JPH0813704B2 - Material for crusher - Google Patents

Description

Detailed Description of the Invention

[0001]

This invention is required to have excellent wear resistance, strength, and fracture toughness.
Dry or wet crusher members, for example, balls of ball mills, containers, container lining materials, containers for medium agitation mills such as attrition mills, container lining materials, stirring screws, stirring rods, rotating disks , Pins, balls, pebble, beads, rollers of roller mill, lining material of crushing chamber, crushing nozzle of jet mill, lining material of crushing chamber,
The present invention relates to a rotor for a hammer mill, a hammer, a pin for a pin mill, a rotor, a rotor for a disc mill, a blade, and a rotating disc for a colloid mill.

[0002]

2. Description of the Related Art As a crusher, a ball mill, a medium stirring mill, or a roller that moves a crushing medium such as balls and beads and crushes an object to be crushed by using impact force, frictional force, and compression force by the kinetic energy. Roller mill that crushes using the compression force of the machine, a jet mill that crushes the crushed object at a high speed with the lining material and crushes by the impact force of the collision, and a rotor that has a hammer, blade, pin, etc. fixed. Hammer mills, pin mills, disc mills that crush the object to be crushed by using the impact force of the rotation of, and colloid mills that use shearing force are widely used.

As the above-mentioned members such as the crushing medium and the lining material of these crushers, those made of natural stone, ceramics such as alumina ceramics and zirconia ceramics, resin, cemented carbide and the like are used. Commonly used. However, a member made of such a material is extremely likely to be worn, and a large amount of abrasion powder is mixed as an impurity in the object to be crushed during pulverization, and the object to be crushed or various materials using the object to be crushed as a raw material. There is a problem of deteriorating physical properties and quality. In particular, when the object to be crushed is to be used as a so-called advanced material such as a fine ceramic material, a magnetic material, or an electronic material, mixing of impurities by abrasion powder becomes a serious problem.

In response to such a demand, Japanese Patent Laid-Open No. 62-1
87157 No. invention, the Al ₂ O ₃ containing 99.9 wt% or more, below the average crystal grain size is 2.5μm of Al ₂ O _3,
A crusher member made of alumina ceramics having a relative density of 98% or more is proposed. However, although this member is excellent in wear resistance and hardness, it has low strength and fracture toughness, and has a problem that it is easily chipped or broken even by a slight impact. Also, in order to develop sufficient wear resistance and hardness, it is necessary to make the purity of Al ₂ O ₃ considerably higher than 99.9%, and even if a slight amount of impurities is mixed in during the production, the grain There is a problem that abrasion due to particle detachment due to a decrease in field strength occurs and wear resistance decreases.

On the other hand, the invention of Japanese Patent Publication No. 2-20587 is Y
₂ O ₃ in an amount of ₂ to 4.5 mol%, the crystal phase contains 10% or more of tetragonal ZrO ₂ and equiaxed ZrO ₂ , and does not substantially contain monoclinic ZrO ₂ , and the average Crystal grain size is 4 μm
The following proposes a crusher member made of zirconia ceramics having a bulk density of 5.8 g / cm ³ or more. This member is excellent in strength and fracture toughness, and is made of SiO ₂ and B
This is useful when a ceramic having a relatively low hardness such as aTiO _{3 is} to be crushed. However, A
There is a problem that abrasion rapidly progresses when crushing a relatively hard material such as l ₂ O ₃ or SiC, or when there is no lubricating medium like a dry crusher.

As described above, it is difficult to say that all the conventional crusher members have the characteristics required for the crusher members, in particular, wear resistance, strength, and fracture toughness in a well-balanced manner. .

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of conventional crusher members, and to provide crusher members having excellent wear resistance, strength and fracture toughness. To provide.

