JP4410044B2 - Zirconia sintered body excellent in wear resistance and durability and method for producing the same - Google Patents

Description

  The present invention relates to a zirconia sintered body excellent in wear resistance and durability and a method for producing the same. The zirconia sintered body according to the present invention has excellent wear resistance and durability even in a hot water or high humidity atmosphere of about 100 ° C. or lower.

  In recent years, ceramics are excellent in wear resistance, corrosion resistance, and the like, so that cases used for structural materials for industrial machines are increasing instead of conventional metals. For example, the production of highly functional materials such as electronic materials requires fine powdering, high dispersion, and high purity. For this reason, as the pulverizer used, a medium agitation pulverizer having a high pulverization / dispersion efficiency by stirring the pulverization / dispersion medium at a high speed from a conventional ball mill has become the mainstream.

Since such a mill has a considerably large load on the grinding / dispersing media, it is pulverized by Y ₂ O ₃ reinforced zirconia (Y-TZP) mainly composed of tetragonal zirconia with excellent impact resistance and wear resistance.・ Distributing media is used. This Y-TZP has excellent mechanical properties, but it transitions from tetragonal zirconia to monoclinic zirconia in a specific temperature range of 200 to 300 ° C. As a result, many defects have been widely known, and a method for preventing such defects has been proposed.

  On the other hand, the Y-TZP grinding / dispersion media has a large wear under load in hot water or high humidity atmosphere of about 100 ° C. or lower, or abrupt increase in wear when used. There was a problem that the wear resistance was lowered. Since the deterioration of the wear resistance in a hot water or high humidity atmosphere of about 100 ° C. or lower occurs even in the sintered body that prevents the thermal deterioration at 200 to 300 ° C., the above-mentioned Patent Document 1 and the like However, the current situation is that it cannot be improved by the method for preventing thermal degradation at 200 to 300 ° C.

  For these reasons, a zirconia sintered body having excellent wear resistance and durability stably for a long period of time has been desired.

Japanese Examined Patent Publication No. 61-21184

  An object of the present invention is to provide a zirconia sintered body that exhibits excellent wear resistance and durability stably for a long period of time, even in warm water or high humidity atmosphere of about 100 ° C. or lower, and a method for producing the same. In the point.

As a result of intensive studies in view of the above situation, the present inventors have found that the decrease in wear resistance in hot water or high humidity atmosphere of about 100 ° C. or lower is the thermal stability at 200 to 300 ° C. It was found that the cause is completely different from that by. And in the zirconia sintered body containing a specific amount of Y ₂ O _{3, the} amount of Al ₂ O ₃ and other components and the average crystal grain size are adjusted to an appropriate range to about 100 ° C. or less. The present inventors have found that it has extremely excellent wear resistance and durability even in warm water or a high humidity atmosphere, and has completed the present invention.

That is, the first of the present invention is (a) a ZrO ₂ —Y ₂ O ₃ -based zirconia sintered body in which ZrO ₂ crystals are mainly tetragonal, and (b) a Y ₂ O ₃ / ZrO ₂ molar ratio. Is in the range of 1.5 / 98.5 to 2.8 / 97.2, (c) Al ₂ O ₃ content is 0.1 to 5.0 wt% , and (d) SiO ₂ content is 0.15 wt% or more, preferably not less than 0.2 wt%, (e) the total amount of SiO ₂ and TiO ₂ exceeds the 0.15 wt%, or less 3.0 wt%, (f) an average crystal grain size Is 0.20 to 0.70 [mu] m, and (g) zirconia for each cycle when 10 cycles of 10 cycle operation at 60 [deg.] C. warm water using a medium stirring mill at a disk peripheral speed of 8 m / sec. The maximum value of the sintered body wear rate (media wear rate) is 50 ppm / h or less. And a zirconia sintered body having excellent wear resistance and durability.
In the second aspect of the present invention, the (A) Y ₂ O ₃ / ZrO ₂ molar ratio is in the range of 1.5 / 98.5 to 2.8 / 97.2, and the Al ₂ O ₃ content is 0.1. was 5.0 wt%, SiO ₂ content of 0.15 wt% or more, preferably not less than 0.2 wt%, the total amount of SiO ₂ and TiO ₂ exceeds the 0.15 wt%, or less 3.0 wt% And using a powder for molding mainly composed of ZrO ₂ having a specific surface area of 3 to 30 m ² / g, preferably 5 to ²⁰ m ² / g and a chlorine content of 50 ppm or less, (B) wet 2. The method for producing a zirconia sintered body having excellent wear resistance and durability according to claim 1 , wherein the zirconia sintered body is excellent in abrasion resistance and durability.

