JPH09188562A - Zirconia-based sintered compact, production of the same and material for crushing part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain zirconia-based sintered compact excellent in mechanical characteristics and low temperature deterioration resistance and capable of sintering at a relatively low temperature, and a material for a crushing part using the sintered material. SOLUTION: This zirconia-based sintered compact contains ZrO2 as a major component, and simultaneously uses 'Y2 O3 ' and 'Yb2 O3 , Er2 O3 , and/or Ho2 O3 ' as a stabilizer with 30-40mol% Y2 O3 content in R2 O3 , 2.0-3.0mol% R2 O3 content and <=1.0mol% Y2 O3 in the sintered compact, and its crystal particles mainly consists of a tetragonal phase or a mixed phase of the tetragonal and a cubic phases. The raw material mixture is prepared by a chemical synthetic or a oxide mixing method so as to make the prescribed raw material composition, the mixture is calcined at a prescribed temperature (500-1200 deg.C) and then the raw material powder obtained through a crushing process is formed and sintered at a prescribed temperature (1300-1650 deg.C). A material for a crushing part is constituted by the zirconia sintered compact and has <=2μm mean particle diameter of the sintered compact and >=6.0g/cm<2> bulk density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth metal oxide-stabilized zirconia-based sintered body having high mechanical properties, a method for producing the same, and a crushing component material.

[0002]

_2. Description of the Related Art In recent years, zirconia (ZrO ₂ ) based sintered materials have been used for ceramic scissors, medical materials, and the like, to which the toughness is applied.
Die for die extrusion that utilizes lubricity, adiabatic engine parts that utilize thermal insulation and thermal expansion properties, or
It is widely used as a constituent material for oxygen sensors and fuel cells that apply oxygen ion conductivity.

Among them, it is known that the zirconia-based sintered body using a rare earth metal oxide (R ₂ O ₃ ) as a stabilizer has particularly excellent mechanical properties as compared with other ceramics. However, products utilizing this characteristic are being actively developed. In recent years, attention has been focused on as a material for crushing such as a crushing medium (media) used for mixing and crushing ceramic materials, metal powders, food-related products, and the like.

The zirconia-based sintered body using a rare earth metal oxide as a stabilizer uses Y ₂ O ₃ as a stabilizer (Japanese Patent Publication No. 61-21184) and Sc ₂ O as a stabilizer. ₃ , Sm
₂ O ₃ , Eu ₂ O ₃ , Gd ₂ O ₃ , Tb ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂
One or two selected from the group consisting of O ₃ , Yb ₂ O ₃ and Lu ₂ O ₃
Using at least one rare earth metal oxide (Japanese Patent Publication No.
No. 5) is proposed.

On the other hand, as a material for pulverizing parts using a rare earth metal oxide-stabilized zirconia-based sintered body, a stabilizer is used.
A material for pulverizing parts using a zirconia-based sintered body which is Yb ₂ O ₃ (Japanese Patent Publication No. 2-20587), and a stabilizer from the group consisting of Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O _3. A crushing component material (Japanese Patent Laid-Open No. 6-39303) using a zirconia-based sintered body that is one or more selected rare earth metal oxides has been proposed.

From the viewpoint of mechanical strength, in general, Yb ₂ O ₃ , E is more preferable than a zirconia-based sintered body using Y ₂ O ₃ as a stabilizer.
A zirconia-based sintered body using one or more rare earth metal oxides selected from the group consisting of r ₂ O ₃ and Ho ₂ O ₃ as a stabilizer is superior. In addition, Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O ₃ are better than zirconia-based sintered bodies using Y ₂ O ₃ as a stabilizer.
Since a zirconia-based sintered body using one or more rare earth metal oxides selected from the group consisting of as a stabilizer has a higher density, it is used as a grinding component material for a grinding medium.
Excellent crushing ability can be obtained even when used for (media).

[0007]

By the way, the zirconia-based sintered body using a rare earth metal oxide as a stabilizer has a tetragonal crystal which is a metastable phase at room temperature among the crystal phases of the zirconia-based sintered body. It transforms into a stable phase of monoclinic crystal, and the volume expansion accompanying this phase transformation causes microcracks in the fired body, causing deterioration due to long-term aging in a low temperature range. Especially 100
Aging in water or steam at up to 300 ° C causes a remarkable deterioration, which is a phenomenon called "low temperature deterioration".