[0008]

In order to achieve the above-mentioned object, the present invention contains Al ₂ O ₃ as a main component,
In the crystal structure, at least 50% by volume is tetragonal ZrO ₂ is included in the range of 20 to 40% by weight, TiO ₂ is included in the range of 1 to 5% by weight, and MgO is 0.1 to 1% by weight.
And the average crystal grain size of Al ₂ O ₃ is 1.5 to 5
μm range and at least 80% of ZrO ₂
Provides a member for a crusher made of ceramics existing in a grain boundary of Al ₂ O ₃ . Preferably ZrO ₂
Has an average crystal grain size d _z of 1.5 to ₃ μm, and the ratio d _A / d _z of the average crystal grain size d _{A of} Al ₂ O ₃ and the average crystal grain size d _{z of} ZrO ₂ is It is in the range of 1-3. Further, the crusher member of the present invention preferably has a relative density of 95% or more. Furthermore, the thermal conductivity at 20 ° C. is preferably in the range of 0.02 to 0.07 cal / cm · sec · ° C. The crusher member of the present invention has a diameter of 1
For 0 mm ball members, 200 ball members were placed in a nylon ball mill with an internal volume of 1000 ml, and further, 36% water and 4% SiC powder with an average particle size of 1 μm were added to the total weight of the ball members. And put the ball mill 1
The weight loss rate after operating for 50 hours at a speed of 00 rpm is 1
% Or less.

Although the wear mechanism of the member for the crusher is not always clear, particles made of ceramics such as Al ₂ O _{3 having} high hardness but low grain boundary strength are subject to particle detachment wear due to grain boundary fracture. It happens preferentially,
Those made of ceramics such as ZrO _{2 having} high strength but relatively low hardness are considered to be worn away by friction preferentially. From such an estimation, the present invention is to disperse ZrO ₂ in the grain boundaries of Al ₂ O ₃ and
By suppressing the development of intergranular cracks in l ₂ O ₃ , making it difficult for intergranular separation wear to improve wear resistance and strength, and to increase the Al ₂ O ₃ crystal grain size. It attempts to promote crack deflection and improve fracture toughness.

The ceramic constituting the member for a crusher of the present invention contains Al ₂ O ₃ as a main component. Then, the average crystal grain size is in the range of 1.5 to 5 μm. If the average crystal grain size is less than 1.5 μm, the crack deflection effect cannot be expected and the fracture toughness cannot be improved. On the other hand, 5 μm
If the value exceeds the range, the area of the grain boundary in one Al ₂ O ₃ crystal grain becomes large, so that grain boundary separation wear is likely to occur and wear resistance is reduced. A more preferable range of the average crystal grain size is 1.5 to 3 μm.

The ceramic used in the present invention contains ZrO ₂ in the range of 20 to 40% by weight.
This ZrO ₂ has at least 50% of its crystal structure.
It is such that the volume% is tetragonal and the balance cubic and / or monoclinic. ZrO ₂ is less than 20 wt%, the ZrO ₂ having a tetragonal crystal structure is less than 50 vol%, can not be expected effect of improving the strength of the by stress-induced transformation to monoclinic tetragonal. On the other hand, ZrO ₂ is 40
When the content is more than wt%, the strength of the ZrO ₂ crystal grains is reduced and the wear resistance is also reduced. Here, ZrO ₂ contains a stabilizer such as Y ₂ O ₃ or CeO ₂ in an amount of about 1.5 to 5 mol% to obtain a tetragonal crystal having a crystal structure of at least 50% by volume. Is metastable at room temperature.

The above-mentioned ZrO ₂ has at least 80
% Are distributed in the grain boundaries of Al ₂ O ₃ which is the main component. Even if it exists in the crystal grains of Al ₂ O ₃ , it is small. As a result, ZrO ₂ can effectively cause stress-induced transformation with respect to cracks that propagate in the crystal grain boundaries of Al ₂ O ₃ , and the growth of grain boundary cracks is suppressed, making it difficult for grain boundary detachment wear to occur. Along with improved wear resistance,
Stress relaxation at the crack tip improves strength.

Further, the ceramic constituting the member for a crusher of the present invention contains TiO ₂ in the range of 1 to 5% by weight. TiO ₂ promotes the growth of Al ₂ O ₃ crystal grains during sintering and appropriately coarsens them so that the deflection action of cracks works effectively and improves fracture toughness.
To expect such an effect, 1% by weight of TiO ₂ is necessary. However, if it exceeds 5% by weight, Al
₂ O ₃ crystal grains become too large.

