DE102014206035A1 - Refractory composite material and method of manufacturing a refractory composite material - Google Patents

Abstract

Task: To provide a refractory composite material with high strength and high thermal conductivity, and air permeability, whereby no fracture and no deformation such as bending arise when used under high temperature conditions. Means for Solving: Fireproof composite material with a Si-SiC sintered body as the base material, the Si-SiC sintered body has a three-dimensional mesh structure which is composed of a framework with a porosity of 1% or less, the SiC content of the framework 35 to 70 wt .-% and the metal Si content is 25 to 60 wt .-%.

Description

Technical area

The present invention relates to a refractory composite material used for a cassette, etc. suitable for use in the degreasing process or the firing process of ceramic electronic components, and a method of manufacturing the same.

General state of the art

In recent years, there has been a demand for a cartridge that can be used for the degreasing process as well as for the firing process in view of increasing the fuel efficiency of small electronic components. A cassette for the degreasing process requires air permeability to release binder rapidly, while a case for the firing process requires not only heat resistance and mechanical strength but also properties that prevent reaction with the fired ceramic electronic component.

As a cassette that meets the requirements of the burning process, a cassette is known, wherein an intermediate layer and a reaction-resistant coating are formed on a base material surface of alumina mullite. Disclosed is a technique in which the cassette is made thinner and a higher kiln efficiency and higher energy efficiency are achieved by using, instead of the base material of alumina mullite, an Si-SiC sintered body as a base material, compared with a sintered body of alumina. Silica has the properties of excellent heat resistance and corrosion resistance as well as a high strength and high thermal conductivity ( Japanese Patent Laid-Open Publication No. 2012-56831 ).

The cassette of Japanese Patent Laid-Open Publication No. 2012-56831 However, it is not suitable for simultaneous use in the degreasing process because it lacks air permeability. As the air-permeable cassette, there is disclosed a technique using a metal net instead of the usual ceramic plate material ( Japanese Patent Laid-Open Publication No. 2011-117669 ).

However, the metal net bends easily in the firing process with its high temperature. In addition, since it has inferior thermal conductivity as compared with a Si-SiC sintered body, the temperature is distributed unevenly among the products placed on the metal net, resulting in the problem of irregular product quality.

With respect to ceramic structural bodies with air permeability, a technique is also known, wherein according to the so-called Schwarzwalder method, an open-cell foam ceramic is produced. Since conventional open-cell foamed ceramic had a problem that cracks could easily be generated on the porous parts of the skeleton, thereby deteriorating its mechanical strength, a technique of increasing the strength was disclosed by adding Si to the porous parts of the SiC foamed ceramic skeleton ( U.S. Patent Publication No. 6635339 ).

With the increased strength of the ceramic U.S. Patent Publication No. 6635339 At the same time, however, the modulus of elasticity also increases, and there is an increase in the elastic modulus with a reduction in thermal shock resistance
(Thermal shock-cracking coefficient R '= σ (1-v) λ / (αE), where σ: strength, E: modulus of elasticity is accompanied, there is the problem that an application for purposes, at the same time a thermal shock resistance and high strength are required , not possible.

Documents of the prior art

patents

• Patent document 1: Japanese Patent Laid-Open Publication No. 2012-56831
• Patent document 2: Japanese Patent Laid-Open Publication No. 2011-117669
• Patent 3: U.S. Patent Publication No. 6635339

Brief description of the invention

Object of the invention

The object of the present invention is to solve the above problems and a refractory composite material having high strength and high heat conductivity, excellent thermal shock resistance and air permeability, which does not crack and deforms such as buckling when used under high temperature conditions, and a process to provide for the same.

Means for solving the problem

The refractory composite material of the present invention, which has been made to solve the aforementioned problems, is a refractory composite material having a Si-SiC sintered body as a base material, and is characterized in that the Si-SiC sintered body has a three-dimensional mesh-like structure consisting of a skeleton having a porosity of 1% or less, wherein the SiC content of the skeleton is 35 to 70% by weight and the metal Si content is 25 to 60% by weight.

The invention according to claim 2 is characterized in that in the refractory composite material of claim 1 in the Si-SiC sintered body, the SiC content of the skeleton is 40 to 65% by weight and the metal Si content is 30 to 55% by weight. % is.

The invention according to claim 3 is characterized in that in the refractory composite material according to claim 1 in the three-dimensional mesh structure, the shape of the pores and the skeleton constituting the three-dimensional mesh structure satisfies a mean value of ≥ 3 for [pore diameter / framework diameter].

The invention according to claim 4 is characterized in that in the refractory composite material according to claim 1, the skeleton of a core portion containing metal-Si as a main component and residual component C, and a surface layer portion whose main component is SiC and as a residual constituent metal Si contains, wherein the content of C in the core portion is 5 to 20 wt .-% and the content of C in the surface layer section is 15 to 50 wt .-%.

