WO2022080318A1

WO2022080318A1 - Method for producing ceramic article, metal ion-containing liquid used therein, and kit for producing ceramic article

Info

Publication number: WO2022080318A1
Application number: PCT/JP2021/037578
Authority: WO
Inventors: 俊介村上; 伸浩安居; 康弘関根; 香菜子大志万; 康志清水
Original assignee: キヤノン株式会社
Priority date: 2020-10-16
Filing date: 2021-10-11
Publication date: 2022-04-21

Abstract

This method for producing a ceramic article using an addition production technique is characterized by comprising: a step for irradiating powder mainly composed of ceramic with an energy beam to solidify the powder, thereby producing a molded object; a step for causing the molded object to absorb a metal ion-containing liquid including water and metal ions; and a step for heating the molded object which has absorbed the metal ion-containing liquid.

Description

Manufacturing method of ceramic articles, metal ion-containing liquid used for it, and kit for manufacturing ceramic articles

The present invention relates to an additional manufacturing technique, particularly a technique for manufacturing a ceramic article by using a powder bed melt-bonding method or a directed energy lamination method.

In applications such as manufacturing prototypes in a short time or manufacturing a small number of parts, the raw material powder is irradiated with an energy beam based on the three-dimensional data of the object to be modeled, and the raw material powder is combined to form a desired model. The additional manufacturing technology to obtain the above is widespread. In modeling using metal powder as a raw material (metal modeling), the powder bed melt-bonding method is widely adopted, and a dense and diverse metal model is obtained. The high density of the metal model is achieved by effectively melting and solidifying the metal powder. Based on the success of such metal modeling, in recent years, efforts to manufacture ceramic articles using additional manufacturing technology have been reported.

Unlike metals, general-purpose ceramics such as aluminum oxide and zirconium oxide have low absorption capacity for laser light. Therefore, a technique is known in which an absorber having a higher absorption capacity for laser light than ceramics is added to the raw material powder, and the absorber absorbs the laser light to melt the raw material powder.

However, due to the high cooling rate in the process of solidifying the molten part, the stress generated in the surface layer and inside of the modeled object and the thermal stress caused by the temperature difference between the non-solidified area and the solidified area cause the modeled object to become Has a problem that cracks are formed and the mechanical strength of the modeled object is lowered. In Patent Document 1, after absorbing a liquid containing a metal component and an organic solvent such that a phase capable of forming a eutectic with the modeled object is generated by heating, the modeled object is heated to melt only the vicinity of the crack. A method for reducing or eliminating cracks is disclosed.

Japanese Unexamined Patent Publication No. 2019-188810

According to Patent Document 1, the mechanical strength of the modeled object can be improved by performing a post-treatment step of absorbing and heating a liquid containing a metal component (metal component-containing liquid) in the modeled object. However, in order to sufficiently reduce or eliminate cracks in the modeled object, it is necessary to repeat the post-treatment process many times. Since the post-treatment step requires at least several hours each time, if it is repeated many times, the productivity will decrease.

The present invention solves such a problem, and the first aspect is a method for manufacturing a ceramic article using an additional manufacturing technique, in which a powder containing ceramic as a main component is irradiated with an energy beam to solidify the powder. A step of producing a modeled product, a step of causing the modeled object to absorb a metal ion-containing liquid containing water and metal ions, and a step of heating the modeled object having absorbed the metal ion-containing liquid. It is characterized by including.

The second aspect of the present invention is a kit for manufacturing a ceramic article for manufacturing a ceramic article by an additional manufacturing technique using an energy beam, which includes a powder containing ceramic as a main component and a metal ion-containing liquid. The metal ion-containing liquid contains water and metal ions, and the metal ions can form a co-crystal with a compound contained in a ceramic model made from a powder containing the ceramic as a main component. It is characterized by producing things.

The third aspect of the present invention is a metal ion-containing liquid used for repairing cracks contained in a ceramic model formed by an additive manufacturing technique, and the metal ion-containing liquid is water and metal ions. The metal ion is characterized by producing a metal oxide capable of forming a co-crystal with the compound contained in the ceramic model.

According to the present invention, it is possible to efficiently manufacture a ceramic article having high accuracy and excellent mechanical strength by using an additional manufacturing method.

It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the powder bed melt-bonding method. It is a figure which shows typically the manufacturing process of the ceramic article using the directed energy stacking method. It is a figure which shows typically the manufacturing process of the ceramic article using the directed energy stacking method. It is a figure which shows typically the manufacturing process of the ceramic article using the directed energy stacking method. It is an example of the phase diagram showing the composition ratio of the component X and the component Y in the case of the eutectic relationship, and the melting temperature and the state at each composition ratio. In the embodiment of the present invention, it is a schematic perspective view which shows the process of irradiating a certain layer while scanning a laser. FIG. 4A is a schematic perspective view showing a process of irradiating a layer to be formed following FIG. 4A while scanning a laser. It is an optical microscope image of the ceramic article obtained in Example 1. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments and specific examples, and can be modified within the scope of the technical idea of the present invention. ..

In Patent Document 1, in order to obtain high mechanical strength, it was necessary to repeat the process of absorbing the metal component-containing liquid in the modeled object and heating it a plurality of times depending on the shape of the modeled object. It is considered that this is because the metal component-containing liquid contains a large amount of an organic solvent having good wettability to the modeled object, so that the metal component-containing liquid once absorbed by the modeled object tends to leak out. Therefore, the inventors have studied the components of the metal component-containing liquid and have completed the present invention.

Specifically, the ceramic model formed by the addition manufacturing method is subjected to heat treatment after absorbing a metal ion-containing liquid containing water and metal ions. As a result, only the vicinity of the cracks contained in the modeled object is locally melted, and the cracks are reduced or eliminated.

The additional manufacturing technique is a technique for forming an object by joining materials based on three-dimensional shape data of a modeling model, and a method of joining materials in layers is widely used. The additional manufacturing technique can realize a ceramic article having a complicated shape or a fine shape, which is difficult to manufacture by a conventional molding method or a removal processing method such as shaving. The additional manufacturing technique for ceramic articles according to the present invention includes an additional manufacturing technique of a powder bed melt coupling method or a directed energy lamination method (so-called cladding method). The metal ion-containing liquid according to the present invention can be suitably used for a model formed by an addition manufacturing method of a powder bed melt-bonding method or a directed energy lamination method.

Hereinafter, a method for manufacturing a ceramic article including a treatment step using a metal ion-containing liquid, a powder and a metal ion-containing liquid used for modeling the ceramic article, and a ceramic article manufactured by the manufacturing method according to the present invention will be described.

(Manufacturing method of ceramic articles)
The method for producing a ceramic article of the present invention includes the following three steps.
(I) A step of irradiating a powder containing ceramics as a main component with an energy beam to solidify the powder to produce a model (ii) The model absorbs a metal ion-containing liquid containing water and metal ions. Step (iii) Step of heating the modeled object that has absorbed the metal ion-containing liquid.

In the following, each process will be specifically described by taking as an example a case where modeling is performed using a powder containing aluminum oxide, which is a general-purpose ceramic, as a main component. However, the technical idea of the present invention is not limited to the powder containing aluminum oxide as a main component, and can be applied to the molding using a powder containing silicon oxide as a main component and other powders. Depending on the purpose, it can also be applied to modeling using powder in which a plurality of types of ceramics are mixed. For example, it can also be applied to modeling using a powder mixed with aluminum oxide, silicon oxide, magnesium oxide, etc. in order to produce a model made of mullite, cordylite, or the like.

In the present invention, the raw material powder for forming the ceramic model may be composed of the powder of the inorganic compound. In the present invention, "ceramics" is used in the sense that it includes not only a polycrystal in which an inorganic compound is sintered but also an inorganic compound composed of an amorphous or a single crystal.

Further, in the present invention, among the objects (powder, modeled object or article) for which the components are discussed, the component contained most in the molar ratio is referred to as the main component. "Main component" is also synonymous with the main component.

<Step (i)>
This is a step of irradiating a powder (raw material powder) containing ceramics as a main component with an energy beam to sintered, melt, and solidify the powder to form a solidified portion and obtain a modeled product. The powder containing ceramics as a main component means a powder in which 90 mol% or more is ceramics when an arbitrary amount of powder of 1 cm ³ or more is analyzed. Preferably, 99 mol% or more is ceramics. When a plurality of types of ceramics are contained, if the total amount is 90 mol% or more, it corresponds to a powder containing ceramics as a main component.

The basic flow of the modeling procedure using the powder bed melt-bonding method will be described with reference to FIGS. 1A to 1H. First, a powder 101 containing ceramics as a main component is placed on a base 130 installed on the stage 151 and spread evenly with a roller 152 to form a powder layer 102 (FIGS. 1A and 1B). The powder layer 102 refers to a powder laid with a predetermined thickness on the stage 151 with a predetermined thickness. The energy beam emitted from the energy beam source 180 is scanned on the surface of the powder layer 102 by the scanner unit 181 based on the three-dimensional shape data of the article to be manufactured, and the energy beam is irradiated to the powder to irradiate the powder in the irradiation range 182. Solidify. In the irradiation range 182, the powder is sintered, melted and solidified by irradiation with an energy beam to form a solidified portion 100 (FIG. 1C). Next, the stage 151 is lowered to newly form the powder layer 102 on the model 100 (FIG. 1D). The newly formed powder layer 102 is irradiated with an energy beam in the same manner as in FIG. 1C to form the solidified portion 100. At this time, if the output of the energy beam is adjusted to such an extent that the surface layer on the side of the newly formed powder layer 102 of the previously formed solidified portion melts, the previously formed solidified portion and the later formed solidified portion are formed. It is possible to join and integrate with the solidified portion to be formed. By repeating these series of steps, a model 110 in which a plurality of solidified portions 100 are integrated is formed (FIGS. 1E and 1F). Finally, the unsolidified powder 103 is removed, and if necessary, unnecessary portions of the modeled object are removed and the modeled object 110, the base, and 130 are separated (FIGS. 1G and 1H).

Next, the basic flow of the modeling procedure using the cladding method will be described with reference to FIGS. 2A to 2C. In the cladding method, powder is ejected from a plurality of powder supply holes 202 provided in the nozzle 201, and the energy beam 203 is irradiated to the region where the powder is focused. When the nozzle 201 is moved to a desired position and the powder melt is placed on the substrate, the melt is solidified after passing through the nozzle 201, and the solidified portion 100 can be additionally formed (FIG. 2A). At this time, by adjusting the output of the energy beam 203 to the extent that the surface layer of the base is melted, as in the powder bed melt-bonding method, the process is repeated and the solidified portion 100 is integrated into the model 110. Can be obtained (FIGS. 2B and 2C). Finally, if necessary, unnecessary parts of the modeled object are removed and the modeled object and the base are separated.

In either method, when the powder is irradiated with an energy beam, the powder absorbs energy, and the energy is converted into heat to melt the powder. When the irradiation to the molten portion is completed by the passage of the energy beam, the molten portion is cooled by the surrounding atmosphere and the adjacent portion, and is sintered or solidified to form a solidified portion. At this time, since the cooling rate in the process of forming the solidified portion is high, stress generated in the surface layer and the inside of the solidified portion (including the integrated solidified portion) and generated between the non-solidified portion and the solidified portion. Cracks are formed by the thermal stress caused by the temperature difference.

For the energy beam to be used, a light source having an appropriate wavelength may be selected according to the absorption characteristics of the powder. In order to perform high-precision modeling, it is preferable to use a laser beam or an electron beam having a narrow beam diameter and high directivity. From the viewpoint of versatility, a YAG laser having a wavelength band of 1 μm, a fiber laser, a CO ₂ laser having a wavelength band of 10 μm, and the like can be mentioned as suitable energy beams.