MgO is a part of Al ₂ O produced during sintering.
₃ Abnormal grain growth is suppressed, the grain size of Al ₂ O ₃ is made uniform, and ZrO ₂ is easily distributed at the grain boundaries, which improves wear resistance and strength. To do. Further, when only TiO ₂ is contained, ZrO ₂ and TiO ₂ react with each other during sintering to produce ZrTiO ₄ , which abnormally grows grains during sintering to form needle-like crystals and Wearability and strength will be greatly reduced, but M
By allowing gO to coexist, such a production reaction can be suppressed. In order to expect such an action, MgO must be at least 0.1% by weight. 0.
If it is less than 1% by weight, a part of Al ₂ O ₃ will grow abnormally and ZrO ₂ will be easily incorporated into the crystal grains. Further, it becomes difficult to suppress the ZrTiO ₄ formation reaction. on the other hand,
If it exceeds 1% by weight, the effect of suppressing the growth of Al ₂ O ₃ crystal grains becomes too strong, and the average crystal grain size cannot be controlled within the above range.

The crusher member of the present invention has an average crystal grain size d _z of ZrO ₂ in the range of 1.5 to 3 μm, and A
When the ratio d _A / d _z of the average crystal grain size d _{A of} l ₂ O ₃ and the average crystal grain size d _{z of} ZrO ₂ is set in the range of 1 to 3, abrasion resistance and strength are further improved. That is, by setting the average crystal grain size of ZrO ₂ and the value of d _A / d _z within the above range, grain boundary separation wear hardly occurs even in ZrO _{2 and} wear resistance is improved. In addition, ZrO ₂ and Al ₂
Appropriate interphase stress acts on O _3, and in addition to the deflection effect of cracks, it is expected that a strengthening mechanism due to complex crack branching will appear.

Further, the crusher member of the present invention has further improved abrasion resistance and strength when the relative density is 95% or more. Here, the relative density represents the relative value of the actual density with respect to the theoretical density as a percentage, and when the relative density is 95% or more, the number of pores existing at the grain boundaries decreases and Grain boundary desorption wear that occurs as the origin of interfacial cracks, and the occurrence of cracks leading to fracture is less likely to occur,
Wear resistance and strength are improved. The theoretical density is calculated by the following formula.

100 / [0.2508 · W _A + 0.2353 · W _T +
0.3868 W _M + W _Z /(6.10+k·x)] where W _A : wt% of Al ₂ O ₃ W _T : wt% of TiO ₂ W _M : wt% of MgO W _Z : wt% of ZrO ₂ k: when the stabilizer of ZrO ₂ is Y ₂ O ₃ , it is −0.
008, a value determined by the type of 0.014 (ZrO ₂ stabilizer in the case of CeO _2, the lattice constant, the molecular weight,
X: ZrO ₂ stabilizer mol%, further, the pulverizer member of the present invention has a thermal conductivity of 0.02 to 0.07 cal / cm · sec · ° C. at 20 ° C. In range. This is preferable when it is a member such as a medium stirring mill.

That is, in a pulverizer such as a medium agitating mill that agitates a pulverizing medium at a high speed, the vigorous agitating motion may generate heat, which may cause deterioration of the object to be crushed by heat or evaporation of a lubricating medium. The pulverization efficiency may decrease due to the change in concentration. Therefore, in these crushers, members such as the container and the lining material are generally cooled, but in order to enhance the cooling effect, the higher the thermal conductivity of the member, the better. In this respect, the member of the present invention has a higher thermal conductivity than the ZrO ₂ ceramic member described above, and a high cooling effect can be obtained. Also,
A member made of ZrO ₂ ceramics or the like needs to be thinned in order to prevent heat accumulation, and the strength as a member may be insufficient. However, the member of the present invention has high strength and high thermal conductivity. , Such worry can be reduced. As described above, the higher the thermal conductivity, the better, but the thermal conductivity of the ceramics used in the present invention is 0.02 to 0.07 cal / cm · se at 20 ° C.
c · Keep in the range of ° C.

In the crusher member according to the present invention, 200 ball members (about 450 g) each having a diameter of 10 mm and having its surface barrel-polished are placed in a nylon ball mill having an internal volume of 1000 ml, and the ball members are 36% water by weight and 4% SiC with an average particle size of 1 μm
The weight loss rate after adding the powder and operating the ball mill for 50 hours at a speed of 100 rpm is 1% or less. Such a value is a value that cannot be expected for a member made of Al ₂ O ₃ ceramics or a member made of ZrO ₂ ceramics.

The crusher member of the present invention can be manufactured, for example, by the following method.

