JPH01282156A - Rolling sleeve - Google Patents

Abstract

PURPOSE:To improve the flexural strength, thermal shock resistance, hardness, and heat conductivity of the title rolling sleeve and to prolong its service life by using a titanium boride sintered compact to form the sleeve. CONSTITUTION:TiB2 having 0.5-3mum average particle diameter, 6mum maximum particle diameter, and >=99wt.% purity, Ni having 6mum average particle diameter, and carbon having 80-150m2/g surface area, 10-50mum average particle diameter, 100mum maximum particle diameter, and >=99.9wt.% purity are mixed. In this case, the (Ni+C) content is controlled to 2.5-25wt.%, the TiB2 content is adjusted to 75.0-97.5wt.%, and the mixing weight ratio of N/C is controlled to 14/0.2-5. The mixture is compacted and sintered in a non-oxidizing atmosphere at 1600-1800 deg.C to obtain a titanium boride sintered compact wherein a matrix layer of the solid soln. of nicked boride and titanium carbide is arranged between titanium particles and having <=5% porosity. The inner surface of the through-hole is lapped with desired precision to obtain a rolling sleeve.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Purpose of the invention [Field of industrial application] The present invention relates to a rolling sleeve, and particularly relates to a rolling sleeve made of a titanium boride ceramic sintered body, and which is suitable for use with stainless steel 1 alloy steel or bearing steel. The present invention relates to a rolling sleeve that is used for rolling a material to be rolled.

[Prior art] Conventionally, this type of rolling sleeve was made of alumina^12.
0. It was proposed that it be formed by sintering materials such as

[Problems to be solved] However, in conventional rolling sleeves, the porosity is set to 0.
Even if it is as small as 1% or less, the bending strength is low at about 250 MPa, the thermal shock resistance is low at about 280"C, and the thermal conductivity is low at about 301/sK, so it is brittle and does not absorb heat during rolling. It has the disadvantage of being easy to accumulate and not having a long life.

Therefore, it has been proposed to form the rolling sleeve by sintering silicon nitride 2Si:+N4, but in this case, the resistance is lower than when forming it by sintering alumina A1□03. Although the folding strength and thermal shock resistance can be improved,
Since the hardness and thermal conductivity were deteriorated, it was still brittle and easily accumulated heat during rolling, so it had the disadvantage that it could not have a long life.

Therefore, in order to solve these drawbacks, the present invention aims to improve not only porosity but also bending strength, thermal shock resistance, hardness, thermal conductivity, etc. by forming a titanium boride ceramic sintered body to extend the lifespan. The purpose of the present invention is to provide a rolling sleeve.

(2) Structure of the invention [Means for solving problems] What are the solutions to the problems provided by Suegan 1?

``In a rolling sleeve made by rolling a wire rod by inserting it through a through hole from one end opening to the other end opening, the matrix layer containing a mixed solid solution of nickel boride and titanium carbide is made of titanium boride. A rolling sleeve characterized in that it is formed of a titanium boride ceramic sintered body disposed between particles and having a porosity of 5% or less.

[Function] The rolling sleeve according to the present invention has a matrix layer in which a mixed solid solution of nickel boride and titanium carbide is disposed between titanium boride particles, and has a porosity of 5% or less. Since it is made of a titanium boride ceramic sintered body, it has the effect of improving bending strength, thermal shock resistance, hardness, thermal conductivity, etc. and extending its life.

[Example] Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a sectional view showing one embodiment of a rolling sleeve according to the present invention.

FIG. 2 is an enlarged sectional view of the embodiment shown in FIG.

FIG. 3 is an optical micrograph showing the structure of the polished surface of the example shown in FIG. 1, and shows the case of Example 18.

FIG. 4 is a scanning electron microphotograph showing the structure of the fracture surface of the example shown in FIG. 1, and shows the case of Example 18.

FIG. 5 is an optical micrograph showing the structure of the etched surface of the example shown in FIG. 1, and shows the case of Example 18.