The powder containing aluminum oxide as a main component preferably contains an oxide of a rare earth element having a eutectic composition with aluminum oxide as a sub-component. In particular, those comprising at least one selected from the group consisting of gadolinium oxide (Gd ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), terbium oxide (Tb ₂ O ₃ ) and praseodymium oxide (Pr ₂ O ₃ ). preferable. For example, when the raw material powder contains _gadrinium oxide that produces a eutectic composition with aluminum oxide, the melting point (eutectic point) in the vicinity of the eutectic composition of the _Al2O3 _- _Gd2O3 system is set to the melting point of aluminum oxide alone. It can be lowered by 300 ° C. or more. Therefore, the powder can be melted with a small amount of heat, and energy diffusion to the periphery of the melted portion is suppressed, so that the molding accuracy is improved. Further, since the raw material powder contains aluminum oxide and gadolinium oxide, the modeled product has a phase-separated structure in which two or more kinds of phases are intricate. As a result, the expansion of cracks is suppressed and the mechanical strength of the modeled object is improved. When the raw material powder contains an oxide of another rare earth element such as yttrium oxide in addition to aluminum oxide, the same effect as that of gadolinium oxide can be obtained.

When the energy beam is a laser beam, if the powder has sufficient absorption capacity for the laser beam, the temperature of the laser beam irradiation part is locally raised, and the influence of heat on the non-modeled part is reduced. Therefore, the modeling accuracy is improved. For example, when using an Nd: YAG laser or fiber laser in the 1 μm wavelength band, terbium oxide (Tb ₄ O ₇ ), placeodim oxide (Pr ₆ O ₁₁ ), Ti ₂ O ₃ , TiO, SiO are used as subcomponents of powder. , ZnO, antimonated tin oxide (ATO), indium-doped tin oxide (ITO), MnO, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , Cu ₂ O, CuO, Cr ₂ O ₃ , CrO ₃ , NiO, V ₂ O ₃ , VO ₂ , V ₂ O ₅ , V ₂ O ₄ , Co ₃ O ₄ , CoO, Transition Metal Carbide, Transition Metal Nitride, Si ₃ N ₄ , AlN, borates, silicates and the like, more preferably containing components exhibiting good energy absorption. The raw material powder may contain both rare earth elements that exhibit good energy absorption for laser beams, such as terbium oxide (Tb ₄ O ₇ ) and praseodymium oxide (Pr ₆ O ₁₁ ), as well as other rare earth elements. preferable. The absorber is a component (element or compound) that exhibits a higher absorption capacity than the main component for light having a wavelength contained in the laser used for modeling. The absorption capacity of the absorber is preferably 10% or more, more preferably 40% or more, and 60% or more with respect to the light of the wavelength contained in the laser beam of the wavelength used. Is even more preferable.

From the above viewpoints, as particularly suitable raw material powders, Al ₂ O ₃ -Gd ₂ O ₃ , Al ₂ O ₃ -Gd AlO ₃ , Al ₂ O ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Gd ₂ O _3- Tb ₄ O ₇ , Al ₂ O ₃ -GdAlO ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -Gd ₂ O ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -GdAlO ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -Y ₂ O ₃ , Al ₂ O ₃ -YAlO ₃ , Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ , Al ₂ O ₃ -Y ₂ O ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -YAlO ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -Tb ₄ O ₇ , Al ₂ O ₃ -Y ₂ O ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -YALo ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -Pr ₆ O ₁₁ , Al ₂ O ₃ -ZrO ₂ , Al ₂ O ₃ -ZrO ₂ -Tb ₄ O ₇ , Al ₂ O ₃ -ZrO ₂ -Pr ₆ O ₁₁ , Al ₂ O ₃ -SiO, Al _{2 O 3-Gd 2 O 3-SiO, Al 2} _{O 3} _- _GdAlO ₃ _- _SiO , Al ₂ O ₃ -Y ₂ O ₃ -SiO , Al ₂ O ₃ -YAlO ₃ -SiO, Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -SiO, Al ₂ O ₃ -ZrO ₂ -SiO, SiO ₂ -Tb ₄ O ₇ , SiO ₂ -Pr ₆ O ₁₁ , (MgO-Al ₂ O ₃ -SiO ₂ ) -Tb ₄ O ₇ , (MgO-Al ₂ O ₃ -SiO ₂ ) -Pr ₆ O ₁₁ , (Al ₂ O ₃ -SiO ₂ ) -Tb ₄ O ₇ , (Al ₂ O ₃ -SiO ₂ ) -Pr ₆ O ₁₁ and the like can be mentioned.

It is preferable that the powder containing ceramics as a main component contains a composition that can be eutectic in a ratio of forming a eutectic composition. The eutectic composition is the composition at the eutectic point shown in the phase diagram, but in the modeling process using the energy beam, the heating state and the cooling state occur at a very high speed, so that the composition is slightly deviated from the eutectic point. Even if there is, a eutectic structure is formed. Therefore, the eutectic composition in the present invention should be defined as a composition range in which a eutectic structure is formed, and includes a range in which the deviation from the eutectic composition as shown in the phase diagram is ± 10 mol%.

In the case of a powder containing ceramics as a main component other than aluminum oxide, it is preferable that the powder having a eutectic composition is contained in a ratio of forming a eutectic composition, similarly to the powder containing aluminum oxide as a main component.

The fact that the component X and the component Y can form a eutectic may be expressed as "the component X and the component Y have a eutectic relationship". Eutectic is a mixture of two or more types of crystals that crystallize simultaneously from a liquid containing two or more components. When the component X and the component Y have a eutectic relationship, a eutectic point (also referred to as a eutectic melting point) exists. The eutectic point is the temperature at which eutectic occurs, and corresponds to the minimum value of the liquid phase curve in the state diagram represented by the temperature on the vertical axis and the component composition ratio on the horizontal axis. The composition corresponding to the eutectic point is called the eutectic composition (or eutectic composition). Therefore, the eutectic point of the component X and the component Y is lower than the melting point of each of the component X and the component Y.

In this specification, a material may be expressed using a chemical formula such as Al ₂ O ₃ and Tb ₄ O ₇ described above, but if the gist of the present invention is satisfied, the element of the actual material may be expressed. The composition ratio does not have to be exactly the same as the ratio in the chemical formula. That is, the valences of the metal elements constituting a certain material may be slightly different from the valences assumed from the chemical formula. For example, in the case of SiO, the constituent element ratio of the absorber is Si: O = 1: 1. Even if it is 30, it is included in the present invention. Preferably, the deviation from the stoichiometric ratio is within ± 20%.

<Process (ii)>
In the step (ii), the ceramic model obtained in the step (i) is made to absorb the metal ion-containing liquid containing water and metal ions.

As mentioned above, many cracks are contained in the modeled object manufactured by the direct modeling method such as the powder bed melt bonding method or the cladding method using the powder containing ceramics as the main component. This is due to the stress generated in the surface layer and inside of the modeled object due to the high cooling rate when the molten part solidifies, and the temperature generated between the non-solidified part and the solidified part due to the low thermal conductivity of the material itself. It is considered to be due to the thermal stress caused by the difference. Since the modeled object is formed by joining such solidified portions, cracks exist in the entire modeled object like a grid in a form substantially dependent on the scanning direction of the energy beam. When the cross section of the modeled object is confirmed with a scanning electron microscope or the like, there are many cracks having a width of several nm to several μm. The length of the crack varies from a few μm to a few mm.

When the metal ion-containing liquid is absorbed by the model having such cracks, the metal ions are distributed in the cracks of the model. Then, by heating the modeled object that has absorbed the metal ion-containing liquid in the step (iii) described later, only the vicinity of the crack can be selectively melted. As a result, it is possible to repair cracks existing in the modeled object and improve the mechanical strength of the modeled object while suppressing the change in the shape of the modeled object.

[Metal ion-containing liquid]
As the metal ion-containing liquid used in the step (ii), a solution containing at least water and metal ions, preferably a solution containing water, metal ions and a stabilizer is used. For example, a sol solution using water as a solvent can be used. As will be described in detail later, the metal ion contained in the metal ion-containing liquid is preferably one in which the oxide can form a eutectic with at least one compound contained in the model, that is, a compound contained in the raw material powder. Particularly preferable elements as metal ions contained in the metal ion-containing liquid are Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn. , Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, Cs, Ba, rare earth elements, Hf, Ta, W. It is also preferable to contain a plurality of these metal ions.

The metal ion-containing liquid according to the present invention is characterized in that it contains water as a solvent. This was done based on the consideration made with respect to Patent Document 1. By including water in the metal ion-containing liquid, the wettability of the metal ion-containing liquid with respect to the modeled object is reduced, and the metal ion-containing solution is once absorbed by the modeled object. Then, a metal ion-containing liquid that does not easily leak is realized. The amount of water contained in the metal ion-containing liquid is preferably 10% by mass or more with respect to the liquid excluding metal ions.

Further, one of the features of the metal ion-containing liquid according to the present invention is that it contains metal ions. By containing a component that contributes to the repair of cracks in the modeled object as metal ions, it becomes possible to invade and repair fine cracks. Therefore, it is possible to repair minute cracks that greatly affect the mechanical strength, especially in a minute modeled object or a microstructure of the modeled object.

Metal ions can be generated by dissolving a raw material containing metal ions such as a metal salt or a metal alkoxide in a solvent. The metal salt is not particularly limited as long as it is water-soluble, and can be selected from the group consisting of nitrates, sulfates, acetates, lactates, and chlorides.

For example, when preparing a metal ion-containing liquid containing zirconium ions (zirconium ion-containing liquid), the raw materials for generating metal ions include zirconium acetate, zirconium nitrate, zirconium oxynitrite, zirconium nitrate, zirconium sulfate, zirconium sulfate ammonium. Zirconium oxysulfate, zirconium chloride Zirconium chloride, zirconium salts such as zirconium lactate, zirconium tetraethoxydo, zirconium tetra n-propoxide, zirconium tetraisopropoxide, zirconium tetra n-butoxide, zirconium tetra t-butoxide, etc. Alkoxides can be used.

When preparing a metal ion-containing liquid containing aluminum ions (aluminum ion-containing liquid), the raw materials for generating metal ions include aluminum salts such as aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum phosphate, and aluminum lactate, and aluminum sec. -Aluminum alkoxides such as butoxide, aluminum ethoxydo, aluminum n-butoxide, aluminum tert-butoxide, aluminum isopropoxide and the like can be used.

When preparing a metal ion-containing liquid containing silicate ions (silicon ion-containing liquid), silicates such as sodium silicate and lithium silicate, tetraethoxysilane, and tetraethoxytitanium are used as raw materials for generating metal ions. Silicon alkoxides such as triethoxyaluminum can be used.

When preparing a metal ion-containing liquid containing lithium ions (lithium ion-containing liquid), as raw materials for generating metal ions, lithium acetate, lithium nitrate, lithium nitrate, lithium sulfate, lithium salts such as lithium lactate, lithium tert butoxide, etc. Lithium alkoxides such as lithium ethoxydo, lithium isopropoxide, and lithium methoxyd can be used.

When preparing a metal ion-containing liquid containing magnesium ions (magnesium ion-containing liquid), as raw materials for generating metal ions, magnesium acetate, magnesium nitrate, magnesium nitrate, magnesium sulfate, magnesium salts such as magnesium lactate, magnesium ethoxydo, etc. Magnesium alkoxides such as magnesium di-tert butoxide can be used.

A metal ion-containing liquid containing zirconium ion, silicate ion, lithium ion or magnesium ion as metal ion is suitable for repairing cracks in a model whose main component is aluminum oxide. Further, a metal ion-containing liquid containing zirconium ions, aluminum ions, lithium ions or magnesium ions as metal ions is suitable for repairing cracks in a model whose main component is silicon oxide.

When the metal ion-containing liquid is absorbed by the modeled object, the metal ions are distributed throughout the modeled object, so it is preferable to add a stabilizer to the metal ion-containing liquid to adjust the characteristics of the liquid. As the stabilizer to be added to the metal ion-containing liquid, at least one selected from the group consisting of organic acids, surfactants and chelating agents is preferable.

Examples of the organic acid include acrylic acid, 2-hydroxyethyl acrylate, 2-acryloxyethyl succinic acid, 2-acryloxyethyl hexahydrophthalic acid, 2-acryloxyethyl phthalic acid, 2-methylhexane acid and 2-. Ethyl hexane acid, 3-methyl hexane acid, 3-ethyl hexane acid and the like are preferable.

Examples of the surfactant include ionic surfactants such as sodium oleate, potassium fatty acid, sodium alkyl phosphate, alkylmethylammonium chloride, and alkylaminocarboxylate, polyoxyethylene laurin fatty acid ester, and polyoxyethylene alkylphenyl. Nonionic surfactants such as ether are preferred.

