KR20200029188A - Method of preparing ceramic core for high temperature part casting - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing a high-temperature part ceramic core having excellent dissolution properties and the ceramic core manufactured using the same. The method for manufacturing a ceramic core for casting in one aspect of the present invention includes the following steps of: coating ceramic powder with an inorganic binder; mixing the powder coated with the inorganic binder and an organic binder to form a ceramic molded body; and heat-treating the ceramic molded body to vitrify the coated inorganic binder. In addition, a method for manufacturing a ceramic core for casting in another aspect of the present invention includes the following steps of: mixing ceramic powder and an organic binder to form a ceramic molded body; coating the surface of particles in the molded body with an inorganic binder; and heat-treating the molded body coated with the inorganic binder to vitrify the coated inorganic binder.

Description

Manufacturing method of ceramic core for casting high-temperature parts {METHOD OF PREPARING CERAMIC CORE FOR HIGH TEMPERATURE PART CASTING}

The present invention relates to a method for manufacturing a ceramic core for high-temperature component casting and a ceramic core manufactured using the same, and more specifically, a method for manufacturing a high-temperature component casting ceramic core for manufacturing high-temperature components made of one-way and single crystals, and It relates to a ceramic core manufactured using this.

Recently, demand for various mechanical parts such as impellers, blades, and vanes has increased. In the production of such hollow type mechanical parts (casting parts), ceramic molds forming an outer shape and ceramic cores providing an inner space are used together, of which ceramic cores are an important part for securing precision and purpose of mechanical parts. . This is because the external shape can be improved by post-casting, but the internal space is difficult to improve by post-casting.

This precision casting core is produced by a series of injection molding processes. However, this molding method has disadvantages of low productivity and high manufacturing cost.

In addition, as the core, a ceramic core is often used, and the conventional ceramic core is a polymer material (for example, wax) for maintaining ceramic particles such as zirconia and silica, and for improving miscibility with the ceramic particles. Or a mixture of organic compounds such as surfactants. The plastic strength, which is important during wax injection and casting, is expressed by sintering between starting particles during heat treatment. Therefore, the thermal and mechanical properties of the ceramic core in the existing process are very dependent on the size and distribution of the starting powder, composition ratio, process parameters, etc., and it is difficult to secure accurate data for manufacturing the ceramic core that meets the required characteristics.

In addition, tens of hours of heat treatment time are required to impart strength to the ceramic core for high temperature component manufacturing. This causes difficulties in core elution after casting.

In addition, when sintering, the ceramic core shrinks, a shape warp phenomenon occurs, and an organic material is vaporized, causing a problem that pores are formed in the core.

Due to this problem, the ceramic core may be destroyed during casting, and it is directly connected to a defect in the casting. In particular, after giving the strength more than necessary, elution is lowered. Moreover, after preparing a mixture of organic compounds such as starting ceramic particles, wax, or surfactant at a high temperature as a slurry, the method of manufacturing a ceramic core using a mold is sensitive to its properties depending on the composition combination ratio of starting materials and manufacturing process conditions. Changes.

Several techniques have been proposed to solve this problem. One of them is to introduce this problem by introducing an organic-inorganic compound conversion process using an inorganic binder, in order to produce a ceramic core having no change in properties according to the composition combination ratio of starting materials, manufacturing process variables, heat treatment conditions, etc. in the manufacturing process. Overcome.

Specifically, the ceramic core manufacturing process using an organic-inorganic conversion process using an inorganic binder, which has been proposed to break the existing ceramic core manufacturing process while having high mechanical and thermal properties, is due to the thickness limitation of the sand casting method and poor flowability of the molten metal. It was suitable for producing thin-walled (thin) castings by overcoming the shrinkage defects of the castings.

However, the core made of the inorganic binder used in this technique, despite several advantages, is somewhat unsuitable for use in one-way and single crystal casting production of high temperature components. High-temperature parts are generally cast in a heating furnace at 1500 ° C. for efficient one-way and single crystal production. The ceramic core described above has been unstable at high temperatures for a long time. Specifically, the inorganic binder that has been applied has the advantage that the vitrification temperature is lowered by the metal alkoxide added as a composite of a silicate and a metal alkoxide, but as it is converted to a liquid at a temperature of 1000 ° C. or higher, it is applied to the core for high temperature component manufacturing. Was insufficient.