The above-mentioned conventional "Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O _3"
As described above, the "zirconia-based sintered body using one or two or more kinds of rare earth metal oxides selected from the group consisting of a zirconia-based sintered body as a stabilizer" is a zirconia-based sintered body using Y ₂ O ₃ as a stabilizer. It is superior in mechanical strength and has a high density compared to the aggregate, but the former “Yb ₂ O ₃ , Er ₂
The zirconia-based sintered body using one or more rare earth metal oxides selected from the group consisting of O ₃ and Ho ₂ O ₃ as a stabilizer is the latter Y ₂ O ₃ as a stabilizer. Compared with the zirconia-based sintered body used, the above-mentioned "deterioration due to long-term aging in a low temperature range" is more likely to occur, and especially the above-mentioned "low temperature deterioration".
It has a drawback that a phenomenon called "is likely to occur".

As a measure for preventing the above "low temperature deterioration", a zirconia-based sintered body containing a boron compound (for example, B ₂ O ₃ ) and Al ₂ O ₃ and / or SiO ₂ has been proposed (JP-A-6- 239662
Publication). However, the crushing component material using this zirconia-based sintered body has a problem in crushing and kneading electronic component materials using B ₂ O ₃ or the like as an additive.

The present invention has been made in view of the above-mentioned drawbacks and problems, and an object of the present invention is to provide a high-density zirconia-based sintered body excellent in mechanical properties and low-temperature deterioration resistance, and the same. It is an object of the present invention to provide a manufacturing method and a crushing part material using the zirconia-based sintered body.

[0011]

A zirconia-based sintered body according to the present invention contains ZrO ₂ as a main component and contains Y ₂ O ₃ and Yb ₂ O within a predetermined range.
1 or 2 selected from the group consisting of ₃ , Er ₂ O ₃ and Ho ₂ O _3.
A zirconia-based sintered body characterized by being obtained by sintering a compound containing a stabilizer comprising one or more rare earth metal oxides, which is particularly excellent in mechanical properties and low temperature deterioration resistance. Is.

The method for producing a zirconia-based sintered body according to the present invention is a chemical synthesis method such as a neutralization coprecipitation method, a hydrolysis method, an alkoxide method or an oxide mixing method so that a predetermined raw material composition is obtained. Prepare a raw material blend by calcination at a predetermined temperature (500 ~ 1200 ℃), then shape the raw material powder obtained through the crushing process, and sinter at a predetermined temperature (1300 ~ 1650 ℃) This makes it possible to obtain a zirconia-based sintered body that can be sintered at a relatively low temperature and that has excellent mechanical properties and low-temperature deterioration resistance.

Further, the crushing component material according to the present invention is
Specified average particle size (2μm or less), Specified bulk density (6.0g
/ Cm ³ or more) and a high-density zirconia-based sintered body excellent in mechanical properties and low-temperature deterioration resistance are used.

That is, the zirconia-based sintered body according to the present invention has "ZrO ₂ as a main component, Y ₂ O ₃ and Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O.
Stabilized with one or more rare earth metal oxides selected from the group consisting of ₃ , and the proportion of Y ₂ O ₃ in the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer is 30-40 mol%
And a crystal grain obtained is mainly composed of a tetragonal phase or a mixed phase of a tetragonal crystal and a cubic crystal. (Claim 1), and in the zirconia-based sintered body, the content of R ₂ O _{3 in} the sintered body is 2.0 to 3.0 mol%.
(Claim 2), The content of Y ₂ O _{3 in} the sintered body is 1.0 mol% or less.
(Claim 3),

Further, the method for producing a zirconia-based sintered body according to the present invention is as follows: "ZrO ₂ is the main component, Y ₂ O ₃ and Yb ₂ O ₃ , Er ₂ O ₃
Y ₂ O which is stabilized with one or more rare earth metal oxides selected from the group consisting of and Ho ₂ O ₃ and which is contained in the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer. ₃ to 30
A method for producing a zirconia-based sintered body which is 40 mol%, wherein (1) as a raw material composition, a content of a stabilizer composed of the rare earth metal oxide (R ₂ O ₃ ) in the sintered body is 2.0 to 3.0 mol%, of which the content of Y ₂ O ₃ is 1.0 mol% or less, the raw materials are blended by a chemical synthesis method such as a neutralization coprecipitation method, a hydrolysis method, an alkoxide method or an oxide mixing method. A step of preparing a product, (2) a step of calcining the above-mentioned compound at 500 to 1200 ° C., (3) a step of molding the above-mentioned crushed product, (4) the above-mentioned molded body
A method for producing a zirconia-based sintered body, comprising a step of sintering at 1300 to 1650 ° C. (Claim 4) is the gist.