FIG. 6 is a scanning electron m* mirror photograph showing the structure of the etched surface of the embodiment of FIG. 1, and shows the case of embodiment 18.

FIG. 7 is a graph showing the results of the X-ray diffraction analysis of the example shown in FIG. It is measured by the diffraction intensity of the line.

FIG. 8 is a scanning electronic microphotograph showing the structure of the fractured surface of the rolling sleeve shown as Comparative Example 1. First, the structure and operation of the rolling sleeve according to the present invention will be described in detail.

The rolling sleeve of the present invention is made of a titanium boride ceramic sintered body, and has an opening 11a expanded at one end and a through hole 11 having a circular cross section. The through hole 11 extends from an opening 11a at one end to an opening 11 at the other end.
It is used for rolling, that is, diameter reduction, by inserting a wire rod (not shown) to be rolled in the direction of b.

Rolling sleeve wear is due to titanium boride Ti in its structure.
B2 particles 20 and titanium boride Ti8. It includes a mesh-like bonding layer 30 for bonding the particles 20.

Titanium boride Ti8. The particles 20 have an average particle size of 0.5 to
IOpm and a maximum particle size of 12 gm, particularly preferably an average particle size of 0.5 to 3 gm and a maximum particle size of 6 pm. Here is titanium boride Ti1l! The basis for setting the average particle size of the particles 20 to 0.5 to 10 pm is that (i) if the average particle size is less than 0.5 JLm, titanium boride Ti82
The surface oxidation of the particles 20 becomes noticeable, and the titanium boride Ti
The aggregation between the Bg particles 20 becomes noticeable, which significantly inhibits the sintering of the titanium boride ceramic sintered body of the present invention, that is, the sleeve sleeve for rolling, and (ii) if the average particle size exceeds 10 lm. , the driving force for sintering becomes smaller, making it difficult to densify the rolling sleeve of the present invention, and existing cracks in the titanium boride TiB2 particles 20 are enlarged, reducing the strength of the rolling sleeve of the present invention. There is a particular thing. In addition, the reason why the maximum particle size of titanium boride TiB2 particles 20 is said to be 12 m is that the maximum particle size is 12 m.
If it exceeds 2 μm, it will exist as coarse particles in the rolling sleeve of the present invention, which will hinder the high density or high strength of the rolling sleeve of the present invention.

A grain boundary phase 21 consisting of a mixed solid solution phase of titanium boride TiB2 and nickel boride Ni and B is formed near the grain boundary of the titanium boride Ti82 particles 20. As a result, the bonding force between the titanium boride TiB2 particles 20 and the bonding layer 30 is made sufficiently large, and as a result, the strength of the rolling sleeve of the present invention is ensured.

The bonding layer 30 is composed of Ti8g+2Ni +C→2NiB+TiC or TiB2+Ni+C+N1Rt+TiC or TiBt+6Ni+(:→2NiJ+Ti) between nickel Ni, titanium boride TiB2, and carbon C.
It is a matrix layer in which a metal boride produced by a reaction of nickel Xi, such as NiB, N1p2, or NiYB, and titanium carbide, TiC, are mixed and dissolved in solid solution, and vacancies have been sufficiently removed. As a result, the bonding force between the titanium boride Tie2 particles 20 is said to be sufficiently large, and the porosity of the sleeve for rolling (
In other words, the value obtained by dividing the pore volume by the total volume) is 5% or less, and as a result, the density and strength of the rolling sleeve pressure of the present invention are ensured. The reason why the pores are substantially removed from the bonding layer, that is, the matrix layer 30, is that the grain size of the boride of nickel Ni, that is, nickel boride NiB, N1Bz, or NiJ, and the grain size of titanium carbide TlC are approximately the same. The reason is that they are homogeneously mixed and dissolved in solid solution with each other.

Furthermore, a manufacturing procedure for an embodiment of the rolling sleeve according to the present invention will be explained.