Thus, by compensating for these disadvantages, it is time to study a ceramic core that has an effective strength even at a high temperature and a long casting process and can exhibit high dissolution properties even after casting.

One object of the present invention is to provide a method for manufacturing a high temperature component ceramic core having excellent elution properties and a ceramic core manufactured using the same, while securing effective strength, in order to manufacture a high temperature component composed of one direction and single crystal.

A method of manufacturing a ceramic core for casting, which is an aspect of the present invention, includes coating a ceramic powder with an inorganic binder; Mixing the powder coated with the inorganic binder and an organic binder to form a ceramic molded body; And heat-treating the ceramic molded body to vitrify the coated inorganic binder.

Another method of manufacturing a ceramic core for casting, which is another aspect of the present invention, comprises mixing a ceramic powder and an organic binder to form a ceramic molded body; Coating the surface of the particles in the molded body with an inorganic binder; And heat-treating the molded body coated with the inorganic binder to vitrify the coated inorganic binder.

As an aspect, the ceramic-based powder may include silicon carbide (SiC).

As an aspect, the inorganic binder may be a liquid silica precursor.

As an aspect, the liquid silica precursor may include at least one compound selected from the group consisting of a silicate-based precursor, a siloxane-based precursor, and a silane-based precursor.

As an aspect, the silicate-based precursor may include tetra-orthosilicate (Tetraethyl orthosilicate).

As an aspect, the siloxane-based precursor may include poly dimethyl siloxane (Polydimethylsiloxane).

As an aspect, the step of coating with the inorganic binder may be performed two or more times.

As an aspect, the heat treatment may be performed at 1400 ° C to 1700 ° C.

Another aspect of the present invention, a ceramic core for casting, is manufactured by the above-described manufacturing method.

According to the present invention, it is possible to use an inorganic binder that does not use a metal silicate, does not convert into a liquid at a high temperature during casting, but rather has a high strength as the temperature increases.

According to the present invention, a ceramic core for casting a high-temperature component having effective strength can be provided in order to manufacture a high-temperature component composed of one-way and single crystals.

According to the present invention, it is possible to provide a ceramic core for a high temperature component having an effective strength even at a casting temperature of 1500 ° C. or higher and a long casting time by applying an inorganic binder that produces a glass material having a high melting point.

According to the present invention, after casting, it is possible to provide a ceramic core for high-temperature parts having high elution properties.

According to the present invention, it is possible to provide a ceramic core for casting a high-temperature component that is not sensitive to the composition ratio and process parameters of the starting material by the strength expression by the inorganic binder.

1 is a flowchart for a method of manufacturing a ceramic core for casting, which is an aspect of the present invention.
2 is a flowchart of a method of manufacturing a ceramic core for casting, which is another aspect of the present invention.
3 (a) to (d) are images for shapes after heat treatment of Comparative Examples 1 to 4.
4 (a) to (d) are images for shapes after heat treatment of Examples 1 to 4.
5 (a) to 5 (f) are XRD result graphs after the heat treatments of Examples 1 to 4.
6 (a) to (f) are microstructure images after the heat treatments of Examples 1 to 4.
7 is a graph showing the strength characteristics for Examples 1 to 4.
8 is a graph showing the strength characteristics of Examples 5 and 6.
9 (a) to (d) are images before and after the dissolution test for Examples 2, 4, 5 and 6.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as “include” or “have” are intended to designate the existence of features, components, and the like described in the specification, and one or more other features or components may not be present or added. It does not mean nothing.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

According to one aspect of the present invention, in order to provide a ceramic core for casting a high-temperature component, an organic binder and an inorganic binder are added to the ceramic powder to prepare a molded body, and the inorganic binder is vitrified at a high temperature to increase the strength of the ceramic core. Can be secured. In addition, additional strength can be secured by adding silicon carbide.

Hereinafter, the present invention will be described in detail through drawings and examples.

