JP2010030798A - Translucent ceramic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive translucent ceramic which can be sintered at low temperature owing to its low melting point, has high relative density, has excellent transparency and is excellent in various thermal properties as well. <P>SOLUTION: The translucent ceramic is composed of a composite oxide as an oxide comprising Zn and Al or an oxide comprising Mg, Zn and Al, and the composite oxide is composed of a single crystal or polycrystal body, and also has a spinel type crystal structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a translucent ceramic made of a complex oxide having a spinel crystal structure.

  Generally, in a liquid crystal display device or the like, a liquid crystal is used by forming a protective layer on the surface for the purpose of protecting the surface from dirt and outside air. When the liquid crystal is used for a CRT or the like, a transparent plastic is used as such a protective layer, and the object is achieved. Further, since protection of a liquid crystal screen in a mobile phone or the like requires strength, glass or the like may be used as such a protective layer.

  Recently, by forming a transparent protective layer (transparent substrate) on the front and back of such a liquid crystal screen, its surface is made transparent (this structure is called a liquid crystal panel), and light is emitted from one of the liquid crystal panels. A liquid crystal projector in which transmitted light is adjusted with a contact lens or the like is commercially available. The transparent substrate for protecting the liquid crystal screen in such a liquid crystal projector not only simply protects the liquid crystal screen from dirt and outside air, but also adiabatic protection to prevent the liquid crystal screen from being heated by a nearby light source, and It is required to have a heat dissipation purpose of dissipating the temperature rise caused by the endothermic phenomenon generated in the liquid crystal screen by the light from the light source. And since this transparent substrate itself also heats up, such a transparent substrate is also required to have heat resistance.

  Therefore, it is conceivable to use glass as the transparent substrate in such applications, and it has been proposed to use single crystal sapphire in which the thermal conductivity of ordinary glass is improved by about 20 to 30 times ( Patent Document 1). Since such single crystal sapphire has high strength and is extremely hard compared to quartz glass, a merit that a transparent substrate can be made thin is also expected. Moreover, since such single crystal sapphire is very expensive, it is economically difficult to use it alone, but it is said that this problem can be solved by using it together with glass.

  As described above, the single crystal sapphire has been expected to be used because it has various properties required for a transparent substrate for a liquid crystal projector, such as heat resistance and light transmittance, and suppressing temperature rise of the liquid crystal, though it is expensive. . However, since single crystal sapphire has the property of birefringence, it requires complicated work such as aligning the crystal axis orientation when assembling a liquid crystal projector, which reduces the production efficiency and the single crystal sapphire itself is expensive. In combination with this, there was a problem of increasing the manufacturing cost.

In order to solve this problem, various substances suitable for a transparent substrate material that does not have birefringence and are inexpensive have been studied. As one of such substances, spinel ceramics, which are translucent ceramics, have been proposed. (Patent Document 2). This spinel ceramic is a cubic ceramic represented by the chemical formula MgAl ₂ O ₄ and has a high thermal conductivity and is a transparent material.

However, such a spinel ceramic has a characteristic that the melting point is as high as 2140 ° C. and is difficult to sinter. For this reason, when this spinel ceramic was sintered at a relatively low temperature, there was a problem that pores remained and the film was not transparent. In order to solve this problem, reducing the residual pores and promoting the densification has a problem in that the manufacturing cost is increased, for example, a high sintering temperature is required and the power consumption of the furnace is increased.
JP 2000-284700 A JP 2007-065696 A

  The present invention has been made in view of the current situation as described above, and the object is to have a low melting point, so that sintering at low temperature is possible, and the relative density is high and the transparency is excellent. Another object of the present invention is to provide an inexpensive translucent ceramic excellent in various thermal characteristics.

  The present inventor examined various ceramics having a spinel crystal structure in order to solve the above-mentioned problems, and a series of ceramics containing Zn has a low melting point, so that the sintering temperature can be lowered. The knowledge that a sintered body having a high relative density can be obtained at low cost was obtained, and the present invention was finally completed by further study based on this knowledge.

  That is, the translucent ceramic of the present invention is composed of a composite oxide that is an oxide containing Zn and Al or an oxide containing Mg, Zn, and Al. Alternatively, it is a polycrystal and has a spinel crystal structure.