Further, the crushing component material according to the present invention is
A crushing part material constituted by using the zirconia-based sintered body according to claim 1, 2 or 3, wherein the average particle diameter of the sintered body is 2 μm or less and the bulk density is 6.0 g / c
A pulverized part material using a zirconia-based sintered body characterized by having a size of at least m ³ . (Claim 5) is the gist.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The zirconia-based sintered body of the present invention, the method for producing the same, and the material for crushing parts will be described in detail below.

First, the zirconia-based sintered body according to the present invention will be described. The zirconia-based sintered body according to the present invention,
As described above, ZrO ₂ is the main component, and Y ₂ O ₃ and Yb ₂ O ₃ , Er ₂
One or more rare earth metal oxides selected from the group consisting of O ₃ and Ho ₂ O ₃ are used as a stabilizer. (Tm ₂ O ₃ and Lu ₂ O ₃ can also be used, but Tm ₂ O ₃ and Lu ₂ O ₃ are very expensive, and when used as a zirconia product, they pose a problem in terms of market competitiveness.)

With respect to the stabilizer used in the present invention, if it is 0.5 mol% or less, in addition to the above Y ₂ O ₃ , Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O ₃ , other rare earth metal oxides (eg, La ₂ O ₃ , CeO ₂ , Pr
₆ O ₁₁ , Nd ₂ O ₃ , Sm ₂ O ₃ , Eu ₂ O ₃ , Gd ₂ O ₃ , Tb ₄ O ₇ , Dy ₂ O ₃ , Tm
₂ O ₃ , Lu ₂ O ₃ , Sc ₂ O _{3 and the} like), which are also included in the present invention. The reason is that even if the content of the other rare earth metal oxides as described above is less than 0.5 mol%, no significant change is observed in the mechanical strength. However, if the content exceeds 0.5 mol%, the mechanical strength is lowered, and the desired zirconia-based sintered body intended in the present invention cannot be obtained, which is not preferable.

In the zirconia-based sintered body according to the present invention, Y ₂ O _{3 in} the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer is used.
Is 30 to 40 mol%. When the proportion of Y ₂ O _{3 in} the rare earth metal oxide (R ₂ O ₃ ) is less than 30 mol%, the strength is improved, but the low temperature deterioration resistance is poor, while 40 mol% is used. If it exceeds the above range, deterioration in low temperature deterioration resistance is not observed, but one having high strength cannot be obtained, which is not preferable.

Further, in the zirconia-based sintered body according to the present invention, the content of the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer is preferably in the range of 2.0 to 3.0 mol%.
When the content of R ₂ O ₃ is less than 2.0 mol%, it is difficult to maintain a stable tetragonal crystal in the obtained zirconia-based sintered body at room temperature, and the change in volume occurs when the tetragonal crystal changes to the monoclinic crystal. Therefore, a desired sintered body cannot be obtained because cracks occur. On the other hand, if the content of R ₂ O ₃ exceeds 3.0 mol%, a material having high strength cannot be obtained, which is not preferable.

Further, in the zirconia-based sintered body according to the present invention, the content of Y ₂ O ₃ as a stabilizer is preferably 1.0 mol% or less. When the content of Y ₂ O ₃ exceeds 1.0 mol%, the low-temperature deterioration resistance is not deteriorated, but a material having high strength cannot be obtained, which is not preferable.

The zirconia sintered body according to the present invention is
The crystal grains in the sintered body are mainly composed of a tetragonal phase or a mixed phase of tetragonal and cubic. The reason for this is that when the crystal grains include monoclinic crystals, the low temperature deterioration resistance tends to decrease, and the zirconia sintered body excellent in low temperature deterioration resistance aimed at by the present invention cannot be obtained. .

Next, a method of manufacturing the zirconia-based sintered body according to the present invention will be described. First, a chemical synthesis method such as a neutralization coprecipitation method, a hydrolysis method, an alkoxide method, or an oxide mixing method is used to prepare ZrO ₂ and R ₂ O _{3 so as} to have the predetermined raw material composition. Next, this raw material powder is calcined within a temperature range of 500 to 1200 ° C., the calcined powder is crushed and then molded, and 1300 to 16
Sintering (main firing) within a temperature range of 50 ° C.