1 is a flowchart for a method of manufacturing a ceramic core for casting, which is an aspect of the present invention.

As shown in Figure 1, the method of manufacturing a ceramic core for casting, which is an aspect of the present invention, is a step of coating a ceramic-based powder with an inorganic binder (S110), mixing the powder coated with the inorganic binder with an organic binder, and forming a ceramic And forming a molded body (S120) and heat-treating the ceramic molded body to vitrify the coated inorganic binder (S130).

First, a ceramic powder is prepared as a starting powder. The ceramic powder may be used independently or by mixing powders having high mechanical properties such as silica, mullite, and zircon flowers. In one of the prior arts, the strength of the core is expressed by the sintering phenomenon between the ceramic particles, which does not dissolve in the alkali metal and causes problems in elution after casting. However, in the present invention, as described later, the strength is expressed by the silica glass formed between the particles by the inorganic binder, and thus it is possible to induce complete elution after casting.

In addition, in one aspect of the present invention, it is preferable to add silicon carbide (SiC) to enhance the strength of the ceramic core used in high temperature components. Silicon carbide is a ceramic with high covalent bonding properties, especially high temperature strength and excellent corrosion resistance.

As one aspect of the present invention, it is preferable to use powders having different particle sizes in order to improve the strength by increasing the filling ratio between particles. For example, the ceramic powder can be used by mixing fused silica having particle sizes of 117 μm, 33 μm, and 17 μm, zircon flower of 10 μm, and silicon carbide of 16 μm, respectively.

Then, a step (S110) of coating the prepared ceramic powder with an inorganic binder is performed. The method of coating with the inorganic binder is not particularly limited, but can be carried out within the range intended by the present invention. Specifically, the ceramic-based powder may be immersed in an inorganic binder solution to coat the inorganic binder on the surface and pores of the particles. Through this, the inorganic binder is coated on the ceramic-based powder, so that the glass material is uniformly distributed between the powders to increase the bonding force between particles, thereby improving the durability of the molded product.

The inorganic binder to be applied is preferably a silica precursor for high elution after unidirectional and single crystal casting. In general, it is efficient to use alumina and zirconia precursors to improve the plastic strength, but it does not provide high dissolution properties after casting, and therefore, silica precursors with high solubility in alkali solutions for elution properties are used for the production of ceramic cores for high temperature parts. It is preferred to use.

In the process of manufacturing a ceramic core using an inorganic binder, the sintering strength of the core is different from the existing process in which the strength is expressed by the sintering between particles, and the strength is caused by the glass material produced by the reaction between the inorganic binders used. , It has higher strength than the existing process. Therefore, the inorganic binder applied in one aspect of the present invention, it is preferable to use a liquid silica precursor for high vitrification between the ceramic core particles.

According to one aspect of the invention, the inorganic binder solution does not contain an alkali metal compound. By the sol-gel reaction, the Si-O-R structure forms a Si-O-Si chain structure through Si-O-H to produce a glassy substance.

As an aspect of the present invention, the liquid silica precursor may include one or more compounds selected from the group consisting of silicate-based precursors, siloxane-based precursors, and silane-based precursors.

Specifically, as an aspect of the present invention, the silicate-based precursor may include tetra-orthosilicate (tetraethyl orthosilicate).

In addition, as an aspect of the present invention, the siloxane-based precursor may include poly dimethyl siloxane (polydimethylsiloxane).

In addition, as an aspect of the present invention, the silane-based precursor is tetramethoxysilane (tetramethoxysilane), tetraethoxysilane (tetraethoxysilane), tetrapropoxysilane (tetrapropoxysilane), tetrabutoxysilane (tetrabutoxysilane), tetraisopropoxy Tetraisopropoxysilane, methoxytriethoxysilane, demethoxydiethoxysilane, ethoxytrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane methyltriethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, tetramethoxymethylsilane, tetramethoxyethylsilane Group consisting of tetramethoxyethylsilane and tetraethoxymethylsilane Since it is possible to include more than one compound selected.

As described above, the liquid silica precursor as an inorganic binder may be a single compound, or may be used by mixing several compounds.