That is, a predetermined amount of ZrO ₂ powder, TiO ₂ powder, and MgO are added to Al ₂ O ₃ powder which is the main component.
Add powder and mix well to make mixed powder. The mixing operation may be wet or dry. The mixed powder is dried if necessary, coarsely pulverized, sieved or granulated. The Al ₂ O ₃ powder preferably has an average particle size in the range of 0.3 to 2 μm because it enables dense sintering. In addition, TiO ₂ , MgO,
It is preferable to use each ZrO ₂ powder having an average particle diameter of 1 μm or less in consideration of uniform dispersion in Al ₂ O ₃ . Further, the purity of each powder described above prevents abnormal growth of crystal grains due to impurities and further improves properties such as wear resistance and strength and fracture toughness.
% Or more is preferable.

Next, the above-mentioned mixed powder is processed by a known molding method,
For example, it is molded into a desired shape using a die molding method, a rubber press molding method, a casting molding method, or an injection molding method, and is sintered. The atmosphere during sintering is an oxidizing atmosphere such as the air. The sintering temperature and time are such that the average crystal grain size of Al ₂ O ₃ is in the range of 1.5 to 5 μm, and ZrO is preferable.
_{2 has} an average crystal grain size of 1.5 to 3 μm, and d
Carefully control _A / d _z to be in the range of 1-3. Further, in order to allow at least 80% of ZrO ₂ to exist in the grain boundary of Al ₂ O ₃ which is the main component, Al ₂ O ₃
Is heated at a slow rate of 0.5 ° C./min or less near the sintering temperature so that ZrO ₂ will not be incorporated into the crystal grains due to rapid grain growth. On the other hand, after the sintering, if the cooling rate is too slow, a large amount of monoclinic ZrO ₂ is precipitated and it becomes impossible to make tetragonal ZrO ₂ at least 50% by volume. Cool with. In addition,
The relative density can be sufficiently increased to 95% or more by general sintering such as pressureless sintering, but the relative density is further increased to further improve the wear resistance and the strength, and the pores are In order to further improve the thermal conductivity by reducing the amount, it is also preferable to subject the obtained ceramics to hot isostatic pressing (HIP treatment).

Next, the obtained ceramics are subjected to mechanical processing such as grinding and polishing, and if necessary, they are attached to obtain a desired crusher member.

[0024]

EXAMPLES Example 1: Al ₂ O ₃ powder having an average particle size of 0.5 μm and a purity of 99.8% and an average particle size of 0.
TiO ₂ powder with a size of 7 μm and a purity of 99.99% 1
% By weight, average particle size 0.3 μm, purity 99.9%
0.1% by weight of MgO powder having an average particle size of 0.7
μm of 20% by weight of ZrO ₂ powder containing 1.5 mol% Y ₂ O ₃ as a stabilizer, using a ball mill,
After wet-mixing in pure water for 24 hours, polyvinyl alcohol was added, and the mixture was sprayed, granulated and dried to obtain a mixed powder. The ZrO ₂ powder was prepared by adding an aqueous solution of YCl _{3 to} an aqueous solution of ZrOCl ₂ · 8H ₂ O and mixing them, adding ammonia water to coprecipitate a hydroxide, washing the coprecipitate with water, and drying the coprecipitate. It was prepared by calcining at 1000 ° C. for 60 minutes.

Next, the above-mentioned mixed powder is filled in a mold, and 1
Applying a pressure of 000kgf / cm ² , length 40mm, width 5mm,
A molded product having a thickness of 4 mm for a strength test was obtained. Also, for wear test, 1000kgf / cm ² using rubber press method.
A spherical molded body having a diameter of 10 mm was obtained under the pressure.

Next, the above two types of molded bodies were sintered in the atmosphere at 1550 ° C. for 2 hours to obtain two types of ceramics for strength test and wear test. At this time, the temperature rising rate was 2 ° C./min up to 1000 ° C., 0.5 ° C./min above that, and the cooling rate was 5 ° C./min.

Regarding the ceramics thus obtained,
The average crystal grain size of Al ₂ O ₃ and ZrO ₂ , the ratio of tetragonal ZrO ₂ and Z existing in the grain boundary of Al ₂ O _3.
The ratio of rO ₂ and the average crystal grain size d _A and Zr of Al ₂ O _3.
The ratio d _A / d _z to the average crystal grain size d _{z of} O ₂ , the relative density, the bending strength, the fracture toughness, the thermal conductivity, and the wear rate due to wear were determined.