Here, the composite oxide is preferably represented by the chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0 <x ≦ 1), more preferably the chemical formula Mg _(1-x) Zn _x Al. ₂ O is indicated by ₄ (where 0.2 ≦ x ≦ 1), more preferably represented by the chemical formula _{Mg (1-x) Zn x} Al 2 O 4 ( provided that 0.8 ≦ x ≦ 1).

  Moreover, it is preferable that the said translucent ceramic does not contain 2nd phases other than the said complex oxide, and it is preferable that it is a sintered compact.

  On the other hand, the present invention also relates to an optical element for a color liquid crystal projector using the above-described translucent ceramics, and also relates to a color liquid crystal projector using the optical element.

  Furthermore, the present invention also relates to a manufacturing method for manufacturing the above translucent ceramic, which includes a preparation step of preparing a raw material powder containing at least one element constituting the composite oxide, and the raw material A molding process for obtaining a molded body by molding powder, a sintering process for obtaining a sintered body by sintering the molded body, and a translucent ceramic by hot isostatic pressing the sintered body And a hot isostatic pressing step to complete the process.

  Another manufacturing method according to the present invention includes a hydroxide powder preparation step of preparing a hydroxide powder as a raw material powder containing at least one element constituting the composite oxide, and the hydroxide powder. A temporary molding step for obtaining a temporary molded body by molding, a heating step for obtaining a heated temporary molded body by heating the temporary molded body, and a hot forged body by hot forging the heated temporary molded body. A hot forging step to obtain, a sintering step to obtain a sintered body by sintering the hot forged body, and a hot to complete a translucent ceramic by hot isostatic pressing the sintered body A hydrostatic pressure pressing step.

  Since the translucent ceramic of the present invention has a low melting point, it can be sintered at a low temperature, has a high relative density and excellent transparency, is excellent in various thermal characteristics, and is inexpensive. Has an effect.

Hereinafter, the present invention will be described in more detail.
<Translucent ceramics>
The translucent ceramic of the present invention comprises a composite oxide that is an oxide containing Zn and Al or an oxide containing Mg, Zn and Al, and the composite oxide is a single crystal or a polycrystal. It is a crystal and has a spinel crystal structure. Thus, the translucent ceramics of this invention may be produced as a single crystal, and may be produced as a polycrystal. However, the crystal structure needs to be a spinel crystal structure. By having such a crystal structure, it is possible to achieve the effect of becoming a transparent material without birefringence.

Here, the spinel crystal structure means that the spinel (MgAl ₂ O ₄ ) has the same crystal structure as the spinel, although the chemical composition is different. It is known that such a spinel crystal structure is represented by a complex oxide represented by a chemical formula of AB ₂ O ₄ (where A is a divalent element and B is a trivalent element).

  The term “translucency” as used in the present invention means that it is substantially transparent. For example, when the thickness of the translucent ceramic of the present invention is 1 mm, light in a wavelength region of 420 to 680 nm is used. A case where the linear transmittance is 85% or more. As described above, the translucent ceramic of the present invention is excellent in transparency, which is considered to be brought about by sufficiently eliminating pores and residual pores in the composite oxide. For this reason, it is preferable that the translucent ceramics of this invention are 99% or more of relative density (what displayed the density with respect to the theoretical value of the said complex oxide in%).

  As described above, the translucent ceramic of the present invention is excellent in transparency and also in various thermal characteristics such as heat resistance, heat insulation and heat dissipation. In addition, the translucent ceramic of the present invention exhibits a characteristic that it is optically isotropic. Each of the excellent characteristics as described above is advantageously shown when the translucent ceramic is a sintered body. Therefore, the translucent ceramic of the present invention is preferably a sintered body.

<Composite oxide>
The composite oxide constituting the translucent ceramic of the present invention is preferably represented by the chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0 <x ≦ 1), more preferably the chemical formula Mg _{(1 -x)} Zn _x Al ₂ O ₄ (where 0.2 ≦ x ≦ 1), more preferably the chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0.8 ≦ x ≦ 1) It is a composite oxide shown.

