JPH0733519A - Highly strong and tough zirconium oxide sintered product material and its production - Google Patents

Abstract

PURPOSE:To obtain the zirconium oxide material having excellent strength and toughness. CONSTITUTION:1. The characteristics of this highly strong and tough zirconium oxide sintered product material comprise (a) ZrO is a main component, the ions of at least one of Mg, Ca, Y and rare earth elements as the second component, and Al ions as the third component are together contained, and (b) the second and third components are dissolved in the crystal lattices of ZrO2 in a solid state. 2. The method for producing the highly strong and tough zirconium oxide sintered product material is to sinter the powder of a raw material comprising the hydroxide or oxide containing the ions of Zr, Mg, Ca and Y and at least one of rare earth elements, and Al ions in a state homogeneously dissolved in atomic levels at 1050-1300 deg.C under 20-200MPa.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zirconium oxide-based high strength / high toughness sintered body material and a method for producing the same.

[0002]

_2. Description of the Related Art ZrO ₂ (zirconium oxide)
Is a material having a high melting point and excellent heat resistance and corrosion resistance. However, cubic crystal from high temperature to normal temperature,
It changes into three crystal structures of tetragonal and monoclinic, and in particular, the phase transition from tetragonal to monoclinic in the cooling process is accompanied by remarkable volume expansion. Since this phase transition occurs reversibly, ZrO ₂ is destroyed due to its volume change during cooling during firing. Therefore, in order to eliminate the above-mentioned drawbacks, ZrO ₂ is added with CaO and M as stabilizers.
Stabilized zirconia capable of maintaining tetragonal crystals at normal temperature has been developed by adding gO, Y ₂ O ₃ , CeO ₂ or the like and dissolving the metal ions in each stabilizer in ZrO ₂ crystals. Stabilized zirconia is excellent in heat resistance, bending strength, etc., and is therefore used as engineering ceramics for machine parts and the like.

However, stabilized zirconia is a so-called brittle material which is excellent in bending strength but inferior in toughness as in general ceramics. Table 1 below shows general bending strength and toughness values of ceramic materials.

[0004]

[Table 1]

As can be seen from Table 1, Y-TZP has a bending strength of 1200 MPa but a toughness value of 6.1, which is not very high. Further, it can be seen that conventional ceramics such as SiC and Al ₂ O ₃ have low bending strength and toughness. On the other hand, there is Ce-TZP having improved toughness, but its bending strength is extremely low. That is, it is no exception in the case of stabilized zirconia that the bending strength and toughness of other ordinary ceramics cannot be imparted at the same time.

In addition, ceramics sintered materials are used for machine parts,
When used as a functional part or the like, particularly when used as a cutting edge or the like, a material excellent in bending strength and toughness is required. As a standard, a bending strength of 1100 MPa or more and a toughness value of 12
Although a value of MPa · m ^1/2 or more is mentioned, the conventional stabilized ZrO ₂ does not meet this criterion.

As described above, in order to put the stabilized ZrO ₂ into practical use in a wider range of applications, conventional stabilized zirconia is still insufficient in terms of bending strength, toughness and the like.
That is, the stabilized zirconia is the above-mentioned Y-TZP, Ce-
Like TZP, its properties vary greatly depending on the kind / addition amount of stabilizer, manufacturing method / conditions, etc. For example, even if the bending strength is improved, the toughness is reduced, or the bending strength and toughness are improved. However, the present situation is that the degree is slight.

In order to solve the above problems, a zirconium oxide-aluminum oxide composite material in which Al ₂ O ₃ is added to stabilized zirconia has been proposed. However, in this material, the solid solution in ZrO ₂ is Ca.
Al ₂ O ₃ is the only metal ion in the stabilizer such as O.
The Al ions therein are not in solid solution and exist in a dispersed state as Al ₂ O ₃ . Therefore, as is clear from the results of 80ZrO ₂ -20Al ₂ O _{3 in} Table 1 showing the characteristic values of this material, even if the bending strength is improved by the addition of Al ₂ O ₃ , the toughness is rather decreased. I will end up.

Similarly, attempts have been made to add Al ₂ O ₃ as a stabilizer, but the chemical affinity of ZrO ₂ and Al ₂ O ₃ is low even if both components are blended and simply calcined. since, Al ions will be present to constitute an Al oxide peculiar crystal structure as the Al ₂ O ₃ in ZrO ₂ i.e. in ZrO _2, Al ions resulting in Al ₂ O ₃ is ZrO It is not possible to obtain a product that is sintered in high density in a solid solution in ₂ .