The average crystal grain size was obtained by polishing the surface of the ceramics and then etching, obtaining the maximum lengths of crystal grains in several directions on a micrograph of the etched surface, and simply averaging.

The proportion of tetragonal ZrO ₂ is the tetragonal (11) which appears near 2θ = 30.2 ° when the surface of the sintered body is carefully mirror-polished and analyzed by an X-ray diffraction method.
1) integrated intensity T (111) of the diffraction peak of the plane and 2θ =
The integrated intensity M (111) of the diffraction peak of the monoclinic (111) plane appearing near 28.2 ° and the diffraction peak of the monoclinic (111 ⁻ ) plane appearing near 2θ = 31.5 ° From the integrated intensity M (111 ⁻ ) of the equation {T (111) / [T (111) + M (111) + M
(111 ⁻ )]} × 100. Here, 1 ^- represents -1.

ZrO ₂ existing at the grain boundary of Al ₂ O ₃
Proportion of from photomicrographs described above, read the number Z _b of ZrO ₂ present in the grain boundaries of Al ₂ O _3, and the number Z _i of ZrO ₂ present in the crystal grains, wherein, [Z _b / (Z _b + Z _i )] × 100.

The relative density was determined by the equation (D _s / D _t ) × 100 from the actual density D _s of the ceramics obtained by the Archimedes method and the theoretical density D _t obtained by the above method. .

Bending strength was obtained by processing ceramics for strength test, and 10 pieces of the length 36 mm, width 4 mm, thickness 3 were obtained.
The test piece of mm was subjected to a 3-point bending test based on JISR1601 to obtain a simple average value. Span length is 3
The crosshead speed was 0 mm and the crosshead speed was 0.5 mm / min.

The fracture toughness is based on JIS R1607,
For 5 test pieces similar to the bending test, an indentation was made at the center in the length direction using a Vickers hardness tester with a load of 10 kgf, and then a bending test was performed in the same manner as above to measure the breaking load. Fracture toughness was calculated and calculated as a simple average value.

The thermal conductivity was determined by the following equation using the well-known laser flash method. The measurement temperature was 20 ° C., the sample was a disk having a diameter of 10 mm and a thickness of 1 mm, the heat source was a ruby laser, and an infrared sensor was used for temperature detection.

0.1388 · L · Q / (t · T _m ) where L: sample thickness Q: heat quantity per unit area given by laser pulse T _m : maximum temperature rise of sample t: T _m The time required to reach half the value of the wear rate is as follows: The wear rate of the spherical ceramics for abrasion test is barrel-polished to make the surface smooth, then 200 pieces (weight: W ₁ ) of them are made into a nylon ball mill with a capacity of 1000 ml. 20 g of SiC powder with an average particle size of 1 μm
And 180 g of water were added, the ball mill was operated at 100 rpm for 50 hours, the spherical ceramics were taken out, washed with ultrasonic waves, dried, and the weight W ₂ was measured. The formula [(W ₁ −W ₂ ) / W ₁ ] × 100.

Al ₂ O ₃ average particle size: 2.9 μm ZrO ₂ average particle size: 1.6 μm d _A / d _z : 1.8 Tetragonal ZrO ₂ ratio: 93 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 95% Relative density: 96.3% Bending strength: 75.8kgf / mm ² Fracture toughness: 5.4MPa ・ m ^1/2 Thermal conductivity: 0.047cal / cm ・ sec ・C. Abrasion rate due to wear: 0.13% Example 2: TiO ₂ powder amount was 3% by weight, MgO powder amount was 0.3% by weight, and ZrO ₂ powder was 2.5 mol%. Test pieces were prepared and tested in the same manner as in Example 1 except that those containing Y ₂ O ₃ were used. The test results are shown below.

