Sintered body and method for producing the same

Abstract

To provide at least one of a sintered body having zirconia as a matrix and exhibiting a color tone visually recognized as a bright yellow not tinged with green or orange and a manufacturing method thereof.SOLUTION: A sintered body according to the present invention contains vanadium and terbium and has zirconia as a matrix, with a mass ratio of vanadium to terbium being 0.12 or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a sintered body having vanadium and terbium and using yellow zirconia as a matrix (base material). In particular, it relates to a sintered body having a strength suitable as an exterior member such as a decorative member and using yellow zirconia as a matrix.

Background Art

[0002] A sintered body using zirconia as a matrix exhibits arbitrary colors by containing a lanthanoid rare earth element or a transition metal element as a coloring element. Since the sintered body using zirconia as a matrix contains a coloring element, in addition to the original high-class feeling and mechanical strength of zirconia, the design property is enhanced, and zirconia sintered bodies exhibiting yellow-based color tones have been studied (for example, Patent Documents 1 to 4).

[0003] For example, as a sintered body using yellow zirconia as a matrix, a sintered body using zirconia containing a Zr—Si—V composite oxide, a Zr—Si—Pr composite oxide, or holmium oxide as a colorant has been reported (Patent Document 1). The sintered body disclosed in Patent Document 1 was yellow with a green tint and pale yellow.

[0004] Also, it has been disclosed that a sintered body using zirconia containing an iron compound as a matrix exhibits yellow (Patent Documents 2 and 3). The sintered bodies disclosed in Patent Documents 2 and 3 were yellow with an orange tint.

[0005] Furthermore, a sintered body using zirconia containing praseodymium oxide and having translucency composed of cubic crystals as a matrix has been reported (Patent Document 4). The sintered body disclosed in Patent Document 4 was yellow with a green tint.

[0006] All of the sintered bodies using zirconia as a matrix reported in the patent documents exhibit yellow-based color tones. However, these color tones were yellow with a green or orange tint, and were color tones in which a color other than yellow was mixed with yellow. [Prior Art Documents] [Patent Documents]

[0007] [Patent Document 1] (Japanese) Unexamined Patent Application Publication No. 2011-020873 [Patent Document 2] (Japanese) Unexamined Patent Application Publication No. 2013-049616 [Patent Document 3] (Japanese) Unexamined Patent Application Publication No. 2008-050246 [Patent Document 4] (Japanese) Unexamined Patent Application Publication No. 2012-096977 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] An object of the present disclosure is to provide at least one of a sintered body and a method for producing the same, which has zirconia as a matrix and exhibits a vivid yellow color tone that does not have green and orange hues. [Means for Solving the Problems]

[0009] In the present disclosure, in a sintered body having zirconia exhibiting yellow as a matrix, suppression of color development other than yellow was examined. As a result, it has been found that by containing a specific element among innumerable coloring elements at a specific ratio, a sintered body exhibiting a color tone visually recognized as vivid yellow without green and orange hues can be obtained.

[0010] That is, the present invention is as defined in the claims, and the gist of the present disclosure is as follows. [1] A sintered body containing vanadium and terbium and having zirconia as a matrix, wherein the mass ratio of vanadium to terbium is 0.12 or more. [2] The sintered body according to [1] above, wherein the content of vanadium is 0.010% by mass or more and 0.20% by mass or less based on the mass of the sintered body. [3] The sintered body according to [1] or [2] above, wherein the content of the terbium is 0.050% by mass or more and 0.60% by mass or less based on the mass of the sintered body. [4] The sintered body according to any one of [1] to [3] above, containing aluminum. [5] The sintered body according to [4] above, wherein the content of the aluminum is 0.10% by mass or more and 15% by mass or less based on the mass of the sintered body. [6] The sintered body according to any one of [1] to [5] above, wherein the zirconia is zirconia containing a stabilizing element. [7] The sintered body according to [6] above, wherein the stabilizing element is one or more selected from the group consisting of yttrium, magnesium, and calcium. [8] The sintered body according to [6] or [7] above, wherein the content of the stabilizing element of the zirconia is 1.0 mol% or more and 6.0 mol% or less. [9] L * a * b * Lightness L in the color system * , Hue a * and Hue b * satisfy the following, the sintered body according to any one of [1] to [8] above. Lightness L * : 80 ≦ L * ≦ 100 Hue a * : -3 ≦ a * ≦ 4, and, Hue b * : 30 < b * ≦ 50

[10] L * a * b * Chroma C in the color system * and Hue angle h satisfy the following, the sintered body according to any one of [1] to [9] above. Chroma C * : 28 ≦ C * ≦ 44, and Hue angle h: 83° < h ≦ 96°

[11] The sintered body according to any one of [1] to

[10] above, wherein the average crystal grain size is 0.2 μm or more and 2 μm or less.

[12] The sintered body according to any one of [1] to

[11] above, having a three-point bending strength of 900 MPa or more.

[13] A method for producing a sintered body according to any one of [1] to

[12] above, characterized by using a composition having zirconia as a matrix, containing 0.010% by mass or more and 0.20% by mass or less of vanadium, 0.050% by mass or more and 0.60% by mass or less of terbium, and having a mass ratio of vanadium to terbium of 0.12 or more.

[14] The method for producing a sintered body according to

[13] above, wherein the composition contains 0.10% by mass or more and 15% by mass or less of aluminum.

[15] A composition having zirconia as a matrix, containing 0.010% by mass or more and 0.20% by mass or less of vanadium, 0.050% by mass or more and 0.60% by mass or less of terbium, and having a mass ratio of vanadium to terbium of 0.12 or more.

[16] The composition according to

[15] above, containing 0.10% by mass or more and 15% by mass or less of aluminum.

[17] A member including the sintered body according to any one of [1] to

[12] above.

Advantages of the Invention

[0011] According to the present disclosure, at least one of a sintered body and a method for producing the same can be provided, which has zirconia as a matrix and exhibits a vivid yellow color tone that is not tinged with green or orange.