In the first step, a ceramic compound is created by blending titanium boride TiR2 powder, nickel Ni powder, and carbon C powder with each other at an appropriate blending ratio.

That is, (i) titanium boride TiB2 having an average particle size of 0.5 to 10 JLm (preferably 0.5 to 1 gm), a maximum particle size of 12 pm (preferably 6 Bm), and a purity of 99% by weight or more; ii) nickel Ni with an average grain size of 1 to 5 m (preferably 1 to 3 j L m) and a maximum grain size of 12 J L m (preferably 6 J L m); and (iii) a specific surface grain size of 50 to 150 m''/g ( Preferably 80 to 150 2/
g) with a purity of 99.9% by weight or more and an average particle size of 10
~10 (1 nm (preferably 10 to 50 nm)) and carbon (such as carbon black) with a maximum particle size of 150 nm (preferably 10100 nm) are blended together to create a ceramic blend. In the ceramic blend, Mixture of nickel i and carbon C 0,1-8
9% by weight (particularly preferably 2.5 to 25.0% by weight) and 11 to 99.9% by weight of titanium boride Ti82 (particularly preferably 751 to 97.5% by weight)
only. Further, the blending ratio of nickel Xi and carbon C is 14:0.1 to 10 (particularly 14:0.
2 to 5 is preferable).

The reason why the purity of titanium boride TiB* is set at 99% by weight or more is to avoid impurities from having an adverse effect during sintering.

The reason why the average particle size of nickel Ni is set to be 1 to 5 pm is that (i) If the average particle size is less than 1 #L, m, the surface oxidation of the nickel Ni particles becomes noticeable, and the oxidation between the nickel Ni particles Agglomeration or nickel Ni particles and titanium boride T
(ii) If the average particle size exceeds 5JL111, the agglomeration between the iB2 particles or the carbon C particles becomes significant, and the sintering of the rolling sleeve of the present invention is significantly inhibited. Existing as coarse particles in the matrix layer 30 of the rolling sleeve 10 or in the grain boundary phase 21 formed near the grain boundaries of the titanium boride TiBz particles 20, reducing the strength etc. of the rolling sleeve of the present invention. It is to become. The maximum particle size of nickel Ni is 12
If the maximum grain size of the gm exceeds 12 μm, existing cracks in the nickel Ni particles will be enlarged, reducing the strength of the rolling sleeve (2) of the present invention.

In addition, the reason why the average particle size of carbon C is set to be 10 to 1100 nm is that (i) If the average particle size is less than 1 Onm, surface oxidation of carbon C particles becomes noticeable, and aggregation between carbon C particles becomes noticeable. As a result, the sintering of the rolling sleeve of the present invention is significantly inhibited, and (11) the average grain size is
If it exceeds QHm, coarse particles will be present in the matrix layer 30, reducing the strength of the rolling sleeve of the present invention. The reason why the maximum particle size of carbon C is 150 nm is that the maximum particle size is 150 nm.
If it exceeds the titanium carbide T produced by the existing cracks in the carbon C particles or the reaction between the titanium boride TiB2
Existing cracks in the iC particles are enlarged and the strength of the rolling sleeve of the present invention is reduced.

Furthermore, the reason why the specific surface area of carbon C is 50 to 150 m''/g is as follows: (i) If the specific surface area is less than 50 mm''/g, the carbon C particles are too large and cannot be replaced with titanium boride TiR. (ii) If the specific surface area exceeds 150 2/g, the carbon C particles will aggregate with each other and the mixture with titanium boride TiB2 and nickel Ni The problem lies in not being able to do anything.

In the $2 step, the ceramic mixture is homogeneously mixed using an appropriate mixer to create a ceramic mixture.

In the third step, the ceramic mixture is mixed with a binder (
For example, polyvinyl alcohol) is placed in an appropriate mold, and then the pressure is applied to an appropriate level (for example, 100 to 800 k).
A pressure of "g/cm" is applied and uniaxial pressure is applied to create a ceramic green compact.