The invention according to claim 5 is characterized in that in the refractory composite material according to claim 1, the skeletal density constituting the three-dimensional mesh structure is different in vertical cross-section and horizontal cross-section, the skeletal density in vertical cross-section being 1.1-40. times the horizontal cross section is.

The invention according to claim 6 is characterized in that in the refractory composite material according to claim 1, the porosity of the Si-SiC sintered body is 50 to 98%.

The invention according to claim 7 is characterized in that the refractory composite material according to claim 1 on the upper layer of the base material has a surface coating with a reaction resistance to the processed workpiece.

The invention according to claim 8 is characterized in that the refractory composite material according to claim 1 has on the surface coating of the base material a compact layer comprising a Si-SiC sintered body having a porosity of 0.1 to 2%.

The invention according to claim 9 is characterized in that in the refractory composite material according to claim 1, the base material has a structure wherein layers of the Si-SiC sintered body having different porosity are laminated one upon the other.

The invention according to claim 10 is characterized in that in the refractory composite material according to claim 9, the uppermost layer of the laminated structure is a compact layer having a porosity of 0.1 to 2.

The invention according to claim 11 is characterized in that the refractory composite material according to claim 1, the edge portion of the base material forms a frame portion comprising a compact layer having a porosity of 0.1 to 2%.

The invention according to claim 12 is characterized in that the refractory composite material according to claim 1 comprises a frame member formed of a nickel alloy carrying the base material.

The invention according to claim 13 is a method for producing the refractory composite material according to claim 1, and characterized by the steps of: a molding step wherein a molding slurry obtained by exposing a SiC powder in an organic solvent and then adding a gelling agent, dipping a urethane foam having a skeleton comprising a three-dimensional mesh structure, and curing the slurry, a drying step of drying the molding obtained in the molding step, and a firing step, wherein dried molding which has undergone the drying step, metal Si is applied, and combustion is carried out under reduced pressure and in a reducing atmosphere to impregnate the skeleton of the dried molding with the metal Si.

Effect of the invention

It is possible to obtain a refractory composite material having high strength and high heat conductivity, excellent thermal shock resistance and air permeability, and when used under high temperature conditions, will not break and deform such as bending by providing Si-SiC with high-strength and high-temperature properties high thermal conductivity is used, and the skeleton whose porosity is 1% or less is a three-dimensional mesh structure, its SiC content being 35 to 70% by weight and its Si content being 25 to 60% by weight and more preferably its SiC content is 40 to 65 wt .-% and its Si content is 30 to 55 wt .-%.

Brief description of the figures

1 (a) shows an overall perspective view of a cassette according to a first embodiment, and 1 (b) shows an enlarged view of the skeleton of the cassette of the first embodiment.

2 Figure 3 shows photographs of the composition of the Si-SiC framework of the cassette of the embodiment in horizontal cross-section and vertical cross-section (photograph taken with a JSM-5600 Scanning Electron Microscope from JEOL).

3 FIG. 10 is a flowchart explaining the manufacturing steps of the first embodiment. FIG.

4 shows a diagram illustrating the manufacturing steps of the first embodiment.

5 FIG. 12 shows applied metal Si on the surface of a urethane foam that has undergone a urethane mold baking step.

6 FIG. 10 is a flowchart explaining the manufacturing steps of the first embodiment. FIG.

7 (a) shows an overall perspective view of a cassette according to a second embodiment, and 7 (b) shows an enlarged view of the skeleton of the first embodiment.

8th shows enlarged illustrations of the second embodiment in vertical cross section and in horizontal cross section (photograph with a scanning electron microscope JSM-5600 from JEOL).

9 FIG. 10 is a flowchart explaining the manufacturing steps of the first embodiment. FIG.

10 (a) shows an overall perspective view of a cassette according to the third embodiment, and 10 (b) shows an enlarged view of the skeleton of the first embodiment.

Embodiments of the invention

In the following, preferred embodiments of the present invention will be described.

First Embodiment: Single Layer Without Compression The refractory composite material of the present embodiment is a cassette having a single-layer structure whose base material is an Si-SiC type. Sintered body is as in 1 (a) shown. The cassette comprises a framework with a three-dimensional mesh-like structure, as in 1 (b) shown. The porosity of the framework is 1% or less.

In the electronic component burning step, etc., the cassette is used at a high temperature (around 1300 ° C) near the melting point of Si (at about 1400 ° C). When the skeleton is formed solely of Si, problems such as creep deformation in the high temperature firing step easily occur, SiO ₂ easily forms due to oxidation on the surface layer, or high oxygen input into the kiln takes place , In contrast, these problems are avoided in the present invention by a composite of Si-SiC, since SiC is very resistant to oxidation and heat and also has a high strength.

