heated to 700 degrees Celsius or more and can be injected into the gaseous state, which can be preheated before injection. In this case, the C2H6 gas may include carbon in the coating layer of the outermost layer, thereby preventing the deposited film from being easily shaved in a subsequent high-speed processing process or the like. A good ratio of C to H or a good ratio of C is good, among which C6H6 has the best durability and is easy to handle.

Further, after the deposition of the third step, a high-speed processing step may be added.

The important chemical reactions of the first and second steps described above can be represented by the following chemical reaction, which is a CVD reaction, wherein the starting product is in the form of a vapor.

(g) = gas and (s) = solid:

H ₂

_{TiCl 4 (g) + 1/2 N} 2 (g) + 2 H 2 (g) -> TiN (s) + 4HCl (g)

700-1000 ° C

In this reaction, the metal is heated to above 700 degrees Celsius or above 1000 degrees Celsius, and the reaction takes place under these conditions and thereafter quenching and tempering of the tool steel to achieve curing, i.e. high hardness, of the base material. Conventionally, the temperature at which the CVD deposition reaction is performed is higher than that, but the CVD coating can be performed at a lower temperature than the conventional one by dividing the deposition step into three stages.

In addition to the TiCl ₄ described above, titanium carbide, titanium nitride, titanium boride, vanadium carbide, chromium carbide, aluminum oxide and silicon nitride may be used in the process according to the present invention. It is possible to achieve a microhardness level between Hv 2000 and Hv = about 4000 depending on what material is used. Titanium carbide or aluminum oxide, especially applied by a CVD-process, has excellent toughness, for example chromium carbide is particularly excellent in abrasion resistance and less affected by cracks or pores. Particularly also titanium carbide is additionally distinguished by favorable friction characteristics.

Due to the scattering performance inherent in precise, uniform and uniform coating CVD-procedures even in complex forms of metal, it is possible to form a uniform uniform coating layer, especially with high precision

This coating also reduces friction with the extrudate, allowing the extrudate to move quickly, thereby reducing cumulative tolerances and facilitating separate assembly.

Preferably, the starting material used in making the extrusion die according to the present invention is a durable steel with good high temperature properties, for example alloyed with Cr, Mo or tungsten, for example ESR (Electro- Slag REmelting) and cemented carbide can be used.

Such a coating method can be applied to the entire extrusion tool, but when such a coating is peeled, the overall quality is adversely affected. In order to minimize the influence of the extrusion on the coating, the shape of the mold is also changed.

2 and 3 are views showing an embodiment of an extrusion tool according to the present invention. The extrusion tool according to the present invention is formed such that the height of the portion of the die 11 is longer than that of the conventional extrusion tool. This increases the amount and density of the extrudate inside the extrusion tool when the extrudate is directed to the core portion, thereby increasing the internal density of the final extrusion result. In the past, the length of the extrusion die was short, which was intended to prevent the inner wall of the extrusion die from being damaged due to the temperature of the extrudate. However, since the durability of the inner and outer walls is increased by CVD coating, Less.

In addition, the overall outer diameter can be made smaller than conventional molds, which increases the concentration of furnace on the core side. In the conventional extrusion mold, when the ratio of the width to the height is 1: 0.8 to 0.9 when the die and mandrel are combined, the extrusion mold according to the present invention is about 1: 1.0 to 1.2. When the ratio exceeds 1: 1.2, the coating portion needs to be strengthened.

FIG. 3 shows a portion where an extrudate is contained in an extruding mold. In order to increase the concentration of the extrudate into a core portion, a conventional mold has a three-letter inlet shape So that more extrusion can be collected at the center. However, according to the present invention, since the extrusion die itself has a more elongated shape, it is not necessary to gather it further inward.

Instead, the lower portion of the die in which the extrudate is placed is provided with a jaw 13 on both sides, as shown in Fig. 4, and a tilting guide 14 between the jaws 13. The tilting guide is almost straight on the inlet side, .

