JPH01286960A - Zirconia-based sintered form and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title sintered form giving excellent thermal conductivity and hardness with reduced mechanical strength drop-off due to low temperature aging, retaining the mechanical strength and toughness inherent in high-strength zirconia, by specifying, within a specific range, the contribution of parallelized model in the composite rule to the composite state of the final sintered form. CONSTITUTION:In such a zirconia-based sintered form as to contain (A) zirconia or a stabilized zirconia containing, in the form of solid solution, pref. <=10mol% of Y2O3, MgO, CaO, CeO2 etc. and (B) 10-50 (pref., 20-40) vol.% of ceramic component(s) other than zirconia, e.g., SiC, AlN, TiN, ZrB2, TiB2, the contribution of parallelized model in the composite rule in said sintered form is specified as 0.2-0.6; thereby, the objective zirconia sintered form giving a thermal conductivity K as high as 0.015-0.1cal/cm.sec. deg.C, with both high mechanical strength and hardness, useful for various sorts of molds, metal-machining tools, internal combustion engine materials, cutter materials, medical materials, etc., can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a zirconia-based sintered body that has high strength and toughness, as well as high thermal conductivity and high hardness, and a method for producing the same.

[Conventional technology]

Conventional zirconia sintered bodies include Y2O,, B4gO, Ca
b.

Zirconia partially stabilized with a stabilizer such as CeO2 is known as a high-strength zirconia sintered body.

However, these partially stabilized zirconias still do not have sufficient hardness and toughness, and various improvements have been made to this end.

Among them, JP-A-58-120571 describes ceramics called high-toughness ceramic sintered bodies. This sintered body is Y2O, MgO.

30499.5% by weight of ZrO2 having a tetragonal and/or cubic structure containing a stabilizer such as CaO;
The rest are #, Si and the periodic table rVa, Va,
It contains 0.5 to 70% by weight of one or a mixture of two or more of Group VIa borides, carbides, nitrides, composites thereof, and Al 203 .

[Problem to be solved by the invention]

However, while the zirconia-based sintered bodies having these compositions have excellent strength and toughness, they have the disadvantage of being inferior in thermal conductivity and roughness.

In other words, high-strength zirconia, which has a mainly tetragonal crystal structure, has excellent strength and toughness at room temperature, but at 150 °C
Aging in air at ~300°C for several tens of hours or more has the disadvantage that the rate of strength decline is as great as 50% or more. In addition, the thermal conductivity is approximately 0°QQ7cal/
sec - cm -t, which belongs to the lowest class of materials among ceramics, and as a result, when these conventional zirconia-based sintered bodies are used as blades, cutting tools, or sliding parts, they are mated with ceramics.

At present, the propagation of frictional heat generated by cutting, cutting, or sliding between plastics or metals is poor, resulting in abnormal heat accumulation and seizure, making it impossible to use this type of application.

The problem to be solved by the present invention is to develop a high-strength zirconia sintered body that exhibits excellent thermal conductivity and hardness without losing its inherent excellent strength and toughness, and with little loss of strength due to low-temperature aging. The goal is to find the conditions for control.

[Means to solve the problem]

The zirconia-based sintered body of the present invention is a zirconia-based sintered body containing zirconia as a main component and 10 to 50% by volume of at least one type of ceramic component different from zirconia, whose composite state is determined according to the compound law. The contribution rate of the parallel model is defined within the range of 0.2 to 0.6, and thereby the thermal conductivity K is 0.015 to 0.6.
It is possible to obtain a zirconia-based sintered body having high thermal conductivity exhibiting a high value of 0.1 cal/cm·sec·”c, as well as high hardness and high strength.

In the present invention, the zirconia is Y2O3゜Mg
It is possible to use a material in which at least one oxide selected from O, CaO and CeO2 is dissolved in solid solution.