? In the JS4 process, the ceramic green compact is subjected to CIP treatment, that is, room temperature isostatic compression molding treatment, by applying an appropriate pressure (for example, a pressure of 800 to 1500 kg/cm2) to form a ceramic compact.

In the fifth step, the ceramic molded body is placed in a non-oxidizing atmosphere (i.e., a neutral or reducing atmosphere) such as a vacuum atmosphere (preferably at an atmospheric pressure of 10-ffTorr or less), an argon atmosphere, or a hydrogen gas atmosphere. Unpressurized state or pressurized state (to mouth ~ 500k)
A ceramic sintered body is obtained by sintering at a temperature of 1500 to 2000°C (preferably 1600 to 1800°C) for an appropriate period of time under a pressure of 1.5 g/am. The basis for this is that titanium T1.Boron B
The purpose is to prevent nickel (Ni) or carbon (C) from being oxidized.

In the sixth step, the inner surface of the through hole 11 of the ceramic sintered body is polished to a desired precision to form a sleeve for rolling.

Through the above steps, the rolling sleeve according to the present invention is manufactured.

In addition, an embodiment of the rolling sleeve according to the present invention will be described using specific numerical values in order to facilitate understanding of the layers.

Nickel N1 has an average particle diameter of 1 pm or lpm and a specific surface area of 1
For a 2.5% by weight mixture created by changing the mixing ratio with carbon black C, which has a purity of 99% by weight at 35mm/H, the average particle size was 3gm and the maximum particle size was 6uLm, and the purity was 99% by weight. Titanium boride TiB2 is 97%
．． Ceramic compound 1 created by blending only 5% by weight
00 parts were placed in a plastic container together with urethane balls and 300 parts of ethylene alcohol, and 2
Wet mixing was carried out for 4 hours, thereby creating a ceramic mixture.

The ceramic mixture was kept at a temperature of 609C for 10 hours to thoroughly dry it. Then ceramic mixture 10
0 parts was placed in a suitable mold together with 2 parts of polyvinyl alcohol as a binder, and uniaxially pressed under a pressure of 100 kg/cm<2> to form a ceramic green compact.

The ceramic green compact was made into a ceramic molded body by applying a pressure of 3000 kg/am'' and subjecting it to CIP treatment, that is, room temperature isostatic compression molding treatment.

The ceramic molded body was heated to a temperature of 17 (10"C) at a heating rate of 15C/min in an argon atmosphere without pressure, and maintained at a temperature of 1700C for 1 hour. It was made into a ceramic sintered body.

The inner surface of the through hole 11 of the ceramic sintered body was polished to a desired precision to obtain a rolling sleeve.

The rolling sleeve has a length of 30 mm and an outer diameter of 30 mm, but the length intersection of the opening 11a at one end is 10 mm. The inner diameter d of the open end of the one end opening 11a was 10 mm, and the inner diameter d2 of the open end of the other end opening 11b was 5.51 layers.

The porosity, bending strength, thermal shock resistance, Vickers hardness and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

A rolled wire rod (not shown) made of 18-8 stainless steel with a diameter of 1.15 mm per wire according to a rolling sleeve is rolled or shrunk to a diameter of 5.51 mm. Diameter processed. The rolling speed at this time, that is, the pulling speed of the wire to be rolled, was an average of 75 m/s and a maximum of 8 m/s.
The speed was 5 m/sec. With the rolling sleeve, it was possible to roll a rolled wire rod having a service life shown in Table 1, and the rolled wire rod had no visible damage or distortion.

Varnish M 辷二巳L Mixture of nickel Ni and carbon black C 5.01
Examples 1 to 7 were each repeated except that titanium boride TiBa was blended in an amount of 95.0% by weight based on the amount of JL.