[0010]

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide a zirconium oxide-based material having both excellent strength and toughness.

[0011]

The inventors of the present invention have conducted extensive studies in view of the above-mentioned problems of the prior art and found that a specific starting material containing Zr ions, Al ions and the like is used under certain conditions. In the case of firing, it was found that the growth of crystal grains is suppressed and the precipitation of Al ₂ O ₃ is also suppressed, and a sintered body in which Mg ions or the like are uniformly solid-solved in the ZrO ₂ crystal lattice is obtained, Further, they have found that this sintered body exhibits excellent strength and toughness, and have completed the present invention.

That is, the present invention relates to the inventions of the following first and second aspects.

1. (a) ZrO ₂ as a main component, at least one ion of Mg, Ca, Y and rare earth as a second component and Al ion as a third component, and (b)
Zirconium oxide-based high strength, characterized in that the second and third components are in solid solution in the ZrO ₂ crystal lattice.
High toughness sintered body material.

2. A raw material powder composed of a hydroxide or an oxide in which at least one kind of Zr ion, Mg, Ca, Y, and rare earth and Al ion is uniformly solid-dissolved at an atomic level is added under a pressure of 20 to 200 MPa under a pressure of 1050 to 1300.
A method for producing a zirconium oxide-based high-strength / high-toughness sintered body material, which comprises firing at ℃.

The present invention will be described in detail below.

The zirconium oxide-based high-strength / high-toughness sintered body material of the present invention comprises (a) ZrO ₂ as a main component, at least one ion of Mg, Ca, Y and a rare earth as a second component, and a third component. Contains Al ions as a component, and (b)
It has a peculiar structure in which the second component and the third component exist in the ZrO ₂ crystal lattice in a solid solution state.

The rare earth ions in the second component are all ions other than Y, that is, Sc, La, Ce, P.
r, Nd, Pm, Sm, Eu, Gd, Tb, Dy, H
Ions of o, Er, Tm, Yb and Lu can be applied.

The content of each of the above components may be appropriately selected depending on the type of the component, desired characteristics, crystal grain size and the like, but it is usually preferable to set the following content. That is,
(i) ZrO ₂ 8 relative to the total amount of ZrO ₂ and the second component
8 to 99.5 mol% and the second component is about 0.5 to 12 mol% as an oxide, and (ii) the third component is Z.
It is about 1 to 40 mol% with respect to the total amount of rO ₂ and the second component.

When the amount of the second component is less than 0.5 mol%, the strength decreases, and when it exceeds 12 mol%, cubic ZrO ₂ begins to precipitate in the sintered body and the toughness of the sintered body is increased. And the strength may decrease, which is not preferable. On the other hand, when the content of the third component is less than 1 mol%, the effect as a stabilizer becomes insufficient, and when it exceeds 40 mol%, Al ions are precipitated in the sintered body as Al ₂ O _3. This may reduce the toughness.

Regarding ZrO ₂ in the sintered material of the present invention, a tetragonal ZrO ₂ phase having an ultrafine crystal structure usually occupies 90% or more of all ZrO ₂ crystals. The crystal grain size of the sintered material of the present invention varies depending on the grain size of the raw material powder, but is usually about 0.02 to 0.1 μm.

Next, a method for producing the sintered body material of the present invention will be described. First, a hydroxide or oxide in which Zr ions, at least one kind of Mg, Ca, Y and at least one kind of rare earth element and Al ions are uniformly solid-dissolved at the atomic level is used as a raw material powder.

The above-mentioned powder preparation method is preferably a solution method, which is one of the known powder preparation methods. For example, (1)
Ammonia water is added to a homogeneous mixed solution of Zr alkoxide, Y alkoxide and Al alkoxide to hydrolyze,
Method for obtaining Zr-Y-Al-O type amorphous powder as coprecipitate, (2) Alcohol-soluble Zr, Y and Al
Various methods such as a method of synthesizing by using a raw material by a coprecipitation method and a method of obtaining a coprecipitate by hydrolyzing a homogeneous mixed solution of an inorganic salt and an organometallic compound to make it a strongly basic solution can be applied.