In addition, as an aspect of the present invention, the step of coating the inorganic binder may be repeatedly performed two or more times. Through this, it is possible to secure the strength intended by the present invention.

In addition, as an aspect of the present invention, after the step of coating the inorganic binder, a drying process is performed to remove H ₂ O and ROH formed in the sol-gel reaction (hydrolysis reaction and condensation reaction) of the inorganic binder precursor. Can. As in the Examples described later, it can be carried out at 80 ° C for about 1 hour.

Then, a step (S120) of forming a ceramic molded body by mixing the powder coated with the inorganic binder and the organic binder may be performed.

The molded body is formed by mixing a ceramic powder mixture and an organic compound. At this time, the organic compound used is a polymer compound to impart molding strength, and is decomposed during heat treatment, which will be described later.

As one aspect of the present invention, a molded article can be produced by adding a polyvinyl alcohol and performing pressure molding.

Then, by heat-treating the ceramic molded body, the step of vitrifying the coated inorganic binder may be performed (S130).

In the process of manufacturing a ceramic core using an inorganic binder, the sintering strength of the core is different from the existing process in which the strength is expressed by the sintering between particles, and the strength is caused by the glass material produced by the reaction between the inorganic binders used. , It has higher strength than the existing process.

 Heat treatment is preferably carried out in a temperature range of 1400 ℃ to 1700 ℃. When the heat treatment temperature is less than 1400 ° C, low strength may be exhibited due to the formation of amorphous glass. On the other hand, when the heat treatment temperature exceeds 1700 ℃, since the resulting glass is converted to a liquid, there is a problem that the core is decomposed during casting.

In addition, the heat treatment time should be appropriately selected depending on the size of the core. According to one aspect of the present invention, heat treatment may be performed for 1 hour to 3 hours.

Another aspect of the present invention, the ceramic core is manufactured by the above-described manufacturing method. This ceramic core has excellent strength and contains a cristobalite phase. In addition, it has high dissolution properties.

Figure 2 is a flow chart for a method of manufacturing another aspect of the present invention, a ceramic core for casting.

As shown in Figure 2, another aspect of the present invention is a method of manufacturing a ceramic core for casting, mixing a ceramic-based powder and an organic binder to form a ceramic molded body (S210), and the particle surface in the molded body as an inorganic binder It includes the step of coating (S220) and heat-treating the molded body coated with the inorganic binder to vitrify the coated inorganic binder (S230).

First, a ceramic powder is prepared. Description of the ceramic-based powder is the same as described above, so the description is omitted here.

Then, the prepared ceramic-based powder and the organic binder may be mixed to form a ceramic molded body (S210). The description of the method for forming the organic binder and the ceramic molded body is the same as described above, so the description is omitted here.

Then, the step of coating the surface of the particles in the molded body with an inorganic binder (S220) may be performed. It is preferable that the molded body is immersed in a solution containing an inorganic binder to coat the particle surface in the molded body with an inorganic binder.

And, by heat-treating the molded body coated with an inorganic binder, the step of vitrifying the coated inorganic binder (S230) may be performed. Description of the heat treatment method is the same as described above, so the description is omitted here.

Another aspect of the present invention, the ceramic core is manufactured by the above-described manufacturing method. This ceramic core has excellent strength and contains a cristobalite phase. In addition, it has high dissolution properties.

Hereinafter, the present invention will be described in more detail through experimental examples.

( Example  1 and 2)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. A ceramic-based powder was prepared by mixing the fused silica powder and zircon flower having an average particle size of 10 µm at 50:50 vol%. The ceramic powder was coated with TEOS. The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded bodies were heat treated at 1400 and 1550 ° C. for 3 hours, respectively, to prepare core test pieces (Examples 1 and 2).

( Example  3 and 4)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. The fused silica powder, zircon flower having an average particle size of 10 μm, and silicon carbide having an average particle size of 16 μm were mixed at 50:50:15 vol% to prepare a ceramic-based powder. The ceramic powder was coated with TEOS. The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded bodies were heat treated at 1400 and 1550 ° C. for 3 hours, respectively, to prepare core test pieces (Examples 3 and 4).