In a cartridge with air permeability, the pore portion formed for the sake of air permeability often acts as a thermal barrier coating, and when a metal mesh of stainless steel or Ni, etc. having a low thermal conductivity is used as the air permeable cassette, heating and cooling are likely to occur Temperature distribution on the cassette and thus uneven temperatures between the products, which are arranged on the cassette, which results in the problem of irregular product quality, while it is light in the firing step with its high temperature by the temperature distribution, ie by a difference in thermal expansion to a deformation of the cassette comes by bending. In contrast, in the present invention, an air-permeable cartridge is formed by forming a Si-SiC sintered body having excellent thermal conductivity as compared with a stainless steel, Ni, etc. metal mesh as a three-dimensional mesh structure, so that these Problems can be avoided.

In the present invention, the amount of the individual components is set so that the SiC content of the skeleton is 35 to 70 wt% and the Si content is 25 to 60 wt%. The chemical components are in accordance with JIS R 2011 (chemical analysis method for carbon and silicon carbide refractory materials). If the SiC content of the skeleton is higher than 70% by weight, pores may be left between the SiC particles, resulting in a problem of reduced strength, and if it is lower than 35% by weight, the heat resistance is lowered. so that the problem of easier creep deformation results in the firing step with its high temperature. When the Si content of the skeleton is higher than 60% by weight, the hot strength decreases, so that there is the problem of easier creep deformation in the firing step with its high temperature, and if it is below 25% by weight, between The SiC particles remain pores, resulting in the problem of reduced strength.

When the Si content of the skeleton is higher than 55% by weight, the Si oxidizes, and it is easier to form SiO ₂ on the surface layer, and if it is lower than 30% by weight, pores may be left between the SiC particles and the SiC can oxidize and SiO ₂ is more easily formed on the surface layer, so that in both cases due to SiO ₂ forming on the surface layer, the thermal shock resistance and the heat resistance decrease, thereby more easily causing problems such as cracking and bending deformation increased oxygen input into the furnace and a reaction with the processed workpiece occur, therefore, from the aspect of extending the life of the product, the amount of the individual components is preferably set so that the SiC content between 40 and 65 wt .-% and the Si Content is between 30 and 55% by weight.

In the present invention, in this way, for SiC having a high elastic modulus (elastic modulus: about 400 GPa) and for Si having a low elastic modulus (elastic modulus: about 100 GPa), the SiC content is set to 35 to 70 wt % and the Si content to 25 to 60 wt .-%, and more preferably the SiC content to 40 to 65 wt .-% and the Si content can be set to 30 to 55 wt .-% is determined by Forming the skeleton reaches a Si-SiC sintered body with reduced elastic modulus. A reduction in the modulus of elasticity is associated with an increase in thermal shock resistance
(Heat shock resistance coefficient R '= σ (1-ν) λ / (αE), where σ: strength, E: modulus of elasticity), according to this configuration, a refractory composite material can be obtained, which in addition to the properties of high strength and high Thermal conductivity also has the property of excellent thermal shock resistance.

In the present embodiment, as a further configuration for reducing the modulus of elasticity of the Si-SiC sintered body, a configuration can be adopted wherein the shape of the pores and the skeleton constituting the three-dimensional mesh structure for mean pore diameter / skeleton diameter is ≥3 Fulfills. By achieving a mean value of ≥ 3 for [pore diameter / framework diameter], it is possible to maintain the strength of the product on the one hand and, on the other hand to achieve a reduction of the modulus of elasticity. The porosity of the cassette is preferably 50 to 98%. When the porosity is 49% or less, sufficient air permeability is not obtained, and when it is 99% or more, it is easy to break due to a significant reduction in strength, and therefore both are not desirable.

As in 1 (b) and 2 shown, the framework is made of a core section 1 and a surface layer portion 3 built on a pore section 2 is applied. [Table 1] (Wt .-%) sample (1) sample (2) sample (3) core section Surface layer portion core section Surface layer portion core section Surface layer portion element Si 80.22 53.19 88.3 66.44 93.99 83.98 unit C 19.78 46.81 11,07 33.56 6.01 16,02 * According to quantitative EDS analysis

Table 1 shows the result of an EDS analysis at any two locations of the composition maps 2 , As shown in Table 1, the individual sections (core section 1 and surface layer section 3 ) to a different content of the constituent elements, wherein at the core portion 1 the content of the element C is 5 to 20% by weight and the content of the element Si is 80 to 95% by weight, while in the surface layer section 3 the content of the element C is 15 to 50% by weight and the content of the element Si is 50 to 85% by weight. The content of free carbon (F.C.) in the skeleton is 0.1% or less, and the element C is present in the skeleton mainly as SiC, therefore, at the core portion 1 with the said elemental content of metal-Si is the main constituent and a small amount of SiC is contained. In the surface layer section 3 Like a conventional Si-SiC sintered body, SiC is the main constituent and has a structure with the pores thereof filled with Si.