The calcination at 500 to 1200 ° C. is one of the important requirements in the production method of the present invention, in order to make the mixed raw material as uniform as possible, and one of ZrO ₂ This is to promote the sintering in the firing process (main firing process) by preliminarily undergoing phase transition of the part.

The lower limit of the calcination conditions, 500 ° C., is the lowest temperature at which part of the monoclinic ZrO ₂ crystal can be transformed into a tetragonal crystal by calcination. In general, the transition from the monoclinic ZrO ₂ to tetragonal Although it is said that "around 1170 ℃", ZrO ₂
The temperature is shifted to the low temperature side by adding a stabilizer to, for example, when using Y ₂ O ₃ as a stabilizer,
A phase transition is observed at a temperature of about ℃. This temperature is
The value varies depending on the type or amount of stabilizer.

On the other hand, the upper limit of the calcination temperature of 1200 ° C. is
The agglomerated powder found in the raw material after calcination is the maximum temperature at which it can be sufficiently crushed in the crushing process, and in the case where calcination is performed above this temperature, agglomerated particles remain after crushing, This is not preferable because it becomes a large breaking point and causes a decrease in strength of the zirconia-based sintered body. Therefore, the calcination temperature in the method of the present invention is preferably 500 to 1200 ° C., but the raw material after the calcination is somewhat agglomerated, so crushing is necessary.

In the method of the present invention, the sintering (main firing) temperature is preferably 1300 to 1650 ° C., particularly 13 ° C., as described above.
50 to 1500 ° C is more preferable. If the temperature is lower than 1300 ° C, only those having low mechanical properties can be obtained. On the other hand, if the temperature is higher than 1650 ° C, abnormal grain growth of crystal grains occurs, which makes it impossible to obtain a high toughness sintered body.

In the method of the present invention, it is particularly preferable to produce the zirconia-based sintered body by pressure sintering. The reason is that it is possible to manufacture a zirconia-based sintered body having higher strength by the pressure sintering process. For example, in the examples described later, those manufactured by firing after CIP molding and having a strength of 1300 MPa or more are HIP
A high-strength sintered body of 1500 MPa or more can be obtained by the treatment (see composition No. 11 in Table 2 below).

Next, the material for crushing parts according to the present invention will be described. The crushing component material according to the present invention is a crushing component material formed by using the zirconia-based sintered body according to the present invention, and the average particle diameter of the sintered body is 2 μm.
The following is characterized by a crushing part material using a zirconia-based sintered body having a bulk density of 6.0 g / cm ³ or more.

With a sintered body having an average particle size of more than 2 μm, good properties in terms of wear resistance and low temperature deterioration resistance cannot be obtained, and the bulk density is 6.0 g / cm ^3.
A sintered body of less than 1 is not preferable because the pulverization efficiency that appears when used as a pulverization medium (media) becomes small and the strength characteristic becomes a low value.

Further, the crushing component material according to the present invention is the zirconia-based sintered body according to the above-mentioned present invention (a phase in which the crystal grains in the sintered body are mainly tetragonal or a mixed phase of tetragonal and cubic). However, when the crystal particles include monoclinic crystals, the low temperature deterioration resistance tends to decrease. This is because low temperature deterioration occurs due to heat and heat during drying after cleaning the device.

The crystal phase of the sintered body (monoclinic, tetragonal,
(Cubic crystal) content is obtained by grinding the surface of the sintered body with a # 600 diamond grindstone, then finishing it to a mirror surface with 1-5 μm diamond grains, and using the formula below from the intensity ratio of the surface by X-ray diffraction. It was

[0034]

[Equation 1]

The average particle size is measured on the surface of the sintered body by #
The surface of the sintered body, which was ground to a mirror surface by grinding with 600 diamond grindstones, was etched with hydrofluoric acid,
A certain area in the electron micrograph that contains 50 or more particles
The number (n) of particles in (S) was counted, and the diameter (d) of a circle having an area equal to the average area (s) per particle was calculated by the following formula. Formula ... d = (4S / π) ^1/2 Then, the diameter (d) was obtained for three or more visual fields of the same sample and defined as the average particle size. The number of particles (n)
Is the sum of the number of particles completely contained in the constant area (S) and 1/2 of the number of particles cut at the boundary line of the constant area. (For details of this measuring method, see JP-B-61-21184.)