Zirconia, which does not contain oxides such as Y2O and MgO, has a crystal structure at high temperatures that is tetragonal, cubic, or a mixed phase of tetragonal and cubic, and when cooled, the tetragonal crystal transforms into monoclinic crystal. This is accompanied by volumetric expansion, and as a result, the ceramic is destroyed. In order to avoid this, pure zirconia has Y2O, M
Stabilize by dissolving oxides such as gO. As a result,
The crystal structure of zirconia after sintering is tetragonal, a mixed phase of tetragonal and cubic, or cubic. In some cases, these crystal structures include a part of monoclinic structure, but the amount thereof is preferably 10 mol % or less based on the total. The type of crystal structure described above varies depending on the type and proportion of the stabilizer added. To obtain a zirconia-based sintered body with excellent strength and toughness, 2 to 5 mol% for Y2O3, 6 to 10 mol% for MgO, and 4 to 9 mol% for CaO.
, CeO□ is dissolved in an amount of 8 to 15 mol % to form a tetragonal crystal structure of 50 mol % or more. Further, the above-mentioned stabilizers include Y2O, MgO, and Cab.

or CeO, but a combination thereof may also be used. In addition to this, La2O3, Yb2L, Er,
It may be stabilized by adding a small amount of a refined oxide such as 0°.

In the present invention, the ceramic components added to zirconia include 10 to 50% by volume of WC, SiC, AIN,
TiN.

It can be at least one ceramic component selected from ZrB2 and TiB2. Further, a preferable amount of additive components is 20 to 40% by volume, which increases the strength and increases the contribution rate of the parallel model.

If the added ceramic component is less than 10% by volume, the thermal conductivity of the zirconia-based sintered body will be low, and when used as a knife, sliding part, or cutting tool, it will be less effective against heat generation due to friction. Furthermore, if the amount added exceeds 50% by volume, a dense zirconia-based sintered body cannot be obtained, and mechanical properties such as strength, toughness, and hardness deteriorate.

In the zirconia-based sintered body of the present invention, a dense zirconia-based sintered body can be obtained at a low temperature by containing the second ceramic component in the above-mentioned ceramic component in an amount of 20% by volume or less, and the strength and hardness of the zirconia-based sintered body can be improved. A sintered body with excellent properties can be obtained, and the electrical conductivity and thermal shock strength can be improved.

As this second ceramic component, the above-mentioned WC, S
Boride, carbide, nitride of group a elements other than the first ceramic component such as +C, AlN, TiN, ZrL and TiB2, composites thereof and alumina (A12
At least one of 03) can be used.

Further, the zirconia-based sintered body of the present invention is required that the contribution rate γ of the parallel model in the composite agent be in the range of Q, 2 to 0.13.

In the present invention, the contribution rate γ of the parallelized model is defined as follows.

When the thermal conductivity K of the zirconia-based sintered body is replaced with an equivalent electric circuit, heat flow rate corresponds to current, temperature difference corresponds to voltage, thermal conductivity, and degree corresponds to electrical conductivity.

Therefore, let K be the thermal conductivity of a zirconia-based sintered body made of two different types of ceramics, and the thermal conductivity of each ceramic is 1. 3. Let the volume fraction be V,
If V2 is used, the thermal conductivity Ko in the case of the series model can be expressed as follows.

In addition, in the parallel model, the thermal conductivity is, Kp ”
If V+ is expressed as + + V2 is 2 '''' (2), a composite ceramic sintered body containing one or more additives in zirconia as a zirconia-based sintered body can be defined in the same way, so it is a series type. n for the model
The general formula of the component a is Kn KI L
It can be expressed as 1 in Ka.

In addition, the general formula for n components/Kp in the case of a parallel model is: K, =V, +V, 2+V3, +...+V,
IK, ...(4).

Here, a two-component zirconia-based sintered body containing, for example, ZrO□ and WC will be explained.

Assuming that each component hardly dissolves in solid solution, K of the composite zirconia-based sintered body is prp
...(5) However, γ. +r,=1
'Salary...(6).

Here γ. represents the contribution rate of the series type, and γ represents the contribution rate of the parallel type.

As a result, the contribution rate γ of the parallel model in the zirconia-based sintered composite can be expressed as from equations (1), (2), (5), and (6).