If the content of element C of the core section 1 is higher than 20 wt .-%, pores in the core section 1 stay behind, so that the strength is reduced. On the other hand, when the content is less than 5% by weight, the hot strength decreases, so that it becomes easier to creep in the high temperature firing step, and therefore, the element C content of the core portion 1 is preferably in the above range.

When the content of element C of the surface layer portion 3 is higher than 50% by weight, pores may remain between the SiC particles, so that the strength is reduced. On the other hand, when the content is less than 15% by weight, the hot strength decreases, so that it becomes easier to creep in the high temperature firing step, and hence the content of element C of the surface layer portion 3 is preferably in the above range.

Hereinafter, the method of manufacturing the cartridge of the present embodiment will be described in detail. The cassette of the present embodiment is made in a gel pouring method from steps ST1 to ST8 3 manufactured. The gel casting method is a powder molding method according to Applicant's invention for obtaining a shaped article of a desired shape, wherein a slurry prepared by adding a powder selected from one or more of a group consisting of ceramic, glass and metal is dispersed on a dispersion medium by means of dispersing agent and hardened by adding a material (gelling agent) capable of gelling to the slurry.

ST1:

Since the cassette of the present embodiment is molded by the gel casting method, the molding slurry is first prepared. The molding slurry of the present embodiment can be prepared by dispersing SiC powder in an organic solvent, then adding a gelling agent to the slurry, or by simultaneously adding and dispersing SiC powder and gelling agent to the organic solvent.

Aside from SiC powder, powders of carbon, boron carbide, etc. may be used as needed. With respect to the particle size of the ceramic powder, there is no particular limitation as far as the slurry can be prepared, and it may be determined as required depending on the molded article selected as a production target.

As the organic solvent serving as the dispersion medium, polyhydric alcohols, e.g. B. diols such as ethylene glycol, etc., or triols such as glycerol, etc., polybasic acids such as dicarboxylic acid, etc., polybasic acid esters such as glutaric acid dimethyl, malonic acid dimethyl, etc., or esters of polyhydric alcohols, etc. call.

The gelling agent should be an organic compound having a reactive functional group that cures the ceramic slurry. As such an organic compound, there may be mentioned prepolymers which cause three-dimensional crosslinking by imparting a crosslinking agent, such as urethane resin, acrylic resin, epoxy resin, phenol resin, etc. Taking into consideration the reactivity with the organic compound in the dispersion medium, as the gelling agent, one having a favorably reactive one is preferable selected functional group. When an ester which is comparatively inert is used as the organic solvent, as the organic compound having the reactive functional group constituting the gelling agent, it is preferable to select an organic compound having a reactive isocyanate group (-N = C = O) and or isothiocyanate group (-N = C = S). In the present embodiment, as described below for ST2, since the molding slurry is formed by impregnating a urethane foam, a urethane resin having high rubber elasticity is preferably used to prevent damage to the SiC slurry molding in connection with elastic deformation (bending, etc.) of the urethane foam to avoid.

Preferably, the molding slurry does not harden during the impregnation of the urethane foam, but it cures rapidly after molding. Therefore, in the production of the ceramic slurry, it is preferable that the temperature of the slurry, the kind and the content of the dispersion medium, the kind and content of the gelling agent, the presence of a catalyst which accelerates the gelation reaction, the kind and content of such a catalyst, etc. to take into account. As for the processability, the slurry viscosity is preferably 50 dPa · s or less at 20 ° C, and more preferably 20 dPa · s or less at 20 ° C.

In the manufacturing step of the molding slurry, the ceramic powder, the dispersion medium and the dispersing agent are prepared and mixed. Subsequently, the final preparation is carried out by adding the gelling agent and the catalyst, etc. to the slurry, which is then defoamed in preparation for impregnating the urethane foam.

The mixing of the molding slurry is carried out in a pot mill or a ball mill, etc., using balls of nylon and mixing at 15 ° C to 35 ° C for 12 hours or longer, and preferably for 72 hours or longer. The defoaming of the sludge is carried out by stirring the sludge in a vacuum atmosphere, the degree of vacuum being -0.090 MPa or less and preferably -0.095 MPa or less, the stirring speed is preferably 100 rpm to 500 rpm, and the stirring time is preferably 5 minutes to 30 minutes.

ST2 to ST4:

After the urethane foam is impregnated with the molding slurry prepared in ST1, excess slurry is squeezed so that no slurry closes the pores of the urethane foam, and the urethane foam is placed on a fixing tool and heated at normal temperature to 40 ° C for several hours to several tens of hours rested for a long time. In this way, the molding slurry gels and hardens, whereby the molding is formed.