As described above, spinel (MgAl ₂ O ₄ ) is expected as a transparent material such as a transparent substrate of a liquid crystal projector, but since its melting point is high, the sintering temperature is also high, and thus low sintering. It was difficult to produce a material having high transparency at temperature. Therefore, by dissolving Zn in this spinel, the melting point is lowered, thereby making it possible to sinter at a relatively low sintering temperature, and manufacturing a highly transparent ceramic at low cost. It is the translucent ceramics of this invention. Incidentally, the melting point of ZnAl ₂ O ₄ (x = 1 in the above chemical formula) in which Mg in the spinel is substantially replaced with Zn is 1960 ° C., which is almost 200 ° C. lower than the melting point of spinel 2140 ° C. . Thus, since the composite oxide of the present invention has a low melting point, the sintering temperature can be set low, which is very advantageous. In the composite oxide, Mg and Zn can maintain a spinel crystal structure at any composition ratio, and the crystal structure of ZnAl ₂ O ₄ is also a spinel crystal structure. Such a spinel crystal structure can be confirmed by powder X-ray diffraction or the like.

Here, x in the chemical formula is such that 0 <x ≦ 1, but the lower limit is more preferably 0.2 or more, and further preferably 0.8 or more. When x is less than 0.2, the melting point is relatively small and the effect of lowering the sintering temperature is small. When Zn is dissolved in MgAl ₂ O ₄ , the thermal conductivity tends to decrease. The decrease in thermal conductivity increases when x is in the range of 0.2 to 0.6. However, when it exceeds 0.8, the thermal conductivity tends to be higher than that of MgAl ₂ O ₄ . The thermal conductivity of ZnAl ₂ O ₄ is the largest in this solid solution system. If it exceeds 0.8, the melting point is remarkably lowered and the effect of lowering the sintering temperature is increased. Therefore, x is preferably 0.8 to 1.0.

In addition, although the translucent ceramics of this invention consist of the said complex oxide, it is preferable not to contain 2nd phases other than such complex oxide especially. This is because such a second phase has a refractive index different from the refractive index of the spinel crystal structure, and thus light scattering occurs at the interface between the two, thereby reducing transparency. For example, when Ti is contained in ZnAl ₂ O ₄ , the melting point decreases to about 1600 ° C. at maximum, and it becomes very easy to sinter, but MgTiO ₃ co-deposits as the second phase to inhibit transparency. Become.

<Coating layer>
The translucent ceramic of this invention can form a coating layer on the surface. Such a coating layer is particularly preferable when it is made of a material having a refractive index lower than that of the light-transmitting ceramic because the light transmittance is good (that is, the transparency is improved). Such a coating layer may be a single layer or a plurality of layers. However, when the coating layer is a combination of two or more layers selected from metal fluorides and metal oxides, translucent ceramics are used. Adhesiveness is good and environmental stability is excellent.

In the case where the coating layer is formed as a multilayer as described above, examples of the metal oxide include SiO ₂ , TiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , Ta ₂ O ₅ , ZrO _2, etc. Examples of the metal fluoride include MgF ₂ , YF ₃ , LaF ₃ , CeF ₃ , BaF _{2 and the} like.

  Such a coating layer is preferably formed by alternately laminating about 2 to 20 layers made of metal oxide and layers made of metal fluoride. The thickness of such a coating layer is usually preferably 5 μm or less.

  Such a coating layer is preferably formed by a physical vapor deposition method (PVD method), and can be performed by a known sputtering method, ion plating method, vacuum vapor deposition method or the like. In particular, it is preferable to use ion assist and plasma assist together because the film performance is improved.

<Application>
Since the translucent ceramics of the present invention have the characteristics as described above, they satisfy the physical properties required for ordinary optical lenses. Since the translucent ceramic of the present invention is optically isotropic in particular, it can be assembled without worrying about the crystal axis orientation when assembling a liquid crystal panel. It is useful to use as an optical element (that is, a transparent substrate). Further, since the translucent ceramic of the present invention has good transparency (light transmissibility), the heat absorption by the light from the light source is small, so that the temperature rise of the liquid crystal can be dissipated. It is useful to use it as an optical element for a projector (that is, a transparent substrate). The present invention also relates to a color liquid crystal projector using such an optical element.