The porosity, bending strength, thermal shock resistance, Vickers hardness Ff1, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Examples 1 to 7 were repeated, respectively, except that 92.5% by weight of titanium boride TiBz was blended with 7.5% by weight of the mixture of nickel Ni and carbon black C. .

For example, in the case of Example 18 (the same applies hereinafter), the surface of the rolling sleeve was photographically observed using an optical microscope, and the results were as shown in FIG. That is, it was found that the bonding layer 30 was arranged in a scattered manner around the titanium boride particles 2o, and that the bonding layer 30 had no pores and was m-dense.

Sleeves for rolling can be broken by applying a moderate amount of force.
When the fracture surface was photographed and observed using a scanning electron microscope, it was found that
It was as shown in Figure 4. That is, titanium boride T
i8. Intragranular fracture occurred in the particles 20, and it was found that the titanium boride TiBz particles 20 were firmly bonded by the bonding layer 30. According to X-ray diffraction analysis, the bonding layer 30 is a matrix layer containing a mixed solid solution of nickel boride NiB and titanium carbide TiC produced by the reaction TiBz+6Ni+C→2NiJ+T+C between titanium boride TiBz, nickel Ni, and carbon black C. (See Figures 5 to 7).

The rolling sleeve was etched on its outer surface by immersing it in aqua regia heated to 60°C for 3 minutes, and then photographed with an optical microscope.
It was as shown in the figure. That is, by measuring the diameter of the titanium boride TiB2 particles 20 produced by the separation of the bonding layer 30 of the titanium boride TiB2 particles due to the etching process, it is possible to determine whether the average particle diameter of the titanium boride Ti8g particles 20 is 2
It was found that the temperature remained at ~1 Opm. In other words, it was found that the titanium boride TiB2 particles 20 had hardly grown compared to the initial state. This is because nickel Ni and carbon black C cause a reaction of TiB2+5 old+C→2NiJ+TiC during sintering, and the growth of titanium boride Ti82 particles 20 is suppressed. Also, titanium boride TiB2 particles 2
X-ray diffraction analysis revealed that a grain boundary phase 21 consisting of a mixed solid solution phase of titanium boride TiB2 and nickel boride NiYB was formed near the grain boundaries of No.
(see figure).

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7 and 2, and the results were as shown in Table 1.

(Examples 22 to 28) Mixture of nickel Xi and carbon black C 10.0
Titanium boride Tie, 9Q, 0% by weight
Examples 1-7 were each repeated, except that only

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the sleeve for rolling were measured and found to be as shown in Table 1.

In addition, the service life of the rolling sleeve (2) was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

(Examples 29 to 35) Mixture of nickel Ni and carbon black C 12.5
87.5% by weight of titanium boride TiBz based on % heavy yang
Examples 1-7 were each repeated, except that B.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve plate were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve (2) was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Mixture of Ni and carbon black C 15.
0fii%, titanium boride Ti1t is 85.01%
Examples 1 to 7 were each repeated, except that only % % was added.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the service life according to the rolling sleeve rule was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

(Examples 43 to 49) Mixture of nickel Ni and carbon black C 17.5
82.5% by weight of titanium boride TiBz
Examples 1-7 were each repeated, except that B.

The porosity, bending strength, thermal shock resistance, Vickers hardness and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the service life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

- Flow side 50-56) Mixture of nickel Xi and carbon black C 20.0
80.0% by weight of titanium boride TiB2
Examples 1-7 were each repeated, except that B.

The porosity, bending strength, a*4 resistance, Vickers hardness, and thermal conductivity of the rolling sleeve F were measured and found to be as shown in Table 1.

Further, the service life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Mixture of nickel Ni and carbon black C 22.5
77.5% by weight of titanium boride TiB2
Examples 1-7 were each repeated, except that B.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the sleeve for rolling were measured and found to be as shown in Table 1.