In the present invention, the wear rate of the zirconia sintered body for each cycle (media) when 10 cycles of 10 cycles of 1 cycle operation at a disk peripheral speed of 8 m / sec in 60 ° C. warm water using a medium stirring mill. The method for measuring the wear rate is as follows.

  That is, 1200 cc of pulverizing / dispersing medium made of a zirconia sintered body is placed in a dyno mill (Shinmaru Enterprises Co., Ltd .: Type KDL-PILOT, Vessel and disk are Nikkato Co., Ltd. high strength zirconia: YTZ). Circulate while adjusting the temperature in the range of 60-65 ° C with 10 liters of hot water 600cc / min held at 60 ° C, and run for 10 cycles with a disk peripheral speed of 8m / sec. The zirconia sintered body wear rate (media wear rate) per time per cycle is measured according to the following equation.

  And the thing whose maximum value of this zirconia sintered compact abrasion rate for every cycle is 50 ppm / hour or less shall be called excellent in abrasion resistance and durability in this specification.

  Hereinafter, each requirement to be satisfied by the zirconia sintered body excellent in wear resistance and durability of the present invention will be described in detail.

The requirement (a) in the present invention is a ZrO ₂ —Y ₂ O ₃ -based zirconia sintered body in which the crystal phase of ZrO ₂ is mainly tetragonal. If the zirconia sintered body contains a large amount of monoclinic crystals, fine cracks are generated around the crystal. When stress is applied, microcracking occurs starting from the fine cracks, resulting in friction, impact, crushing, etc. This is not preferable because the resistance to the resistance is lowered. At the same time, the durability in hot water or high humidity atmosphere of about 100 ° C. or lower is lowered, which is not preferable. On the other hand, if a large amount of cubic crystals are contained, not only the mechanical properties are lowered, but also Y ₂ O ₃ tends to be unevenly distributed in the vicinity of the crystal grain boundary, resulting in a decrease in durability.

  In the present invention, the presence / absence and content of monoclinic zirconia (M), which is a zirconia crystal phase, and the amounts of tetragonal zirconia (T) and cubic zirconia (C) are as follows. By X-ray diffraction. That is, the surface of the sintered body and the processed sintered body product are transformed from tetragonal to monoclinic by stress-induced phase transformation, and the true crystalline phase cannot be identified. And measured by X-ray diffraction in a diffraction angle range of 27 to 34 degrees, and the presence and content of monoclinic zirconia are obtained from the following equation.

  In addition, tetragonal zirconia and cubic zirconia are measured in the diffraction angle range of 70 to 77 degrees by X-ray diffraction in the same manner as the method for confirming the presence or absence of monoclinic zirconia, and obtained by the following formula. .

  In the present invention, it is possible to allow up to 5% by volume of cubic zirconia obtained from the X-ray diffraction and up to 3% by volume of monoclinic zirconia.

The requirement of (b) in the present invention is that the Y ₂ O ₃ / ZrO ₂ molar ratio is within the range of 1.5 / 98.5 to 2.8 / 97.2, preferably 1.7 / 98.3 to 2 It is preferable that it is in the range of 1.8 / 98.2 to 2.5 / 97.5, particularly within the range of 0.7 / 97.3. It may typically be in the HfO ₂ that may contain minor amounts mixed into ZrO ₂ in the raw materials, handling ZrO ₂ and the total amount of HfO _2, including the HfO ₂ amount as ZrO ₂ amount.
When the Y ₂ O ₃ / ZrO ₂ molar ratio is less than 1.5 / 98.5, the amount of monoclinic zirconia in the sintered body increases, cracks are generated inside the sintered body, and a load is applied. If it is used for a long time, cracks develop and cracks and chips occur, resulting in a decrease in wear resistance. On the other hand, when the Y ₂ O ₃ / ZrO ₂ molar ratio exceeds 2.8 / 97.2, thermal degradation at 200 to 300 ° C. decreases, but conversely in the present invention, hot water of about 100 ° C. or lower or high This is not preferable because wear resistance and durability are lowered in a humidity atmosphere.