Chelating agents include glycolic acid, ascorbic acid, citric acid, malonic acid, gluconic acid, oxalic acid, succinic acid, malic acid, tartaric acid, hydroxy acids such as lactic acid, glycine, alanine, glycine, glutamic acid, aspartic acid, histidine, Amino acids such as phenylalanine, asparagine, arginine, glutamine, cystine, leucine, lysine, proline, serine, tryptophan, valine, tyrosine, diethylenetriamine 5 acetic acid (DTPA), hydroxyethylethylenediamine 3 acetic acid (HEDTA), triethylenetetraamine 6 acetic acid ( TTHA), 1,3-propanediamine 4-acetic acid (PDTA), 1,3-diamino-6-hydroxypropane 4-acetic acid (DPTA-OH), hydroxyethylimino diacetic acid (HIDA), dihydroxyethylglycine (DHEG), glycol Aminocarboxylic acids such as etherdiamine tetraacetic acid (GEDTA), dicarboxymethyl glutamic acid (CMGA), and (S, S) -ethylenediamine disuccinic acid (EDDS), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP). , 2-phosphobutanone-1,2,4-tricarboxylic acid (PBTC), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and phosphonic acid such as nitrilotris (methylenephosphonic acid), aromatics such as salicylic acid. Group acids are preferred.

The combination of the raw material that generates metal ions and the stabilizer may be any combination. However, depending on the amount of the stabilizer added, the wettability of the metal ion-containing liquid to the modeled object may decrease. The content of the stabilizer contained in the metal ion-containing liquid is preferably 10 mol% or more and 300 mol% or less, and more preferably 50 mol% or more and 200 mol% or less with respect to the metal ion. The content of components contained in the metal ion-containing liquid is measured by ICP-MS for metal ions and by nuclear magnetic resonance (NMR) or liquid chromatography-mass spectrometry (LC-MS) for organic components such as stabilizers. can do.

The method for producing a metal ion-containing liquid obtained by mixing a metal salt with water or a metal salt with water and a stabilizer is not limited. The raw materials may be mixed all at once, the metal salt and the stabilizer may be mixed and then water may be added and mixed, or the metal salt and water may be mixed and then the stabilizer may be added. It may be mixed, or the stabilizer and water may be mixed and then the metal salt may be mixed. Depending on the combination of the metal salt and the stabilizer, it is also preferable to heat at an appropriate temperature at the time of mixing.

When the metal ion-containing liquid is absorbed by the ceramic model, the metal ions spread in the cracks. The method for allowing the modeled object to absorb the metal ion-containing liquid is not particularly limited as long as the metal ions can be uniformly interposed on the surface constituting the crack of the modeled object. The modeled object may be impregnated by immersing it in the metal ion-containing liquid, or the metal ion-containing solution may be atomized and sprayed on the modeled object, or may be applied to the surface with a brush or the like to be absorbed. Further, a plurality of these methods may be combined, or the same method may be repeated a plurality of times.

When the size of the modeled object becomes large, it is preferable to use a method of immersing the modeled object in a metal ion-containing liquid and degassing under reduced pressure in order to sufficiently distribute the metal ions to the inside of the modeled object. Alternatively, a method in which the modeled object is placed in a closed container, degassed under reduced pressure, and then immersed in a metal ion-containing liquid is also preferable. Since a metal ion-containing liquid containing water as a solvent has a smaller wettability with respect to ceramics than an organic solvent, these methods using vacuum degassing are particularly preferable.

As described above, the metal ion-containing liquid of the present invention has low wettability with respect to ceramics, so that the metal ion-containing liquid once incorporated into the cracks of the modeled object does not easily flow out of the modeled object. That is, many metal ions that function to repair cracks can be retained in the cracks of the modeled object.

The metal ions incorporated into the cracks of the modeled object become metal oxides in the process of heat treatment in the step (iii) described later, and the generated metal oxides eutectic with at least one of the compounds contained in the modeled object. Form. As a result, the melting point in the vicinity of the crack of the modeled object in which the metal ion is present can be locally lowered.

One type of compound contained in the model that absorbs the metal ion-containing liquid is component X, and the metal oxide produced by heating the metal ion contained in the metal ion-containing liquid is component Y, and component X and component Y are used. And are in a eutectic relationship. At this time, the local melting caused by the crack is presumed to be due to the following phenomenon.

When the metal ion-containing liquid is absorbed by the modeled object, the amount of metal ions contained in the metal ion-containing liquid is present not only on the surface of the modeled object but also on the surface constituting the crack of the modeled object. When the heat treatment is performed in this state, the metal ions existing on the surface constituting the crack of the modeled object are oxidized in the process of the heat treatment to become the component Y. When the temperature near the region where the component Y exists approaches the eutectic point of the component X and the component Y, the amount of the component Y and the eutectic composition or the composition ratio close to the eutectic composition of the component X are formed. It begins to melt at a eutectic point lower than the melting point of the object, forming a fusion of component X and component Y. Further, as the fusion with the surrounding component X progresses, the melting point of the fusion becomes higher than the confocal because the ratio of the component X in the fusion increases, and crystals are precipitated from the fusion to reduce or eliminate cracks. It is thought that it will contribute to. As a result, it is considered that the crack can be repaired by melting and recrystallizing only the region near the crack while maintaining the shape of the modeled object. This process has the advantage of being easy to control because it proceeds and is completed simply by maintaining the heat treatment in a constant state.

In this way, the portion where the crack is repaired by impregnation with the metal ion-containing liquid and heat treatment has higher mechanical strength because the bond between the tissues is stronger than the method of filling the crack with glass or the like to repair it. It is thought that a model can be obtained. Further, since the bias of the extreme composition is smaller than that of the method of filling the cracks with glass or the like, it is possible to realize a relatively homogeneous model in terms of physical properties other than the mechanical strength.

There are many possible combinations of component X and component Y, but among them, the melting point _Ti of component Y, which is a metal oxide formed from metal ions, is the melting point _Tm of component X that can form a eutectic with component Y. It is preferable that the relationship is higher than that. FIG. 3 shows an example of a phase diagram showing the composition ratio of the component X and the component Y when the component X and the component Y have a eutectic relationship, and the relationship between the temperature and the state at each composition ratio. The horizontal axis represents the composition ratio, and the component X is 100% at the left end, and the proportion of the component X decreases and the proportion of the component Y increases as it approaches the right end.

Assuming that the melting point of the component X is T _m , the melting point of the component Y is _Ti , and the eutectic point between the component X and the component Y is _{TE, the respective temperatures are in the relationship of T E <T m and T E} _< _T _i _. Meet. In this case, it is preferable to set the maximum temperature TS reached by the heat treatment performed after absorbing the metal component-containing liquid so as to satisfy the relationship of _TE ≤ _TS < _T _m . Both _TE and _TS are set to be lower than the melting point _TA of the modeled object.

Further, if T _m < _Ti , a high effect can be obtained even if the number of times of absorbing the metal ion-containing liquid and the number of times of heating are small. As shown in FIG. 3, since T _m <Ti, the ratio of the component X in the _eutectic composition of the component X and the component Y is high, and the ratio of the component Y is small in the vicinity of the crack. This is because can be melted at the eutectic point. It should be noted that T _m < _Ti is a preferable condition, not an essential condition.

For example, when the main component of the modeled product is aluminum oxide (Al ₂ O ₃ ; melting point T _m = 2070 ° C.), the main component of the metal ions contained in the metal ion-containing liquid is zirconium oxide (ZrO ₂ ; melting point) by heating. A component having Ti ₌ 2715 ° C.) is suitable. Examples of metal salts that generate metal ions that become zirconium oxide by heating include zirconium acetate, zirconium oxyacetate, zirconium oxychloride, and zirconium oxynitrite. Al ₂ O ₃ and Zr O ₂ are in a relationship capable of forming a eutectic, and the eutectic point _TE is about 1840 ° C. That is, Al ₂ O ₃ and Zr O ₂ are a combination that _satisfies the above-mentioned preferable relationship, T _m <Ti. Therefore, ZrO ₂ is generated in the vicinity of the crack from the metal ion of the metal ion-containing liquid to be absorbed by the crack, so that the maximum temperature _TS at the time of heat treatment can be set in the range of 1840 ° C ≤ _TS <2070 ° C. can. Then, the vicinity of the crack can be selectively melted at a temperature sufficiently lower than the melting point of Al ₂ O ₃ , and the crack can be reduced or eliminated.

When the model contains two components, Al ₂ O ₃ and Gd Al O ₃ , the melting point of the model is determined according to the composition ratio of these two components. For example, assuming that the model contains two components in a eutectic composition, the melting point _TA is about 1720 ° C. (eutectic point). When repairing cracks in such a model, the metal ion-containing liquid used is preferably one containing metal ions mainly composed of a component that becomes zirconium oxide by heating. The melting point Ti of ZrO ₂ is ₂₇₁₅ ° C., but since the eutectic point TE of the three components of Al ₂ O ₃ and Gd AlO ₃ and _ZrO ₂ is about 1662 ° C., the melting point _TA of the modeled product is about 1720 ° C. By heating at a sufficiently low temperature _TS , cracks can be reduced or eliminated.

Not limited to the above example, a combination of at least one kind of compound (component X) constituting a modeled object and a metal oxide (component Y) formed by heating a metal ion can be considered. .. Examples of preferable combinations in which component X and component Y _satisfy the relationship of T _m <Ti are [SiO ₂ ] and ZrO ₂ , [SiO ₂ ] and BeO, [SiO ₂ ] and MgO, [SiO ₂ ] and Al. ₂ O ₃ , [SiO ₂ ] and CaO, [SiO ₂ ] and SrO, [SiO ₂ ] and BaO, [SiO ₂ ] and Sc ₂ O ₃ , [SiO ₂ ] and Y ₂ O ₃ , [SiO ₂ ] Ti ₂ O ₃ , [SiO ₂ ] and ZrO ₂ , [SiO ₂ ] and HfO ₂ , [SiO ₂ ] and Ta ₂ O ₅ , [SiO ₂ ] and Cr ₂ O ₃ , [SiO ₂ ] and MnO, [SiO 2] ₂ ] and CoO, [SiO ₂ ] and NiO, [SiO ₂ ] and ZnO, [Al ₂ O ₃ ] and BeO, [Al ₂ O ₃ ] and MgO, [Al ₂ O ₃ ] and CaO, [Al ₂ O] ₃ ] and SrO, [Al ₂ O ₃ ] and Sc ₂ O ₃ , [Al ₂ O ₃ ] and Y ₂ O ₃ , [Al ₂ O ₃ ] and Ti ₂ O ₃ , [Al ₂ O ₃ ] and ZrO ₂ . , [Al ₂ O ₃ ] and HfO ₂ , [Al ₂ O ₃ ] and Cr ₂ O ₃ , [Al ₂ O ₃ and Re AlO ₃ (Re is a rare earth)] and ZrO ₂ , [Al ₂ O ₃ and Re ₃ Al. ₅ O ₁₂ (Re is rare earth)] and ZrO ₂ , [Al ₂ O ₃ and Re AlO ₃ (Re is rare earth)] and HfO ₂ , [Al ₂ O ₃ and Re ₃ Al ₅ O ₁₂ (Re is rare earth)] Examples thereof include, but are not limited to, HfO ₂ , [Mg ₂ Al ₄ Si ₅ O ₁₈ ] and Mg ₂ SiO ₄ , [Mg ₂ Al ₄ Si ₅ O ₁₈ ] and MgSiO ₃ . In the above description, the composition of the compound constituting the modeled product and which can correspond to the component X is shown in [], and the composition of the metal oxide is shown following [].

The component Y, which is a metal oxide, is preferably a component having a content of less than 3 mol% of a ceramic model that absorbs a metal ion-containing liquid. As a result, it becomes easy to locally melt only the vicinity of the crack portion by heating, and deformation of the modeled object can be suppressed. The content of the component Y of the ceramic model that absorbs the metal ion-containing liquid is more preferably less than 2 mol%, still more preferably less than 1 mol%.