<Manufacturing method>
The production method for producing the translucent ceramic of the present invention comprises a preparation step of preparing a raw material powder containing at least one element constituting the composite oxide, and a molding for obtaining a molded body by molding the raw material powder. A sintering process for obtaining a sintered body by sintering the formed body, and a hot isostatic pressing for completing a translucent ceramic by hot isostatic pressing (HIP) of the sintered body And a process.

Here, the preparation step is not particularly limited, and any method can be adopted as long as it is a preparation method capable of obtaining such raw material powder. As the raw material powder, one type or two or more types can be used. The chemical composition of such raw material powder is not particularly limited, but it is preferable to use an oxide containing at least one element constituting the composite oxide. For example, it is possible to use a mixed powder obtained by blending MgO powder as required to ZnO powder and Al ₂ O ₃ powder. The compounding ratio in this case is preferably compounded so as to be the stoichiometric composition of the finally produced composite oxide. Moreover, it is preferable that the average particle diameter of such raw material powder shall be 1 micrometer or less.

  Next, the molding step is not particularly limited, and any method can be adopted as long as such a molded body can be obtained. In addition, the magnitude | size and shape of the molded object obtained are not specifically limited.

Subsequently, the sintering step can be performed at a relatively low temperature that is about 300 to 400 ° C. lower than the melting point of the target composite oxide. During sintering, on the molded body, it is preferable to put an oxide powder of zinc, such as ZnO and ZnAl ₂ O _4. Since zinc in the spinel structure is easily sublimated, it is highly effective in preventing zinc sublimation from the surface of the molded body by covering with zinc-containing powder.

  Next, in the hot isostatic pressing process, the pressure medium is not particularly limited, but it is preferable to use an industrially available inert gas. In general, the temperature is set to a temperature slightly higher than the sintering temperature, whereby the closed pores contained during the sintering are crushed and the translucency is improved.

  Then, after annealing at a temperature of about 1000 ° C. and cooling to room temperature, the translucent ceramic of the present invention can be manufactured.

  Thus, by finally performing a hot isostatic pressing (HIP) step, pores and residual pores in the composite oxide are sufficiently eliminated, and translucency (linear transmittance of light in the wavelength region of 420 to 680 nm). ) Will be dramatically improved. Therefore, hot isostatic pressing is extremely important in the present invention. The hot isostatic pressing process of the present invention includes annealing and cooling operations as described above.

  In addition, when an oxide is used as the raw material powder, it can be manufactured by the above-described manufacturing method. However, when a cheaper hydroxide is used as the raw material powder, it is preferable to employ the following manufacturing method. . That is, another manufacturing method according to the present invention includes a hydroxide powder preparation step of preparing a hydroxide powder as a raw material powder containing at least one element constituting the composite oxide, and the hydroxide powder. A temporary molding step for obtaining a temporary molded body by molding, a heating step for obtaining a heated temporary molded body by heating the temporary molded body, and a hot forged body by hot forging the heated temporary molded body. A hot forging step to obtain, a sintering step to obtain a sintered body by sintering the hot forged body, and a hot to complete a translucent ceramic by hot isostatic pressing the sintered body And a hydrostatic pressure pressing step.

Thus, when using hydroxide powder as raw material powder, it is preferable to shape | mold by hot forging. When the hydroxide powder compact is sintered as it is, a large volume shrinkage occurs when the hydroxide is converted to oxide at a temperature of about 400 ° C. or higher, and the relative density is lower than that at room temperature. As the knotting begins, it becomes difficult to densify. Therefore, after temporarily forming the hydroxide powder, it is heated at 400 ° C. or higher in an atmospheric furnace different from the sintering furnace, and this heated temporary molded body is loaded into a forging die that has been heated to about 400 ° C. in advance. Then, hot forging is performed at a pressure of several thousand kg / cm ² , which is a pressure much higher than the molding pressure of normal ceramics. By overheating in the atmospheric furnace, the hydroxide is converted into an oxide, and forging is performed at a high pressure at the same temperature, thereby forming a molded body having a higher relative density.

Here, the hydroxide powder preparation step is not particularly limited, and any method can be adopted as long as it is a preparation method capable of obtaining such hydroxide powder. For example, a mixed powder in which Mg (OH) ₂ powder is blended with Zn (OH) ₂ powder and Al (OH) ₃ powder as required can be used. The compounding ratio in this case is preferably compounded so as to be the stoichiometric composition of the finally produced composite oxide. Moreover, it is preferable that the average particle diameter of such a hydroxide powder shall be 1 micrometer or less.