As in 4 (A) shown is the urethane foam from a scaffolding section 4 and a cavity portion 5 formed in ST2, as in 4 (B) shown, the SiC sludge moldings 10 at the cavity section 5 is formed adjacent.

ST5 to ST6:

Subsequently, a drying is carried out at 40 ° C to 100 ° C for 3 to 12 hours; then heating takes place for 3 to 12 hours at 100 ° C to 200 ° C to burn the urethane mold, that is, a processing to eliminate the elasticity of the urethane foam.

In the course of drying, the SiC sludge molding is pulled 10 together. When an aqueous slurry containing water is used as the dispersion medium, it is not possible to reduce the shrinkage amount of the SiC slurry molded body during drying 10 to ensure, since there is no swelling of the urethane foam when impregnated with the molding slurry, resulting in the problem that easily cracks in the SiC sludge molding 10 can form. On the other hand, in the present embodiment, an organic solvent is used as the dispersion medium, so that the urethane foam can swell upon impregnation with the molding slurry, thereby ensuring certainty about the shrinkage amount of the SiC slurry molding 10 When drying is achieved and can be prevented that during drying cracks in the SiC sludge molding 10 form.

ST7 to ST8:

As in 4 (C) and 5 is shown on the surface of the urethane foam, which was made inelastic, metal Si 7 is applied, and under an inert gas atmosphere at 1400 ° C to 1500 ° C for 1 to 3 hours carried out a heating. The scaffolding section 4 of the urethane foam burns at about 500 ° C, and by, as in 4 (D) shown the cavities caused by burning off the scaffolding section 4 are impregnated with metal Si 7, a new refractory composite material (porosity 50 to 98%) is obtained, which has a compact SiC-Si skeleton having a three-dimensional mesh structure. According to this method, the impregnation with the metal Si 7 via the scaffold, which is the SiC sludge molding 10 forms, why a uniform impregnation is possible without the metal Si 7 the cavity section 5 clogged.

As needed, as in 6 Also, after the step ST8, a step ST9 for baking a coating having reaction resistance may be provided, and on the side of the upper layer of the base material forming the contact surface with the workpiece, a surface coating having reaction resistance with respect to the workpiece may be formed. The surface coating is formed of a material of low reactivity with respect to the workpiece, the material varying depending on the type of workpiece. For example, in the case of a ceramic capacitor formed of barium titanate, it is preferable to use a zirconia compound having a low reactivity thereto. As the zirconia compound, a zirconia compound comprising at least one of stabilized zirconia stabilized with calcium oxide (CaO) or yttria (Y ₂ O ₃ ) comprising BaZrO ₃ and CaZrO _{3 may be} suitably used as the most suitable zirconia in consideration of the reactivity to be selected. Depending on the type of electronic component, a sprayed-on film containing a eutectic with alumina and zirconia may also be used as the surface coating. There is no particular limitation on the method of forming the surface coating, and the most appropriate method may be used such as spraying, spray coating, etc.

According to need, it is possible to form a frame portion at the edge portion of the base material after sealing the pores by impregnating the edge portion of the base material with the molding slurry prepared in ST1 by curing, drying and Si impregnation as described in ST5 to ST8 above. which comprises a compact Si-SiC layer having a porosity of 0.1 to 2%.

Depending on requirements, it is also possible to use a frame element that carries the base material. Preferably, the frame member is formed of a nickel alloy, etc. In this case, in order to absorb the thermal expansion difference between the base material comprising the Si-SiC sintered body and the nickel alloy, it is preferable not to fix the base material and the frame member and leave a certain distance between the frame member and base material.

Second Embodiment: Single layer, with densification of the urethane foam

In step ST3 "fix to a desired thickness / shape" 3 and 6 the urethane foam can be fixed by compression.

By densifying the urethane foam in this manner before hardening the molding slurry (ST4), the skeletal density of the novel three-dimensional mesh refractory composite material can be increased, whereby increased strength can be obtained. As in 7 (a) This also makes it possible to make the cassette thinner.

The refractory composite material of the present embodiment, which is obtained by compressing the urethane foam, has, as in 7 (b) shown a flat framework structure and, as in 8th shown, a different framework density in the vertical cross section and in the horizontal cross section. When the skeletal density ratio between the vertical cross section and the horizontal cross section is larger than 40 times, sufficient air permeability can not be obtained on the side surface (vertical cross section). In addition, at the effective area (horizontal cross section), clogging by the mud occurs so that sufficient air permeability is not obtained, and therefore the ratio is preferably 40 times or less. When the skeletal density ratio between the vertical cross section and the horizontal cross section is smaller than 1.1 times, sufficient effect with respect to the solidification of the cartridge can not be obtained, and therefore the ratio is preferably 1.1 times or more.

