KR101231353B1 - Hot press sintering apparatus and press element - Google Patents

Abstract

Hot press sintering apparatus according to the embodiment, the chamber; A mold member positioned in the chamber, the mold member including a mold space portion in which a raw material is filled; A pressing member for press molding the raw material in the mold member; And a heating member for heating the inside of the chamber. The urging member includes a urging portion adjacent to the mold space portion and a heat insulating portion located in the urging portion.

Description

HOT PRESS SINTERING APPARATUS AND PRESS ELEMENT}

The present disclosure relates to a hot pressure sintering apparatus and a press member used therein.

A hot press sintering apparatus such as a hot press is an apparatus for producing a sintered body by sintering a raw material into a desired shape by applying pressure and increasing pressure. The inside of the hot pressurized sintering apparatus is maintained at a constant temperature so that the shape and properties of the sintered compact may be improved only when the raw material is sufficiently heated.

However, in the hot pressure sintering apparatus, heat may be released by parts connected to a press apparatus for pressurization and the like. Then, characteristics such as density of the sintered compact may be lowered, and this problem may be more highlighted when manufacturing a relatively large sized sintered compact.

Embodiments provide a hot press sintering apparatus capable of suppressing heat release to improve sintering characteristics and improve density of a sintered compact.

Hot press sintering apparatus according to the embodiment, the chamber; A mold member positioned in the chamber, the mold member including a mold space portion in which a raw material is filled; A pressing member for press molding the raw material in the mold member; And a heating member for heating the inside of the chamber. The urging member includes a urging portion adjacent to the mold space portion and a heat insulating portion located in the urging portion.

The insulating portion may be located on one surface of the pressing portion. The insulating portion may be plate-shaped.

The heat insulating part may include a first part positioned on one surface of the pressing part and a second part surrounding a side surface of the pressing part. The insulating portion may be cap-shaped.

The thermal conductivity of the heat insulation part may be lower than the thermal conductivity of the pressurized part.

The insulating portion may comprise a composite material. The composite material may comprise a carbon fiber reinforced carbon composite material. The composite material may be a vertical weave.

It may further include a vertical movement member for moving the pressing member up and down, wherein the heat insulating portion may be located between the pressing portion and the vertical movement member.

The pressurized portion may comprise graphite. The graphite may have an impurity content of 20 ppm (parts per million) or less.

According to one embodiment, the pressing member used in the hot pressure sintering apparatus includes a pressing portion for applying pressure and a heat insulating portion positioned at one end of the pressing portion.

According to the hot pressurizing and sintering apparatus according to the embodiment, a larger amount of heat can be supplied to the raw material by minimizing the internal heat loss by suppressing heat release by the vertically moving member by the heat insulating portion. Accordingly, sintering can be made more easily, whereby sintering characteristics can be improved and properties such as density of the sintered body can be improved. In addition, by minimizing the internal heat loss it is possible to reduce the power ratio when driving the hot pressure sintering apparatus.

At this time, the pressing portion includes graphite, and as the pressing member includes a heat insulating portion including a composite material, the size of the pressing member can be reduced by the high strength composite material. In addition, the pressurized portion may reduce the amount of expensive composite materials including graphite, thereby reducing costs.

1 is a schematic cross-sectional view of a hot pressure sintering apparatus according to an embodiment.
2 is a perspective view illustrating a mold member of the hot pressurizing and sintering apparatus according to the embodiment.
3 is a perspective view illustrating a lower insulating portion of the hot pressurizing and sintering apparatus according to the embodiment.
Figure 4 is a perspective view showing a modification of the lower insulating portion that can be applied to the hot pressure sintering apparatus according to the embodiment.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all formed directly or through another layer.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a hot pressure sintering apparatus according to an embodiment. 2 is a perspective view illustrating a mold member of a hot pressurized sintering apparatus according to an embodiment, and FIG. 3 is a perspective view illustrating a lower heat insulation part of the hot pressurized sintering apparatus according to an embodiment.