As the supply source of Zr, the second component and the third component used in the above powder preparation method, the raw materials used in the known solution method can be used. Examples of the Zr source include zirconium isopropoxide, zirconium acetylacetonate, zirconium oxychloride, zirconium chloride and the like. Examples of the second component source include yttrium isopropoxide, yttrium acetylacetonate, calcium chloride, magnesium nitrate and the like. Examples of the third component source include aluminum isopropoxide, aluminum acetylacetonate, aluminum chloride, aluminum nitrate and the like. The composition of the raw material powder, the same as (i) ZrO ₂ 88-99.5 mole% of and the second with respect to the total amount of the ZrO ₂ and the second component
The component is about 0.5 to 12 mol% as an oxide, and (ii) the third component is mixed so as to be about 1 to 40 mol% with respect to the total amount of ZrO ₂ and the second component.

The particle size of the raw material powder may be appropriately controlled according to the target particle size of the final sintered body. This control can be performed under the conditions of hydrolysis and the like, and depending on the conditions, it is also possible to prepare a fine powder of about 0.1 μm or less.

The raw material powder thus obtained is molded into a predetermined shape and then fired. In this case, calcination may be performed in advance before forming. The calcination conditions vary depending on the composition of the raw material powder and the like, but usually about 800 to 1 under normal pressure in air.
It is about 000 ° C. As the above-mentioned molding method, the method in the usual production of ceramics can be applied as it is.

The firing conditions differ depending on the composition of the raw material powder, the desired characteristics of the sintered body, etc. and are not uniform, but the pressure is usually about 20 to 200 MPa, preferably 1 in a reducing atmosphere.
The firing temperature is usually 1050-1
The temperature is set to about 300 ° C, preferably 1100 to 1250 ° C. In the present invention, since firing is performed below the precipitation temperature of Al ₂ O ₃ to densify, it is necessary to perform firing under pressure as described above. The firing temperature may exceed 1300 ° C. as long as Al ₂ O ₃ does not precipitate in the sintered body. Further, in the production method of the present invention, the above-mentioned molding and pressure firing can be simultaneously performed by the hot isostatic press molding method (HIP).

[0027]

In the material of the present invention, Mg ions as the second component and Al ions as the third component are uniformly dissolved in ZrO ₂ as a solid solution and stabilized. And 90 of all crystals
% Or more is occupied by the tetragonal ZrO ₂ phase having an ultrafine crystal structure. Therefore, when external stress is applied to the material of the present invention, the individual crystal grains are uniformly stressed, and as a result, the induced transformation from the tetragonal ZrO ₂ phase to the monoclinic ZrO ₂ phase uniformly occurs over a wide area. . Therefore, not only high strength is exhibited based on the ultrafine crystal structure, but also high toughness is exhibited due to relaxation of external stress.

[0028]

According to the manufacturing method of the present invention, it is possible to obtain a sintered material having a unique structure in which ZrO ₂ is solid-solubilized with Mg ions and Al ions.

The material according to the present invention can attain particularly excellent strength and toughness at the same time because of its unique structure.

Therefore, the material of the present invention is useful for machine parts, functional parts, wear resistant members, structural members and the like. In particular, a crystal grain size of 0.05 μm or less is useful as a cutting edge for a tool that requires sharp cutting edge machining accuracy.

[0031]

EXAMPLES Examples and comparative examples will be shown below to further clarify the features of the present invention. The identification of tetragonal crystals and the presence / absence of Al ₂ O ₃ phase precipitation in this example were carried out by an X-ray diffraction measuring device.

Example 1 ZrO ₂ : Y ₂ O ₃ = 9 in isopropanol at 82 ° C.
7: 3 (molar ratio), ZrO ₂ (3Y): Al ₂ O ₃ = 7
After refluxing zirconium isopropoxide, yttrium isopropoxide and aluminum isopropoxide in a ratio of 5:25 (molar ratio) for 24 hours, 28% ammonia water was added to the homogenized mixed solution to cause hydrolysis, resulting in The co-precipitate was filtered and dried.

The obtained powder was calcined in air at 900 ° C. to obtain a tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-solved. This powder is tetragonal ZrO ₂
It was confirmed by X-ray diffraction analysis that it consisted of only the phase (t-ZrO ₂ ) and that Al ₂ O ₃ was not precipitated. Then
The calcined powder was subjected to capsule HIP treatment under the conditions of 200 MPa and 1200 ° C.

The sintered body thus obtained had a tetragonal structure of 100%, a toughness value (K _IC ) of 14.5 MPa · m ^1/2 and a bending strength of 1300.
It was MPa. Moreover, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.1 μm or less. In addition, it was confirmed by X-ray diffraction analysis that Al ₂ O ₃ was not precipitated in this sintered body. The result is shown in FIG.