As described above, in order to eliminate the crack, it is necessary to have an appropriate amount of the component Y on the surface of the modeled object facing the crack. The amount of the component Y present on the surface constituting the crack of the modeled object depends on the number of times the metal ion-containing liquid is absorbed by the modeled object and the concentration of the metal ions in the metal ion-containing liquid depending on the size and shape of the modeled object to be absorbed. You should adjust it.

The metal ions do not need to be densely filled in the cracks of the modeled object, and the metal ions of the metal ion-containing liquid may be present almost uniformly on the surface of the modeled object facing the cracks of the modeled object.

The concentration of metal ions in the metal ion-containing liquid is not particularly limited, but there is a preferable concentration depending on the purpose.

If the metal ion content in the metal ion-containing liquid is high, a large amount of component Y can be imparted to the surface of the modeled object constituting the crack by performing the step (ii) once. Therefore, cracks can be sufficiently reduced or eliminated even if the number of steps (ii) and steps (iii) is small. On the other hand, if the metal ion-containing liquid contains a large amount of metal ions, the amount of the component Y applied to the surface of the modeled object facing the crack in each step (ii) becomes too large, and the modeled object melts. , It may be easy to cover a wide area around the crack.

From this point of view, the metal ion content of the metal ion-containing liquid is preferably 10% by mass or more and 80% by mass or less, and more preferably 30% by mass or more and 60% by mass or less in terms of metal oxide. Further, in the metal ion-containing liquid applied to a model having a fine shape, the metal ion content of the metal ion-containing liquid is preferably 10% by mass or more and less than 50% by mass in terms of metal oxide. It is preferably 15% by mass or more and less than 30% by mass.

Taking advantage of the above-mentioned characteristics, in the initial stage of the process of repairing cracks, a metal ion-containing liquid having a high metal ion content is used to efficiently reduce the cracks to some extent, and then a metal having a low metal ion content is used. It is also preferable to repair cracks using an ion-containing liquid. As described above, by using a combination of a plurality of types of metal ion-containing liquids having different metal ion contents, it is possible to more efficiently reduce or eliminate cracks while ensuring shape accuracy.

Since the metal ion-containing liquid contains water as a solvent and has low wettability to the modeled object, the metal ion-containing liquid once absorbed inside the modeled object is difficult to leak and invades the crack in one step (iii). The resulting metal ions can be used for repairing cracks as they are. Therefore, by adjusting the amount of metal ions contained in the metal ion-containing liquid, it is possible to control the number of repetitions of the steps (ii) and (iii) required for repairing the cracks. When a metal ion-containing liquid having a high metal ion content is used, the number of steps (ii) and (iii) required to repair cracks is larger than that in the case of using a metal ion-containing liquid containing no water as a solvent. Can be reduced.

Further, there may be a step of correcting the fluctuation of the adhesion amount of the metal ion-containing liquid on the surface of the ceramic model after the metal ion-containing liquid is absorbed by the ceramic model obtained in the step (i). Further, the fluctuation correction may be performed after the heat treatment at less than 1000 ° C.

<Process (iii)>
In the step (iii), the ceramic model that has absorbed the metal ion-containing liquid is heat-treated.

By the step (ii), the metal ions are widely distributed in the surface layer of the modeled object and the cracks inside the modeled object. For example, in a model in which a zirconium oxide metal ion-containing liquid is absorbed in a model containing aluminum oxide as a main component, the vicinity of cracks locally approaches the eutectic composition of Al ₂ O ₃ and Zr O ₂ . Therefore, the composition in the vicinity of the crack has a lower melting point than the portion away from the crack. Utilizing this difference in composition distribution and melting point, the temperature is equal to or higher than the eutectic point of the metal ion oxide contained in the metal ion-containing liquid and the compound component constituting the model, and lower than the melting point of the material constituting the model. Then, heat the modeled object. In the case of a model in which a zirconium oxide metal ion-containing liquid is absorbed in a model containing aluminum oxide as a main component, the eutectic point (about 1720 ° C.) or higher of Al ₂ O ₃ and Zr O ₂ of Al ₂ O ₃ It is advisable to heat at a temperature below the melting point (about 2070 ° C.). As a result, while the shape of the modeled object is maintained, only the portion where the metal ion-containing liquid exists in the modeled object, that is, the vicinity of the crack of the modeled object is partially melted.

If the model is composed of two types of components, and these two components and zirconium oxide form a eutectic (three-phase eutectic) with three components, the eutectic points of these three components are two components. The temperature is lower than the eutectic point. In this case, the step (iii) can be carried out at a lower temperature than when the modeled object is composed of one component, and even if the modeled object is relatively large in size, the temperature unevenness of heating in the modeled object can be reduced. preferable. Further, when the article to be manufactured is an oxide, the step (iii) can be easily carried out in an electric furnace or the like in an atmospheric atmosphere if the temperature is relatively low.

For example, Al ₂ O ₃ -Gd ₂ O ₃ is a material capable of forming a three-phase eutectic with zirconium oxide. When the step (ii) of absorbing a metal ion-containing liquid containing zirconium ions into a model formed from a powder containing Al ₂ O ₃ -Gd ₂ O ₃ as a component, the surface constituting the crack of the model is subjected to the step (ii). Zirconium ions will be present. When the heat treatment is performed in this state, the zirconium ions existing on the surface constituting the crack of the modeled object become zirconium oxide in the process of the heat treatment, and zirconium oxide is generated on the surface of the modeled object facing the crack. In the vicinity of zirconium oxide present on the surface of the model that constitutes the crack, the amount of zirconium oxide present on the surface and the composition ratio at which a three-phase eutectic can be formed or the composition ratio in the vicinity thereof are Al ₂ O. ₃ -Gd ₂ O ₃ melts at a temperature lower than the melting point of the model. After that, it recrystallizes and contributes to the repair of cracks.

In this way, if the vicinity of the crack is brought close to the composition ratio at which a three-phase eutectic can be formed, the melting point can be significantly lowered locally. In the case of a model formed from a powder containing Al ₂ O ₃ -Gd ₂ O ₃ , the maximum temperature near the crack of the model in which the zirconium ion-containing liquid was absorbed in step (ii) is 1600 ° C or higher and 1710 ° C. It is good to heat it so that it becomes as follows. More preferably, it may be heated to 1662 ° C or higher and lower than 1710 ° C.

As described above, in order to melt only the vicinity of the crack, it is necessary to appropriately set the temperature of the heat treatment performed after the metal ion-containing liquid is absorbed by the crack of the modeled object. Here, a certain compound contained in the modeled object is referred to as a component X, and an inorganic oxide produced from a metal ion-containing liquid is referred to as a component Y. When the component X and the component Y are in the eutectic relationship shown in the phase diagram of _FIG . 3, the maximum temperature _TS that the vicinity of the crack of the modeled object reaches by the heat treatment in the step (iii) is TE ≤ _TS <. It is preferable to set it to T _m . More preferably, TE _≤ _TS <T _m- (T _m - _TE ) / 2. As a result, the vicinity of the crack can be selectively melted at a temperature sufficiently lower than the melting point _TA of the modeled object to repair the crack, so that the shape of the modeled object can be easily maintained.

The heating time does not matter as long as the vicinity of the crack reaches the above maximum temperature. For example, in the step (iii), the modeled object may be heated at a temperature at which the vicinity of the crack is desired to be reached. It is considered that by heating at such a temperature, the cracks and their vicinity are melted and moved in a direction in which the surface energy is reduced, so that the cracks are reduced or disappear. Then, as the heating further progresses, it is considered that the metal oxide diffuses into the crystalline / non-crystalline inside of the modeled product, and the crystal is recrystallized in a state containing the metal oxide component. It is presumed that such an action has the effect of increasing the mechanical strength of the modeled object, rather than simply filling the cracks with glass.

If heat treatment is performed at an appropriate temperature in the presence of metal ions on the surface constituting the crack of the modeled object, the vicinity of the crack melts as described above, which has the effect of reducing or extinguishing the crack. The concentration of the metal ion in the vicinity of the crack can be adjusted by adjusting the concentration of the metal ion in the metal ion-containing liquid, the method for causing the crack to absorb the metal ion-containing liquid, the number of times, and the like. The greater the amount of metal ions present in the crack, the easier it is to repair a wide range of cracks.

For example, in the case of a modeled product containing aluminum oxide (Al ₂ O ₃ ) as a main component, increasing the amount of zirconium oxide present in the vicinity of the crack makes it easier to melt the vicinity of the crack in a wider area. In order to selectively melt the vicinity of cracks and repair cracks, considering that the temperature of the eutectic point is about 1840 ° C, it is preferable to heat at a temperature of 1840 ° C or higher and 2070 ° C or lower, more preferably. It is 1850 ° C. or higher and 2060 ° C. or lower.

Further, in the case of a model formed from a powder containing Al ₂ O ₃ -Gd ₂ O ₃ as a main component, a phase containing Al ₂ O ₃ as a main component and a phase containing Gd AlO ₃ as a main component are included. .. Considering that the eutectic point of about 1662 ° C. is used in this model after absorbing the zirconium metal ion-containing liquid in the step (iii), the temperature of 1662 ° C. or higher and 1710 ° C. or lower in the step (iii). It is good to heat with. In the step (iii), the zirconium ion that has penetrated from the crack into the entire model becomes a metal oxide, and the metal oxide melts together with the compound component of the model, and the vicinity of the crack is selectively melted to repair the crack. do. Then, the metal oxide diffuses into the crystalline and amorphous interior and recrystallizes. As a result, the resulting ceramic article contains a three-phase eutectic of a phase containing ZrO ₂ as a main component, a phase containing Al ₂ O ₃ as a main component, and a phase containing GdAlO ₃ as a main component. At least formed. Further, when a powder of terbium oxide (Tb ₄ O ₇ ) is added as a sub-component to a powder containing Al ₂ O ₃ -Gd ₂ O ₃ as a component, the modeled product contains Al ₂ O ₃ as a main component. A phase and a phase containing (GdTb) AlO ₃ as a main component are included. In this case as well, cracks can be reduced or eliminated by heating at a temperature of 1662 ° C. or higher and 1710 ° C. or lower (step (iii)).

The model formed in step (i) contains a large amount of amorphous components because it is irradiated with an energy beam, melted, and then solidified by quenching. However, most of the amorphous components contained in the modeled product change to crystalline in the process of heat treatment in the step (iii). Further, as heating progresses, the metal ion oxide of the metal ion-containing liquid diffuses into the crystal of the model and recrystallizes, and two or more kinds of phases are formed in the model, so that the mechanical strength is high. Is obtained. From these viewpoints, in the step (iii), it is preferable to heat the modeled object for a certain period of time or longer. The holding time of the maximum temperature Ts in the step (iii) is preferably 1 minute or more, and more preferably 5 minutes or more in total. On the other hand, if the heat treatment time is too long, the grain size of the crystal grains constituting the ceramic model may become too large, resulting in a decrease in mechanical strength. Therefore, the holding time of the maximum temperature Ts in the step (iii) is preferably 2 hours or less in total, and more preferably 1 hour or less. More preferably, it is 30 minutes or less.

The heating method is not particularly limited. A ceramic model that has absorbed a metal ion-containing liquid may be heated by irradiating it with an energy beam, or it may be heated by placing it in an electric furnace. When heating with an energy beam, it is necessary to grasp in advance the relationship between the input heat amount of the energy beam and the temperature of the modeled object by thermoelectric pair or the like so that the modeled object is heated to the above-mentioned preferable temperature. Above all, an electric furnace or the like capable of adjusting the temperature lowering rate after heating is suitable because it can suppress the formation of new cracks.

When the step (ii) and the step (iii) are repeated, metal oxides generated from the metal ions contained in the metal ion-containing liquid are contained in the model each time unless cracks disappear from the model. Spread. Then, the difference in the concentration of the main component of the crystal grain becomes small between the vicinity of the crack of the modeled object and the portion other than the vicinity of the crack. As a result, the difference between the melting point (eutectic point) in the vicinity of the crack portion of the modeled object and the melting point in the portion other than the vicinity of the crack becomes small, and it becomes difficult to selectively melt the vicinity of the crack. From the viewpoint of melting only the vicinity of cracks, the difference in melting points is preferably 20 ° C. or higher, more preferably 30 ° C. or higher. For example, for a model formed from a powder containing aluminum oxide as a main component, if the zirconium oxide component in the model is less than 3 mol%, the shape change of the model is suppressed and only the vicinity of the crack is formed. It is preferable because it can be melted. More preferably, it is less than 2 mol%. More preferably, it is less than 1 mol%.