( Example  5)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. A ceramic-based powder was prepared by mixing the fused silica powder and zircon flower having an average particle size of 10 µm at 50:50 vol%. The ceramic powder was coated with TEOS. Two additional coatings were performed using TEOS. The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded body was heat treated at 1400 ° C. for 3 hours to prepare a core test piece (Example 5).

( Example  6)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. The fused silica powder, zircon flower having an average particle size of 10 μm, and silicon carbide having an average particle size of 16 μm were mixed at 50:50:15 vol% to prepare a ceramic-based powder. The ceramic powder was coated with TEOS. Two additional coatings were performed using TEOS. The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded body was heat treated at 1550 ° C. for 3 hours to prepare a core test piece (Example 6).

( Comparative example  1 and 2)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. A ceramic-based powder was prepared by mixing the fused silica powder and zircon flower having an average particle size of 10 µm at 50:50 vol%. The ceramic-based powder was coated with an inorganic binder mixed with TEOS, NaOMe, and Isobutyl alcohol in a ratio of 38 (0.18): 56 (1.5): 6 (0.08) in weight percent (mol%). The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded body was heat treated at 1000 and 1400 ° C for 3 hours, respectively, to prepare core test pieces (Comparative Examples 1 and 2).

( Comparative example  3 and 4)

Fused silica powders with average particles 17 μm, 33 μm and 117 μm were prepared 1: 1: 1. The fused silica powder, zircon flower having an average particle size of 10 μm, and silicon carbide having an average particle size of 16 μm were mixed at 50:50:15 vol% to prepare a ceramic-based powder. The ceramic-based powder was coated with an inorganic binder mixed with TEOS, NaOMe, and Isobutyl alcohol in a ratio of 38 (0.18): 56 (1.5): 6 (0.08) in weight percent (mol%). The ceramic powder coated with the inorganic binder was dried at 80 ° C. for 1 hour.

The dried powder was mixed with 10% by weight of polyvinyl alcohol compared to the powder, and press-molded to prepare a molded body. The molded body was heat treated at 1000 and 1400 ° C. for 3 hours, respectively, to prepare core test pieces (Comparative Examples 3 and 4).

Hereinafter, various experimental methods and results of Examples 1 to 8 and Comparative Examples 1 to 4 described above will be described.

( Experimental Example  One)

For Comparative Examples 1 to 4, an image of the shape after heat treatment was taken and is shown in FIG. 3. As shown in Fig. 3, the core test piece made of an inorganic binder composed of a conventionally applied alkyl silicate and sodium ethoxide is a glassy sodium silicate after heat treatment at 1000 ° C (Comparative Examples 1 and 3) regardless of whether silicon carbide is present. The strength was expressed by the formation of, but after heat treatment at 1400 ° C, it was found that the glass was converted to a liquid phase during heat treatment, and the test piece completely collapsed. Therefore, an inorganic binder containing a metal alkoxide is not suitable as an inorganic binder for producing a ceramic core for high temperature parts of the present invention.

( Experimental Example  2)

For Examples 1 to 4, an image of the shape after heat treatment was taken, and shown in FIG. 4. As shown in FIG. 4, it was found that unlike Comparative Examples 1 to 4, after heat treatment at 1400 ° C., there was no shape change such as cracking or dimensional deformation. That is, the core made of the ceramic powder coated with the silica precursor used in the present invention can withstand a high casting temperature and a long casting time, indicating that it is suitable for manufacturing high-temperature parts in one direction and single crystal.

( Experimental Example  3)

For Examples 1 and 3, XRD results after heat treatment at 1000 ° C. are shown in FIGS. 5 (a) and (d). For Examples 1 to 4, XRD results after heat treatment are shown in FIGS. 5 (b), (c), (e), and (f), respectively. As shown in Fig. 5, when SiC 0%, heat treatment at 1000 ° C, amorphous glassy substance was formed, and only the peak of the zirconia crystal phase was observed. On the other hand, when silicon carbide was added, missanite was produced by silicon carbide at 1000 ° C or higher, which is predicted to be the cause of increasing the plastic strength. In addition, it was confirmed that the amorphous glass phase was converted to cristobalite at 1400 ° C or higher.