Also it is possible to use those substituted with one or more other rare earth oxides up to 30 mol% of Y ₂ O ₃ amount. As such rare earth oxides, CeO ₂ , Nd ₂ O ₃ , Yb ₂ O ₃ , Dy ₂ O _{3 and the} like are preferable from the viewpoint of inexpensiveness.

The requirement (c) in the present invention is that the Al ₂ O ₃ content is 0.1 to 5.0 wt% . The addition of Al ₂ O ₃ not only has an effect of improving the sinterability and homogenizing the microstructure, but also has an effect of suppressing the characteristic deterioration in hot water or high humidity atmosphere of about 100 ° C. or lower. When the Al ₂ O ₃ content is less than 0.1 wt%, there is no effect of adding Al ₂ O ₃ , and when it exceeds 5.0 wt%, there are many Al ₂ O ₃ crystal grains at the ZrO ₂ crystal grain boundary. Therefore, wear resistance and durability are lowered, which is not preferable.

The requirement (d) in the present invention is that the SiO ₂ content is 0.15 wt% or more . In the present invention, the SiO ₂ content needs to be 0.15 wt% or more, more preferably 0.2 wt% or more. When the SiO ₂ content is less than 0.15 wt%, the durability in hot water or high humidity atmosphere of about 100 ° C. or lower is not preferable. On the other hand, if the SiO ₂ is too large, there is a case where the second phase is often formed wear resistance and durability is deteriorated ZrO ₂ grain boundaries.

The requirement (e) in the present invention is that the total amount of SiO ₂ and TiO ₂ exceeds 0.15 wt% and is 3.0 wt% or less. In the present invention, the total amount of SiO ₂ and TiO ₂ needs to be more than 0.15 wt% and not more than 3.0 wt%, preferably 0.25 to 2.5 wt%. In order to improve durability, it is necessary not only to contain a predetermined amount of SiO ₂ but also to contain TiO ₂ at the same time. When the total amount of SiO ₂ and TiO ₂ is 0.15 wt% or less, the durability is inferior, which is not preferable. On the other hand, when the total amount of SiO ₂ and TiO ₂ exceeds 3.0 wt%, there are many second phases at the ZrO ₂ crystal grain boundary and the second phase width is widened, resulting in a decrease in wear resistance and durability. May happen. Further, TiO ₂ is preferably contained in an amount of less 2.0 wt%.

The requirement (f) in the present invention is that the average crystal grain size is 0.20 to 0.70 μm. In the present invention, the average crystal grain size is required to be 0.20 to 0.70 μm, and more preferably 0.25 to 0.60 μm. When the average crystal grain size is less than 0.20 μm, the thermal stability is improved at 200 to 300 ° C., but this is not preferable because the durability in a hot water or high humidity atmosphere of about 100 ° C. or lower is deteriorated. When the average crystal grain size exceeds 0.70 μm, the wear resistance is lowered, which is not preferable. The average crystal grain size is an average value obtained by polishing a cross section of the zirconia sintered body to a mirror surface, then performing thermal etching or chemical etching, then observing with a scanning electron microscope and measuring 10 points by the intercept method. The calculation formula is as follows.

The requirement of (g) in the present invention is that the zirconia sintered body wears for each cycle when it is operated for 10 cycles in a cycle of 10 hours at a disk peripheral speed of 8 m / sec in 60 ° C. warm water using a medium stirring mill. The maximum value of the rate is 50 ppm / h or less. When the maximum value of the zirconia sintered body wear rate exceeds 50 ppm / h, the wear of the zirconia sintered body powder becomes large and at the same time, the zirconia sintered body wear rate for each batch is not stable. In particular, when the pulverization is performed using a medium stirring mill, this defect appears remarkably, which is not preferable.

In the present invention, bulk density 5.80 g / cm ³ or more and more preferably 5.85 g / cm ³ or more. When the bulk density is less than 5.80 g / cm ³ , there will be many pores that become defects, resulting in a decrease in strength and hardness, resulting in a decrease in durability as well as a decrease in wear resistance. Is not preferable. Further, the defect amount is preferably 5% or less. The defects shown here include not only pores but also dents after grain removal that occurs when mirror-finishing is performed by grinding and polishing a cross section of a zirconia sintered body (media). In this defect amount measurement method, a mirror-finished surface is photographed with a scanning electron microscope having a predetermined magnification (usually 1000 to 3000 times), and the photograph is subjected to image analysis to obtain a defective portion and a non-defective portion. The ratio of the area occupied by the defective portion in the entire image is calculated by separation by valuation. When the amount of defects exceeds 3%, even if the bulk density is 5.80 g / cm ³ or more, not only the wear resistance but also the durability is inferior.