Ceramic articles having a small grain size and sufficiently reduced cracks that contribute to mechanical strength have particularly excellent mechanical strength. Such a ceramic article can be realized by shortening the integrated heating time required for reducing cracks (hereinafter referred to as integrated heating time) as much as possible and suppressing grain growth. In the present invention, the heat treatment time refers to the time maintained at the maximum temperature Ts in one step (iii) unless otherwise specified. Further, the integrated heating time refers to the time during which the step (iii) is maintained at the maximum temperature Ts in one heat treatment when the step (iii) is carried out only once, and the step (iii) is repeatedly carried out a predetermined number of times. In the case, it is assumed that the time held at the maximum temperature Ts is added up each time.

Further, when a powder composed of a plurality of kinds of materials such as a powder containing a main component and an auxiliary component such as an absorber is used, it is preferable that the integrated heating time in the step (iii) is short. A ceramic article having a phase-separated structure containing three or more kinds of phases including a phase of a main component and a phase of two kinds of composite compounds containing at least one kind of a metal element constituting the main component can be obtained. As will be described in detail later, a ceramic article having such a layer-separated structure has superior mechanical strength to a ceramic article composed of one type of phase or two types of phases.

(Ceramics article)
The ceramic article of the present invention is an article containing ceramics as a main component, which is manufactured by using the additive manufacturing technique, and can achieve both the free shape characteristic of the additive manufacturing technique and excellent mechanical strength. Among the additional manufacturing techniques, it is preferably manufactured by using a powder bed melt-bonding method or a directed energy lamination method.

Ceramic articles having particularly excellent mechanical strength are shaped by using a powder composed of a plurality of compounds of a main component and a sub component, and after absorbing a metal ion-containing liquid having an appropriate metal ion concentration, step (iii). It can be produced by shortening the integrated heating time according to the above. The obtained ceramic article having particularly excellent mechanical strength is a phase containing at least three types of a phase of a main component, a phase of two types of a composite compound containing at least one type of a metal element constituting the main component, and a phase of two types of a composite compound. It has a separated structure.

The main components of the ceramic article are preferably aluminum oxide, silicon oxide, mullite, cordylite and the like. Among them, aluminum oxide is widely used as a general-purpose ceramic article and has a relatively high thermal conductivity, so that it is suitable for an additional manufacturing technique of a direct molding method.

Hereinafter, a ceramic article containing aluminum oxide as a main component will be described as an example, but the technical idea of the present invention is not limited to the ceramic article containing aluminum oxide as a main component.

For example, when molded using aluminum oxide powder and powder containing gadolinium oxide powder that can form a eutectic with aluminum oxide as an auxiliary component, it is mainly composed of _{Al2O 3} _phase , _GdAlO3 phase _, and _Gd2O3 phase. The modeled object to be formed is formed.

When the metal ion-containing liquid is absorbed into this model and heat-treated, if the cumulative heating time is short, in addition to the Al ₂ O ₃ phase, Gd AlO ₃ phase, and Gd ₂ O ₃ phase, Gd ₄ Al ₂ O ₉ A ceramic article containing a phase and a phase derived from the metal ion of the metal ion-containing liquid can be formed. The Al ₂ O ₃ phase corresponds to the main component phase, and the GdAlO ₃ phase and the Gd ₄ Al ₂ O ₉ phase are two types of complex compound phases containing at least one metal element constituting the main component. Applicable. On the other hand, when the integrated heating time becomes long, the equilibration of the components and the expansion of the particle size progress, and the types of phases contained in the ceramic article are reduced from the initial stage of the heat treatment.

The ceramic article obtained by absorbing a metal ion-containing liquid containing zirconium ion in a model containing aluminum oxide as a main component is a ZrO2 phase having a fluorite structure as a metal ion _- derived phase of the metal ion-containing liquid. May include.

Since the ceramic article in which the crack is sufficiently repaired with a short integrated heating time contains three types of phases, it has better mechanical strength than the one with a long integrated heating time. It is considered that the reason why the ceramic article has excellent mechanical strength is the particle size of the crystal grains contained in the ceramic article and the existence of the phase composed of the composite compound.

As described above, if the cumulative heating time in the step (iii) is short, the heat treatment is completed before the coarse particles are formed. Therefore, the ceramic article is composed of a small particle size, and the particle size and the machine of the article are formed. There is a correlation with the target strength. The particle size preferable for obtaining a ceramic article having excellent mechanical strength is 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less.

Furthermore, since the ceramic article having a short integrated heating time contains three or more kinds of composite compounds, it is composed of a complicated phase separation structure composed of these multiple kinds of phases. In general, a compound compound containing a plurality of metal components often has higher toughness than a compound containing one type of metal component, and it is considered that such a complicated phase-separated structure also contributes to the improvement of mechanical strength. Be done.

It is believed that the complex compound is produced from the main component and subcomponents during the melting and solidification of step (i) and / or the heat treatment of step (iii). For example, when a powder containing gadolinium oxide powder as an auxiliary component is used as the main component of aluminum oxide powder, the above-mentioned GdAlO ₃ phase and Gd ₄ Al _2O ₉ phase correspond to the composite compound. It is considered that GdAlO ₃ is mainly produced by eutectic with Al ₂ O ₃ in the step (i). On the other hand, the Gd ₄ Al ₂ O ₉ phase is mainly composed of atoms between the Gd ₂ O ₃ phase, which is the undissolved raw material, and the Al ₂ O ₃ phase and the Gd AlO ₃ phase during the heat treatment of the step (iii). It is thought to be produced in the solid phase diffusion process. Therefore, when the integrated heating time in the step (iii) is long, the Gd ₄ Al ₂ O ₉ phase disappears and the phase composition of the ceramic article becomes an equilibrium state, but the mechanical strength decreases.

Therefore, in the case of a ceramic article formed from a powder containing a main component and an auxiliary component by an additional manufacturing technique, the mechanical strength obtained differs depending on the type of the main component, but the machine can be repaired by repairing cracks in a short integrated heating time. The target strength can be further enhanced.

Preferred combinations of main component and sub-component are Al ₂ O ₃ -Gd ₂ O ₃ , Al ₂ O ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Gd ₂ O ₃ -Tb ₄ O ₇ , Al ₂ O _3- GdAlO ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Pr ₆ O ₁₁ , Al ₂ O _{3-Gd 2 O 3-Pr 6 O 11, Al 2 O 3} _-GdAlO ₃ _-Pr ₆ _O ₁₁ _, _Al ₂ _O ₃ -Y ₂ O ₃ , Al ₂ O ₃ -YAlO ₃ , Al ₂ O ₃ -Y ₂ O ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -YAlO ₃ -Tb ₄ O ₇ , Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -Tb ₄ O ₇ , Al ₂ O ₃ -Y ₂ O ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -YAlO ₃ -Pr ₆ O ₁₁ , Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -Pr ₆ O ₁₁ , Al ₂ O ₃ -ZrO ₂ -Tb ₄ O ₇ , Al ₂ O ₃ -ZrO ₂ -Pr ₆ O ₁₁ , Al ₂ O ₃ -SiO, Al ₂ O ₃ -Gd ₂ O ₃ -SiO, Al ₂ O ₃ -GdAlO ₃ -SiO, Al ₂ O ₃ -Y ₂ O ₃ -SiO, Al ₂ O ₃ -YAlO ₃ -SiO, Al ₂ O ₃ -Y ₃ Al ₅ O ₁₂ -SiO, Al ₂ O _3- ZrO ₂ -SiO, SiO ₂ -Tb 4 O ₇ , SiO ₂ -Pr ₆ O ₁₁ , (MgO-Al ₂ O ₃ -SiO ₂ ) -Tb ₄ O ₇ , (MgO-Al ₂ O ₃ _- SiO ₂ )- Examples thereof include Pr ₆ O ₁₁ , (Al ₂ O ₃ -SiO ₂ ) -Tb ₄ O ₇ , and (Al ₂ O ₃ -SiO ₂ ) -Pr ₆ O ₁₁ . In the case of these combinations, a composite oxide is produced as a composite compound. From the viewpoint of making the phase separation structure more complicated, it is preferable that at least one of the complex compounds and the main component have a relationship capable of forming an eutectic. The notation Al ₂ O ₃ -Gd ₂ O ₃ indicates the main component on the left side of the hyphen and the sub component on the right side. In the notation (Al ₂ O ₃ -SiO ₂ ) -Tb ₄ O ₇ , the component enclosed in () indicates the main component, and the sub-component is indicated on the right side of the hyphen outside ().

In terms of improving the mechanical strength with a complicated phase separation structure, it is preferable that the number of types of phases contained in the ceramic article is large. Therefore, in addition to the three phases of the main component phase and the two complex compound phases containing at least one of the metal elements constituting the main component and at least one of the metal elements constituting the subcomponent, further. It is preferable to include another phase. The other phase may be a compound derived from the metal ion of the metal ion-containing liquid used in the step (ii). In this case, the compound derived from the metal ion preferably has a relationship capable of forming an eutectic with at least one of the main component and the two types of complex compounds, and more preferably has a relationship capable of forming an eutectic with the main component. preferable. The inclusion of another phase further complicates the phase separation structure of the ceramic article and improves the mechanical strength. Further, the presence of a certain amount or more of the metal oxide generated from the metal ions of the metal ion-containing liquid means that the cracks have been sufficiently repaired. On the other hand, if the amount of metal ion-derived components contained in the ceramic article is too large, the shape accuracy of the article tends to decrease. Therefore, the metal oxide generated from the metal ions of the metal ion-containing liquid in the ceramic article is preferably contained in an amount of 0.3 mol% or more and 5 mol% or less, more preferably 0.5 mol% or more and 3 mol% or less. Is.

The ceramic article according to the present invention can be easily produced by using a ceramic article manufacturing kit containing a powder containing ceramic as a main component and the above-mentioned metal ion-containing liquid containing water and metal ions. ..

First, the evaluation method in the present invention will be described.

<Analysis of components of metal ion-containing liquid>
The content of metal ions contained in the metal ion-containing liquid was measured by ICP-MS.

<Mechanical strength>
The mechanical strength of the article was evaluated by a three-point bending test based on R1601, which is a JIS standard for a room temperature bending strength test of fine ceramics. For 3-point bending strength, for each of the 5 test pieces, the maximum load when broken is P [N], the distance between external fulcrums is L [mm], and the width of the test piece is w [. mm], when the thickness of the test piece is t [mm]
3 × P × L / (2 × w × t2) (Equation 1)
Was calculated using the above, and the average value was used.

<Relative density>
The relative density [%] of the article was calculated by dividing the bulk density of the article (weight divided by volume) by the theoretical density. The theoretical density was calculated from the crystal structure. The crystal structure was identified by performing X-ray diffraction measurements and performing Rietveld analysis.

<Crystal structure>
The ceramic article was mirror-polished, and the crystal structure and composition of the phases constituting the ceramic article were investigated by X-ray diffraction, electron beam diffraction, SEM-EDX and TEM-EDX, and the phase separation structure was analyzed by SEM-EBSD.

Furthermore, SEM-EDX and EBSD were simultaneously analyzed at 10 different locations with a field size of 100 μm × 100 μm on the measurement surface, and mapping was performed for the composition and crystal phase. If a small phase is included, the composition and crystal structure can be analyzed in the same manner by using a transmission electron microscope (TEM).

For the grain size of the crystal grains constituting the phase, 300 or more crystal grains in the same phase observed on the measurement surface are observed using EBSD, and the median value of the equivalent circle diameter of each crystal grain is calculated. be able to.

<Composition analysis>
The content of Si, Tb, Pr, Al and Zr contained in powders, shaped objects or ceramic articles is measured by inductively coupled plasma emission spectrometry (ICP-AES), and the content of other elements is GDMS or ICP-. Measured by MS.