The framework density can be measured by the following method. First, the refractory composite is embedded in a phenol resin, etc., whereupon the refractory composite is cut and ground in the vertical and horizontal directions to prepare measurement samples. Next, a compositional image of the vertical sectional area and the horizontal sectional area of the measurement samples are taken using a JSM Scanning Electron Microscope JSM-5600 from JEOL in a field of view of 0.1 cm ² . The composition photographs utilize the brightness difference between the elements so that the Si-SiC framework section and the cavity section are clearly visible. Next, the obtained composition images are converted into a bivalent black-and-white image using image processing software under constant brightness conditions, and the respective total number of pixels of the skeleton portion and the cavity portion is measured. For example, the freeware ImageNos (version 1.04) can be used as picture editing software. In this way, based on the total number of pixels of the skeleton portion relative to the total number of pixels in the field of view, the skeleton density can be determined (skeleton density = total number of pixels of the skeleton portion / total number of pixels of the skeleton portion and the cavity portion). Thus, the framework density ratio between the vertical cross section and the horizontal cross section can be calculated (framework density ratio = skeleton density at the vertical cross section / skeleton density at the horizontal cross section). However, since the framework is randomly arranged in a three-dimensional mesh structure, the framework density can not be obtained from cross-sectional composition images of a single field of view. For calculating the framework density, cross-sectional composition images of at least 5 fields of view each and more are preferable 10 or more fields of view are used on the vertical cross section and the horizontal cross section.

In step S13, fix "to a desired thickness / shape" 3 and 6 For example, the urethane foam can be fixed by compacting using a mold of a certain shape. By fixing the urethane foam in a predetermined shape in this manner before hardening the molding slurry (ST4), the dimensional freedom of the novel three-dimensional mesh refractory composite material can be increased, so that cassettes of complicated shape can also be produced. As cassettes of complicated shape, for example, capsules or cassettes can be made with feet for stacking.

Third embodiment: multiple layers

As in 9 4, prior to hardening of the molding slurry (ST4), a step ST10 may be provided for applying and integrally forming a urethane foam layer having a different compression rate.

The refractory composite material of the present embodiment has, as in FIG 10 As shown, a laminated structure wherein layers of different skeleton density are laminated on each other. Considered, for example, the roller transport in a roller hearth furnace, which, depending on the type of use, the most suitable lamination structure can be formed by about a first layer 8th a compact High-strength layer is and a second layer 9 is a layer with high air permeability. In this case, the first layer 8th the compact layer while the second layer 9 has the three-dimensional mesh structure, therefore, on the surface and the side surfaces of the second layer 9 a high air permeability can be obtained. The uppermost layer may also be formed as a compact layer having a porosity of 0.1 to 2%.

Exemplary embodiments A

On the basis of cassettes of the following embodiments 1 to 6 and the comparative examples 1 to 2, the occurrence of cracks and deformations was checked by bending; for the embodiments 1 to 6, no cracks and deformations could be determined by bending, while in Comparative Examples 1 to 2 each cracks and / or deformations were determined by bending.

Embodiment 1

In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 150 × 150 × 5 mm was dipped, excess sludge was removed, and The slurry was cured, and the molded body on which a SiC - (- C, -B ₄ C) layer was thus formed on the skeleton surface of the urethane foam was dried at 120 ° C., thereby preparing a SiC molded body has been. Next, metal Si was applied to the SiC molded body in a weight ratio of 90%, and was fired at 1500 ° C under reduced pressure and in a reducing atmosphere to obtain a 5 mm thick Si-SiC cassette having three-dimensional mesh structure with air permeability was produced. The porosity of the produced air permeable cassette was 95%.

Embodiment 2

In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 150 × 150 × 5 mm was dipped, excess sludge was removed, and using a fixing tool, the urethane foam was pressed and compacted to a thickness of 1 mm, whereupon the slurry hardened, whereby a 1 mm thick SiC molded body was produced. The same as in Embodiment 1 was then fired, whereby a 1 mm thick cassette with air permeability was prepared. The porosity of the produced air permeable cassette was 60%. The skeletal density ratio calculated as described under [0055] was 1.4 times.

Embodiment 3

In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 180 × 180 × 5 mm was dipped, excess sludge was removed, and by means of a box-shaped fixing tool, the urethane foam was fixed in the shape of a firing capsule, whereupon the slurry hardened, whereby a 5 mm thick box-shaped SiC molded body was produced. As in Example 1 was then fired, whereby a 5 mm thick combustion capsule was made with air permeability. The porosity of the produced air-permeable capsule was 95%.

Embodiment 4

On one surface or both surfaces of the SiC molded body obtained in Embodiment 1, the SiC molded body obtained in Embodiment 2 was adhered, and the SiC molded body thus formed in one piece was fired as in Embodiment 1, whereby a 6 to 7 mm thick cassette with air permeability was obtained, which had a multi-layered structure.