Example 2 A coprecipitate prepared in the same manner as in Example 1 was added to 100% in air.
It was calcined at 0 ° C. to obtain tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-dissolved. This powder is tetragonal ZrO
It was confirmed by X-ray diffraction analysis that it consisted of only _two phases and that Al ₂ O ₃ was not precipitated. Then, the calcined powder was subjected to capsule HIP under the conditions of 200 MPa and 1130 ° C.
Processed.

The obtained sintered body was 100% tetragonal, toughness (K _IC ) 13.2 MPa · m ^1/2 , bending strength 1320.
It was MPa. Further, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.05 μm or less. In addition, X indicates that Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. The results were similar to those in Example 1.

Example 3 ZrO ₂ : Y ₂ O ₃ = 97.5 in benzene at 80 ° C.
2.5 (molar ratio), ZrO ₂ (2.5Y): Al ₂ O ₃
After refluxing zirconium acetylacetonate, yttrium acetylacetonate and aluminum acetylacetonate at a ratio of 75:25 (molar ratio) for 24 hours, 28% ammonia water is added to the homogenized mixed solution to hydrolyze, The resulting coprecipitate was filtered and dried.

The obtained powder was calcined in air at 900 ° C. to obtain a tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-solved. This powder is tetragonal ZrO ₂
X is that it is composed of only phases and Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. Then calcined powder 2
Capsule HIP treatment was performed under the conditions of 00 MPa and 1200 ° C.

The obtained sintered body was 100% tetragonal, toughness (K _IC ) 13.0 MPa · m ^1/2 , bending strength 1440.
It was MPa. Moreover, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.1 μm or less. Further, it was confirmed by X-ray diffraction analysis that Al ₂ O ₃ was not deposited. The results were similar to those in Example 1.

Example 4 A coprecipitate prepared in the same manner as in Example 3 was added to 100% in air.
It was calcined at 0 ° C. to obtain tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-dissolved. This powder is tetragonal ZrO
It was confirmed by X-ray diffraction analysis that it consisted of only _two phases and that Al ₂ O ₃ was not precipitated. Then, the calcined powder was capsule HIPed under the conditions of 200 MPa and 1230 ° C.
Processed.

The sintered body thus obtained had a tetragonal structure of 100%, a toughness value (K _IC ) of 14.2 MPa · m ^1/2 and a bending strength of 1290.
It was MPa. Further, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.05 μm or less. In addition, X indicates that Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. The results were similar to those in Example 1.

Example 5 ZrO ₂ : Y ₂ O ₃ = 97.5 in benzene at 80 ° C.
2.5 (molar ratio), ZrO ₂ (2Y): Al ₂ O ₃ = 7
After refluxing zirconium acetylacetonate, yttrium acetylacetonate and aluminum acetylacetonate in a ratio of 5:25 (molar ratio) for 24 hours, 28% ammonia water is added to the homogenized mixed solution to cause hydrolysis, The co-precipitate was filtered and dried.

The obtained powder was calcined in air at 900 ° C. to obtain a tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-dissolved. This powder is tetragonal ZrO ₂
X is that it is composed of only phases and Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. Then calcined powder 2
Capsule HIP treatment was performed under the conditions of 00 MPa and 1230 ° C.

The obtained sintered body had a tetragonal structure of 100%, a toughness value (K _IC ) of 12.8 MPa · m ^1/2 and a bending strength of 1445.
It was MPa. Further, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.05 μm or less. In addition, X indicates that Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. The results were similar to those in Example 1.

Example 6 ZrO ₂ : Y ₂ O ₃ = 97: 3 in benzene at 80 ° C.
(Molar ratio), ZrO ₂ (3Y): Al ₂ O ₃ = 92: 8
Zirconium acetylacetonate, yttrium acetylacetonate, and aluminum acetylacetonate were refluxed for 24 hours at a ratio of (molar ratio), and then 28% ammonia water was added to the homogenized mixed solution to cause hydrolysis, resulting in coprecipitation. The material was filtered and dried.

The obtained powder was calcined in air at 900 ° C. to obtain a tetragonal-stabilized ZrO ₂ powder in which Y ions and Al ions were solid-solved. This powder is tetragonal ZrO ₂
X is that it is composed of only phases and Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. Then calcined powder 2
Capsule HIP processing was performed under the conditions of 00 MPa and 1250 ° C.