Embodiments for Carrying Out the Invention

[0012] An example of an embodiment of the sintered body of the present disclosure will be shown and described. The terms in this embodiment are as shown below.

[0013] A "sintered body" is a composition having a definite shape composed of crystal particles, and is a composition in a state heat-treated at a temperature equal to or higher than the sintering temperature. A "zirconia sintered body" is a sintered body essentially composed of zirconia, or more precisely, a sintered body having zirconia as a matrix (base material). A "colored zirconia sintered body" is a zirconia sintered body containing a coloring element.

[0014] A "stabilizing element" is an element having a function of stabilizing the crystal phase of zirconia by solid-solution in zirconia.

[0015] A "coloring element" is an element having a function of coloring zirconia.

[0016] A "composition" is a substance having a definite composition, and examples include one or more selected from the group consisting of powders, granules, compacts, green compacts, and sintered bodies. A "zirconia composition" is a composition essentially composed of zirconia, or more precisely, a composition having zirconia as a matrix (base material).

[0017] A "powder" is an aggregate of a plurality of powder particles and is a composition having fluidity. A "zirconia powder" is a powder essentially composed of zirconia, or more precisely, a powder having zirconia as a matrix (base material). A "powder composition" is a composition composed of a plurality of powders, and in particular, is a composition in a state where a compound, which is a precursor of a coloring element, and zirconia powder are uniformly mixed, and is a composition having fluidity.

[0018] A "compact" is a composition having a definite shape composed of powder particles aggregated by physical force, and in particular, is a composition in a state where heat treatment has not been performed after imparting the shape (for example, after molding). A "zirconia compact" is a compact essentially composed of zirconia, or more precisely, a compact having zirconia as a matrix (base material). Also, a compact is used interchangeably with a "press-compacted body".

[0019] "Color tone" refers to the CIE L * a * b * represented by the colorimetric system (CIE 1976 (L * a * b * ) color space), measured by black background measurement under the following conditions using a spectrophotometer (e.g., CM-700d, manufactured by Konica Minolta Inc.) equipped with an illumination and light-receiving optical system compliant with the geometric condition c of JIS Z 8722 for a measurement sample with a thickness of 1 mm and a surface roughness (Ra) ≤ 0.02 μm * , chromaticity a * and b * . Light source: D65 light source Viewing angle: 10° Measurement diameter: 8 mm Measurement method: SCI Measurement background: black plate

[0020] "Chroma" is one of the indicators indicating the vividness of the color tone, and is a value obtained from chromaticity a * and b * by the following formula. C * =(a *2 +b *2 ) 0.5

[0021] In the above formula, C * is the chroma, and a * and b * are chromaticity a * and b * , respectively.

[0022] "Hue angle" is one of the indicators indicating the hue, and is a value obtained from chromaticity a * excluding lightness L * and b * by the following formula. h = tan -1 (b * / a * )

[0023] In the above formula, h is the hue angle, and a *and b * are chromaticity a * and b * respectively. When the hue angle is 0°, it shows the color rendering of red. When the hue angle is 90°, it shows the color rendering of yellow. When the hue angle is 180°, it shows the color rendering of green. When the hue angle is 270°, it shows the color rendering of blue.

[0024] The "three-point bending strength" is the value obtained by a three-point bending test in accordance with JIS R1601. The measurement of the three-point bending strength should be carried out using a column-shaped sample with a distance between supports of 30 mm, a width of 4 mm, and a thickness of 3 mm. The average value of 10 measurements can be used as the three-point bending strength.

[0025] The "average crystal grain size" is obtained by the planimetric method using SEM observation images. That is, draw a circle with a known area on the SEM observation image, measure the number of crystal grains (Nc) inside the circle and the number of crystal grains (Ni) on the circumference of the circle, and after making the total number of crystal grains (Nc + Ni) be 125 ± 25, the average crystal grain size can be obtained using the following formula. Average crystal grain size = (Nc + (1 / 2)×Ni) / (A / M 2 )

[0026] In the above formula, Nc is the number of crystal grains inside the circle, Ni is the number of crystal grains on the circumference of the circle, A is the area of the circle, and M is the magnification of scanning electron microscope observation (for example, 5,000 - 10,000 times). If the number of crystal grains (Nc + Ni) in one SEM observation image is less than 100, (Nc + Ni) can be made 125 ± 25 using multiple SEM observation images.

[0027] For the sintered body used for SEM observation, a sintered body with a surface roughness of Ra ≦ 0.02 μm that has been subjected to thermal etching treatment (for example, treatment at 1300°C - 1500°C in the atmosphere) can be used.

[0028] The "measured density" is the ratio of the volume measured by the Archimedes method to the mass measured by mass measurement (g / cm 3 ).

[0029] The "BET specific surface area" may be measured by the BET multipoint method (five points) using nitrogen as the adsorption gas in accordance with JIS R 1626. The following conditions can be exemplified as specific measurement conditions for the BET specific surface area. Adsorption medium: N 2 Adsorption temperature: -196 °C Pretreatment conditions: Degassing treatment in an air atmosphere at 250 °C for 1 hour or more

[0030] The BET specific surface area can be measured using a general device (for example, TriStar II 3020, manufactured by Shimadzu Corporation).

[0031] The "average particle diameter" is D50 in the volume particle diameter distribution of a powder or powder composition measured by the wet method, and can be measured using a general device (for example, MT3300EXII, manufactured by Microtrac·BEL Corporation). As the measurement sample, a powder obtained by removing slow aggregation by a dispersion treatment such as ultrasonic treatment and dispersed in pure water to form a slurry may be used. It is preferable to measure the volume particle diameter distribution by the wet method with the slurry adjusted to pH = 3.0 to 6.0.

[0032] "Atmospheric pressure sintering" is a method of sintering by heating a sintered object (such as a compact or a green body) without applying an external force during sintering. The "sintering temperature" is the highest temperature reached during sintering, and the "sintering time" is the time for maintaining the sintering temperature.