( Experimental Example  4)

For Examples 1 and 3, images of the microstructure after heat treatment at 1000 ° C are shown in FIGS. 6 (a) and (d). For Examples 1 to 4, images of the microstructure after heat treatment are shown in FIGS. 6 (b), (c), (e), and (f), respectively. As shown in FIG. 6, the difference due to the presence or absence of addition of silicon carbide was not large, but as the heat treatment temperature increased, it was confirmed that more crystals were formed on the powder particles or on the surface and that the size was also increased.

( Experimental Example  5)

For Examples 1 to 4, the strength characteristics were measured, and the result graph is shown in FIG. 7. As shown in FIG. 7, as the heat treatment temperature increased, a cristobalite phase, which is a crystalline phase, was generated, and the plastic strength was increased. In addition, it was confirmed that the sintering strength is further improved when silicon carbide contains crystalline missaite.

( Experimental Example  6)

For Examples 5 and 6, strength characteristics were measured, and the result graph is shown in FIG. 8. As shown in FIG. 8, it was confirmed that as the number of coatings increased, the strength was improved by increasing the coating efficiency of the silica precursor.

( Experimental Example  7)

For Examples 2, 4, 5 and 6, after immersion in a 40% by weight sodium hydroxide solution at 70 ° C, an elution test was conducted. The images were taken immediately after immersing the test piece in the solution and after a certain period of time has elapsed, and the respective images are shown in Figs. As shown in Figure 8 (a) to (d), regardless of the presence of silicon carbide or the number of coating of the silica precursor, it was found that it is completely dissolved in sodium hydroxide (NaOH) solution.

Therefore, the introduction of an inorganic binder of a silica precursor in manufacturing one-way and single-crystal high-temperature parts proved to be suitable for manufacturing a ceramic core, and when manufacturing and applying a solid ceramic core, a hollow mechanical part with high dimensional stability and complete elution It can be applied to the casting of.

Although described above with reference to preferred embodiments of the present invention, those skilled in the art variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You can understand that you can.

Claims (11)

Coating the ceramic powder with an inorganic binder;
Mixing the powder coated with the inorganic binder and an organic binder to form a ceramic molded body; And
A method of manufacturing a ceramic core for casting, comprising heat-treating the ceramic molded body and vitrifying the coated inorganic binder.
Mixing a ceramic powder and an organic binder to form a ceramic molded body;
Coating the particle surface in the molded body with an inorganic binder; And
A method of manufacturing a ceramic core for casting, comprising heat-treating the molded body coated with the inorganic binder to vitrify the coated inorganic binder.
The method according to claim 1 or 2,
The ceramic-based powder comprises silicon carbide (SiC), a method of manufacturing a ceramic core for casting.
The method according to claim 1 or 2,
The inorganic binder is a liquid silica precursor, a method of manufacturing a ceramic core for casting.
According to claim 4,
The liquid silica precursor comprises a silicate-based precursor, a siloxane-based precursor and one or more compounds selected from the group consisting of a silane-based precursor, a method for producing a ceramic core for casting.
The method of claim 5,
The silicate-based precursor includes tetra-orthosilicate (Tetraethyl orthosilicate), a method of manufacturing a ceramic core for casting.
The method of claim 5,
The siloxane-based precursor comprises a poly dimethyl siloxane (Polydimethylsiloxane), a method for producing a ceramic core for casting.
The method of claim 5,
The silane-based precursors are tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraisopropoxysilane, methoxytrie Methoxytriethoxysilane, dimethoxydiethoxysilane, ethoxytrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane ethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, tetramethoxymethylsilane, tetramethoxyethylsilane and tetraethoxymethylsilane One or more compounds selected from the group consisting of tetraethoxymethylsilane A method of manufacturing a ceramic core for casting comprising a.
The method according to claim 1 or 2,
The step of coating the inorganic binder is carried out two or more times, a method of manufacturing a ceramic core for casting.
The method according to claim 1 or 2,
The heat treatment is carried out at 1400 ℃ to 1700 ℃, a method of manufacturing a ceramic core for casting.
A ceramic core for casting manufactured by the method of claim 1 or 2.

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