(Example 1)
Α-Al ₂ O ₃ powder with an average particle size of about 20 μm, Gd ₂ O ₃ powder with an average particle size of about 35 μm, and Tb ₂ O _3.5 powder (Tb ₄ O ₇ powder) with an average particle size of about 5 μm. The powders were prepared and weighed each powder so that the molar ratio was Al ₂ O ₃ : Gd ₂ O ₃ : Tb ₂ O _3.5 = 77.4: 20.8: 1.8. Each weighing powder was mixed with a dry ball mill for 30 minutes to obtain a mixed powder (raw material powder). The average particle diameter in the present invention is the median diameter, which is the particle diameter (D50) at which the cumulative frequency is 50%.

When the composition of the raw material powder was analyzed by ICP emission spectroscopic analysis, the content of zirconium oxide was less than 1 mol%.

Using the powder bed melt bonding method, 5 rectangular parallelepipeds of 5 mm × 42 mm × 6 mm were produced as shaped objects in the same manner as in the process shown in FIG. ProX DMP 100 (trade name) manufactured by 3D SYSTEMS, which is equipped with a 50 W fiber laser (beam diameter: 65 μm), was used to form the model.

Specifically, first, a first layer of 20 μm thick powder layer made of the raw material powder was formed on an alumina base 130 using a roller (FIGS. 1A and 1B). Next, a 30 W laser beam was scanned at a drawing speed of 140 mm / s and a drawing pitch of 100 μm. As shown in FIG. 4A, the powder is irradiated while scanning the laser beam so that the drawing line is at an angle of 45 degrees to each side of the rectangle, and the powder in the rectangular region of 5 mm × 42 mm is melted and solidified. The solidified portion 100 was formed (FIG. 1C).

Next, a powder layer having a thickness of 20 μm is newly formed by a roller so as to cover the solidified portion 100, and the powder layer is irradiated while scanning the laser beam to obtain the material powder in a rectangular region of 5 mm × 42 mm. It was melted and solidified to form a solidified portion 100 (FIGS. 1D and 1E). At this time, as shown in FIG. 4B, the laser was scanned in a direction orthogonal to the drawing line of the first layer to melt and solidify the powder. Such a process was repeated until the height of the solidified portion became 6 mm, and a modeled product having a size of 42 mm × 5 mm × 6 mm was produced.

When the surface of these shaped objects was observed with an optical microscope, the Ra of the unevenness on the surface of the shaped objects was 20 μm or less. The image of the optical microscope is shown in FIG. As can be seen from FIG. 5, cracks depending on the drawing direction of the laser beam were formed. That is, there were cracks extending in a direction at an angle of approximately 45 degrees to each side of the rectangle.

Each of the above-mentioned shaped objects was separated from the alumina base and processed into W40 mm × D4 mm × H3 mm for a three-point bending strength test by polishing. When the polished surface was observed by SEM, cracks having a width of several nm to several μm were formed depending on the drawing direction of the laser beam. That is, similar to the observation result with the optical microscope, grid-like cracks were formed in the direction of approximately 45 degrees to each side of the rectangle.

A metal ion-containing liquid containing zirconium ions was prepared as a metal ion-containing liquid as follows. Zirconium oxide has a eutectic relationship with aluminum oxide, which is the main component of the model.

Using zirconium acetate and water, mix the zirconium so that the concentration of zirconium is 30% by mass in terms of metal oxide and 58% by mass of water with respect to the liquid obtained by removing metal ions from the metal ion-containing liquid, and stir uniformly. A metal ion-containing liquid containing zirconium ions was obtained.

After immersing the above-mentioned model processed for testing in the metal ion-containing liquid containing zirconium ions in an atmosphere reduced to 400 Pa, the environment is returned to atmospheric pressure and left for 30 minutes to form the metal ion-containing solution. I let something absorb it.

Subsequently, the modeled object that had absorbed the metal ion-containing liquid containing zirconium ions was placed in an electric furnace and heated. The temperature was raised to 1680 ° C. in the air atmosphere for 2 hours, and the temperature was maintained at 1680 ° C. for 20 minutes, and then the energization was terminated and the mixture was cooled by natural cooling to obtain the ceramic article of Example 1. In Example 1, a cycle in which a heat treatment step (step (iii)) is performed once for each step (step ii) of absorbing a metal ion-containing liquid containing zirconium ions in each model. Was repeated twice to prepare five ceramic articles for a three-point bending strength test.

The dimensional accuracy of the manufactured ceramic article was evaluated. Specifically, the rate of change in the length of each side of the article obtained after the step (ii) and the length of each side of the modeled object before the step (iii) is dimensional accuracy (referred to as shape accuracy). In some cases). The dimensional accuracy of Example 1 was within 1% with respect to the dimensions (W40 mm × D4 mm × H3 mm) of the shaped object after polishing before performing the step (ii) and the step (iii). In addition, the ratio of the length of each side of the modeled object and the ceramic article is almost the same and has a similar shape, and bending of the modeled object and unevenness of the surface due to the steps (ii) and the process (iii) can be seen. There wasn't.

The average value of the relative density of ceramic articles was 95.6%.

When a 3-point bending test was performed on 5 ceramic articles 5 using a compression tester manufactured by Instron, the average value of the 3-point bending strength was 170 MPa.

Analysis of the ceramic articles used in the three-point bending test revealed that the phase consisted of Al ₂ O ₃ , the phase composed of Gd AlO ₃ , the phase composed of Gd ₄ Al ₂ O ₉ , the Gd ₂ O ₃ phase, and the oxidation of the fluorite structure. At least five types of phases containing zirconium as a main component were included. The main metal elements contained in the zirconium oxide-based phase of the fluorite structure were Zr, Gd, and Tb, and the metal elements other than Zr, Gd, and Tb were less than 1 mol%. In addition, the ratio of rare earth elements among the metal elements contained in the phase containing zirconium oxide as a main component of the fluorite structure was 30 mol% on average. There is no bias in the distribution of the phase containing zirconium oxide as the main component in the article, and it can be seen that zirconium oxide diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements. As a result, it is considered that a ceramic article having high mechanical strength was obtained. When the amount of Zr contained in the ceramic article was examined, the amount of Zr among the metal elements constituting the ceramic article of this example was 0.8 mol% in terms of _ZrO2 . It is considered that the ceramic article also contains a state in which Tb is solid-solved in the Gd site in the phase containing Gd as a constituent element. The same applies to the other examples.

(Example 2)

It contains zirconium acetate, water, and 2-hydroxyethyl acrylate as a stabilizer, the concentration of zirconium is 30% by mass in terms of zirconium oxide, and 47% by mass of water with respect to the liquid containing metal ions from which metal ions are removed. , 2-hydroxylethyl acrylate with respect to zirconium ion was mixed so as to be 30 mol%, and uniformly stirred to prepare a metal ion-containing liquid containing zirconium ion. Five ceramic articles were produced in the same manner as in Example 1 except that the metal ion-containing liquids used were different.

For the obtained ceramic article, the three-point bending strength, dimensional accuracy, relative density, and the crystal structure and composition of the phases constituting the ceramic article were analyzed in the same manner as in Example 1.

The evaluation results of the relative density and the three-point bending strength are shown in Table 1 together with the results of Example 1. The average value of the relative density was 95.8%, and the average value of the three-point bending strength was 172 MPa.

The dimensional accuracy of the ceramic article of Example 2 was also excellent at 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

Further, the ceramic article of Example 2 also had the same phase separation structure as that of Example 1. Specifically, 5 of a phase consisting of Al ₂ O ₃ , a phase consisting of Gd AlO ₃ , a phase consisting of Gd ₄ Al ₂ O ₉ , a Gd ₂ O ₃ phase, and a phase containing zirconium oxide having a fluorite structure as a main component. Included a variety of phases. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. It was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Example 3)
A metal ion-containing liquid having a zirconium ion concentration of 20% by mass, 29% by mass of water for a liquid obtained by removing metal ions from a metal ion-containing liquid, and 200 mol% of 2-hydroxylethyl acrylate with respect to zirconium ions was used. , Five ceramic articles were produced in the same manner as in Example 2, except that the cycle in which the step (iii) was carried out once and then the step (iii) was carried out once was repeated three times.

The evaluation results of the relative density and the three-point bending strength are shown in Table 1 together with the results of Example 1. The average value of the relative density was 96.0%, and the average value of the three-point bending strength was 164 MPa.

The dimensional accuracy of the ceramic article of Example 3 was also excellent at 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

Further, the ceramic article of Example 3 also had the same phase separation structure as that of Example 1. Specifically, 5 of a phase consisting of Al ₂ O ₃ , a phase consisting of Gd AlO ₃ , a phase consisting of Gd ₄ Al ₂ O ₉ , a Gd ₂ O ₃ phase, and a phase containing zirconium oxide having a fluorite structure as a main component. Included a variety of phases. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. It was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Example 4)
A metal ion-containing liquid having a zirconium ion concentration of 20% by mass, 13% by mass of water for a liquid obtained by removing metal ions from a metal ion-containing liquid, and 288 mol% of 2-hydroxylethyl acrylate for zirconium ions was used. , Five ceramic articles were produced in the same manner as in Example 2, except that the cycle in which the step (iii) was carried out once and then the step (iii) was carried out once was repeated three times.

The evaluation results of the relative density and the three-point bending strength are shown in Table 1 together with the results of Example 1. The average value of the relative density was 95.9%, and the average value of the three-point bending strength was 160 MPa.

The dimensional accuracy of the ceramic article of Example 4 was also excellent at 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

Further, the ceramic article of Example 4 also had the same phase separation structure as that of Example 1. Specifically, 5 of a phase consisting of Al ₂ O ₃ , a phase consisting of Gd AlO ₃ , a phase consisting of Gd ₄ Al ₂ O ₉ , a Gd ₂ O ₃ phase, and a phase containing zirconium oxide having a fluorite structure as a main component. Included a variety of phases. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. It was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Example 5)
A metal ion-containing liquid having a zirconium ion concentration of 44% by mass, 10% by mass of water for a liquid obtained by removing metal ions from a metal ion-containing liquid, and 30 mol% of 2-hydroxylethyl acrylate for zirconium ions was used. , Five ceramic articles were produced in the same manner as in Example 2, except that the cycle in which the step (iii) was carried out once and then the step (iii) was carried out once was repeated three times.

The evaluation results of the relative density and the three-point bending strength are shown in Table 1 together with the results of Example 1. The average value of the relative density was 96.2%, and the average value of the three-point bending strength was 163 MPa.

The dimensional accuracy of the ceramic article of Example 5 was also excellent at 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

Further, the ceramic article of Example 5 also had the same phase separation structure as that of Example 1. Specifically, 5 of a phase consisting of Al ₂ O ₃ , a phase consisting of Gd AlO ₃ , a phase consisting of Gd ₄ Al ₂ O ₉ , a Gd ₂ O ₃ phase, and a phase containing zirconium oxide having a fluorite structure as a main component. Included a variety of phases. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. It was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Example 6)
A metal ion-containing liquid having a zirconium ion concentration of 15% by mass and water of 29% by mass with respect to the liquid obtained by removing the metal ions from the metal ion-containing liquid was used. Further, 5 ceramic articles were produced in the same manner as in Example 1 except that the cycle in which the step (iii) was carried out once and then the step (iii) was carried out once was repeated four times.

When observed with an optical microscope each time the step (ii) and the step (iii) were repeated, cracks remained in the modeled object when three cycles were performed.

For the produced ceramic article, the three-point bending strength, dimensional accuracy, relative density, and the crystal structure and composition of the phases constituting the ceramic article were analyzed in the same manner as in Example 1. The average value of the relative density was 96.3%, and the average value of the three-point bending strength was 153 MPa. The evaluation results are shown in Table 1.

The ceramic article of Example 6 was also excellent in dimensional accuracy of 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

The ceramic article according to this embodiment also had a phase-separated structure. Specifically, it contained three types of phases: a phase composed of Al ₂ O ₃ , a phase composed of Gd AlO ₃ , and a phase having a fluorite structure containing zirconium oxide as a main component. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. Furthermore, it was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component in the article, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements. Was done. The phase consisting of Gd ₄ Al ₂ O ₉ was not included.