[0033] This embodiment is a sintered body containing vanadium and terbium and having zirconia as a matrix, characterized in that the mass ratio of vanadium to terbium is 0.12 or more.

[0034] The sintered body of this embodiment is a sintered body having zirconia, preferably zirconia containing a stabilizing element, as a matrix, and is mainly composed of crystal particles of zirconia.

[0035] The stabilizing element is preferably one or more selected from the group consisting of yttrium, magnesium, and calcium, and more preferably yttrium. Yttrium, magnesium, and calcium function as stabilizing elements with little influence on the color tone of zirconia.

[0036] The content of the stabilizing element (hereinafter, the content of the stabilizing element is also referred to as the "amount of stabilizing element", and when the stabilizing element is yttrium or the like, it is also referred to as the "amount of yttrium" or the like) is preferably 1.0 mol% or more or 1.5 mol% or more, and 6.0 mol% or less or 5.0 mol% or less.

[0037] When the stabilizing element is yttrium, the amount of yttrium is preferably 2.0 mol% or more, 2.3 mol% or more, or 2.6 mol% or more, and 6.0 mol% or less, 5.0 mol% or less, or 3.4 mol% or less.

[0038] The amount of stabilizing element [mol%] is the molar ratio of the stabilizing element in terms of oxide to the total of zirconium in terms of zirconia and the stabilizing element in terms of oxide in the sintered body. For example, when the stabilizing element is yttrium, the amount of yttrium [mol%] is the molar ratio [mol%] of yttrium in terms of Y 2 2O3 to the total of zirconium in terms of ZrO 2 2 and yttrium in terms of Y 2 2O 3 3, and is obtained from {Y 2 2O 3 3[mol] / (ZrO 2 2+Y 3 2O 2 3)[mol]}×100. The conversion of the stabilizing element to oxide is exemplified by yttrium being Y 2 2O 3 3, magnesium being MgO, and calcium being CaO. 2 2O 3 3

[0039] The sintered body of the present embodiment contains vanadium and terbium, and the mass ratio of vanadium to terbium (hereinafter also referred to as "V / Tb ratio") is 0.12 or more. 4 O 7 V per converted mass of terbium 2 O 5 is the converted mass of vanadium, V 2 O 5 [g] / Tb 4 O 7 [g] can be calculated.

[0040] The V / Tb ratio is 0.12 or more, more preferably 0.15 or more, and 0.80 or less, 0.70 or less, or 0.60 or less. When the V / Tb ratio satisfies this range, a sintered body exhibiting a bright yellow color without green or orange tinges can be obtained. When the V / Tb ratio is less than 0.12, the obtained sintered body tends to exhibit an orange color tone. On the other hand, when the V / Tb ratio is 0.80 or less, the obtained sintered body exhibits a color tone that is visually recognized as yellow.

[0041] The sintered body of this embodiment has a V 2 O 5 It is preferable that the vanadium content is 0.010 mass % or more or 0.020 mass % or more and 0.20 mass % or less or 0.15 mass % or less, calculated as vanadium content.

[0042] In this embodiment, the mass of the sintered body is the total mass [g] of the metal elements contained in the sintered body converted into oxides. For example, the mass of a sintered body containing vanadium, terbium, and aluminum and having a matrix of zirconia containing yttrium is ZrO 2 Converted mass of zirconium [g], Y 2 O 3 Converted mass of yttrium [g], V 2 O 5 Converted mass of vanadium [g], Tb 4 O 7 The converted mass of terbium [g] and Al 2 O3 It is the total mass [g] obtained by summing the mass [g] of the converted aluminum.

[0043] The sintered body of the present embodiment contains terbium in an amount of 0.050 mass% or more or 0.070 mass% or more, and 0.60 mass% or less or 0.50 mass% or less in terms of Tb 4 O 7 with respect to the mass of the sintered body, and preferably contains terbium.

[0044] The sintered body of the present embodiment contains aluminum in an amount of 0.10 mass% or more or 0.20 mass% or more, and 15 mass% or less, 12 mass% or less, or 10 mass% or less in terms of Al 2 O 3 with respect to the mass of the sintered body, and preferably contains aluminum. By the content of aluminum being within the above range, the sintered body contains crystal particles of alumina.

[0045] In the sintered body of the present embodiment, each of the elements vanadium, terbium, and aluminum functions as a coloring element. The state of existence of these elements in the sintered body is arbitrary, but examples include oxides containing one or more selected from the group of vanadium, terbium, and aluminum. Vanadium oxide (V 2 O 5 ), terbium oxide (Tb 4 O 7 ), and alumina (Al 2 O 3 ) as the oxide of aluminum can be exemplified. Further, vanadium, terbium, and aluminum may each be in a state of being dissolved in zirconia containing a stabilizing element at least partially.

[0046] The sintered body of the present embodiment preferably comprises, in addition to crystal particles of zirconia containing a stabilizing element, crystal particles of alumina (Al 2 O 3 ), and crystal particles of an oxide containing at least one of vanadium and terbium.

[0047] The sintered body of the present embodiment may contain impurities as long as they do not affect the color tone, and examples of the impurities include hafnia (HfO 2 ). The content of hafnia as an unavoidable impurity varies greatly depending on the raw ore and the manufacturing method, but for example, it can be exemplified as 2.0% by mass or less. In the present embodiment, for the calculation of values related to the composition such as the calculation of the mass of the sintered body, it may be calculated by regarding hafnia as zirconia (ZrO 2 ).

[0048] However, it is preferable that the sintered body does not contain impurities that affect the color tone. Examples of the impurities that affect the color tone include at least one selected from the group consisting of tin, zinc, lead, chromium, and cadmium, and the content of each of these impurities is preferably 500 ppm by mass or less, more preferably 100 ppm by mass or less.