  A method for producing a zirconia sintered body having excellent wear resistance and durability according to the present invention will be described.

An aqueous solution of a zirconium compound (eg, zirconium oxychloride) and an aqueous solution of an yttrium compound (eg, yttrium chloride) are uniformly mixed so that the content of ZrO ₂ and Y ₂ O ₃ is a predetermined molar ratio, hydrolyzed, and water After obtaining a Japanese product, dehydrating and drying, calcining at 400 to 1250 ° C. to obtain a zirconia powder, or wet mixing with water or an organic solvent in the form of an oxide or salt, dehydrating, After drying, a method of calcining at 400 to 1250 ° C. to obtain zirconia powder is employed. Components other than Y ₂ O ₃ may be added in a predetermined amount as an aqueous salt solution when mixing an aqueous solution or oxide of a zirconium compound and an yttrium compound, or water may be added during pulverization / dispersion of the calcined powder described later. You may add with forms, such as an oxide, a carbonate, and an oxide.

  The obtained calcined powder is pulverized and dispersed by a wet method and dried to obtain a molded powder. If necessary, add a molding aid and adjust the size with a spray dryer.

Molding the powder particle size mainly composed of ZrO ₂ obtained has a specific surface area 3~30m ² / g, preferably it is necessary that 5 to 20 m ² / g. When these ranges are exceeded, the sinterability and formability will be reduced as described later, and the zirconia sintered body obtained by sintering has many pores and defects, resulting in wear resistance. In addition, the durability is inferior.

Further, the molded powder containing ZrO ₂ as a main component needs to have a chlorine content of 50 ppm or less, more preferably 30 ppm or less. When the amount of chlorine exceeds 50 ppm, the formability is lowered, and there are many defects in the obtained zirconia sintered body, the strength is lowered, and the wear resistance and durability are inferior. For removal of chlorine, methods such as powder washing and neutralization with aqueous ammonia can be employed.

Rolling granulation molding method using the obtained molded powder mainly composed of ZrO ₂ and using water-containing alcohols, paraffin hydrocarbons and other organic solvents, soluble polymers or water A zirconia sintered body is formed by a clay molding method, a cast molding method and a submerged granulation molding method.

  The sintered body formed by the above method has excellent resistance to resistance because the amount of defects inside the sintered body can be significantly smaller than a sintered body obtained by CIP molding (hydrostatic press molding) using powder dried by a spray dryer or the like. A zirconia sintered body having wear and durability can be obtained. When water is contained in the solution used during molding as described above, an appropriate second phase is formed at or near the crystal grain boundary, and the grain boundary strength is increased, resulting in wear resistance and impact resistance. In addition to improving, there is an effect of showing excellent durability.

  As a solution used at the time of molding, an alcohol containing water, an organic solvent such as paraffinic hydrocarbons, a soluble polymer, or the like is used. When water is contained in the solution used at the time of molding, an appropriate second phase is formed at or near the crystal grain boundary, and the grain boundary strength is increased to improve wear resistance and impact resistance. It has the effect of exhibiting excellent durability.

  Next, the obtained compact is fired at about 1200 to 1550 ° C. in the atmosphere to obtain a sintered body.

Furthermore, if there is a defect inside the sintered body by performing HIP (hot isostatic press) treatment as necessary, these defects can be reduced or reduced, and resistance to friction, impact, crushing, etc. is increased. It is possible to improve wear resistance and durability. The HIP treatment is preferably carried out under pressure of 1150 to 1550 ° C. and 500 to 2000 atmospheres in an inert atmosphere such as Ar or N ₂ or an O ₂ atmosphere after atmospheric pressure sintering.

  The surface contaminated in the firing process of the zirconia sintered body thus obtained can be removed by polishing or the like.