  Next, the temporary molding step is a step of molding the hydroxide powder, but the size and shape of the temporary molded body to be obtained are not particularly limited.

  Then, the said heating process is a process of heating the said temporary molded object at the temperature of about 400-700 degreeC, and obtaining a heated temporary molded object, The said hot forging process hot-forges this heated temporary molded object. It is a process to do.

  In addition, the conditions similar to the conditions already demonstrated above can be employ | adopted for the sintering process and hot isostatic pressing process performed after that.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
The translucent ceramics described in Table 1 were produced as follows.

(A) an average particle diameter in preparation process raw material powder was prepared MgO powder, ZnO powder and Al ₂ O ₃ powder is 0.3μm, respectively. These powders were blended at the molar ratios shown in Table 1 (the powders that did not contain the corresponding powder were described as “none” and the molar ratio was “0”). This molar ratio is consistent with the stoichiometric composition of the finally obtained translucent ceramic (in Table 1, “x” in the chemical formula is expressed as “x in the chemical formula” in the section of the HIP body. did). The raw material powder used has a purity of 99.99% or more.

(B) Molding step A molded body (diameter 20 mm, thickness 5 mm) was produced by molding the raw material powder blended above at a pressure of 250 kg / cm ² .

(C) Sintering Step The molded body produced above was loaded on the bottom of a carbon crucible, and ZnAl ₂ O ₄ powder was loaded thereon so that the molded body was completely hidden. This was loaded into a sintering furnace and sintered at the sintering temperature described in Table 1 in an air atmosphere and atmospheric pressure for 2 hours to obtain a sintered body.

(D) Hot isostatic pressing step The sintered body obtained above was heated in argon gas at a temperature of 800 ° C./hour up to the temperature (HIP temperature) shown in Table 1, and 1 under each pressure shown in Table 1. A hot isostatic pressing process was performed by maintaining the time. Then, it annealed at 1000 degreeC for 24 hours, and annealed at the cooling rate of 0.5 degree-C / min to room temperature. Then, translucent ceramics (thickness 1mm) were manufactured by grind | polishing the surface. In Table 1, sample no. 1 to 5 are translucent ceramics of the present invention. 6-7 are the translucent ceramics of a comparative example. Whether or not the crystal structure of the generated phase of the translucent ceramic was “spinel type” was confirmed by powder X-ray diffraction, and “spinel” was indicated for those having “spinel crystal structure”.

<Example 2>
The translucent ceramics described in Table 2 were produced as follows.

(E) Hydroxide powder preparation step Mg (OH) ₂ powder, Zn (OH) ₂ powder, and Al (OH) ₃ powder each having an average particle diameter of 0.3 μm were prepared as raw material powders. These powders were blended in the molar ratios shown in Table 2 (the powders not containing the corresponding powders were described as “none” and the molar ratio was “0”). This molar ratio is consistent with the stoichiometric composition of the finally obtained translucent ceramic (in Table 2, “x” in the above chemical formula is expressed as “x in the chemical formula” in the section of the HIP body. did). The raw material powder used has a purity of 99.99% or more.

(F) Temporary molding process The raw material powder mix | blended above was shape | molded by the pressure of 50 kg / cm < ² >, and the temporary molded object (diameter 20mm, thickness 5mm) was produced.

(G) Heating process The temporary molded object produced above was heated at 700 degreeC with the tubular atmospheric furnace, and the heated temporary molded object was obtained by hold | maintaining for 15 minutes at the temperature.

(H) Hot forging step The heated temporary molded body obtained above was loaded into a mold of a 100-ton hot forging device. This mold was previously heated to 400 ° C. using a heater built in the mold. And this hot temporary compact was hot forged at a pressure of 9000 kg / cm ² to obtain a hot forged body.

(I) Sintering process The hot forging body obtained above was sintered like the (c) sintering process of Example 1, and the sintered compact was obtained.