[0049] The average crystal grain size of the sintered body of the present embodiment is 0.2 μm or more or 0.5 μm or more, and 2 μm or less or 1 μm or less. When the average crystal grain size is 2 μm or less, the sintered body has sufficient strength to be used as a member such as a decorative article.

[0050] The crystal structure of zirconia in the sintered body of the present embodiment includes tetragonal crystal, and it is preferable that the main phase of the crystal structure is tetragonal crystal. Further, the zirconia crystal structure of the sintered body of the present embodiment may be a mixed crystal of tetragonal crystal and cubic crystal. Tetragonal crystal is a crystal structure having optical anisotropy. By including tetragonal crystal, light is easily reflected, so that the color tone of the sintered body loses transparency. Furthermore, since the main phase of the zirconia crystal structure is tetragonal crystal, the sintered body of the present embodiment has high strength.

[0051] The measured density of the sintered body of the present embodiment is 5.70 g / cm 3 or more or 6.00 g / cm 3 or more, and 6.10 g / cm 3 or less or 6.07 g / cm 3 or less can be exemplified.

[0052] The sintered body of this embodiment has a three-point bending strength of 800 MPa or more, 900 MPa or more, or 1000 MPa or more, and is 1600 MPa or less, 1500 MPa or less, or 1400 MPa or less. When the three-point bending strength is within the above range, it has a strength that can be moderately processed, and moreover, it has a strength that can be used for main applications that require aesthetic properties, such as exterior members and decorative members.

[0053] The color tone of the sintered body of this embodiment is L * a * b * In the lightness L * , chromaticity a * and chromaticity b * in the color system, it is preferably satisfied as follows. Lightness L * : 80 ≦ L * ≦ 100, preferably 83 ≦ L * ≦ 95 Chromaticity a * : -3 ≦ a * ≦ 4, preferably -2 ≦ a * ≦ 3, and Chromaticity b * : 30 < b * ≦ 50, preferably 35 ≦ b * ≦ 45 The sintered body of this embodiment does not satisfy any of the above lightness L * , chromaticity a * or chromaticity b * , but by satisfying the above-mentioned lightness L * , chromaticity a * and chromaticity b * , it exhibits a vivid yellow color tone without green and orange hues.

[0054] The chroma (C * ) of the sintered body of this embodiment can be exemplified as 28 or more, 29 or more, or 30 or more, and also 44 or less, 43 or less, or 42 or less.

[0055] The hue angle (h) of the sintered body of this embodiment is preferably more than 83°, 84° or more, or 85° or more, and 96° or less, less than 96°, or 95° or less. By satisfying this range of the hue angle, a color tone that does not have a green or orange tint and is visually recognized as yellow is exhibited.

[0056] As a preferable sintered body of this embodiment, a sintered body having a chroma (C * ) of 28 or more, 29 or more, or 30 or more, and 44 or less, 43 or less, or 42 or less, and a hue angle (h) of more than 83°, 84° or more, or 85° or more, and 96° or less, less than 96°, or 95° or less, and having zirconia as a matrix can be mentioned.

[0057] The sintered body of this embodiment can be applied not only to various decorative members such as jewelry, watch parts, and exterior parts of portable electronic devices, but also to the uses of conventional zirconia sintered bodies such as structural materials, optical materials, and dental materials.

[0058] Next, the manufacturing method of the sintered body of this embodiment will be described.

[0059] The sintered body of this embodiment can be manufactured by a method for manufacturing a sintered body, which is characterized by using a composition having zirconia as a matrix and containing 0.010% by mass or more and 0.20% by mass or less of vanadium, 0.050% by mass or more and 0.60% by mass or less of terbium, and a mass ratio of vanadium to terbium of 0.12 or more.

[0060] The composition is preferably one or more selected from the group of powder compositions, compacts, and green compacts, preferably at least one of the powder composition and the compact, and more preferably the powder composition.

[0061] The powder composition may be a composition in which a vanadium compound, a terbium compound, and a powder having zirconia as a matrix are uniformly mixed.

[0062] The vanadium compound may be a compound or salt containing vanadium(V), and is preferably at least one selected from the group consisting of vanadium(V) oxide 2 O 5 ), ammonium vanadate, vanadium hydroxide, vanadium nitrate, and vanadium chloride, and more preferably vanadium oxide.

[0063] The terbium compound may be a compound or salt containing terbium (Tb), and is preferably at least one selected from the group consisting of terbium(III) oxide (Tb 4 O 7 ), terbium acetate, terbium hydroxide, terbium nitrate, and terbium chloride, and more preferably terbium(III) oxide.

[0064] In this embodiment, the mass of the composition is the total mass [g] of the metal elements contained in the composition in terms of oxide. For example, in a sintered body containing vanadium, terbium, and aluminum and having yttrium-containing zirconia as a matrix, the mass of the composition is the mass [g] of zirconium in terms of ZrO 2 , the mass [g] of yttrium in terms of Y 2 O 3 , the mass [g] of vanadium in terms of V 2 O 5 , the mass [g] of terbium in terms of Tb 4 O 7 , and the mass [g] of aluminum in terms of Al 2 O 3 , which is the total mass [g].

[0065] The content of the vanadium compound is 0.010% by mass or more or 0.020% by mass or more, and 0.20% by mass or less or 0.15% by mass or less in terms of vanadium(V) oxide 2 O 5 ) with respect to the mass of the composition.

[0066] The content of the terbium compound is 0.010% by mass or more or 0.020% by mass or more, and 0.20% by mass or less or 0.15% by mass or less in terms of terbium(III) oxide (Tb 4 O 7)It may be 0.050 mass% or more or 0.070 mass% or more in terms of conversion, and 0.60 mass% or less or 0.50 mass% or less.

[0067] The mass ratio of vanadium to terbium in the composition is, in terms of Tb 4 O 7 the mass of vanadium converted in terms of the mass of terbium, and V 2 O 5 the mass of vanadium converted. The mass ratio of vanadium to terbium in the composition is preferably 0.12 or more or 0.15 or more, and 0.80 or less, 0.70 or less, or 0.60 or less.