FIGS. 1 to 3 each model the dispersion state of the ceramic component particles (WC) in the zirconia (Zr02) as equivalent electric circuits.

FIG. 1 shows a series type, FIG. 2 shows a parallel type, and FIG. 3 shows a mixed type.

In other words, the form of dispersion in each figure is shown on the left, the equivalent electric circuit is shown on the right, and the relational expressions (corresponding to relational expressions (3) and (4) above) are shown for the thermal conductivity at that time. 1st
As shown in Fig. and Fig. 2. Furthermore, Fig. 3 shows the above-mentioned zirconia (
This shows that the relationship in the dispersion state of ceramic component particles (WC) in ZrOz) is expressed as the above relational expressions (5) and (6).

That is, K is the thermal conductivity of the zirconia-based sintered body, K and vl are the thermal conductivity and volume % of ZrO2, respectively, and 2 is the thermal conductivity and volume % of the added ceramic component, respectively.
Then, these relationships can be expressed by the above-mentioned relational expressions, and in particular, in the present invention, the contribution rate expressed as γ is used as the gB factor of the zirconia ceramic.

Furthermore, the degree of dispersion of the ceramic component is controlled by the contribution rate γ of the parallel type in terms of the magnitude of thermal conductivity, mechanical properties such as strength and hardness, and in the above equation (7), γ, When is 0.5, it is considered to be a tissue in which 2rO□ and anus are uniformly dispersed. In the present invention, T according to equation (7) can be allowed in the range of 0.2 to 0.6. Preferably, it is controlled to be between 0.4 and 0.6.

The contribution rate γ of the parallel type is 0.2 to 0. The reason for the need for a range of This is because although it improves the porosity and strength, it causes a decrease in porosity and strength.

The contribution rate in the composite rule is determined by the structure of the zirconia-based sintered body, that is, the particle size of ZrO□ and additives, the shape and form of particles, and the distribution of particle size, that is, the dispersion state of particles, the size and distribution of pores, and the sintered body. The microstructure of ZrO, and I
It is thought that it depends on the bonding state of the grain boundaries with the IC and the structure within the grains.

By setting the parallel type contribution factor T within the above range, a sintered body with high thermal conductivity, excellent hardness 9 strength and thermal shock strength can be obtained. Further, in a preferable range of 0.4 to 0.6, a more uniform structure can be obtained, and one with excellent mechanical and thermal properties can be obtained.

For zirconia-based sintered bodies, the parallel model contribution rate is 0.2~
When it is in the range of 0.6, there is very little decrease in strength due to aging, and the corrosion resistance is also excellent. For example, Zr
150 °C when O, contains 10 to 50% by volume of wC and the parallelized model contribution rate is in the range of 0.2 to 0.6.
Even after aging at 300° C. for 1,000 hours, the decrease in strength is less than 10% of the initial value, and the transformation rate from tetragonal to monoclinic ZrO is also less than 10% of the initial value.

One of the reasons why the rate of strength reduction and monoclinic transformation is small is that IIc, SiC, #N, TiN, and Z have a smaller Young's modulus and coefficient of thermal expansion than ZrO.
Residual stress measurements of sintered bodies containing rL and TiB2 revealed that a compressive stress field acts on ZrO and the particle matrix, and that ZrO has the effect of suppressing transformation and that additives that do not induce transformation
This is thought to be due to the fact that even if the ZrO particles are transformed, the added ceramic component stops the transformation or absorbs the energy of the transformation when it is present at the grain boundary with O2.

Furthermore, the zirconia-based sintered body of the present invention has improved the drawback of low high-temperature strength that conventional high-strength zirconia has.
It has the advantage that there is little decrease in strength even at temperatures above 0°C.

The reason for this is not clear, but because ceramic components that are difficult to deform plastically even at high temperatures are uniformly dispersed in ZrO2, crack propagation is inhibited due to the dispersion strengthening mechanism and interaction between precipitates and cracks. It is thought that the high temperature strength is improved because it is suppressed at high temperatures.