The obtained sintered body was 100% tetragonal, the toughness value (K _IC ) was 13.4 MPa · m ^1/2 , and the bending strength was 1350.
It was MPa. Further, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was 0.05 μm or less. In addition, X indicates that Al ₂ O ₃ is not precipitated.
Confirmed by line diffraction analysis. The results were similar to those in Example 1.

Comparative Example 1 Water was added to 80 parts by weight of ZrO ₂ powder added with 3 mol% Y ₂ O ₃ and 20 parts by weight of Al ₂ O ₃ powder to make a slurry, and then ZrO ₂ (3Y) beads were added. It was bead milled for 500 hours. The slurry is then dried and C
After temporary molding by IP, 1300-1500 ° C in the atmosphere
It was baked in. The obtained sintered body was placed in Ar at 1450 ° C. 196
HIP sintering was performed under a pressure of MPa. The obtained sintered body has a toughness value (K _IC ) of 5.0 MPa · m ^1/2 and a bending strength of 1
It was 681 MPa. When X-ray diffraction analysis was performed on this sintered body, no solid solution of Al ions in ZrO ₂ was observed. The result is shown in FIG.

Comparative Example 2 A sintered body was obtained in the same manner as in Comparative Example 1 except that HIP sintering was performed at 1550 ° C. The obtained sintered body has a toughness value (K _IC ).
It was 5.0 MPa · m ^1/2 and bending strength was 1681 MPa. As a result of X-ray diffraction analysis of this sintered body, no solid solution of Al ions in ZrO ₂ was observed as in Comparative Example 1.

Comparative Example 3 A sintered body was obtained in the same manner as in Comparative Example 1 except that the amount of Y ₂ O ₃ added was 2 mol%. The obtained sintered body has a toughness value (K
_IC ) was 4.8 MPa · m ^1/2 and bending strength was 1813 MPa. As a result of X-ray diffraction analysis of this sintered body, no solid solution of Al ions in ZrO ₂ was observed as in Comparative Example 1.

Comparative Example 4 A sintered body was obtained in the same manner as Comparative Example 3 except that HIP sintering was performed at 1550 ° C. The obtained sintered body has a toughness value (K _IC ).
The bending strength was 4.0 MPa · m ^1/2 and the bending strength was 1777 MPa. As a result of X-ray diffraction analysis of this sintered body, no solid solution of Al ions in ZrO ₂ was observed as in Comparative Example 1.

Comparative Example 5 Comparative Example 1 except that a slurry obtained by adding water to 60 parts by weight of ZrO ₂ powder added with 3 mol% Y ₂ O ₃ and 40 parts by weight of Al ₂ O ₃ powder was used. A sintered body was obtained in the same manner. The obtained sintered body has a toughness value (K _IC ) of 4.9 MPa.
-It was m1 / ² and bending strength was 1992 MPa. When X-ray diffraction analysis of this sintered body was performed, ZrO 2 was obtained in the same manner as in Comparative Example 1.
_No solid solution of Al ions in ₂ was observed.

Comparative Example 6 A sintered body was obtained in the same manner as in Comparative Example 5 except that HIP sintering was performed at 1550 ° C. The obtained sintered body has a toughness value (K _IC ).
The bending strength was 4.8 MPa · m ^1/2 and the bending strength was 1866 MPa. As a result of X-ray diffraction analysis of this sintered body, no solid solution of Al ions in ZrO ₂ was observed as in Comparative Example 1.

Comparative Example 7 ZrO ₂ : Y ₂ O ₃ = 9 in isopropanol at 82 ° C.
7: 3 (molar ratio), ZrO ₂ (3Y): Al ₂ O ₃ =
After refluxing zirconium isopropoxide, yttrium isopropoxide and aluminum isopropoxide at a ratio of 5:95 (molar ratio) for 24 hours, 28% ammonia water was added to the homogenized mixed solution to cause hydrolysis, resulting in The precipitate was filtered and dried.

The obtained powder was calcined in air at 1000 ° C. and then subjected to capsule HIP treatment under the conditions of 200 MPa and 1200 ° C.

The obtained sintered body had a tetragonal structure of 30%, a toughness value (K _IC ) of 5.6 MPa · m ^1/2 and a bending strength of 390 MPa.
Met. Further, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was about 2.5 μm.
In addition, when this sintered body was subjected to X-ray diffraction analysis, Comparative Example 1
Similarly to the above, no solid solution of Al ions in ZrO ₂ was observed.