(Example 7)
Five ceramic articles were produced in the same manner as in Example 1 except that the holding time at 1680 ° C. in the step (iii) was set to 80 minutes.

The evaluation results of the relative density and the three-point bending strength are shown in Table 1 together with the results of Example 1. The average value of the relative density was 97.5%, and the average value of the three-point bending strength was 151 MPa.

The dimensional accuracy of the ceramic article of Example 7 was also excellent at 1% or less. Further, as in the case of the ceramic article of Example 1, the ratio of the lengths of the respective sides of the modeled object and the ceramic article is almost the same and has a similar shape, and the modeling by the step (ii) and the step (iii) is performed. No bending or surface irregularities were observed.

The ceramic article according to this embodiment also had a phase-separated structure. Specifically, it contained three types of phases: a phase composed of Al ₂ O ₃ , a phase composed of Gd AlO ₃ , and a phase having a fluorite structure containing zirconium oxide as a main component. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. Furthermore, it was confirmed that there was no bias in the distribution of the phase containing zirconium oxide as the main component in the article, and that the zirconium oxide component diffused from the cracks into the model and recrystallized as a phase-separated structure while incorporating rare earth elements. Was done. The phase consisting of Gd ₄ Al ₂ O ₉ was not included. Moreover, the average particle size of the crystal grains was as large as 80 μm.

(Example 8)
In this example, an article containing silicon dioxide as a main component was prepared.

Prepare SiO ₂ powder and Tb ₂ O _3.5 powder (Tb ₄ O ₇ powder) powder having an average particle diameter of about 38 μm, and the molar ratio is SiO ₂ : Tb ₂ O _3.5 = 98.2: 1.8. Each powder was weighed so as to be. The main component of SiO ₂ powder is cristobalite. Each weighing powder was mixed with a dry ball mill for 30 minutes to obtain a mixed powder. When the composition of the mixed powder was analyzed by ICP emission spectroscopic analysis, the content of zirconium oxide was less than 1% by mass.

Similar to Example 1, five 5 mm × 42 mm × 6 mm rectangular parallelepiped shaped objects were produced by the powder bed fusion bonding method. The modeling process is the same as in Example 1, except that the laser beam is scanned at an output of 47.5 W, a drawing speed of 60 mm / s, and a drawing pitch of 80 μm.

When the surface of the modeled object produced with an optical microscope was observed, the Ra of the unevenness on the surface of the modeled object was 30 μm or less. Similar to FIG. 5, cracks extending in a direction at an angle of approximately 45 degrees with respect to each side of the rectangle existed on the surface of the modeled object.

The modeled object was separated from the alumina base and processed into W40 mm x D4 mm x H3 mm by polishing for a three-point bending strength test. When the polished surface was observed by SEM, cracks having a width of several nm to several μm were formed depending on the drawing direction of the laser beam. Similar to the observation result with the optical microscope, the cracks extended in a direction at an angle of about 45 degrees with respect to each side of the rectangle and formed a grid pattern.

A metal ion-containing liquid containing zirconium ions similar to that in Example 1 was absorbed by the modeled object (step (ii)), placed in an electric furnace, and heated (step (iii)). In the step (iii), the temperature was raised to 1670 ° C. in 2 hours in the air atmosphere, the temperature was maintained at 1670 ° C. for 50 minutes, the energization was terminated, and the mixture was cooled by natural cooling. The cycle of performing the step (iii) once and then performing the step (iii) once was repeated twice.

When the dimensional accuracy of the obtained ceramic article was evaluated, it was within 1% with respect to the dimensions (W40 mm × D4 mm × H3 mm) of the shaped object after polishing before performing the step (ii) and the step (iii). rice field. In addition, the ratios of the lengths of the sides of the modeled object and the ceramic article were almost the same and had similar shapes, and no bending or surface irregularities due to the steps (ii) and the steps (iii) were observed. ..

The average value of the relative density was 82.4%, and the average value of the 3-point bending strength was 13 MPa.

Analysis of the phases contained in the ceramic article revealed that they contained three types of phases: a phase consisting of SiO ₂ , a phase consisting of Si ₂ Tb ₂ O ₇ , and a phase containing zirconium oxide having a fluorite structure as a main component. rice field. Further, SiO ₂ was cristobalite, and its proportion was 98% by mass.

(Example 9)
In this example as well, an article containing silicon dioxide as a main component was produced.

Prepare SiO ₂ powder, Al ₂ O ₃ powder, and SiO powder having an average particle diameter of 5 μm as an absorber, and the molar ratio is SiO ₂ : Al ₂ O ₃ : SiO = 66.5: 30.0: 3.5. Each powder was weighed so as to be. The main component of SiO ₂ powder is cristobalite. Each weighing powder was mixed with a dry ball mill for 30 minutes to obtain a mixed powder.

When the composition of the mixed powder was analyzed by ICP emission spectroscopic analysis, the content of zirconium oxide was less than 1% by mass. Next, a rectangular parallelepiped object of 5 mm × 42 mm × 6 mm was produced in the same manner as in Example 4, except that the laser beam was scanned at an output of 40 W, a drawing speed of 140 mm / s, and a drawing pitch of 110 μm.

When the surface of the produced model was observed with an optical microscope, the Ra of the unevenness on the surface of the model was 30 μm or less. Similar to FIG. 5, cracks extending in a direction at an angle of approximately 45 degrees to each side of the rectangle existed on the surface of the modeled object.

Each of the above-mentioned shaped objects was separated from the alumina base and polished to W40 mm × D4 mm × H3 mm for a three-point bending strength test. When the polished surface was observed by SEM, cracks having a width of several nm to several μm were formed depending on the drawing direction of the laser beam. Similar to the observation result with the optical microscope, the cracks extended in a direction at an angle of about 45 degrees with respect to each side of the rectangle and formed a grid pattern.

The modeled object was made to absorb the same metal ion-containing liquid containing zirconium ions as in Example 1 (step (ii)), and was placed in an electric furnace and heated (step (iii)). In the step (iii), the temperature was raised to 1680 ° C. in 2 hours in the air atmosphere, the temperature was maintained at 1680 ° C. for 20 minutes, the energization was terminated, and the mixture was cooled by natural cooling. The step (iii) and the step (iii) were carried out once each.

When the dimensional accuracy of the obtained ceramic article was evaluated, it was within 1%. In addition, the ratio of the length of each side of the modeled object and the ceramic article is almost the same and has a similar shape, and bending of the modeled object and unevenness of the surface due to the steps (ii) and the process (iii) can be seen. There wasn't.

The average value of the relative density was 85.0%, and the average value of the three-point bending strength was 58 MPa.

(Comparative Example 1)
In the same manner as in Example 1, five shaped objects of W40 mm × D4 mm × H3 mm were produced. When the surface of the modeled object was observed with an optical microscope, Ra of the unevenness on the surface of the modeled object was 20 μm or less.

In this comparative example, in producing a ceramic article, a step of absorbing a metal ion-containing liquid (step (ii)) and a step of heating a model impregnated with a metal ion-containing liquid containing zirconium ions (step (iii)). )) Was not carried out.

As for the model of Comparative Example 1, the crystal structure and composition of the phases constituting the three-point bending strength and the relative density model were evaluated in the same manner as in Example 1. The average value of the relative density was 94.4%, and the average value of the three-point bending strength was 18 MPa. Table 1 shows the evaluation results of the three-point bending strength and the relative density.

The ceramic article of Comparative Example 1 was composed of a phase composed of Al ₂ O ₃ , a phase composed of Gd AlO ₃ , and an amorphous phase having a fluctuating composition. Further, the article had cracks extending in a direction at an angle of approximately 45 degrees with respect to each side of the rectangle, depending on the drawing direction of the laser beam. The width of the crack was several nm to several μm.

(Comparative Example 2)
In the same manner as in Example 1, five W40 mm × D4 mm × H3 mm shaped objects were prepared, and when the surface of the shaped objects was observed with an optical microscope, the Ra of the unevenness on the surface of the shaped objects was 20 μm or less. ..

The modeled object was treated in the same manner as in Example 1 except that the step (step (ii)) of absorbing the metal ion-containing liquid into the obtained modeled object was not performed, and the product was subjected to a three-point bending strength test. Five ceramic articles of W40 mm × D4 mm × H3 mm were produced. As a step (iii), the temperature was raised to 1670 ° C. in 2.5 hours in an air atmosphere, the temperature was maintained at 1680 ° C. for 2 hours, the energization was terminated, and the step of cooling by natural cooling was repeated twice.

Similar to Example 1, for the ceramic article of Comparative Example 2, the three-point bending strength, the relative density, and the crystal structure and composition of the phases constituting the ceramic article were analyzed.

The average value of the relative density was 93.8%, and the average value of the three-point bending strength was 30 MPa.

The ceramic article of Comparative Example 2 was composed of two phases, a phase composed of Al ₂ O ₃ and a phase composed of Gd Al O ₃ . Further, in the ceramic article of Comparative Example 2, cracks extending in a direction at an angle of approximately 45 degrees with respect to each side of the rectangle remained depending on the drawing direction of the laser beam. The width of the crack was several nm to several μm.

(Comparative Example 3)
When five shaped objects of W40 mm × D4 mm × H3 mm were prepared in the same manner as in Example 1 and the surface of the modeled object was observed with an optical microscope, the Ra of the unevenness on the surface of the modeled object was 20 μm or less.

The metal ion-containing liquid was prepared as follows by using an organic solvent instead of water. A solution prepared by dissolving 85% by mass of zirconium butoxide (zirconium (IV) butoxide (hereinafter referred to as Zr (On-Bu) 4)) in 1-butanol was prepared. The solution of Zr (On-Bu) 4 was dissolved in 2-propanol (IPA), and ethyl acetoacetate (EAcAc) was added as a stabilizer. The molar ratio of each component was Zr (On-Bu) 4: IPA: EAcAc = 1.00: 2.95: 2.00. Then, by stirring at room temperature for about 3 hours, a zirconium ion-containing liquid having a zirconium ion concentration of 30% by mass in terms of zirconium oxide was prepared.

Five ceramic articles were produced in the same manner as in Example 1, except that a metal ion-containing liquid containing an organic solvent was used and the cycle of performing the step (ii) and the step (iii) was carried out three times. Unlike the first embodiment, the cycle of performing the steps (ii) and the step (iii) was carried out three times because cracks remained in the modeled object in the second time.

The obtained ceramic articles were evaluated for three-point bending strength, dimensional accuracy, and relative density in the same manner as in Example 1. The average value of the relative density was 95.2%, and the average value of the three-point bending strength was 164 MPa. The results are shown in Table 1.

The dimensional accuracy of the ceramic article of Comparative Example 3 was also excellent at 1% or less. Further, similarly to the ceramic article of Example 1, the modeled object and the ceramic article had similar shapes.

Furthermore, the crystal structure and composition of the phases constituting the ceramic article were analyzed.

The ceramic article of Comparative Example 3 had the same phase-separated structure as that of Example 1. That is, it was composed of three phases: a phase composed of Al ₂ O ₃ , a phase composed of Gd AlO ₃ , and a phase having a fluorite structure containing zirconium oxide as a main component. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb.

There was no bias in the distribution of the phase containing zirconium oxide as the main component, and the zirconium oxide component diffused from the cracks into the modeled object and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Comparative Example 4)
The point that the concentration of zirconium ion in the metal ion-containing liquid used in Comparative Example 3 was adjusted to 15% by mass in terms of zirconium oxide and used, and the point that the cycle of performing the step (ii) and the step (iii) was carried out five times. 5 ceramic articles were produced in the same manner as in Example 3. Unlike the third embodiment, the cycle of performing the step (ii) and the step (iii) was carried out five times because cracks remained in the modeled object after four times.

The obtained ceramic articles were evaluated for three-point bending strength, dimensional accuracy, and relative density in the same manner as in Example 1. The average value of the relative density was 96.5%, and the average value of the three-point bending strength was 145 MPa. The results of Example 1 are shown in Table 1. The dimensional accuracy of the ceramic article of Comparative Example 4 was excellent at 1% or less, and the modeled object and the ceramic article had similar shapes.