Al ₂ O ₃ average particle size: 3.0 μm ZrO ₂ average particle size: 1.7 μm d _A / d _z : 1.8 Tetragonal ZrO ₂ ratio: 91 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 92% Relative density: 97.5% Bending strength: 82.0 kgf / mm ² Fracture toughness: 5.4 MPa ・ m ^1/2 Thermal conductivity: 0.045 cal / cm ・ sec ・C. Abrasion rate due to abrasion: 0.11% Example 3: The amount of TiO ₂ powder was 5% by weight, the amount of MgO powder was 1% by weight, and the amount of ZrO ₂ powder was 5%.
Example 1 except that one containing mol% Y ₂ O ₃ was used.
A test piece was prepared and tested in the same manner as in. The test results are shown below.

Al ₂ O ₃ average particle size: 3.4 μm ZrO ₂ average particle size: 2.0 μm d _A / d _z : 1.7 Tetragonal ZrO ₂ ratio: 85% by volume Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 91% Relative density: 95.5% Bending strength: 79.3 kgf / mm ² Fracture toughness: 5.0 MPa ・ m ^1/2 Thermal conductivity: 0.045 cal / cm ・ sec ・Deterioration rate due to abrasion: 0.13% Example 4: A test piece was prepared and tested in the same manner as in Example 1 except that the amount of ZrO ₂ powder was 30% by weight. The test results are shown below.

Al ₂ O ₃ average particle size: 2.8 μm ZrO ₂ average particle size: 2.0 μm d _A / d _z : 1.4 Tetragonal ZrO ₂ ratio: 81 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 93% Relative density: 96.8% Bending strength: 92.4 kgf / mm ² Fracture toughness: 5.8 MPa ・ m ^1/2 Thermal conductivity: 0.042 cal / cm ・ sec ・C. Abrasion rate due to abrasion: 0.23% Example 5: TiO ₂ powder amount was 3% by weight, MgO powder amount was 0.3% by weight, and ZrO ₂ powder was 2.
A test piece was prepared and tested in the same manner as in Example 1 except that the one containing 5 mol% of Y ₂ O ₃ was used and the amount thereof was 30% by weight. The test results are shown below.

Al ₂ O ₃ average particle size: 3.1 μm ZrO ₂ average particle size: 2.1 μm d _A / d _z : 1.5 Tetragonal ZrO ₂ ratio: 80 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 95% Relative density: 96.5% Bending strength: 88.3 kgf / mm ² Fracture toughness: 5.8 MPa ・ m ^1/2 Thermal conductivity: 0.043 cal / cm ・ sec ・C. Abrasion rate due to wear: 0.25% Example 6: TiO ₂ powder amount was 3% by weight, MgO powder amount was 0.3% by weight, and ZrO ₂ powder was 2.
Test pieces were prepared and tested in the same manner as in Example 1 except that the one containing 5 mol% of Y ₂ O ₃ was used and the amount thereof was 40% by weight. The test results are shown below.

Al ₂ O ₃ average particle size: 2.9 μm ZrO ₂ average particle size: 2.2 μm d _A / d _z : 1.3 Tetragonal ZrO ₂ ratio: 73 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 90% Relative density: 96.1% Bending strength: 74.2 kgf / mm ² Fracture toughness: 6.3 MPa ・ m ^1/2 Thermal conductivity: 0.038 cal / cm ・ sec ・C. Abrasion rate due to wear: 0.28% Example 7: TiO ₂ powder amount was 5% by weight, MgO powder amount was 1% by weight, and ZrO ₂ powder was 5 mol%.
Of Y ₂ O ₃ was used, and a test piece was prepared in the same manner as in Example 1 except that the amount was 40% by weight.
Tested. The test results are shown below.

Al ₂ O ₃ average particle size: 3.0 μm ZrO ₂ average particle size: 2.4 μm d _A / d _z : 1.3 Tetragonal ZrO ₂ ratio: 70% by volume Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 89% Relative density: 95.3% Bending strength: 73.1 kgf / mm ² Fracture toughness: 6.0 MPa ・ m ^1/2 Thermal conductivity: 0.038 cal / cm ・ sec ・C. Abrasion rate due to wear: 0.29% Example 8: TiO ₂ powder amount was 3% by weight, MgO powder amount was 0.3% by weight, and ZrO ₂ powder was 2.
One containing 5 mol% Y ₂ O ₃ was used, and 155
After sintering at 0 ° C, the temperature was 1350 in an argon atmosphere.
A test piece was prepared and tested in the same manner as in Example 1 except that hot isostatic pressing was performed at a temperature of 2000 ° C and a pressure of 2000 kgf / cm ² . The test results are shown below.