[0068] The composition may contain an aluminum compound. The aluminum compound may be any compound or salt containing aluminum (Al), preferably a compound or salt that is alumina (Al 2 O 3 ) or an aluminum compound that is a precursor thereof. It is preferably one or more selected from the group consisting of alumina, aluminum hydroxide, aluminum nitrate, and aluminum chloride, more preferably alumina, and even more preferably α-alumina.

[0069] The content of the aluminum compound is 0.10 mass% or more or 0.20 mass% or more in terms of aluminum oxide (Al 2 O 3 ) conversion based on the mass of the composition, and may be 15 mass% or less, 12 mass% or less, or 10 mass% or less.

[0070] The powder having zirconia as a matrix is preferably zirconia containing a stabilizing element, more preferably zirconia containing yttrium as a stabilizing element, and even more preferably zirconia containing yttrium in a state where a zirconia sol containing yttria has been heat-treated. In the present embodiment, the "zirconia sol" is a sol in which zirconium dioxide is hydrated and crosslinked, and is preferably a zirconia sol obtained by at least one of a hydrothermal synthesis method and a hydrolysis method, and more preferably a zirconia sol obtained by a hydrolysis method.

[0071] The powder having zirconia containing yttrium as a matrix may be a mixed powder containing two or more selected from the group consisting of yttria powder, a powder having zirconia containing yttrium as a matrix, and a powder having zirconia not containing a stabilizing element as a matrix. Further, it may be a mixed powder containing two or more powders having zirconia containing yttrium as a matrix and different yttrium concentrations.

[0072] The amount of the stabilizing element is preferably 1.0 mol% or more or 1.5 mol% or more, and 6.0 mol% or less or 5.0 mol% or less.

[0073] When the stabilizing element is yttrium, the amount of yttrium is preferably 2.0 mol% or more, 2.3 mol% or more or 2.6 mol% or more, and 6.0 mol% or less, 5.0 mol% or less or 3.4 mol% or less.

[0074] The composition can be obtained, for example, by mixing powders with a matrix of an aluminum compound, a vanadium compound, a terbium compound, and zirconia in any manner (hereinafter also referred to as the "mixing step"). Further, it may be a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound, a vanadium compound, a terbium compound, and yttrium in any manner, or a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound, a vanadium compound, and a terbium compound and powders with a matrix of zirconia containing yttrium in any manner, or a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound and vanadium, a terbium compound, and powders with a matrix of zirconia containing yttrium in any manner, or a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound and vanadium, a terbium-containing zirconia matrix powder, and powders with a matrix of zirconia containing yttrium in any manner, or a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound, vanadium, and yttrium, and a terbium compound in any manner, or a composition obtained by mixing an aluminum compound, a vanadium compound, and powders with a matrix of zirconia containing terbium and yttrium in any manner, and also a composition obtained by mixing powders with a matrix of zirconia containing an aluminum compound, vanadium, and yttrium, and powders with a matrix of zirconia containing terbium and yttrium in any manner. As a preferred production method, there may be mentioned mixing powders with a matrix of zirconia containing an aluminum compound, a vanadium compound, a terbium compound, and yttrium in any manner.

[0075] In the production method of the present embodiment, the mixing method may be any method as long as the compound, which is a precursor of the coloring element, and the zirconia powder are uniformly mixed. At least either dry mixing or wet mixing can be exemplified, and wet mixing is preferred.

[0076] The BET specific surface area of the powder with zirconia as the matrix is 5 m 2 / g or more and 20 m 2 / g or less is preferable. In the amount of the stabilizing element of the composition, by satisfying the BET specific surface area within this range, the sintered body obtained by the composition is likely to have a strength that can be used for main applications such as exterior members and decorative members.

[0077] The average particle size of the powder composition of this embodiment is preferably 0.3 μm or more and 0.7 μm or less.

[0078] The molded body is in a state where the powder composition is molded. The molded body may have an arbitrary shape in consideration of shrinkage due to sintering. The shape of the molded body may be an arbitrary shape according to the application, and at least one selected from the group of disc shape, column shape, polyhedron shape, columnar shape, plate shape, spherical shape, and substantially spherical shape can be exemplified.

[0079] The molded body can be obtained by molding the composition by a known method, for example, at least one selected from the group of uniaxial pressing, cold isostatic pressing, slip casting, and injection molding.

[0080] By sintering the molded body, a sintered body is obtained. The sintering method is arbitrary, and known sintering methods such as atmospheric pressure sintering and hot pressing can be mentioned. For simplicity, the sintering method is preferably atmospheric pressure sintering, and more preferably atmospheric pressure sintering in an air atmosphere. Note that the atmospheric pressure sintering in this embodiment is a method of sintering by simply heating the object to be sintered without applying an external force during sintering. In the case of atmospheric pressure sintering, it can be exemplified that the holding temperature exceeds 1300 °C and is 1600 °C or less, preferably 1400 °C or more and 1550 °C or less, and the holding time is 1 hour or more and 5 hours or less, preferably 2 hours or more and 4 hours or less. It is preferable not to hold at a specific temperature in the temperature range of 1300 °C or less during heating, for example, the holding time in the temperature range of 1300 °C or less is preferably 30 minutes or less.

[0081] In the case of atmospheric pressure sintering, it can be exemplified that the holding temperature exceeds 1300 °C and is 1600 °C or less, preferably 1400 °C or more and 1550 °C or less, and the holding time is 1 hour or more and 5 hours or less, preferably 2 hours or more and 4 hours or less. It is preferable not to hold at a specific temperature in the temperature range of 1300 °C or less during heating, for example, the holding time in the temperature range of 1300 °C or less is preferably 30 minutes or less.

[0082] The manufacturing method of this embodiment may include at least one of a polishing process for polishing the sintered body or a processing process for processing the shape. The polishing process polishes the surface of the sintered body after sintering. By polishing, a sintered body having a surface state suitable for the intended use, such as imparting a gloss to the surface, can be obtained. The processing process processes the sintered body into an arbitrary shape. Thereby, the sintered body can be made into a shape according to the use. The polishing process and the processing process may be performed in any order.