(1) Since the zirconia sintered body of the present invention has excellent wear resistance and durability even in warm water or high humidity atmosphere of about 100 ° C. or lower, it can be used as a known grinding and dispersion medium. Compared to conventional media, it can be used effectively, and can also be used effectively in fields where wear resistance is required in warm water or high humidity atmospheres.
(2) The zirconia sintered body having excellent wear resistance and durability according to the present invention can be used not only for pulverizing / dispersing media but also for a wide range of industrial wear-resistant structural members such as bearing balls.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Examples and Comparative Examples Zirconium oxychloride having a purity of 99.6% and yttrium nitrate having a purity of 99.9% were mixed in an aqueous solution so as to have the compositions shown in Tables 1 and 3. Next, this aqueous solution is hydrolyzed under heating reflux, dehydrated and dried to obtain hydrated zirconium in which Y ₂ O ₃ is dissolved, and calcined at 600 to 1200 ° C. for 1 hour, and the obtained zirconia powder is obtained. Was wet crushed and dispersed. Note that the components other than Y ₂ O _3, and mixed a predetermined amount added during the pulverization in the form of oxides or salts. Next, the obtained slurry was dried and sized to obtain powders for molding, and these powders were used for rolling granulation molding using water. Sample No. In No. 12, the wax emulsion was added to the pulverized and dispersed slurry by 3 wt% with respect to the powder, spray-dried, and CIP molded at a pressure of 70 MPa. Tables 1 and 3 show the specific surface area and the chlorine content of the obtained molded powder. Next, it was fired at 1200 to 1600 ° C. and allowed to cool to obtain a spherical zirconia sintered body having a diameter of 1 mm. These zirconia sintered bodies were finished by barrel polishing and used as samples for evaluation.

The chemical compositions and characteristics of these zirconia sintered bodies are shown in Tables 1 to 4. Sample No. 1 to 10 are zirconia sintered bodies of the present invention. 11 to 22 are comparative products that do not satisfy at least one of the requirements of the present invention. Sample No. 18 and no. For No. 20, since the bulk density of the obtained zirconia sintered body was low, properties other than the bulk density were not measured.

  Next, 1200 cc of the sample zirconia sintered body (media) obtained above is put into a dyno mill (Shinmaru Enterprises Co., Ltd .: type KDL-PILOT, vessel and disk are made of Nikkato Co., Ltd. high strength zirconia: YTZ) having an internal volume of 1,400 cc. A test that circulates 10 liters of hot water held at 60 ° C. at 600 cc / min while adjusting the temperature within the range of 60 to 65 ° C., and operates 10 cycles with a disk peripheral speed of 8 m / sec and 10 hours as one cycle. The wear rate of the zirconia sintered body per hour for each cycle was measured. The wear rate of the zirconia sintered body was calculated as the weight change rate per hour before and after the test. Tables 2 and 4 show the maximum values of the wear rate of the zirconia sintered body for each cycle. In addition, in FIG. The relationship between the wear rate of each cycle of 4, 14, and 16 and the test time is shown.

  Furthermore, in order to clarify the difference between the durability in hot water or high humidity atmosphere of about 100 ° C. or lower and the thermal deterioration at 200 to 300 ° C., a test is performed by holding the sample at 250 ° C. for 1500 hours. The results of examining the presence or absence of subsequent cracks are also shown in Tables 2 and 4 in the section of thermal degradation / presence / absence of cracks.

From the results shown in Tables 2 and 4, it is clear that durability in warm water or high humidity atmosphere of about 100 ° C. or lower and thermal deterioration at 200 to 300 ° C. are completely different.
Furthermore, it is clear that the zirconia sintered body according to the present invention has a wear rate of 50 ppm / h or less and exhibits excellent wear resistance even in hot water.

＊熱劣化テストによるクラックの有無を示す。

* Indicates the presence or absence of cracks in the thermal degradation test.