Further, the service life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Mixture of nickel Ni and carbon black C 25.0
75.0% by weight of titanium boride TiB
Examples 1-7 were each repeated, except that B.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

(Examples 71 to 77) Except that 92.5% by weight of titanium boride TiBa was blended with 7.5% by weight of the mixture of nickel Ni and carbon black C, and the sintering temperature was 1500°C. , Examples 1-7 were repeated, respectively.

Porosity of rolling sleeve, bending strength, thermal I# impact resistance,
The Vickers hardness and thermal conductivity were measured and were as shown in Table 2.

Further, the service life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Examples 78-84 Examples 7I-77 were repeated, respectively, except that the sintering temperature was 1600<0>C.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

In addition, Examples 15 to 21 of the durability of rolling sleeve cutting
When measured in the same manner as above, the results were as shown in Table 2.

(Examples 85-91) Examples 71-77 were repeated, respectively.

The porosity, flexural strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve (2) were measured and found to be as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 15 to 21, and the results were as shown in the t52 table.

Examples 92-98 Examples 71-77 were repeated, respectively, except that the sintering temperature was 1800°C.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve (■) were measured, and the results were as shown in Table 2. The results were measured in the same manner as shown in Table 2.

Comparative Example 1 Examples 1-70 were repeated except that nickel N1 and carbon black C were removed from the ceramic formulation.

In other words, the average particle size is 3JLm, the maximum particle size is 61Lm, and the purity is 99% by weight titanium boride TjB2100ff.
1 was placed in a suitable mold together with 2 parts of polyvinyl alcohol as a binder, and uniaxially pressed under a pressure of 100 kg/cm2 to prepare a ceramic green compact.

The ceramic green compact was made into a ceramic molded body by applying a pressure of 300 kg/am'' and subjecting it to CIP treatment, that is, room temperature isostatic compression molding treatment.

The ceramic molded body is heated to a temperature of 1700°C at a heating rate of 15°C/min in an unpressurized argon atmosphere and maintained at a temperature of 1700°C for 1 hour to undergo ceramic sintering. As a body.

The rolling sleeve was prepared by polishing the inner surface of the through hole 11 to a desired precision.

The rolling sleeve was broken by applying a moderate force, and the broken surface was photographed and observed using a scanning electron microscope.
It was as shown in the figure. That is, titanium boride TiB
It was found that the bond between the titanium boride TiB particles was not very strong because the grain boundary fracture of the particles was dominant.

In addition, the porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 2 Examples 1-7 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 3 Examples 8-14 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, #r impact resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 4 Examples 15-21 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 5 Examples 22-28 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 6 Examples 29-35 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 7 Examples 36-42 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, flexural strength, /8 impact resistance, Vickers hardness and thermal conductivity of the rolling sleeve were measured and found to be as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 8 Examples 43-49 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example 9 Examples 50-56 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, flexural strength 9, 8 impact resistance, Vickers hardness and thermal conductivity of the rolling sleeve were measured and were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 4.

(Comparative Example +n) Examples 57-63 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Comparative Example II Examples 64-70 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured, and the results were as shown in Table 1.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 1.

Examples 71-77 were repeated except that nickel Xi and carbon black C were removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Comparative Example 13 Examples 78-84 were repeated except that nickel Ni and carbon black C were removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Comparative Example m Examples 85-91 were repeated except that nickel Ni and carbon black C were removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Examples 92-98 were repeated except that nickel N1 and carbon black C were removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness Σ, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Examples 71 to 77 were repeated except that carbon black C was removed from the ceramic composition to determine the porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve. The measurements were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Comparative Example 17 Examples 78-84 were repeated except that carbon black C was removed from the ceramic formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Comparative Example 18 Examples 85-91 were repeated except that carbon black C was removed from the Ceraminx formulation.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleeve were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Comparative Example 19 Examples 92-98 were repeated except that carbon black C was removed from the ceramic formulation.

Porosity of rolling sleeve, bending strength, thermal 1tI impact resistance,
The Vickers hardness Σ and thermal conductivity were measured and were as shown in Table 2.