Examples

[0083] Hereinafter, this embodiment will be described by way of examples. However, this embodiment is not limited to these examples.

[0084] (Average particle size) The average particle size was measured by measuring the particle size distribution by the laser diffraction / scattering method using a Microtrac particle size distribution analyzer (device name: MT3300EXII, manufactured by Microtrac Bell). The measurement conditions are shown below. Light source: Semiconductor laser (wavelength: 780 nm) Voltage: 3 mW Measurement sample: Pulverized slurry Refractive index of zirconia: 2.17 Refractive index of solvent (water): 1.333 Calculation mode: HRA

[0085] As a pretreatment, the sample powder was suspended in pure water to form a slurry, and then this was dispersed using an ultrasonic homogenizer (device name: US-150T, manufactured by Nippon Seiki Co., Ltd.) for 3 minutes. The slurry was measured with a pH of 3.0 to 6.0.

[0086] (BET specific surface area) The BET specific surface area was measured by the BET multipoint method (5 points) according to the following conditions in accordance with JIS R 1626 using an automatic specific surface area and pore size analyzer (device name: Tristar II 3020, manufactured by Shimadzu Corporation). Adsorption medium: N 2 Adsorption temperature: -196 °C Pretreatment conditions: Atmospheric atmosphere, degassing treatment at 250°C for 1 hour or more

[0087] (Measured density) The density of the sintered body was measured by a method according to JIS R1634 to obtain the measured density.

[0088] (Color tone) The color tone of the sintered body sample was measured by a method according to JIS Z8722. A general spectrocolorimeter (device name: CM-700d, manufactured by Konica Minolta) was used for the measurement. The following conditions are listed as the measurement conditions. Light source: D65 light source Field of view angle: 10° Measurement diameter: 8 mm Measurement method: SCI Measurement background: Black plate

[0089] A disc-shaped sintered body sample with a diameter of 20 mm and a thickness of 2.7 mm was used. After grinding the surface of the sintered body sample and performing mirror polishing until the surface roughness (Ra) ≤ 0.02 μm, the polished surface was used as the evaluation surface and the color tone was evaluated. The effective area for color tone evaluation was 8 mm in diameter.

[0090] (Three-point bending strength) The bending strength of the sintered body sample was measured by a three-point bending test according to JIS R1601. The measurement was carried out using a column-shaped sintered body sample with a span between supports of 30 mm, a width of 4 mm, and a thickness of 3 mm, and the average value of 10 measurements was taken as the bending strength.

[0091] (Average crystal grain size) The average crystal grain size was obtained by the planimetric method using the SEM observation image of the sintered body sample obtained by observation using a field emission scanning electron microscope (device name: JSM-IT500, manufactured by JEOL Ltd.). Prior to the measurement, the sintered body sample was mirror polished until the surface roughness (Ra) ≤ 0.02 μm and then subjected to thermal etching treatment as a pretreatment. The conditions for SEM observation are as follows. Accelerating voltage: 15 kV Observation magnification: 10,000 times

[0092] A circle was drawn on the SEM observation image so that the total number of crystal particles (Nc) inside the circle and the number of crystal particles (Ni) on the circumference of the circle was 125 ± 25, and the average crystal grain size was determined from the following formula. Average crystal grain size = (Nc + (1 / 2) × Ni) / (A / M 2 )

[0093] In the above formula, Nc is the number of crystal particles inside the circle, Ni is the number of crystal particles on the circumference of the circle, A is the area of the circle, and M is the magnification of scanning electron microscope observation (10,000 times). When the number of crystal particles (Nc + Ni) in one SEM observation image is less than 100, (Nc + Ni) was set to 125 ± 25 using a plurality of SEM observation images.

[0094] Example 1 3 mol% yttrium-containing zirconia powder (BET specific surface area: 6.8 m 2 / g, manufactured by Tosoh Corporation), high-purity alumina powder (manufactured by Sumitomo Chemical Co., Ltd.), vanadium oxide (manufactured by Wako Pure Chemical Industries, Ltd.) and terbium oxide (manufactured by Japan Yttrium Co., Ltd.) were mixed with pure water and wet-mixed using a ball mill to obtain a slurry. The obtained slurry was dried at 110 °C in an air atmosphere to obtain a mixed powder having the following composition.

[0095] Al 2 O 3 : 3.0 mass% V 2 O 5 : 0.045 mass% Tb 4 O 7 : 0.075 mass% 3 mol% yttrium-containing zirconia: the balance The dried mixed powder was filled into a mold, made uniform by tapping, and then formed at a uniaxial forming pressure of 1000 kg / cm 2 to obtain a formed body (compacted powder), which was sintered at normal pressure under the following conditions.

[0096] Sintering atmosphere: under air atmosphere Sintering temperature: 1500 °C Heating rate: 100 °C / hour Sintering time: 2 hours The obtained sintered body is composed of zirconia containing 3 mol% of yttrium, with an aluminum content of 3.0% by mass, a vanadium content of 0.045% by mass, and a terbium content of 0.075% by mass, and a V / Tb ratio of 0.60. When the surface of the sintered body (hereinafter, also referred to as the "fired surface") was visually observed, it exhibited a vivid yellow without a green or orange tint.

[0097] Also, when the surface of the zirconia sintered body was polished to a sample surface roughness of ≤0.02 μm, it was visually confirmed that the polished surface of the sintered body exhibited yellow. The three-point bending strength of the sintered body in this example was 1030 MPa, and the average particle size was 0.83 μm. By SEM observation, zirconia crystal particles and alumina particles were confirmed on the polished surface and cross-section of the sintered body.