Referring to FIG. 1, the hot pressurized sintering apparatus 100 according to the present embodiment includes a chamber 10 in which a vacuum is maintained, a mold member 20 and a heat insulating part 70 located in the chamber 10. The pressing member 30, the heating member 40, the heat insulating member 50, and the vertical movement member 80 that vertically moves the pressing member 30 may be included. This will be described in more detail as follows.

Chamber 10 may be closed to maintain a vacuum. Thereby, oxidation of the heating member 40 etc. which are located in the chamber 10 can be prevented, and it can prevent that a contaminant mixes in a raw material during a sintering process.

A vacuum jump 102 for the vacuum is positioned outside the chamber 10 to maintain the vacuum, and the vacuum pump 102 and the chamber 10 may be connected through the opening / closing valve 104 and the exhaust port 106. . As a result, the air may be selectively discharged to maintain the interior of the chamber 10 at a predetermined level of vacuum. In addition, a separate gas supply source (not shown), an open / close valve (not shown), and an injection hole (not shown) may be positioned to inject an inert gas into the chamber 10.

The raw material 60 is filled in the mold member 20 located in the chamber 10.

Referring to FIG. 2, the mold member 20 is inserted into the first mold portion 22 constituting the outer shape and the opening 22a of the first mold portion 22 and includes a mold space portion 24a. The second mold part 24 is included. A raw material (reference numeral 60 in Fig. 1, below) is filled into the mold space portion 24a, and the raw material 60 is pressed by a pressing member (reference numeral 30 in Fig. 1, below) in a desired shape. The raw material is sintered.

In this case, the second mold part 24 may be formed with a narrower area than the upper part. For example, the second mold part 24 may have a shape in which the area gradually decreases from the top to the bottom. The opening 22a of the first mold part 22 may have a shape corresponding to the outer shape of the second mold part 24. That is, the opening 22a may have a shape in which the area gradually decreases from the top to the bottom.

As a result, the second mold part 24 can be easily inserted into the first mold part 22 by inserting the second mold part 24 into the opening 22a of the first mold part 22.

At this time, a value obtained by subtracting the radius R2 of the mold space portion 24a from the radius R1 of the second mold portion 24 measured at the upper portion of the second mold portion 24 is a and the second mold portion 24 is obtained. When b is the value obtained by subtracting the radius R4 of the mold space portion 24a from the radius R3 of the second mold portion 24 measured at the lower portion of b), the ratio of b to a is 0.1 to 0.9 days. Can be. This is to prevent the second mold part 24 from being separated from the first mold part 22 by inserting the second mold part 24 in close contact with the opening 22a of the first mold part 22.

If the value obtained by subtracting the radius R4 of the mold space portion 24a from the radius R3 of the second mold portion 24 measured at the lower portion of the second mold portion 24 is 0, the second mold portion 24 There is a high risk of breakage at the bottom. Therefore, the lower portion of the second mold portion 24 may have a larger area than the mold space portion 24a.

The mold member 20 may include a material that can withstand high temperatures, for example graphite.

In the present embodiment, the second mold portion 24 constituting the mold space portion 24a filled with the raw material contains graphite of high purity (for example, 99.99 to 99999%), and the second mold portion 24 is The first mold part 22 to be inserted may include graphite of general purity (eg, 90% or more and less than 99.99%).

As such, the second mold part 24 directly contacting the raw material may be formed of high purity graphite to prevent the mold member 20 from being damaged at high temperature and high pressure. For example, the conventional mold member made of graphite of general purity has a breaking strength of 30 MPa, whereas the mold member 20 according to the present embodiment may have a breaking strength of 60 MPa. As such, it can be seen that in the present embodiment, the fracture strength can be approximately twice that, and the damage can be effectively prevented. Thereby, the cost of component replacement of a hot pressure sintering apparatus (reference numeral 100 of FIG. 1, below same) can be reduced.

At the same time, the first mold part 22 may be formed of graphite of general purity, thereby reducing the manufacturing cost of the mold member 20.