As for the particle size of the zirconia-based sintered body of the present invention, it is desirable that the particle size of ZrL is in the range of 0.3 to 0.8 mm. 0
．． At 3 seconds or less, the effect of the so-called stress-induced transformation mechanism, which improves strength and toughness by transforming tetragonal zirconia particles into monoclinic crystals, decreases, resulting in a decrease in strength and toughness. Moreover, if it exceeds 0.8 IEn, tetragonal zirconia particles are easily transformed into monoclinic zirconia during the cooling process after sintering, resulting in a decrease in strength and toughness.

In addition, in a sintered body in which AIN is added to zirconia, zirconia reacts with AlN depending on the sintering temperature and atmosphere.
Compounds such as 20□ and ZrN may be formed.

In addition, ZrO□ and SiC react, and another compound (
For example, a glass phase) is formed, and there are problems such as a decrease in strength due to the refinement of the internal structure of cubic or tetragonal ZrO2 particles or the transformation of tetragonal ZrO2 particles to monoclinic.

Therefore, the grain structure of the zirconia-based sintered body of the present invention includes zirconia particles and WC, SiC, #N, and TiN.

It is preferable that particles of ceramic components such as ZrB2 and TiB2 are mutually uniformly dispersed without forming a solid solution with each other.

Here, in order to avoid the reaction between ZrO and AlN, it is necessary to add Aii around the AlN particles during the process of creating the mixed powder.
' It is effective to form a film of 202 particles and sinter it.

To form an Al 20 , l film around AlN,
This is possible by using AlN powder heat-treated in air at a temperature of 300° C. to 800° C. for several hours to several tens of hours.

In addition, in order to avoid the reaction between ZrO2 and SiC,
#, 01. Er20. , B, C or C etc. from 1 to
It is effective to use a mixed powder containing 10% by weight.

Some of the zirconia-based sintered bodies of the present invention have high thermal conductivity, excellent hardness and strength, and are electrically conductive, so electrical discharge machining is possible, and as a result, WC, TiN,
Structures containing ZrB1 and TlB2 can be subjected to complex processing and precision processing necessary for use as dies and mold parts.

The zirconia-based sintered body of the present invention having the above characteristics can be produced, for example, as follows.

First, zirconia powder with a purity of 99.5% or more is mixed with ittria (Y2O3), magnesia (MgO), calcia (Cab), and ceria (with a purity of 99.5% or more).
A powder in which at least one oxide selected from CeO, ) is dissolved in solid solution, and tungsten carbide (WC) with a purity of 99.5% or more.

Silicon carbide (SiC), aluminum nitride (All!
N), titanium nitride (TiN), zirconium boride (
A mixed powder with 10 to 50% by volume of at least one ceramic powder selected from ZrL) and titanium boride (Ti82) is prepared.

This mixed powder has a 90% particle size of 2 to 4p and a 50% particle size of 0.5 to 1. Q, can, specific surface area is 3-15m'
Mix and grind wetly using a ball mill or an attritor so that the weight of the mixture is 1/g. Next, the slurry of the mixed powder is granulated and dried using a spray dryer, or dried while being uniformly stirred using a mixer, etc., to create a homogeneous dry powder.

In particular, in order to make the contribution rate of the compound law in the range of 0.2 to 0.6, the 90% particle diameter should be 2 to 4 m, the 50% particle diameter should be 0.5 to 1°0Js, the specific surface area should be 3 to 15 m'/ WC, SiC, UN, TiN, 2rB2, and TiB2 powders are uniformly wrapped in a sol of ZrO containing Y2O3, MgO, CaO, or CeO2 as a solid solution, and then this mixture is temporarily heated at 500 to 900 °C. It is preferable to create a ZrO□-based powder by pulverizing after baking and then granulating or drying while stirring uniformly with a mixer or the like. At this time, a dispersant may be used as necessary to reduce agglomeration. In the case of granulation drying or stirring drying, predetermined zirconia and additive components are mixed in a slurry. For wet mixing using a mixer, etc., the ratio of powder to solvent (water, acetone, etc.) is selected, and for mixing and grinding using a ball mill or attritor, the ratios of powder, solvent, and balls are selected to be optimal. At this time, if a static drying method such as a normal dryer is used, zirconia powder in which the above-mentioned oxide is solidly dissolved, that is, partially stabilized zirconia powder, and the additive components WC, SiC, MN,
Due to the large difference in specific gravity between TiN, ZrL, TiB, etc., the zirconia powder and additive components will aggregate separately, making it impossible to obtain a homogeneous sintered body after molding and sintering, resulting in poor thermal conductivity. 1. It causes a decrease in strength, hardness, etc. More preferably, a more homogeneous powder can be obtained by pulverizing the powder after granulation and drying using less than half the amount of solvent used in normal mixed pulverization and drying while preventing precipitation.