Al ₂ O ₃ average particle size: 3.1 μm ZrO ₂ average particle size: 1.8 μm d _A / d _z : 1.7 Tetragonal ZrO ₂ ratio: 95% by volume Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 92% Relative density: 99.8% Bending strength: 105.5 kgf / mm ² Fracture toughness: 6.0 MPa ・ m ^1/2 Thermal conductivity: 0.049 cal / cm ・ sec ・C. Abrasion rate due to abrasion: 0.08% Example 9: TiO ₂ powder amount was 3% by weight, MgO powder amount was 0.3% by weight, and ZrO ₂ powder was 2.
A material containing 5 mol% Y ₂ O ₃ was used, and the amount thereof was 30 wt%, and after sintering at 1550 ° C., the temperature was 1350 ° C. and the pressure was 2000 kgf / in an argon atmosphere.
Test pieces were prepared and tested in the same manner as in Example 1 except that hot isostatic pressing was performed at cm ² . The test results are shown below.

Al ₂ O ₃ average particle size: 3.2 μm ZrO ₂ average particle size: 2.1 μm d _A / d _z : 1.5 Tetragonal ZrO ₂ ratio: 87 volume% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 93% Relative density: 99.7% Bending strength: 118.5 kgf / mm ² Fracture toughness: 6.5 MPa ・ m ^1/2 Thermal conductivity: 0.045 cal / cm ・ sec ・℃ Wear rate: 0.12%

[0045]

Comparative Example Comparative Example 1: The amount of TiO ₂ powder was 3% by weight, the amount of MgO powder was 0.3% by weight, and the ZrO ₂ powder containing 2.5 mol% Y ₂ O _3. use,
A test piece was prepared and tested in the same manner as in Example 1 except that the amount was 5% by weight. The test results are shown below.

Al ₂ O ₃ average particle diameter: 3.8 μm ZrO ₂ average particle diameter: 1.0 μm d _A / d _z : 3.8 Tetragonal ZrO ₂ ratio: 92 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 81% Relative density: 93.3% Bending strength: 48.1 kgf / mm ² Fracture toughness: 4.1 MPa ・ m ^1/2 Thermal conductivity: 0.053 cal / cm ・ sec ・C. Abrasion rate due to abrasion: 0.82% Comparative Example 2: TiO ₂ powder amount was 3 wt%, MgO powder amount was 0.3 wt%, and ZrO ₂ powder was 2.
A test piece was prepared and tested in the same manner as in Example 1 except that the one containing 5 mol% of Y ₂ O ₃ was used and the amount thereof was 50% by weight. The test results are shown below.

Al ₂ O ₃ average particle diameter: 2.3 μm ZrO ₂ average particle diameter: 2.5 μm d _A / d _z : 0.9 Tetragonal ZrO ₂ ratio: 64% by volume Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 90% Relative density: 89.4% Bending strength: 49.3 kgf / mm ² Fracture toughness: 5.9 MPa ・ m ^1/2 Thermal conductivity: 0.027 cal / cm ・ sec ・Deterioration rate due to abrasion: 0.55% Comparative Example 3: The amount of TiO ₂ powder was 3% by weight, MgO powder was not added, and ZrO ₂ powder of 2.5 mol% Y was used.
Test pieces were prepared and tested in the same manner as in Example 1 except that those containing ₂ O ₃ were used. The test results are shown below.

Al ₂ O ₃ average particle size: 6.8 μm ZrO ₂ average particle size: 1.3 μm d _A / d _z : 5.2 Tetragonal ZrO ₂ ratio: 83 vol% Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 69% Relative density: 92.0% Bending strength: 48.2 kgf / mm ² Fracture toughness: 4.5 MPa ・ m ^1/2 Thermal conductivity: 0.041 cal / cm ・ sec ・Deterioration rate due to abrasion: 0.73% Comparative Example 4: Neither TiO ₂ powder nor MgO powder was used, but ZrO ₂ powder containing 2.5 mol% Y ₂ O ₃ was used. Test pieces were prepared and tested in the same manner as in Example 1 except that the sintering temperature was set to 1600 ° C. The test results are shown below.