[0036]

According to the zirconia-based sintered body of the present invention, it is possible to provide a zirconia-based sintered body having excellent mechanical properties and low-temperature deterioration resistance. Further, according to the production method of the present invention, a raw material prepared by a chemical synthesis method such as a neutralization coprecipitation method, a hydrolysis method, an alkoxide method or an oxide mixing method so that a predetermined raw material composition is obtained, After calcining this at a predetermined temperature, the raw material powder obtained through the crushing step is molded, and by firing at a predetermined temperature, it has high mechanical properties,
It is possible to obtain a zirconia-based sintered body excellent in low-temperature deterioration resistance.

Further, the crushing component material according to the present invention (using a zirconia-based sintered body having the composition specified in the present invention and satisfying the crystal constitution phase, the average particle size and the bulk density specified in the present invention) According to the conventional crushing part material), it is possible to provide a crushing part material having high mechanical properties, excellent low temperature deterioration resistance and abrasion resistance, and good crushing efficiency.

[0038]

Next, examples of the present invention will be described together with comparative examples.
The present invention will be described more specifically, but the present invention is not limited to the following examples, and various changes and modifications can be made without departing from the gist of the present invention.

Example 1 In this Example 1, starting materials were prepared by the neutralization coprecipitation method. That is, using a ZrOCl ₂ aqueous solution as a zirconia (Zr) source and an RCl ₃ aqueous solution as a rare earth metal (R) source, mixing and mixing so as to have the composition shown in Table 1, and adding ammonia water to form a hydroxide. A starting mixture was prepared by coprecipitation and drying.

[0040]

[Table 1]

Next, calcination was performed at the temperatures shown in Table 2 (however, the composition No. 11 in Table 2 having a calcination temperature of 0 ° C. was not calcinated), and the obtained calcined powder was obtained. Was crushed in ion-exchanged water with a "planetary ball mill using a zirconia pot and a ball", and 3% by weight of an acrylic copolymer resin was added to carry out spray granulation. CIP this granulated powder at a pressure of 100 MPa
It was molded and subjected to main firing at the temperatures shown in Table 2.

Regarding each of the obtained zirconia-based sintered bodies, "Bending strength test method for fine ceramics (JIS R160
3 point bending strength based on 1) "Vickers hardness (JIS R161
0) "" Fracture toughness value determined by the IF method (JIS R1607) "
The "low temperature deterioration resistance of the sintered body" was measured. Table 2 shows the results.
Shown in The "low temperature deterioration resistance" of the sintered body was determined by placing the test piece for 3-point bending strength in an autoclave and holding it in hot water at 200 ° C for 50 hours. It was judged by measuring the degree of deterioration. ○ indicates 20% or less strength deterioration before the test, △ indicates 20 to 50% strength deterioration before the test, and × indicates 50% or more before the test. Deterioration of strength was observed.

[0043]

[Table 2]

From Table 2, the content of stabilizer R ₂ O ₃ and Y ₂ O ₃
And the amount ratio relationship of one or more rare earth metal oxides selected from the group consisting of Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O ₃ is within the predetermined range of the present invention, it is high. It can be understood that a zirconia-based sintered body that exhibits strength and is excellent in low-temperature deterioration resistance can be obtained. And even if it falls outside one of the predetermined ranges defined in the present invention, the zirconia-based sintered body of the present invention cannot be obtained.

[0045] For example, the present invention is a Y ₂ O ₃ as essential components as a stabilizer "occupied in the rare earth metal oxide _{(R 2 O 3) Y 2} O 3
Although the proportion of is defined as 30 to 40 mol% ", even using the comparative example and Y ₂ O ₃ composition No.2,3,4 without using Y ₂ O ₃ occupied in R ₂ O ₃ Y ₂ Composition No. 6, 10, 14 with O ₃ ratio less than 30 mol%
In all of the comparative examples (Y ₂ O ₃ ratio: 25, 28, 27 mol%), the low temperature deterioration resistance was poor. Further, even in combination with the composition No.1 and Y ₂ O ₃ using only Y ₂ O ₃ as a stabilizer Y ₂
The composition ratio of O ₃ exceeds 40 mol% No.9 (ratio of Y ₂ O _3: 55
In the comparative example (mol%), the bending strength was low.