The embodiment items of the present invention are listed below.
1. (A) ZrO ₂ crystal is a predominantly tetragonal structure is _ZrO 2 _-Y 2 _{O 3} zirconia sintered _{body, (b) Y 2 O 3} / ZrO 2 molar ratio of 1.5 / 98.5～ in the range of 2.8 / 97.2, a 0.1 to 5.0% is (c) _Al 2 _{O 3} content is at (d) SiO ₂ content of more than 0.15 wt%, ( e) The total amount of SiO ₂ and TiO ₂ is more than 0.15 wt% and not more than 3.0 wt%, (f) the average crystal grain size is 0.20 to 0.70 μm, and (g) the medium stirring mill The maximum wear rate of the zirconia sintered body for each cycle when 10 cycles of 10-hour operation for 1 hour at a disk peripheral speed of 8 m / sec in warm water at 60 ° C. using JIS is 50 ppm / h or less. Zirconia-based sintered body with excellent wear resistance and durability.
2. _{2. The} zirconia sintered body excellent in wear resistance and durability according to item 1 above, wherein the Y ₂ O ₃ / ZrO ₂ molar ratio is in the range of 1.7 / 98.3 to 2.7 / 97.3.
3. _{2. The} zirconia sintered body having excellent wear resistance and durability according to item 1, wherein the Y ₂ O ₃ / ZrO ₂ molar ratio is in the range of 1.8 / 98.2 to 2.5 / 97.5.
4). The preceding item wherein up to 30 mol% of the Y ₂ O ₃ addition amount is substituted with another rare earth oxide selected from the group consisting of CeO ₂ , Nd ₂ O ₃ , Yb ₂ O ₃ , and Dy ₂ O _3. A zirconia sintered body having excellent wear resistance and durability according to any one of 1 to 3.
5). 5. The zirconia sintered body having excellent wear resistance and durability according to any one of 1 to 4 above, wherein the content of SiO ₂ is 0.2 wt% or more.
6). 6. The zirconia sintered body excellent in wear resistance and durability according to any one of 1 to 5 above, wherein the total amount of SiO ₂ and TiO ₂ is 0.25 to 2.5 wt%.
7). 7. The zirconia sintered body having excellent wear resistance and durability according to item 6, wherein the content of TiO ₂ is 2.0 wt% or less.
8). A pulverizing / dispersing medium comprising the zirconia sintered body according to any one of 1 to 7 above.
9. (A) Y ₂ O ₃ / ZrO ₂ molar ratio is in the range of 1.5 / 98.5 to 2.8 / 97.2, and Al ₂ O ₃ content is 0.1 to 5.0 wt% . The SiO ₂ content is 0.15 wt% or more , the total amount of SiO ₂ and TiO ₂ exceeds 0.15 wt% and is 3.0 wt% or less, and the specific surface area is 3 to 30 m ² / g. Item 1. The above item 1 characterized in that (B) wet molding is performed using a molding powder mainly composed of ZrO ₂ having a chlorine content of 50 ppm or less, and (C) firing at 1200 to 1550 ° C in the atmosphere. Of producing a zirconia sintered body having excellent wear resistance and durability.
10. Following the step (C) of the previous item 9, (D) wear resistance and durability according to the previous item 9, which is processed at 1150 to 1550 ° C. and 500 to 2000 atm in an inert atmosphere or an oxygen-containing atmosphere. Method for producing a zirconia sintered body excellent in performance.
11. 11. The method for producing a zirconia sintered body having excellent wear resistance and durability according to item 9 or 10, wherein the specific surface area is 5 to ²⁰ m ² / g.

Sample No. in Example and Comparative Example. It is a graph which shows the relationship between the abrasion rate of each cycle of 4, 14, and 16 and test time.

Claims (2)

(A) ZrO ₂ crystal is a predominantly tetragonal structure is _ZrO 2 _-Y 2 _{O 3} zirconia sintered _{body, (b) Y 2 O 3} / ZrO 2 molar ratio of 1.5 / 98.5～ in the range of 2.8 / 97.2, a 0.1 to 5.0% is (c) _Al 2 _{O 3} content is at (d) SiO ₂ content higher 0.15 wt%, ( e) The total amount of SiO ₂ and TiO ₂ is more than 0.15 wt% and not more than 3.0 wt%, (f) the average crystal grain size is 0.20 to 0.70 μm, and (g) the medium stirring mill The maximum wear rate of the zirconia sintered body for each cycle when 10 cycles of 10-hour operation for 1 hour at a disk peripheral speed of 8 m / sec in warm water at 60 ° C. using JIS is 50 ppm / h or less. Zirconia-based sintered body with excellent wear resistance and durability. (A) The Y ₂ O ₃ / ZrO ₂ molar ratio is in the range of 1.5 / 98.5 to 2.8 / 97.2, and the Al ₂ O ₃ content is 0.1 to 5.0 wt% . The SiO ₂ content is 0.15 wt% or more , the total amount of SiO ₂ and TiO ₂ exceeds 0.15 wt% and is 3.0 wt% or less, and the specific surface area is 3 to 30 m ² / g. the ZrO ₂ chlorine content is 50ppm or less by using a molding powder mainly, (B) and molded by a wet, claim 1, characterized by firing at 1,200-1,550 ° C. (C) in the air The manufacturing method of the zirconia sintered compact excellent in abrasion resistance and durability as described .

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