In this case, in order to further prevent damage to the mold member 20, a release sheet 26 including graphite of high purity may be attached to an inner wall of the second mold part 24 forming the mold space part 24a. As a result, damage to the mold member 20 and the pressing member 30 can be effectively prevented, thereby further reducing component replacement costs of the hot pressure sintering apparatus 100.

Referring again to FIG. 1, the pressing member 30 for press molding the raw material in the mold member 20 is positioned. The pressing member 30 may include a lower pressing member 31 positioned below the raw material and an upper pressing member 32 positioned above.

These lower and upper pressing members 31 and 32 include a pressing portion adjacent to the mold space portion and a heat insulating portion 70 positioned at the pressing portion. The pressing portion includes first members 31a and 32a which are substantially pressurized, and second members 31b and 32b positioned adjacent to the mold space portion. The second members 31b and 32b play a role of mitigating an impact applied to the raw material when pressurized. For example, the second members 31b and 32b may have a plate shape.

This pressurized portion may be made of a material that can withstand high temperatures. For example, the first members 31a and 32a and the second members 31b and 32b may be made of graphite or the like. For example, it may include graphite having an impurity content of 20 ppm (parts per million) or less. The purity of the sintered compact formed after sintering by the pressurized part containing such high purity graphite can be improved. For example, when the silicon carbide sintered body is formed using the hot pressurizing and sintering apparatus 100, the silicon carbide sintered body may have a purity of 5 N (99.999%) or more.

In addition, a graphite sheet (not shown) including 99.99 to 99.9% of graphite is further disposed on the material facing surfaces of the second members 31b and 32b to prevent damage to the raw material or the pressing member 30. .

And the heat insulation parts 71 and 72 are located between the press part and the vertical movement members 81 and 82, and serve to prevent the heat dissipation by the vertical movement members 81 and 82. FIG. In more detail, the vertical movement members 81 and 82 may receive the driving force for vertical movement of the lower and upper pressing members 31 and 32 from a press machine (not shown), or the like. And extend outside). Accordingly, heat may be discharged to the outside by the vertically moving members 81 and 82, and the upper and lower pressing members 31 and 32 have heat insulating parts 71 and 72 to prevent this from happening in the present embodiment.

The heat insulation portions 71 and 72 may include a lower heat insulation portion 71 positioned at the lower end of the lower pressurizing member 31 and an upper heat insulation portion 72 positioned at the upper end of the upper pressurization member 32. . As a result, heat can be prevented from being discharged to the outside along the vertical movement members 81 and 82.

In order to minimize heat dissipation by the vertically moving members 81 and 82, the lower and upper insulating portions 71 and 72 are pressurized portions (that is, the first members 31a and 32a and / or the second members 31b and 32b). It is desirable to have a thermal conductivity lower than)). And it is desirable to have a high heat resistance to withstand high temperatures.

In one example, the lower and upper insulating portions 71 and 72 may comprise a composite material. Among them, a carbon fiber reinforced carbon composite material (C / C composite) may be used as the composite material having excellent heat resistance and low thermal conductivity. Carbon fiber reinforced carbon composite materials include carbon fiber reinforcements in the carbon matrix. Phenolic resin, pitch, furan resin, pyrolysis carbon by chemical vapor deposition (CVD) may be used as the carbon base, and polyacrylonitrile (PAN), pitch, etc. may be used as the carbon fiber reinforcing material. Can be.

In addition, such carbon fiber reinforced carbon composite materials have a lower thermal conductivity than the graphite forming the pressurized portion. For example, graphite has a thermal conductivity of 180 W / m · K, while such carbon fiber reinforced carbon composite material has a thermal conductivity of approximately 50 W / m · K or less, and thus is moved to the vertically moving members 81 and 82. It can reduce heat transfer. At this time, the horizontally woven carbon fiber reinforced carbon composite material has a thermal conductivity of approximately 45 to 50 W / mK, and the vertically woven carbon fiber reinforced carbon composite material is approximately 10 W / mK or less. Has thermal conductivity. Thus, the lower and upper insulating portions 71, 72 comprise vertically woven carbon fiber reinforced carbon composite material, which can further reduce heat loss.