Instead, when you reach the tip of the chin, do not let it thicken any more, and make the jaw part protrude from the die, and naturally induce it to go inward.

Since the shape of the inlet is a more natural tubular shape, it is possible for the extrudate to pass through the extrusion die quickly.

Also, as shown in the drawing, the inlet of the extrudate appears to be divided into two entrances, so that it is shaped so as to be close to the ellipse so as not to interfere with the flow of the extrudate. Therefore, when viewed from above, the jaw is triangular in shape, with the lower side protruding outward, rounded, and both sides embedded inward to form a round shape. By this shape, the entrance of the extrudate becomes a form in which two ellipses face as shown in the figure.

5 shows the core portion, and the left side is the core portion of the extrusion die according to the present invention, and the right side is the core portion of the conventional extrusion die. Since the core portion of the extrusion die according to the present invention has a water guide portion at the end thereof formed to be shorter than the conventional one, the water guide portion can be formed to be short because of its high degree of concentration toward the extrusion die core. Can be made shorter.

11: die 12: mandrel
13: jaw portion 14: inclination guide

Claims (13)

As an extrusion tool processed using a CVD surface treatment method,
The extrusion tool is composed of an upper mold and a lower mold
Between the lower mold and the upper mold, a core forming the shape of the extrudate is formed,
The core, the upper mold, and the lower mold may be formed by a vapor phase deposition process using carbides, nitrides, oxides, and mixtures thereof, and at least one of titanium carbide, titanium nitride, titanium boride, vanadium carbide, chromium carbide, aluminum oxide, Characterized in that the material is coated with a material selected from the group consisting of a material selected from the group consisting of aluminum oxide, aluminum aluminum nitride, aluminum aluminum nitride, aluminum chromium nitride, and nitrides and carbides of these materials. The process according to claim 1, wherein the coating is carried out in three steps. 3. The method of claim 2, wherein the first stage coating is roughened and allows for electrical discharge prior to coating so that the coating is better deposited on the metal surface, 4. An extrusion tool according to claim 3, characterized in that the second stage coating comprises an adhesive. 5. The method of claim 4, wherein the third step coating comprises a gas, a compound of C, H, to cause deposition to increase the content of C on the coated side. The extrusion tool according to claim 5, wherein the gas composed of C and H is C ₆ H ₆ . The extrusion tool according to claim 6, wherein the extrusion tool has a width: height ratio of 1: 1.1 to 1.2 when the die and mandrel are defective. [8] The apparatus according to claim 7, wherein the jaw portion is protruded on both sides of the extrusion tool, and each of the jaw portions has a triangular shape, and the lower side thereof is protruded outward and rounded, , The extrusion tool processed using the CVD surface treatment method The CVD surface treatment method according to claim 8, wherein the jaw portion is formed by protruding outward from the inlet, wherein a slope guide is formed between the jaw portions, the groove being substantially straight at the inlet and thicker toward the inside. Extruded tool A method of processing an extruded tool that has been processed using a CVD surface treatment method,
A material selected from the group consisting of carbides, nitrides, oxides and mixtures thereof and titanium carbide, titanium nitride, titanium boride, vanadium carbide, chromium carbide, aluminum oxide, silicon nitride, titanium, aluminum oxide, titanium aluminum nitride, aluminum chromium nitride, , A nitride of these materials, and a carbide, in the form of a gas; and
And a second step of depositing the material provided in the first step by CVD process at 700 degrees Celsius and 1000 degrees Celsius
A method for processing an extruded tool that has been processed using a CVD surface treatment method, characterized in that the second step comprises a three-step deposition step The method according to claim 10, wherein the first deposition process of the second step is carried out after the step of machining the metal surface by electric discharge machining to smoothly process the extruded tool using the CVD surface treatment method 12. The method of claim 11, wherein the second deposition process of the second step comprises an adhesive material, a method of processing an extruded tool machined using a CVD surface treatment method 13. The method of claim 12, wherein the third deposition step of the second step further comprises providing a gaseous compound consisting of C, H, How to process

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