The additive components used in the present invention have inferior oxidation resistance compared to zirconia. Therefore, in granulation drying using an oxidizing solvent such as water, it is necessary to set the rotational speed of the atomizer and the drying temperature conditions of the inlet through which the mixed slurry first passes, so that the added components are not oxidized. In particular, in the case of WC, the drying temperature at the inlet should be set from 130 to 23
0 °C, rotation speed from 10,000 to 15,000 pp
By drying and granulating in the range of m, or by granulating and drying using an organic solvent in a N2 or inert gas closed circulation type device with an oxygen partial pressure of 1% or less, it becomes homogeneous without oxidation. A fine powder can be obtained.

By molding and sintering this powder, a more excellent zirconia-based sintered body can be produced.

Further, the above mixed powder can be molded using a normal molding method, for example,
Isostatic pressure molding (rubber press), mold molding.

Injection molding, extrusion molding, etc. can be used, but unlike oxide ceramics, it is necessary to select a binder and degrease the binder in a neutral or vacuum atmosphere. In the case of the zirconia-based sintered body of the present invention, which has high thermal conductivity and hardness, as well as excellent strength, toughness, and thermal equilibrium strength, pressure sintering (PAS), hot pressing, After pre-sintering by HP), hot isostatic pressing (HIP)
It is preferable to apply

Pressure sintering is more convenient for producing dense sintered bodies than vacuum sintering or normal pressure sintering in a neutral atmosphere.

For example, in a zirconia-based sintered body in which 10 to 50% by volume of lIC is added to 2rO, open pores remain after vacuum sintering, resulting in a dense sintered body even when processed by hot isostatic pressing (IIIP). However, when created using the pressure sintering method, open pores disappear at a relative density of 95 to 97%, so the old P treatment has the effect of obtaining a sintered body that has approximately the theoretical density. There is.

In pressure sintering, a molded body made by a normal molding method is placed in an inert atmosphere, such as nitrogen (N2) or argon (Ar).
It is carried out by raising the temperature to 1550°C to 1800°C under a gas atmosphere at a pressure of 5 to 300 kg/cffl and maintaining it at that temperature. Preferably the pressure is between 50 and 30
By applying pressure sintering with a pressure of 0 kg/cm", it is possible to avoid the additive components from reacting with the stabilized zirconia during sintering to form other compounds, and to avoid the stoichiometric composition of the additive components. This helps to prevent deviation and evaporation, or the formation of other compounds due to the reaction of added components with carbon or atmospheric gas at high temperatures.Also, in the case of pressure sintering, grain growth can be suppressed up to high temperatures. Therefore, sintering can be performed at higher temperatures.

In addition, in hot pressing, the mixed powder is placed in a carbon die of the desired shape under a pressure of 100 kg in a non-oxidizing atmosphere.
/cd or more and a temperature of 1450°C to 1750°C to create a sintered body.

In this way, after pre-sintering the relative density of the sintered body by pressure sintering or hot pressing under conditions such that the relative density of the sintered body becomes 96% or more, preferably 98% or more, the pressure is 1
．． 000 kg/cd or more, temperature 1450℃~17
Sintered at 00°C using the old P method.

In the above, the relative density of the preliminary sintered body was set to be 96% or more, compared to zirconia powder, because the additive component is a difficult-to-sinter material and is difficult to plastically deform. This is because a denser sintered body cannot be obtained even by HTP treatment.