Since the lower and upper insulating portions 71 and 72 have similar shapes to each other, the lower insulating portion 71 will be described first with reference to FIG. 3. The lower heat insulating part 71 may include a first part 71a positioned on a lower surface of the pressing part of the lower pressing member (reference numeral 31 of FIG. 1), and a second part formed while surrounding the side surface of the pressing part ( 71b). As such, when the lower pressing member 71 has a cap shape, the lower pressing member 71 may be inserted into and fixed to the end portion of the pressing portion, thereby further improving the mounting stability.

In this case, the thicknesses of the first and second portions 71a and 71b may be 5 mm to 200 mm. If the thickness is less than 5mm, the heat loss reduction effect may be small, and if the thickness exceeds 200mm, the manufacturing cost may increase.

Referring to FIG. 1, likewise, the upper thermal insulation portion (reference numeral 72 of FIG. 1) may also include a first portion 72a and a second portion 72b.

In the present embodiment, but including both the upper and lower insulating portions 71 and 72, but the embodiment is not limited to this, it is also possible that only one of the two is provided.

Referring back to FIG. 1, a heating member 40 for heating the inside of the chamber 10 is positioned outside the mold member 20. As the heating member 40, various methods for heating the mold member 20 may be applied. For example, the heating member 40 may include graphite, and may be heated by the power supplied from the outside to heat the mold member 20.

The insulating member 50 positioned between the heating member 40 and the chamber 10 serves to maintain the mold member 20 at a temperature suitable for the reaction. The heat insulating member 50 may include graphite to withstand high temperatures.

According to the hot pressurizing and sintering apparatus 100 according to the embodiment, the heat dissipation by the internal parts, in particular the vertically moving members 81 and 82, is suppressed by the lower and upper insulating portions 71 and 72 to minimize internal heat loss. As a result, a larger amount of heat can be supplied to the raw material 60. Accordingly, sintering can be made more easily, whereby sintering characteristics can be improved and sintering density of the sintered body can be improved. In addition, by minimizing the internal heat loss it is possible to reduce the power ratio when the hot pressure sintering apparatus 100 is driven.

When manufacturing a relatively large sintered body (for example, 300Φ or more), heat transfer may be more difficult. In this case, using the hot pressurized sintering apparatus 100 of the present embodiment may improve the sintering characteristics and the sintered body. The sinter density improving effect can be further doubled.

In addition, the lower and upper heat insulating portions 71 and 72 in which the pressurized portions of the lower and upper urging members 31 and 32 include graphite, and which comprise a composite material at the ends of the lower and upper urging members 31 and 32. When using, as compared with the case of using a composite material as a whole, while reducing the amount of expensive composite materials used, strength and hardness can be improved.

Meanwhile, in FIGS. 1 and 3, the lower and upper insulation portions 71 and 72 have cap shapes, but the shapes of the lower and upper insulation portions 71 and 72 may be variously modified. For example, as shown in FIG. 4, the heat insulating part 171 may have a plate shape located on one surface of the upper or lower pressing members 31 and 32. According to this, the heat insulation part 171 can be manufactured by a simple process. In the hot pressurizing and sintering apparatus 100, a sintered body may be formed using various non-oxide ceramic materials as a raw material. For example, the susceptor may be manufactured using silicon carbide as a raw material.

Hereinafter, a method of manufacturing the susceptor using the hot pressure sintering apparatus 100 of the embodiment will be described in more detail with reference to FIG. 1.

First, the raw material 60 is prepared. This raw material 60 may contain silicon carbide.

More specifically, it is also possible to use silicon carbide powder as the raw material 60. Alternatively, a solvent and a resin may be mixed together with silicon carbide as a raw material, and then granulated powder may be used. Phenolic resin may be used as the resin, and the solvent may include an alcohol or an aqueous substance. Examples of the alcohol-based substance include methanol, ethanol, and isopropyl alcohol (IPA), and water may be used as the aqueous substance. However, the embodiment is not limited thereto.