(J) Hot isostatic pressing process The sintered body obtained above was subjected to hot isostatic pressing in the same manner as the (d) hot isostatic pressing process of Example 1. Then, it annealed at 1000 degreeC for 24 hours, and annealed at the cooling rate of 0.5 degree-C / min to room temperature. Then, translucent ceramics (thickness 1mm) were manufactured by grind | polishing the surface. In Table 2, sample no. Nos. 11 to 13 are translucent ceramics of the present invention. 14 is a translucent ceramic of a comparative example. Whether or not the crystal structure of the generated phase of the translucent ceramic was “spinel type” was confirmed by powder X-ray diffraction, and “spinel” was indicated for those having “spinel crystal structure”.

<Evaluation>
(1) Relative density Relative density of the molded body (temporary molded body), sintered body, and HIP body (translucent ceramic) of Examples 1 and 2 above (the density relative to the theoretical value of the composite oxide is expressed in%). Are measured by the Archimedes method, and the results are shown in Tables 1 and 2.

(2) Linear transmittance Each translucent ceramic obtained in Examples 1 and 2 was subjected to mirror polishing using diamond slurry, and the linear transmittance (thickness 1 mm) was measured with a spectrophotometer. As a result, the linear transmittance at a wavelength of 420 nm to 680 nm was lowest at 420 nm, and thus the linear transmittance at 420 nm was measured for each translucent ceramic. The results are shown in Tables 1 and 2.

(3) Thermal conductivity A test piece having a diameter of 10 mm was cut out from each of the translucent ceramics (thickness 1 mm) obtained in Examples 1 and 2 above, and the thermal conductivity at room temperature was measured by a laser flash method. The results are shown in Tables 1 and 2.

  As can be seen from Tables 1 and 2, the translucent ceramic of the present invention is the same as the translucent ceramic of the comparative example, although it is sintered at a low temperature (that is, can be manufactured at low cost). In comparison, the relative density was high and the linear transmittance was also high.

When x was 1.0, that is, the composition was ZnAl ₂ O ₄ , the thermal conductivity was higher than that of MgAl ₂ O ₄ . Therefore, the translucent ceramic of the present invention has an excellent effect of having a high relative density and excellent transparency even when sintered at a relatively low temperature, and having excellent thermal characteristics and low cost depending on the composition. Was confirmed.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (10)

A translucent ceramic made of a composite oxide which is an oxide containing Zn and Al or an oxide containing Mg, Zn and Al,
The composite oxide is a light-transmitting ceramic that is a single crystal or a polycrystal and has a spinel crystal structure. The translucent ceramic according to claim 1, wherein the composite oxide is represented by a chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0 <x ≦ 1). The translucent ceramics according to claim 1, wherein the composite oxide is represented by a chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0.2 ≦ x ≦ 1). The translucent ceramic according to claim 1, wherein the composite oxide is represented by a chemical formula Mg _(1-x) Zn _x Al ₂ O ₄ (where 0.8 ≦ x ≦ 1).   The translucent ceramic according to claim 1, wherein the translucent ceramic does not include a second phase other than the composite oxide.   The translucent ceramic according to claim 1, wherein the translucent ceramic is a sintered body.   The optical element for color liquid crystal projectors using the translucent ceramics in any one of Claims 1-6.   A color liquid crystal projector using the optical element according to claim 7. It is a manufacturing method which manufactures the translucent ceramics in any one of Claims 1-6,
Preparing a raw material powder containing at least one element constituting the composite oxide;
A molding step of obtaining a molded body by molding the raw material powder;
A sintering step of obtaining a sintered body by sintering the molded body;
A hot isostatic pressing step of completing the translucent ceramic by hot isostatic pressing the sintered body;
The manufacturing method which manufactures translucent ceramics containing this. It is a manufacturing method which manufactures the translucent ceramics in any one of Claims 1-6,
A hydroxide powder preparation step of preparing a hydroxide powder as a raw material powder containing at least one element constituting the composite oxide;
A temporary molding step of obtaining a temporary molded body by molding the hydroxide powder;
A heating step of obtaining a heated temporary molded body by heating the temporary molded body;
A hot forging step of obtaining a hot forged body by hot forging the heated temporary molded body;
A sintering step of obtaining a sintered body by sintering the hot forged body;
A hot isostatic pressing step of completing the translucent ceramic by hot isostatic pressing the sintered body;
The manufacturing method which manufactures translucent ceramics containing this.