Further, the useful life of the rolling sleeve was measured in the same manner as in Examples 1 to 7, and the results were as shown in Table 2.

Example 20) Comparative Example 1 above was repeated, except that the ceramic formulation was silicon nitride, Si:In2.

The porosity, bending strength, thermal shock resistance, Vickers hardness, and thermal conductivity of the rolling sleep were measured and were as shown in Table 3.

Furthermore, the useful life of the rolling sleeve is approximately 1 ton,
It was destroyed when the rolling process, that is, the diameter reduction process, of one rolled wire rod was completed (see Table 3).

Comparative Example 21 Comparative Example 1 above was repeated except that the ceramic formulation was alumina A1□03.

The porosity, flexural strength, 8 impact resistance, Vickers hardness and thermal conductivity of the rolling sleeve were measured and found to be as shown in Table 3.

Moreover, the useful life of the rolling sleeve is about 1 ton,
A single-mouth rolled wire rod is rolled, that is, diameter-reduced, and the final λ
(See Table 3).

As is clear from a comparison of Examples 1 to 98 and Comparative Examples 1 to 2 described above, according to the present invention, by forming the rolling sleeve from a titanium boride ceramic sintered body, the life of the rolling sleeve can be greatly extended. It can be expanded to

(3) Effects of the Invention As is clear from the above description, the rolling sleeve according to the present invention is a rolling sleeve formed by rolling a wire rod by inserting it into the through hole from one end opening to the other end opening. In particular, a matrix layer containing a mixed solid solution of nickel boride and titanium carbide is arranged between titanium boride particles, and a titanium boride ceramic sintered body having pores of 5% or less is used. It's being formed.

(1) It has the effect of sufficiently suppressing the generation of pores in the matrix layer between the titanium boride Ti82 particles, and (ii) it has the effect of sufficiently suppressing the generation of pores in the matrix layer between the titanium boride Ti82 particles, and (ii) it has the effect of improving the bending strength, thermal shock resistance, hardness, thermal conductivity, etc. As a result, (iii) it has the effect of extending the lifespan.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of a rolling sleeve according to the present invention, FIG. 2 is an enlarged cross-sectional view of FIG. 1-Embodiment, and FIG.
Figure 1 is an optical IA microscope photograph showing the structure of the polished surface of Example 1, Figure 4 is a scanning electron microscope photograph showing the structure of the fractured surface of Example 1, and Figure 5 is , 4 is an optical microscope photograph showing the structure of the etched surface of Example 11a, FIG. 6 is a scanning electron WJ microscopic mirror showing the structure of the etched surface of Example 1 of FIG. The figures are graphs showing the results of X-ray diffraction analysis of the Example shown in FIG. 1, and FIG. 8 is a scanning electron microscope v/! showing the structure of the fractured surface of the rolling sleeve shown as Comparative Example 1. This is a mirror photo.艮・・・・・・・・・・・・Rolling sleeve 1.1
.........Through hole 11a...
......One end opening 11b...
...Other end opening 20 ...... Titanium boride particles 21 ...... Grain boundary phase 30 ...... ... Matrix layer patent applicant Niss TK Ceramics Research Institute Co., Ltd. (1 other person) Agent Patent attorney Takao Kudo Figure 1 ρ Enter Figure 2 1 Puff; U, no ShiZ Cμl'TI No. 4 Shi1 Fig. 5, C Shimezu r D1 No. Ci::<I Fig. 7 TiB2 TiC Angle Fig. 8

Claims (2)

[Claims] (1) In a rolling sleeve formed by rolling a wire rod by inserting it through a through hole from one end opening to the other end opening, a matrix layer containing a mixed solid solution of nickel boride and titanium carbide is formed by boron. A rolling sleeve characterized in that it is formed of a titanium boride ceramic sintered body disposed between titanium oxide particles and having a porosity of 5% or less. (2) The titanium boride particles have an average particle size of 0.5 to 10 μm,
) The rolling sleeve described in item ).