Al ₂ O ₃ average particle size: 1.0 μm ZrO ₂ average particle size: 0.5 μm d _A / d _z : 2.0 Tetragonal ZrO ₂ ratio: 93% by volume Al ₂ O ₃ particles Of ZrO ₂ existing in the boundary: 85% Relative density: 98.5% Bending strength: 60.0 kgf / mm ² Fracture toughness: 3.9 MPa ・ m ^1/2 Thermal conductivity: 0.042 cal / cm ・ sec ・Deterioration rate due to abrasion: 0.48% Comparative Example 5: TiO ₂ powder, MgO powder, ZrO ₂ powder were not used, and Al ₂ O ₃ powder had an average particle size of 0.
A test piece was prepared and tested in the same manner as in Example 1 except that a material having a thickness of 8 μm and a purity of 99.5% was used and the sintering temperature was 1650 ° C. The test results are shown below.

Al ₂ O ₃ average particle size: 5.3 μm Relative density: 96.8% Bending strength: 38.0 kgf / mm ² Fracture toughness: 3.2 MPa · m ^1/2 Thermal conductivity: 0.058 cal / cm · sec · ° C Abrasion loss rate: 1.25% Comparative Example 6: Al ₂ O ₃ powder, TiO ₂ powder, MgO powder were not used, average particle size 0.7 μm, 2.5 mol% No. ₂ Y ₃ O ₃ -containing ZrO ₂ powder was used, and a test piece was prepared and tested in the same manner as in Example 1 except that the sintering temperature was 1450 ° C. The test results are shown below.

ZrO ₂ average particle size: 0.4 μm Tetragonal ZrO ₂ ratio: 93% by volume Relative density: 99.1% Bending strength: 124.0 kgf / mm ² Fracture toughness: 7.8 MPa · m ^1/2 Thermal conductivity: 0.007cal / cm ・ sec ・ ℃ Wear rate due to wear: 2.21%

[0052]

The crusher member of the present invention is made of Al ₂ O ₃
At least 50 in the crystal structure.
It contains tetragonal ZrO ₂ in the range of 20 to 40 wt%, TiO ₂ in the range of 1 to 5 wt%, and Mg.
O in the range of 0.1 to 1% by weight, the average crystal grain size of Al ₂ O ₃ is in the range of 1.5 to 5 μm, and ZrO
_Since at least 80% of ₂ is composed of ceramics existing in the grain boundary of Al ₂ O ₃ , it is clear from the comparison between Examples and Comparative Examples that wear resistance, strength and fracture toughness are Are both excellent. These characteristics are that the average crystal grain size d _{z of} ZrO ₂ is in the range of 1.5 to ₃ μm, and the average crystal grain size d _A and Zr of Al ₂ O ₃ are the same.
When the ratio d _A / d _{z of} O _{2 to} the average crystal grain size d _z is in the range of 1 to 3, it is further improved. Further, when the relative density of the sintered body is 95% or more, it is further improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B02C 17/22

Claims (5)

[Claims] 1. ZrO ₂ containing Al ₂ O ₃ as a main component and having at least 50% by volume of the crystal structure is tetragonal.
In the range of 20 to 40% by weight, TiO ₂ in the range of 1 to 5% by weight, MgO in the range of 0.1 to 1% by weight, and the average grain size of Al ₂ O ₃ is 1. 5 to 5 μm, and at least 80% of ZrO ₂ is Al ₂
A member for a crusher made of ceramics existing in a grain boundary of O ₃ . _2. The average crystal grain size d _{z of} ZrO ₂ is 1.5 to 3.
in the range of μm and the average grain size d of Al ₂ O ₃
The ratio d _A / d _z between the average crystal grain size d _z of _A and ZrO ₂ is 1
The member for a crusher according to claim 1, which is in a range from 3 to 3. 3. The crusher member according to claim 1, which has a relative density of 95% or more. 4. The thermal conductivity at 20 ° C. is 0.02 to 0.
The crusher member according to claim 1, 2 or 3, which is in the range of 07 cal / cm · sec · ° C. 5. Regarding ball members having a diameter of 10 mm, 200 ball members are placed in a nylon ball mill having an internal volume of 1000 ml, and further 36% of the total weight of the ball members is set.
Water and 4% of SiC powder having an average particle size of 1 μm are put, and the weight loss rate after the ball mill is operated at a speed of 100 rpm for 50 hours is 1% or less. 4 crusher members.