Embodiment 5

On one surface of the SiC molded article obtained in Embodiment 2 was bonded a SiC molded article having a thickness of 1 mm formed by curing the SiC slurry without using urethane foam and the SiC integrally formed in this way Moldings were fired as in Embodiment 1, thereby producing a 2 mm-thick air-permeable cassette having a multilayered structure comprising a compact high-strength layer.

Embodiment 6

The edge portion of the SiC molded body obtained in Embodiment 2 was impregnated in a width of 5 mm with SiC slurry to close its pores and cured, and the thus formed SiC molded body was formed as in the embodiment 1, thereby producing a 1 mm-thick air permeable cassette having a 5 mm wide edge portion with a compact layer of high strength.

Embodiment 7

On one surface or both surfaces of the Si-SiC sintered body obtained in Embodiment ₂ , sludge comprising ZrO ₂ and / or Al ₂ O ₃ -SiO _{2 was} applied by spraying, followed by firing at 1350 ° C , whereby a layer of ZrO ₂ and / or Al ₂ O ₃ -SiO _{2 was} formed.

Comparative Example 1

A cassette was made from a Ni metal mesh.

Comparative Example 2

It was a 1 mm thick cassette after in the Japanese Patent Laid-Open Publication 2012-56831 prepared method described.

Exemplary embodiments B

Embodiment 8

In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 150 × 150 × 5 mm was dipped, excess sludge was removed, and using a fixing tool, the urethane foam was pressed to a thickness of 1 mm, whereupon the slurry hardened, whereby a 1 mm thick SiC molded body was produced. The same as in Embodiment 1 was then fired, whereby a 1 mm thick cassette with air permeability was prepared. The porosity of the produced air permeable cassette was 60%. The total content of SiC in the skeleton was 46.5% by weight, the content of Si was 48.4% by weight, and the content of C in the core portion of the skeleton was 19.8% by weight and the content of C im Surface layer section was 46.8 wt .-%. The ratio [pore diameter / framework diameter] was 4.9.

Embodiment 9

With a urethane foam of 150.times.150.times.3 mm, a 1 mm thick air permeable cassette was produced in the same method as in Embodiment 8. FIG. The porosity of the produced air permeable cassette was 70%. The content of SiC in the skeleton as a whole was 54.1% by weight, the content of Si was 40.0% by weight, and the content of C in the core portion of the skeleton was 11.1% by weight and the content of C im Surface layer section was 33.6 wt .-%. The ratio [pore diameter / framework diameter] was 4.6.

Embodiment 10

With a urethane foam of 150.times.150.times.2 mm, a 1 mm thick air permeable cassette was produced in the same method as in Embodiment 8. The porosity of the produced air permeable cassette was 80%. The total content of SiC in the skeleton was 58.8% by weight, the content of Si was 35.8% by weight, and the content of C in the core portion of the skeleton was 6.0% by weight and the content of C im Surface layer portion was 16.0 wt%. The ratio [pore diameter / framework diameter] was 3.9.

Comparative Example 3

In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 150 × 150 × 5 mm was prepared dipped, excess sludge was removed, and with the aid of a fixing tool, the urethane foam was pressed to a thickness of 1 mm, whereupon the sludge hardened, whereby a 1 mm thick SiC molded body was produced. Next, on the SiC molded body was applied metal Si in a weight ratio of 60%, and under reduced pressure and reducing atmosphere was fired at 1500 ° C, thereby producing a 1 mm thick air permeable cassette. The porosity of the produced air permeable cassette was 60%. The total content of SiC in the skeleton was 73.3% by weight, the content of Si was 21.6% by weight, and the content of C in the core portion of the skeleton was 10.1% by weight and the content of C im Surface layer section was 55.7 wt%. The ratio [pore diameter / framework diameter] was 3.6.

Comparative Example 4

In the same procedure as in Comparative Example 3, a 1 mm thick SiC molded body was prepared, and next, SiC molded body was coated with metal Si in a weight ratio of 120%, and fired at 1500 ° C under reduced pressure and reducing atmosphere , which produced a 1 mm thick cassette with air permeability. The porosity of the produced air permeable cassette was 60%. The total content of SiC in the framework was 28.4% by weight, the content of Si was 66.2% by weight, and the content of C in the core portion of the skeleton was 11.4% by weight and the content of C im Surface layer section was 13.6 wt .-%. The ratio [pore diameter / framework diameter] was 4.2.