In addition, it is also possible to place the raw material 60 in the mold space portion 24a in the form of powder of silicon carbide powder or granulated powder, and the powders are formed by pre-pressing or the like into a shaped body having a desired shape. It is also possible to locate in the mold space part 24a.

In the state where the lower pressing member 31 is located in the mold member 20, the raw material is filled in the mold member 20, and the upper pressing member 32 is used while the high temperature is maintained by the heating member 40. To pressurize the raw material.

Then, silicon carbide is sintered into the mold member 20, the lower pressurizing member 31 and the upper pressurizing member 32 by high temperature and high pressure, and a susceptor is manufactured. For example, the susceptor manufactured in the hot press sintering apparatus 100 may have a density of 3.15 g / cm ³ or more and a high purity of 99.999% or more.

Hereinafter, the examples will be described in more detail with reference to Preparation Examples and Comparative Examples. The preparation example is only presented in order to demonstrate an Example more clearly, and an Example is not limited to a preparation example.

Manufacturing example

A phenolic resin and silicon carbide powder having a central particle size of 1.8 μm were mixed with a solvent of IPA.

The mixed raw materials were then granulated using a spray dryer.

Subsequently, the granulated raw material was charged into a hot pressure sintering apparatus and then hot pressed at a pressure of 40 MPa at a temperature of 2100 ° C. to form a susceptor. At this time, the pressurized portion of the hot pressure sintering apparatus contained graphite having an impurity of 20 ppm or less, and at this end, a cap-shaped heat insulating portion including a carbon fiber reinforced carbon composite material was located.

Comparative example

A susceptor was manufactured in the same manner as in Preparation Example 1, except that the hot pressure sintering apparatus did not have a heat insulating portion.

The density and purity of the susceptors prepared by Preparation Examples and Comparative Examples were measured and shown in Table 1.

Density [g / cm ³ ] water[%] Manufacturing example 3.15 99.9997 Comparative example 3.08 99.9

Referring to Table 1, it can be seen that the density and purity of the susceptor manufactured by the comparative example are very high. That is, it can be seen that the hot pressurizing and sintering apparatus according to the present embodiment can improve the density and purity of the manufactured susceptor.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. In addition, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (13)

chamber;
A mold member positioned in the chamber, the mold member including a mold space portion in which a raw material is filled;
A pressurizing portion for press-molding the raw material in the mold member; And
A heating member for heating the inside of the chamber,
The pressing portion includes a pressing portion adjacent to the mold space portion and a heat insulating portion located in the pressing portion,
The hot pressurizing sintering apparatus of which the thermal conductivity of the said heat insulation part is lower than the thermal conductivity of the said press part. The method of claim 1,
Hot press sintering apparatus wherein the heat insulating portion is located on one surface of the pressing portion. The method of claim 2,
Hot pressurizing sintering apparatus whose said heat insulation part is plate shape. The method of claim 1,
And the heat insulating part includes a first part located on one surface of the pressing part and a second part surrounding a side surface of the pressing part. 5. The method of claim 4,
Hot pressurizing sintering apparatus whose said heat insulation part is cap shape. delete The method of claim 1,
Hot-pressurizing sintering apparatus in which the said heat insulation part contains a composite material. The method of claim 7, wherein
Hot press sintering apparatus wherein the composite material comprises a carbon fiber reinforced carbon composite material. The method of claim 7, wherein
Hot press sintering apparatus wherein the composite material is a vertical weave. The method of claim 1,
Further comprising a vertical movement member for moving the pressing member up and down,
The hot pressurizing sintering apparatus in which the said heat insulation part is located between the said press part and the said vertical movement member. The method of claim 1,
And said pressurized portion comprises graphite. The method of claim 11,
The graphite is hot pressure sintering apparatus having an impurity content of 20 ppm (parts per million) or less. delete

Images