〔Example〕

Example 1 ZrO□ powder with an average particle diameter of 0.5-1 containing 2.5 mol% of Y2O as a stabilizer, WC (purity 99%, average particle diameter 0.6 Jin), and SiC (purity 99.5%) , average particle size 0.4 mm) powder was wet-pulverized and mixed into the composition shown in Table 1. After mixing, the powder has a 90% particle size of 3.2 mm, 50
It was a fine powder with a % particle size of 0.9p and a specific surface area of 11.5 m''/g.

Next, this mixed powder was stirred in water with a mixer and then granulated and dried. The drying conditions are: the artificial side temperature of the drying air is 200°C.
℃, outlet side temperature 107 ℃, atomizer rotation speed 12
．． 000 rpm.

Next, the dried powder was rubber pressed at a molding pressure of 2 tons/ctl, and then pressure sintered. Pressure sintering is performed at a pressure of 50 kg/ctl and a temperature of 1650 ml in an argon atmosphere.
The temperature was maintained at 1700°C for 2 hours. The relative density of the pre-sintered body thus obtained was 96-97.5%.

Next, this pre-sintered body was heated to 1°C under a non-oxidizing gas atmosphere.
Pressure 2000 kg/c at 550℃ and 1600℃
Hold for 90 minutes under the conditions of i, and perform hot isostatic pressing (HIP).
) A sintered body was obtained.

For comparison, Zr[1, powder and
(purity 99%, average particle size 1.5 p) and SiC (purity 99%, average particle size 1.3 m+) powders were wet mixed in a mixer so that the compositions were 20 and 30% by volume, respectively.

The powder after mixing had a 90% particle size of 4.5 m, a 50% particle size of 1.2 m, and a specific surface area of 6 m'/g.

Next, the wet-mixed powder was statically dried in a dryer. Furthermore, this mixed powder was filled into a graphite mold, and the sintering temperature was 150°C.
A sintered body was prepared by hot pressing at 0° C. and 1600° C. under a pressure of 200 kg/cat for 1 hour.

After cutting and processing test pieces for bending test of 3 x 4 x 40 and measuring thermal conductivity of diameter 19 x 2 from these sintered bodies, we created a parallel model of various physical properties and compound rules as shown in Table 1. The contribution rate was measured.

As is clear from Table 1, it is clear that the sintered body of the present invention is a high-strength, high-toughness material with high thermal conductivity.

Furthermore, if the contribution rate (T,) of the parallelized model is within the range of the present invention, the thermal conductivity is high, the porosity is low, and the strength (TR3) is high.
It can be seen that it has high hardness and excellent properties.

(Methods for measuring various physical properties) (1) Flexural strength (TRS) is JIS B12O
3, and the average value of five measurements is shown.

(2) Vickers hardness measured by Vickers hardness tester (load 2)
Measured at 0 kg.

(3) Thermal conductivity is TXP- manufactured by Miki Engineering.
400 at room temperature (24° C.) by the laser flash method.

Example 2 ZrO powder with an average particle size of 0.5Jin containing 2.5 mol% of Yaks as a stabilizer and WC (purity 99%, average particle size 0.6p) were wet-pulverized and mixed in the composition shown in Table 2. , the same powder properties as in Example 1 were obtained.

Furthermore, 30 volumes of 1% (W, Ti) were added to the above ZrO powder.
, Ta) C(WC:TiC:TaC=5:3:2.
Average particle size 0.9p) and (T+Bz Tic
) (Tic: 4.8%, average particle size 0.8p).

20% by volume and 30% by volume of SiC with a total of 0*, Al
Os was added and wet-pulverized and mixed to produce powders having the compositions shown in Table 2.

The powder after mixing has a 90% particle size of 2.5 to 4.0 tan
, 50% particle size is 0.7-1. OIIJR was a fine powder with a specific surface area of 6 to 11 m'/g.

Next, the wet-pulverized slurry having the above composition was taken out into a container, and the container was placed in a bathtub kept at a temperature of 90° C., and the slurry was uniformly stirred with a mixer to evaporate water and dried.