Comparative Example 5

* Chemische Bestandteile: Gemäß JTS R 2011
* Elementverhältnis: Gemäß guantitativer EDS-Analyse
* Wärmeschock-Bruchwiderstandskoeffizient R': Angabe des indexierten Werts mit Vergleichsbeispiel 5 als Referenz In an organic solvent, SiC (-C, -B ₄ C) was dispersed, into which SiC slurry to which urethane resin (isocyanate and catalyst) was mixed, a urethane foam of 150 × 150 × 5 mm was dipped, excess sludge was insufficiently removed and using a fixing tool, the urethane foam was pressed to a thickness of 1 mm, whereupon the slurry hardened, whereby a 1 mm thick SiC molded body was produced. Next, on the SiC molded body was applied metal Si in a weight ratio of 60%, and under reduced pressure and in a reducing atmosphere was fired at 1500 ° C, whereby a 1 mm thick air permeable cassette was produced. The porosity of the produced air permeable cassette was 40%. The total content of SiC in the skeleton was 68.8% by weight, the content of Si was 23.8% by weight and the content of C in the core portion of the skeleton was 11.1% by weight and the content of C im Surface layer portion was 55.4 wt%. The ratio [pore diameter / framework diameter] was 1.3. Exemplary embodiments B [Table 2]

* Chemical ingredients: According to JTS R 2011
* Element Ratio: According to guantitative EDS analysis
* Thermal shock crack resistance coefficient R ': Indication of the indexed value with Comparative Example 5 as a reference

After producing the cassettes of the embodiments 8th to 10 and the comparative examples 3 to 5 the thermal shock resistance and the heat resistance were tested, wherein in the embodiments 8th to 10 in any case, an improvement in thermal shock resistance and heat resistance over the comparative examples 3 to 5 was determined.

LIST OF REFERENCE NUMBERS

1

Core section of the Si-SiC framework

2

pore section

3

Surface layer portion of the Si-SiC skeleton

4

Scaffolding section of the urethane foam

5

cavity portion

7

Metal-Si

8th

first shift

9

second layer

10

SiC slurry form body

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2012-56831 [0003, 0004, 0008, 0078]
• JP 2011-117669 [0004, 0008]
• US 6635339 [0006, 0007, 0008]

Cited non-patent literature

• JIS R 2011 [0038]

Claims (13)

The refractory composite material having a Si-SiC sintered body as a base material, characterized in that the Si-SiC sintered body has a three-dimensional mesh-like structure composed of a skeleton having a porosity of 1% or less, wherein the SiC content of the skeleton 35 to 70 wt .-% and the metal Si content 25 to 60 wt .-% is. Refractory composite material according to claim 1, characterized in that the SiC content is 40 to 65 wt .-% and the Si content 30 to 55 wt .-%. The refractory composite material according to claim 1, characterized in that in the three-dimensional mesh structure, the shape of the pores and the skeleton constituting the three-dimensional mesh structure satisfies an average value of ≥ 3 for [pore diameter / framework diameter]. The refractory composite material according to claim 1, characterized in that the skeleton is made up of a core portion containing metal Si as the main component and residual component C, and a surface layer portion whose main component is SiC and which contains metal Si as a residual component, wherein the Content of C in the core portion is 5 to 20% by weight, and the content of C in the surface layer portion is 15 to 50% by weight. The refractory composite material according to claim 1, characterized in that the skeletal density forming the three-dimensional mesh structure is different in vertical cross-section and horizontal cross-section, the skeletal density in the vertical cross-section being 1.1 to 40 times the horizontal cross-section. The refractory composite material according to claim 1, characterized in that the porosity of the Si-SiC sintered body is 50 to 98%. A refractory composite material according to claim 1, characterized by a surface coating having a reaction resistance to the processed workpiece on the upper layer of the base material. A refractory composite material according to claim 1, characterized in that it has on the surface coating of the base material a compact layer comprising a Si-SiC sintered body having a porosity of 0.1 to 2%. The refractory composite material according to claim 1, characterized in that the base material has a structure wherein layers of the Si-SiC sintered body having different porosity are laminated one upon another. A refractory composite material according to claim 9, characterized in that the uppermost layer in the laminated structure is a compact layer having a porosity of 0.1 to 2%. The refractory composite material according to claim 1, characterized in that the edge portion of the base material forms a frame portion comprising a compact layer having a porosity of 0.1 to 2%. A refractory composite material according to claim 1, characterized by a frame member formed of a nickel alloy carrying the base material. A method of producing the refractory composite material according to claim 1, characterized by the steps of: forming step by dipping a urethane foam into a molding slurry obtained by dispersing an SiC powder in an organic solvent and then adding a gelling material; which has a skeleton comprising a three-dimensional mesh structure and the slurry is hardened, a drying step wherein the molding obtained in the molding step is dried, and a firing step wherein metal-Si is applied to the dried molded article having undergone the drying step, and firing is carried out at reduced pressure and in a reducing atmosphere to impregnate the skeleton of the dried molded article with the metal-Si.

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