Comparative Example 8 ZrO ₂ : Y ₂ O ₃ = 9 in isopropanol at 82 ° C.
7: 3 (molar ratio), ZrO ₂ (3Y): Al ₂ O ₃ = 1
Zirconium isopropoxide, yttrium isopropoxide, and aluminum isopropoxide were refluxed for 24 hours at a ratio of 000: 0 (molar ratio), and then 28% ammonia water was added to the homogenized mixed solution to cause hydrolysis to occur. The co-precipitate was filtered and dried.

The obtained powder was calcined in air at 1200 ° C. and then subjected to capsule HIP treatment under the conditions of 200 MPa and 1250 ° C.

The sintered body thus obtained had a tetragonal structure of 100%, a toughness value (K _IC ) of 6.2 MPa · m ^1/2 and a bending strength of 720 MP.
It was a. Moreover, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was about 1.5 μm.

As is clear from the results of Comparative Examples 7 and 8, when the addition of Al ions exceeds 40 mol% as Al ions, the toughness value and bending strength are both low due to the precipitation of Al ₂ O ₃ , and the addition of Al ions Is Al ₂ O ₃ of 0.
It can be seen that when the content is less than 5 mol%, the addition effect is not exhibited and the toughness value and bending strength are poor.

Comparative Example 9 ZrO ₂ : Y ₂ O ₃ = 8 in isopropanol at 82 ° C.
6:14 (molar ratio), ZrO ₂ (14Y): Al ₂ O ₃
After refluxing zirconium isopropoxide, yttrium isopropoxide and aluminum isopropoxide at a ratio of 75:25 (molar ratio) for 24 hours, 28% ammonia water is added to the homogenized mixed solution to hydrolyze, The resulting coprecipitate was filtered and dried.

The obtained powder was calcined in air at 900 ° C., and then, under the condition of 200 MPa and 1160 ° C., capsule H
IP treatment was performed.

The obtained sintered body had a tetragonal structure of 80%, a toughness value (K _IC ) of 3.1 MPa · m ^1/2 and a bending strength of 610 MPa.
Met. Moreover, when the crystal grain size of the sintered body was measured by the SEM photograph, the grain size was about 1.5 μm.

As is clear from the results of Comparative Example 9, when the proportion of the second component of the present invention exceeds 12 mol%, cubic ZrO ₂ is formed in the crystal lattice, and the toughness value and bending strength cannot be improved. Recognize.

[Brief description of drawings]

FIG. 1 is a diagram showing a result of an X-ray diffraction analysis after sintering of samples manufactured in Example 1 and Comparative Example 1.

[Explanation of symbols]

 1 ... Result of Example 1 2 ... Result of Comparative Example 1

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Kume, 1-1-15 Kasugadekita, Konohana-ku, Osaka-shi, Osaka (72) Inventor Ryoichi Shikata 8-1, Nishikinaka-cho, Kaizuka-shi, Osaka Osaka Cement Shares Inside the company (72) Inventor Kakei Ichiro, 8-1, Nishikinakamachi, Kaizuka, Osaka Prefecture Osaka Cement Corporation (72) Inventor, Nobuaki Shiokawa, 8-1, Nishikinakacho, Kaizuka City, Osaka Prefecture Osaka Cement Corporation

Claims (5)

[Claims] 1. (a) ZrO ₂ as a main component, at least one ion of Mg, Ca, Y and a rare earth as a second component, and Al ions as a third component, and (b) the second component. And a zirconium oxide-based high-strength, high-toughness sintered body material, characterized in that the third component is solid-solved in the ZrO ₂ crystal lattice. 2. (i) ZrO ₂ is contained in an amount of 88 to 99.5 mol% and a second component in an amount of 0.5 to 12 mol% as an oxide based on the total amount of ZrO ₂ and the second component, and ii) 1 to 40 mol% of the third component based on the total amount of ZrO ₂ and the second component
The sintered body material according to claim 1, which contains. 3. The sintered body material according to claim 1, wherein the crystal grains have a grain size of 0.1 μm or less. 4. Tetragonal ZrO ₂ is 90% of all ZrO ₂ crystals.
It is above, The sintered compact material in any one of Claim 1 thru | or 3. 5. A raw material powder consisting of a hydroxide or an oxide in which at least one kind of Zr ion, Mg, Ca, Y and at least one kind of rare earth and Al ion is uniformly dissolved at an atomic level, under a pressure of 20 to 200 MPa. Zirconium oxide-based high strength characterized by firing at 1050-1300 ° C
Manufacturing method of high toughness sintered body material.