[0098] Example 2 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was prepared to have the following composition. Al 2 O 3 : 10% by mass V 2 O 5 : 0.035% by mass Tb 4 O 7 : 0.075% by mass 3 mol% yttrium-containing zirconia: the balance The obtained sintered body is composed of zirconia containing 3 mol% of yttrium, with an aluminum content of 10% by mass, a vanadium content of 0.035% by mass, and a terbium content of 0.075% by mass, and a V / Tb ratio of 0.47. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0099] Example 3 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was prepared to have the following composition.

[0100] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.085 mass% Tb 4 O 7 : 0.50 mass% 3 mol% yttrium-containing zirconia: the balance The obtained sintered body has an aluminum content of 0.25 mass%, a vanadium content of 0.085 mass%, and a terbium content of 0.50 mass%, and a V / Tb ratio of 0.17. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0101] Example 4 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0102] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.045 mass% Tb 4 O 7 : 0.30 mass% 3 mol% yttrium-containing zirconia: the balance The obtained sintered body has an aluminum content of 0.25 mass%, a vanadium content of 0.045 mass%, and a terbium content of 0.30 mass%, and a V / Tb ratio of 0.15. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0103] Example 5 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0104] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.10 mass% Tb 4 O 7 : 0.30 mass% 3 mol% yttrium-containing zirconia: the balance The obtained sintered body has an aluminum content of 0.25 mass%, a vanadium content of 0.10 mass%, and a terbium content of 0.30 mass%, and a V / Tb ratio of 0.33. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the as-fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0105] Example 6 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0106] Al 2 O 3 : 5.0 mass% V 2 O 5 : 0.045 mass% Tb 4 O 7 : 0.075 mass% 3 mol% yttrium-containing zirconia: the balance The obtained sintered body has an aluminum content of 5.0 mass%, a vanadium content of 0.045 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.60. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the as-fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0107] Example 7 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0108] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.010 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.010 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.13. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0109] Example 8 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0110] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.020 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.020 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.27. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0111] Example 9 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0112] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.030 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.030 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.40. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without any green or orange tint.

[0113] Example 10 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0114] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.080 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.080 mass%, and a V / Tb ratio of 0.44. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without any green or orange tint.

[0115] Example 11 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0116] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.095 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.095 mass%, and a V / Tb ratio of 0.37. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired skin surface and the polished surface were visually observed, they exhibited a vivid yellow color without any green or orange tint.

[0117] Example 12 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0118] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.10 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.50 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.10 mass%, and a V / Tb ratio of 0.35. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired skin surface and the polished surface were visually observed, they exhibited a vivid yellow color without any green or orange tint.

[0119] Example 13 A sintered body of this example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0120] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 0.25 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.47. The balance is composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without any green or orange tint.

[0121] Example 14 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0122] Al 2 O 3 : 1.0 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 1.0 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.47. The balance is composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without any green or orange tint.

[0123] Example 15 A sintered body of this example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0124] Al 2 O 3 : 5.0 mass% V 2 O 5 : 0.035 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The obtained sintered body has an aluminum content of 5.0 mass%, a vanadium content of 0.035 mass%, and a terbium content of 0.075 mass%, and a V / Tb ratio of 0.47. The balance is a sintered body composed of zirconia containing 3 mol% of yttrium. When the fired surface and the polished surface were visually observed, they exhibited a vivid yellow without a green or orange tint.

[0125] Comparative Example 1 A sintered body of this comparative example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0126] Al 2 O 3 : 3.0 mass% V 2 O 5 : 0.045 mass% Zirconia containing 3 mol% yttrium: the balance The sintered body of this comparative example does not contain terbium as a coloring element. Both the fired surface and the polished surface exhibited a yellow with a green tint when visually observed.

[0127] Comparative Example 2 A sintered body of this comparative example was obtained in the same manner as in Example 1, except that the mixture was made to have the following composition.

[0128] Al 2 O 3 : 3.0 mass% Tb 4 O 7 : 0.075 mass% Zirconia containing 3 mol% yttrium: the balance The sintered body of this comparative example does not contain vanadium as a coloring element, and both the fired surface and the polished surface exhibited orange when observed visually.

[0129] Comparative Example 3 The sintered body of this comparative example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0130] V 2 O 5 : 0.50 mass% 3 mol% yttrium-containing zirconia: the balance The sintered body of this comparative example does not contain terbium as a coloring element, and both the fired surface and the polished surface exhibited yellow with a green tint when observed visually.

[0131] Comparative Example 4 The sintered body of this comparative example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0132] V 2 O 5 : 0.030 mass% 3 mol% yttrium-containing zirconia: the balance The sintered body of this comparative example does not contain terbium as a coloring element, and both the fired surface and the polished surface exhibited yellow with a green tint when observed visually.

[0133] Comparative Example 5 The sintered body of this comparative example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0134] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.045 mass% Tb 4 O 7 : 0.50 mass% 3 mol% yttrium-containing zirconia: the balance The sintered body of this comparative example had a V / Tb ratio of 0.09, and both the fired surface and the polished surface exhibited an orange color when observed visually.

[0135] Comparative Example 6 A sintered body of this comparative example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0136] Al 2 O 3 : 0.25 mass% V 2 O 5 : 0.055 mass% Tb 4 O 7 : 0.50 mass% 3 mol% yttrium-containing zirconia: the balance The sintered body of this comparative example had a V / Tb ratio of 0.11, and both the fired surface and the polished surface exhibited a yellow color with an orange tint when observed visually.

[0137] Comparative Example 7 A sintered body of this comparative example was obtained in the same manner as in Example 1, except that it was mixed to have the following composition.

[0138] Al 2 O 3 : 0.50 mass% V 2 O 5 : 0.055 mass% Tb 4 O 7 : 0.50 mass% 3 mol% yttrium-containing zirconia: the balance The sintered body of this comparative example had a V / Tb ratio of 0.11, and both the fired surface and the polished surface exhibited a yellow color with an orange tint when observed visually.

[0139] The evaluation results of the sintered bodies of the examples and comparative examples are shown in Table 1.