Furthermore, "R ₂ O ₃ : 2.0-
Composition No. 5 (R ₂ O ₃ : 1.9 mol%) outside the range of “3.0 mol%”
In the comparative example, without sintering, R ₂ O ₃ the composition exceeds 3.0 mol% Nanba18,19: In the comparative example of (R ₂ O ₃ 3.1,3.3 mol%), but low flexural strength there were. Further, the composition N outside the range of “content of Y ₂ O ₃ : 1.0 mol% or less” specified in the present invention
The comparative examples of o.13 and 17 (Y ₂ O ₃ : 1.1 mol%, 1.1 mol%) also had low bending strength.

On the other hand, the content of the stabilizer R ₂ O ₃ and Y ₂
1 selected from the group consisting of O ₃ and Yb ₂ O ₃ , Er ₂ O ₃ and Ho ₂ O ₃
Even if a raw material mixture prepared so that the amount ratio relationship of one kind or two or more kinds of rare earth metal oxides falls within the predetermined range of the present invention is used, "500 to 1200" specified in the present invention under calcination conditions.
The zirconia-based sintered body of the present invention cannot be obtained under the conditions outside the range of “° C.”. For example, as a calcination condition, a comparative example of calcination at 1300 ° C. outside the range specified by the present invention and In the comparative example which was not calcined (see the column of composition No. 11 in Table 2),
The bending strength was low at 910MPa and 850MPa, and the low temperature deterioration resistance was also poor.

Further, as a sintering (main firing) condition, a comparative example sintered at 1700 ° C., which is outside the range of “1300 to 1650 ° C.” specified in the present invention, and a comparative example sintered at 1250 ° C. (Table 2) Composition N
(Refer to column o.11), the former high-temperature sintered material had a reaction with the baking platform and the bending strength was low at 840 MPa, while the latter low-temperature sintered material had an extremely high bending strength of 560 MPa. It was low, and none of the zirconia-based sintered bodies desired in the present invention was obtained.

"(HIP treatment)" in the column of composition No. 11 in Table 2 is a sintered body which was calcined at 1000 ° C and finally calcined at 1500 ° C, which was further HIP treated at 1400 ° C and 200 MPa. . By further HIPing in this way, a sintered body having a high strength of 1530 MPa can be obtained.

Although the starting material was prepared by the neutralization coprecipitation method in Example 1, the same results as in the neutralization coprecipitation method of Example 1 were also obtained in the starting materials prepared by the oxide mixing method. was gotten. That is, zirconium oxide (ZrO ₂ ) and rare earth metal oxide (R ₂ O ₃ ) are weighed, using ion-exchanged water as a solvent, in a planetary ball mill using a zirconia pot and a ball. A zirconia-based sintered body was produced under the same conditions as in Example 1, using the starting material obtained by the oxide mixing method obtained by kneading and drying. The obtained zirconia-based sintered body had the same characteristics as the zirconia-based sintered body of Example 1 obtained by the neutralization coprecipitation method.

(Example 2) Using the raw material prepared by the method of Example 1 above, it was calcined at a calcining temperature shown in Table 3 below and molded into a ball shape having a diameter of 1/2 inch. After that, calcination (main calcination) was also carried out at the temperature shown in Table 3 to prepare a grinding medium.

An abrasion test was carried out using the obtained grinding media. For the abrasion test, a 2 liter alumina ball mill pot was used, and the sample media was 3.6 kg and 800 c.
The water of c and the fused alumina powder (# 325) as a crushed object were put therein, and the mixture was rotated at a rotation speed of 100 rpm for 48 hours, and the reduction amount of the media weight before and after the test was measured. Table 3 shows the composition No. of the raw materials used, the amount of wear of the grinding media, and the average particle size after grinding.

[0053]

[Table 3]

As is clear from Table 3, the material for crushing using the zirconia-based sintered body of the present invention has a small wear resistance, a high crushing efficiency of the crushed object, and an excellent resistance to low temperature deterioration. Therefore, it was confirmed that the wear rate did not change even after the hot water test (holding in hot water at 200 ° C. for 50 hours) (see composition No. 11 in Table 3).

[0055] In contrast, Comparative Examples Comparative Example of Y ₂ O ₃ alone composition No.1 as a stabilizer, the composition does not use the Y ₂ O ₃ No.2, Y ₂ O ₃ and Yb ₂ O _{Although the} composition No. ₃ was used in combination, the comparative examples of compositions No. 10 and 13 outside the range specified in the present invention were inferior to the examples of composition No. 11.