Further, when the crystal structure and composition of the phases constituting the ceramic article were analyzed, they had the same phase separation structure as in Example 1. That is, it contained three types of phases: a phase composed of Al ₂ O ₃ , a phase composed of Gd AlO ₃ , and a phase having a fluorite structure containing zirconium oxide as a main component. The main metal elements constituting the phase containing zirconium oxide as a main component of the fluorite structure were Zr, Gd, and Tb. It was also confirmed that the distribution of the phase containing zirconium oxide as a main component was not biased, and that the zirconium oxide component diffused from the crack portion into the modeled object and recrystallized as a phase-separated structure while incorporating rare earth elements.

(Comparative Example 5)
In the same manner as in Example 4, five W40 mm × D4 mm × H3 mm shaped objects were produced. When the surface of the modeled object was observed with an optical microscope, Ra of the unevenness on the surface of the modeled object was 30 μm or less.

In this comparative example, a step of absorbing the metal ion-containing liquid into the produced modeled object (step (iii)) and a step of heating the modeled object impregnated with the metal ion-containing liquid (step (iii)) are performed. Neither was carried out.

For the ceramic article of Comparative Example 5, the three-point bending strength, the relative density, and the crystal structure and composition of the phases constituting the model were evaluated in the same manner as in Example 1. The average value of the relative density was 80.3%, and the average value of the three-point bending strength was 4 MPa. Table 1 shows the evaluation results of the three-point bending strength and the relative density.

The ceramic article of Comparative Example 5 was composed of a phase made of SiO ₃ , a phase made of Si ₂ Tb ₂ O ₇ , and an amorphous phase having a fluctuating composition.

(Comparative Example 6)
In the same manner as in Example 5, five W40 mm × D4 mm × H3 mm shaped objects were produced. When the surface of the modeled object was observed with an optical microscope, Ra of the unevenness on the surface of the modeled object was 30 μm or less.

Neither the step of absorbing the metal ion-containing liquid into the produced model (step (iii)) nor the step of heating the model impregnated with the metal ion-containing liquid (step (iii)) was performed. ..

As for the model of Comparative Example 6, the crystal structure and composition of the phases constituting the three-point bending strength and the relative density model were evaluated in the same manner as in Example 1.

The average value of the relative density was 83.2%, and the average value of the 3-point bending strength was 8 MPa. Table 1 shows the evaluation results of the three-point bending strength and the relative density.

The ceramic article of Comparative Example 6 was composed of a phase made of SiO ₃ , a phase made of Si ₂ Tb ₂ O ₇ , and an amorphous phase having a fluctuating composition.

(Discussion)
From the results shown in Table 1, the following was found.
From the comparison between Example 1 and Comparative Example 3 and Example 6 and Comparative Example 4, by using a metal ion-containing liquid using water as a solvent, the number of steps (ii) and steps (iii) is small and the number of cracks in the modeled object is small. Can be reduced, and a larger three-point bending strength is obtained. From this, it was confirmed that the mechanical strength of the modeled product can be improved by using the metal ion-containing liquid according to the present invention with a smaller number of post-treatment steps.

Further, from the comparison between Example 1 and Example 6, when the concentration of zirconium ion in the metal ion-containing liquid is high, high mechanical strength can be obtained even if the number of steps (iii) and step (iv) is small. You can see that. Further, it can be seen that when the number of times the step (iii) is performed is large and the integrated heating time is long, the number of constituent phases decreases and the mechanical strength decreases. Further, from the comparison between Example 1 and Example 2, even if the concentration of zirconium ion in the metal ion-containing liquid is the same, the addition of the stabilizer increases both the relative density and the mechanical strength of the obtained article. You can see that. Further, from the comparison between Example 1 and Comparative Example 1 and Comparative Example 2, it can be seen that high mechanical strength cannot be obtained unless the step (ii) and the step (iii) are performed on the modeled object. Further, from the comparison between Example 1 and Example 7, if the firing temperature holding time in the step (iii) is long, the integrated heating time becomes long, the crystal grain size of the obtained article becomes large, and the mechanical strength may decrease. I understand.

The ceramic articles of Examples 8 and 9 containing silicon oxide as a main component had relative densities of 82.4% and 85.0%, respectively, which were porous. It is presumed that this is due to the high viscosity of the silicon oxide component when melted by laser irradiation, resulting in a porous state. Despite the fact that the produced model was porous, mechanical strength of 13 MPa and 58 MPa was obtained by using the metal ion-containing liquid of the present invention. On the other hand, in Comparative Examples 5 and 6 in which the step (iii) and the step (iv) were not carried out, the three-point bending strength was as low as 4 MPa and 8 Mpa.

As described above, by using the metal ion-containing liquid of the present invention, it is possible to improve the mechanical strength of the modeled product produced by the additive manufacturing technique while achieving high shape accuracy with a small number of post-treatment steps. can do. Then, it becomes possible to obtain a ceramic article having a high mechanical strength while having a complicated shape or a fine shape.

The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are attached in order to publicize the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2020-174679 filed on October 16, 2020 and Japanese Patent Application No. 2021-163593 submitted on October 4, 2021. All of the contents are incorporated here.

Claims

A method for manufacturing ceramic articles using additional manufacturing technology.
A process of irradiating a powder containing ceramics as a main component with an energy beam to solidify the powder to produce a model.
A step of causing the modeled object to absorb a metal ion-containing liquid containing water and metal ions,
The step of heating the modeled object that has absorbed the metal ion-containing liquid, and
A method for manufacturing a ceramic article, which comprises.
The method for producing a ceramic article according to claim 1, wherein the metal ion-containing liquid contains 10% by mass or more of water with respect to a liquid obtained by removing metal ions from the metal ion-containing liquid.
The method for producing a ceramic article according to claim 1 or 2, wherein the metal ion content of the metal ion-containing liquid is 10% by mass or more and 80% by mass or less in terms of metal oxide.
The method for producing a ceramic article according to claim 3, wherein the metal ion content of the metal ion-containing liquid is 30% by mass or more and 60% by mass or less in terms of metal oxide.
The invention according to any one of claims 1 to 4, wherein the metal ion-containing liquid further contains, as a stabilizer, any one selected from an organic acid, a surfactant, and a chelating agent. How to manufacture ceramic articles.
The method for producing a ceramic article according to claim 5, wherein the content of the stabilizer in the metal ion-containing liquid is 10 mol% or more and 300 mol% or less with respect to the metal ions.
The method for producing a ceramic article according to claim 6, wherein the content of the stabilizer in the metal ion-containing liquid is 50 mol% or more and 200 mol% or less with respect to the metal ions.
One of claims 1 to 7, wherein in the step of heating the model, the metal ion-containing liquid produces a metal oxide capable of forming a eutectic with the compound contained in the model. The method for manufacturing a ceramic article according to.
The method for producing a ceramic article according to claim 8, wherein the metal oxide can form a eutectic with the main component of the modeled product.
8. The method for manufacturing a ceramic article according to.
The method for producing a ceramic article according to any one of claims 1 to 10, wherein the modeled product contains aluminum oxide, and the metal ion-containing liquid contains zirconium ion or silicate ion as the metal ion. ..
The method for producing a ceramic article according to any one of claims 1 to 10, wherein the modeled product contains silicon oxide, and the metal ion-containing liquid contains zirconium ions or aluminum ions as the metal ions.
The method for producing a ceramic article according to any one of claims 1 to 12, wherein the modeled object further contains an oxide of a rare earth element.
The method for producing a ceramic article according to claim 13, wherein the oxide of the rare earth element is at least one selected from the group of gadolinium oxide, yttrium oxide, terbium oxide and praseodymium oxide.
The ceramic article according to any one of claims 1 to 14, wherein in the step of absorbing the metal ion-containing liquid, the metal ion-containing liquid is absorbed by the modeled object under a reduced atmosphere. Production method.
The method for manufacturing a ceramic article according to any one of claims 1 to 15, wherein the energy beam to be irradiated in manufacturing the modeled object is a laser beam or an electron beam.
The method for manufacturing a ceramic article according to any one of claims 1 to 16, wherein the step of absorbing the metal ion-containing liquid and the step of heating the modeled object are repeated a plurality of times.
A kit for manufacturing ceramic articles for manufacturing ceramic articles by additional manufacturing technology using an energy beam.
It contains a powder containing ceramics as the main component and a metal ion-containing liquid.
The metal ion-containing liquid contains water and metal ions, and contains water and metal ions.
A kit for manufacturing ceramic articles, wherein the metal ions can form a metal oxide that forms a eutectic with a compound contained in a ceramic model formed from a powder containing the ceramic as a main component.
The kit for manufacturing ceramic articles according to claim 18, wherein the metal ion-containing liquid contains 10% by mass or more of water with respect to a liquid obtained by removing metal ions from the metal ion-containing liquid.
The kit for manufacturing ceramic articles according to claim 18 or 19, wherein the metal ion content of the metal ion-containing liquid is 10% by mass or more and 80% by mass or less in terms of metal oxide.
The kit for manufacturing ceramic articles according to claim 20, wherein the metal ion content of the metal ion-containing liquid is 30% by mass or more and 60% by mass or less in terms of metal oxide.
The invention according to any one of claims 18 to 21, wherein the metal ion-containing liquid further contains, as a stabilizer, any one selected from an organic acid, a surfactant, and a chelating agent. Kit for manufacturing ceramic articles.
The kit for manufacturing ceramic articles according to claim 22, wherein the content of the stabilizer in the metal ion-containing liquid is 10 mol% or more and 300 mol% or less with respect to the metal ions.
The kit for manufacturing ceramic articles according to claim 23, wherein the content of the stabilizer in the metal ion-containing liquid is 50 mol% or more and 200 mol% or less with respect to the metal ions.
The kit for manufacturing a ceramic article according to any one of claims 18 to 24, wherein the metal ion produces the metal oxide by heat treatment.
The kit for manufacturing a ceramic article according to any one of claims 18 to 25, wherein the metal ion can form a metal oxide that forms a eutectic with the compound contained in the powder.
The kit for manufacturing ceramic articles according to claim 26, wherein the metal oxide can be eutectic with the main component of the powder.
One of claims 18 to 27, wherein the main component of the powder containing the ceramic as a main component is aluminum oxide, and the metal ion-containing liquid contains zirconium ion or silicate ion as the metal ion. Kit for manufacturing ceramic articles according to.
The invention according to any one of claims 18 to 27, wherein the main component of the powder containing the ceramic as a main component is silicon oxide, and the metal ion-containing liquid contains zirconium ion or aluminum ion as the metal ion. The described kit for manufacturing ceramic articles.
A metal ion-containing liquid used for repairing cracks contained in a ceramic model formed by additional manufacturing technology.
The metal ion-containing liquid contains water and metal ions, and the metal ions can form a metal oxide that forms a eutectic with a compound contained in the ceramic model. ..
The metal ion-containing liquid according to claim 30, wherein the metal ion-containing liquid contains 10% by mass or more of water with respect to the liquid obtained by removing the metal ions.
The metal ion-containing liquid according to claim 30 or 31, wherein the content of the metal ion is 10% by mass or more and 80% by mass or less in terms of metal oxide.
The metal ion-containing liquid according to claim 32, wherein the metal ion content is 30% by mass or more and 60% by mass or less in terms of metal oxide.
The metal ion-containing liquid according to any one of claims 30 to 33, further comprising any one selected from an organic acid, a surfactant, and a chelating agent as a stabilizer.
The metal ion-containing liquid according to claim 34, wherein the content of the stabilizer is 10 mol% or more and 300 mol% or less with respect to the metal ion.
The metal ion-containing liquid according to any one of claims 30 to 35, wherein the metal ion can form a metal oxide capable of forming a eutectic with the compound contained in the model.
The metal ion-containing liquid according to claim 36, wherein the metal ion can form a metal oxide capable of forming a eutectic with the main component of the ceramic model.
The invention according to any one of claims 30 to 37, which is used when the ceramic model contains aluminum oxide, and the metal ion-containing liquid contains zirconium ion or silicate ion as a metal ion. Metal ion-containing liquid.
The invention according to any one of claims 30 to 37, which is used when the main component of the ceramic model is silicon oxide, and the metal ion-containing liquid contains zirconium ions or aluminum ions as metal ions. The metal ion-containing liquid according to the above.