[0140]

Table 1

[0141] Examples show that when L * is 80 or more and 100 or less, a * is -3 or more and 4 or less, and b * is more than 30 and 50 or less, a sintered body can be obtained. On the other hand, all comparative examples exhibit color tones such as yellow. However, from Comparative Examples 1, 3, and 4, when only vanadium is used as the coloring element, a * becomes -3 or less. Also, from Comparative Example 2, when only terbium is used as the coloring element, it can be confirmed that a * exceeds 4. Further, from Comparative Examples 5 to 7, when the V / Tb ratio is outside the range of this embodiment, a * exceeds 4, so L * is 80 or more and 100 or less, a * is -3 or more and 4 or less, and b * is more than 30 and 50 or less, it can be confirmed that a sintered body cannot be obtained.

[0142] From Examples 7 to 9, it can be confirmed that the larger the vanadium content, the smaller a * becomes. Also, from Examples 10 to 12, it can be confirmed that the larger the terbium content, the larger a * becomes. It was confirmed that when the vanadium content is high, the color tone of the sintered body has a greenish tint, and when the terbium content is high, the color tone of the sintered body has a reddish tint. From these facts, when vanadium and terbium are included as coloring elements, it is presumed that the absorption bands of vanadium and terbium interact and weaken the green and orange color development in the sintered body.

[0143] Also, from Examples 13 to 15, it can be confirmed that the larger the aluminum content, the larger L * becomes.

[0144] The three-point bending strengths of Examples 1 and 2 were 1030 MPa and 1058 MPa, respectively.

[0145] Furthermore, for the examples and comparative examples, the chroma (C *) and the hue angle (h) were calculated. The results are shown in Table 2.

[0146]

Table 2

[0147] From Table 2, it can be confirmed that in all of the examples, the chroma is 30 or more, and the hue angle exceeds 83° and is 96° or less. On the other hand, from Comparative Example 2, it can be confirmed that the sintered body with only terbium added as the coloring element has a low hue angle of 72.6°. Also, from Comparative Examples 1, 3, and 4, it can be confirmed that the sintered bodies with only vanadium added as the coloring element all have a hue angle exceeding 96°.

[0148] It was confirmed that Examples 1 to 15, Comparative Example 1, Comparative Example 2, and Comparative Examples 4 to 7 have a chroma of 30 or more and exhibit a vivid color tone. However, since Comparative Examples 1, 2, and 4 to 7 have a hue angle of 83° or less or exceed 96°, it can be confirmed that they do not exhibit a color tone that is visually recognized as yellow with a green and orange tint.

[0149] Furthermore, from Comparative Examples 5 to 7, it can be confirmed that even when vanadium and terbium are included as the coloring elements, if the V / Tb ratio is outside the range of this embodiment, the hue angle will be less than 83°.

Claims

1. A sintered body containing vanadium and terbium and having zirconia as a matrix, wherein the mass ratio of vanadium to terbium is 0.12 or more and 0.80 or less in terms of oxide.

2. The sintered body according to claim 1, wherein the content of vanadium is 0.010% by mass or more and 0.20% by mass or less in terms of oxide.

3. The sintered body according to claim 1 or 2, wherein the content of terbium is 0.050% by mass or more and 0.60% by mass or less in terms of oxide.

4. The sintered body according to any one of claims 1 to 3, containing aluminum.

5. The sintered body according to claim 4, wherein the content of aluminum is 0.10% by mass or more and 15% by mass or less in terms of oxide based on the mass of the sintered body.

6. The sintered body according to any one of claims 1 to 5, wherein the zirconia is zirconia containing a stabilizing element.

7. The sintered body according to claim 6, wherein the stabilizing element is one or more selected from the group consisting of yttrium, magnesium, and calcium.

8. The sintered body according to claim 6 or 7, wherein the content of the stabilizing element of zirconia is 1.0 mol% or more and 6.0 mol% or less in terms of oxide.

9. L ＊ a ＊ b ＊ The lightness L in the color system ＊ , the chromaticity a ＊ and the chromaticity b ＊ satisfy the following, claim The sintered body according to any one of claims 1 to 8. Brightness L ＊ : 80 ≤ L ＊ ≤ 100 Chromaticity a ＊ : -3 ≤ a ＊ ≤ 4, and Chromaticity b ＊ : 30 < b ＊ ≤ 50

10. L ＊ a ＊ b ＊ The chroma C in the color system ＊ and the hue angle h satisfy the following, of claims 1 to 9 The sintered body according to any one of the claims. Chroma C ＊ : 28 ≤ C* ≤ 44, and hue angle h: 83° < h ≤ 96°

11. The sintered body according to any one of claims 1 to 10, having an average crystal grain size of 0.2 μm or more and 2 μm or less.

12. The sintered body according to any one of claims 1 to 11, having a three-point bending strength of 900 MPa or more.

13. A method for producing a zirconia sintered body according to any one of claims 1 to 12, characterized by using a composition having zirconia as a matrix, containing vanadium in an amount of 0.010% by mass or more and 0.20% by mass or less in terms of oxide, terbium in an amount of 0.050% by mass or more and 0.60% by mass or less in terms of oxide, and the mass ratio of vanadium to terbium being 0.12 or more and 0.80 or less in terms of oxide.

14. The method for producing a sintered body according to claim 13, wherein the composition contains aluminum in an amount of 0.10% by mass or more and 15% by mass or less in terms of oxide.

15. A composition having zirconia as a matrix, containing vanadium in an amount of 0.010% by mass or more and 0.20% by mass or less in terms of oxide, terbium in an amount of 0.050% by mass or more and 0.60% by mass or less in terms of oxide, and the mass ratio of vanadium to terbium being 0.12 or more and 0.80 or less in terms of oxide.

16. The composition according to claim 15, containing aluminum in an amount of 0.10% by mass or more and 15% by mass or less in terms of oxide.

17. A member including the sintered body according to any one of claims 1 to 12.

Images