Next, the dried powder was filled into a graphite mold and sintered at a temperature of 150
A sintered body was produced by hot pressing at 0°C and 1600°C under a pressure of 200 kg/car for 1 hour. Further, this sintered body was subjected to old P treatment under the same conditions as in Example 1 to produce a sintered body, and the results shown in Table 2 were obtained.

In the sintered body of the present invention, the contribution rate of the parallelized model of the compound law is 0.
It can be seen that within the range of 2 to 0.6, the thermal conductivity, hardness and strength are both high, and the sintered body has few pores.

(Hereinafter, this page margin) [Effects of the Invention] The zirconia-based sintered body of the present invention has a uniform structure, high thermal conductivity, strength, toughness, and hardness.

It has excellent mechanical and thermal properties such as thermal shock strength, and can be used at temperatures of 200°C to 300°C, which is a drawback of conventional high-strength zirconia.
It can significantly eliminate the decrease in strength due to aging, corrosion resistance, and high temperature strength at temperatures above 600℃, making it ideal as a material for various molds, metal cutting tools, woodworking blades, resin cutting blades, sliding parts, etc. It can be used widely.

A. Sub-combustion chamber, turbocharger, piston cap, cylinder, cylinder lychee, plate exhaust valve head, and cast turbine 7JL that require high-temperature strength and thermal shock resistance (high thermal conductivity, low thermal expansion).

Materials for internal combustion engines such as combustors, nose cones, sinirads, exhaust valves, and various insulation materials.

B.Dice, nozzles, capillaries, precision measurement blocks and gauges that require wear resistance, high strength, and thermal shock resistance,
rings, heating cylinders, insulation spacers, insulation sleeves,
Mechanical seals, plunger pumps, punches, springs,
Coil springs, drawing tools, cutting tools, bearings, balls for bearings, balls for crushers, guide rolls, rolling rolls.

Materials for various industrial machines such as slurry pump impellers, screws, sleeves, valves, orifices, tiles, wire wrapping sleeves, drivers, thread guides, etc.

C1 wear resistance, toughness, thermal conductivity UA that requires strength
m, Cutters for paper, film, magnetic tape, cigarettes, etc. (slitters, round blades, laser blades), razors, clipper blades,
Cutting tools materials such as various scissors, various knives, and various kitchen knives.

D, a scalpel requiring hardness 1 surface smoothness and biocompatibility;
Medical equipment materials or medical materials such as vinsets, femoral heads, tooth roots, dental crowns, joints, bone fixatives, etc.

Decorative materials for E9 watch parts, etc.

F. A material for mold parts for plastic and metal molding that takes advantage of electrical discharge machining. Corrosion resistant mold.

Sports equipment such as fishing line guides, skis, skates, and golf equipment that require G, wear resistance, corrosion resistance, toughness, and low coefficient of friction.
Leisure equipment materials.

H9 Abrasion resistance, corrosion resistance 1 Writing instrument materials such as ballpoint pen balls and pen nibs that require surface smoothness.

[Brief explanation of the drawing]

FIGS. 1 to 3 are diagrams illustrating the state of heat conduction in the dispersed state of ceramic component particles (WC) in the zirconia (ZrO2) as an equivalent electric circuit. Patent applicant Toshi Co., Ltd. (and 1 other person) representative
Person Aya Otsuka Figure 1 <1 Figure 2 Figure 3

Claims (2)

[Claims] 1. In a zirconia-based sintered body containing zirconia as a main component and at least one ceramic component different from zirconia, the contribution rate of a parallelized model of the compound law in the sintered body is 0.2 to 0.6. A zirconia-based sintered body characterized by being within the range of. 2. A mixed powder consisting mainly of zirconia powder and at least one type of ceramic powder different from zirconia is wet-mixed and pulverized to produce a powder with a 90% particle size of 2 to 4 μm and a 50% particle size of 0. .5-1.0
Production of a zirconia-based sintered body characterized by forming a slurry of fine powder with a specific surface area of 3 to 15 m^2/g in μm, then drying the slurry, molding the obtained powder, and sintering it. Method.