[0056]

The zirconia-based sintered body according to the present invention is Zr
O ₂ as a main component and Y ₂ O ₃ and Yb ₂ O ₃ , Er ₂ O ₃ and Ho within a predetermined range
It is characterized in that a composition containing one or more rare earth metal oxides selected from the group consisting of ₂ O ₃ and containing a stabilizer in a predetermined range is sintered, whereby mechanical properties and resistance are improved. The present invention provides a zirconia-based sintered body that is excellent in low-temperature deterioration.

In addition, in the method for producing a zirconia-based sintered body according to the present invention, a raw material mixture is prepared by a chemical synthesis method or an oxide mixing method so that a predetermined raw material composition is obtained, and the raw material mixture is prepared at a predetermined temperature (500 to 500). After calcination at 1200 ° C), the raw material powder obtained through the crushing step is molded, and characterized by firing at a predetermined temperature (1300 to 1650 ° C), which has high mechanical properties that have never existed before, and The effect that the zirconia-based sintered body excellent in low temperature deterioration resistance can be manufactured is produced.

Further, according to the present invention, various characteristics such as high strength, lubricity, heat insulation, thermal expansion characteristics, and oxygen ion conductivity are provided, and by utilizing these characteristics, industrially wide application fields can be obtained. It is possible to provide a desired zirconia-based sintered body, and it is also possible to provide a zirconia-based sintered body excellent in low-temperature deterioration resistance, and its industrial utility is extremely large.

Furthermore, according to the crushing component material using the zirconia-based sintered body having the composition according to the present invention, the crushing material having high strength, excellent wear resistance and low temperature deterioration resistance and good crushing efficiency Part materials can be provided. Such a crushing component material of the present invention is used for crushing a lining material, a crushing medium (media), etc. used in various crushing devices for finely crushing particles of ceramics, metals, organic polymers, etc. in a dry or wet manner. It is extremely useful industrially as a part material.

Claims (5)

[Claims] 1. A method comprising ZrO ₂ as a main component, Y ₂ O ₃ , Yb ₂ O ₃ and Er ₂ O ₃
Y ₂ O which is stabilized with one or more rare earth metal oxides selected from the group consisting of and Ho ₂ O ₃ and which is contained in the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer. ₃ to 30
The zirconia-based sintered body is 40 mol% and the obtained crystal grains are mainly composed of a tetragonal phase or a mixed phase of tetragonal and cubic. 2. The zirconia-based sintered body according to claim 1, wherein the content of the stabilizer (R ₂ O ₃ ) in the sintered body is 2.0 to
A zirconia-based sintered body characterized by being 3.0 mol%. 3. The zirconia-based sintered body according to claim 1 or 2, wherein the content of Y ₂ O ₃ which is a stabilizer in the sintered body is 1.0 mol% or less. And a zirconia-based sintered body. 4. Y ₂ O ₃ , Yb ₂ O ₃ , and Er ₂ O ₃ containing ZrO ₂ as a main component.
Y ₂ O which is stabilized with one or more rare earth metal oxides selected from the group consisting of and Ho ₂ O ₃ and which is contained in the rare earth metal oxide (R ₂ O ₃ ) as a stabilizer. ₃ to 30
A method for producing a zirconia-based sintered body which is 40 mol%, wherein (1) as a raw material composition, a content of a stabilizer composed of the rare earth metal oxide (R ₂ O ₃ ) in the sintered body is 2.0 to 3.0 mol%, of which the content of Y ₂ O ₃ is 1.0 mol% or less, the raw materials are blended by a chemical synthesis method such as a neutralization coprecipitation method, a hydrolysis method, an alkoxide method or an oxide mixing method. A step of preparing a product, (2) a step of calcining the above-mentioned compound at 500 to 1200 ° C., (3) a step of molding the above-mentioned crushed product, (4) the above-mentioned molded body
A method for producing a zirconia-based sintered body, comprising a step of sintering at 1300 to 1650 ° C. 5. A crushing component material formed by using the zirconia-based sintered body according to claim 1, 2, or 3, wherein the average particle diameter of the sintered body is 2 μm or less and the bulk density is Is 6.0 g / cm ³ or more, a crushing part material using 3 zirconia-based sintered bodies.