KR101412519B1 - Method for manufacturing boron nitride sintered body by adding sintering agent - Google Patents

Abstract

The present invention relates to a method for producing a boron nitride sintered body to which a sintering assistant is added and a method for producing a boron nitride sintered body according to the present invention comprises preparing a mold for hot- step; Boron oxide (B ₂ O _3), including the purity of the boron oxide at least 95% of boron nitride powder raw material (B ₂ O ₃₎ the removal of boron oxide (B ₂ O ₃₎ removing step; Preparing a boron nitride powder to prepare a boron nitride powder to which the sintering aid is added to the boron nitride powder raw material; Pressurizing the boron nitride powder to prepare a preliminary sintered body of boron nitride; And placing the preliminary sintered body in the hollow of the mold to produce a sintered boron nitride body through hot pressing and sintering.
According to the present invention, the sintering assistant is prepared by adding 1 wt% to 5 wt% of an optimum amount of at least one of the sintering aids to 100 wt% of the boron nitride powder to which the boron nitride powder raw material and the sintering assistant are added, High-density boron nitride sintered body having a high density of 1.6 g / cm < 3 > to 2.0 g / cm < 3 > and a high strength of 34 MPa or more through optimum conditions of sintering temperature, sintering pressure, sintering temperature- Can be produced.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing a sintered body of boron nitride,

More particularly, the present invention relates to a method for producing a boron nitride sintered body by adding boron oxide (B ₂ O ₃ ), silicon nitride (Si ₃ N ₂ , N ₄ ), aluminum nitride (AIN), boron (B), aluminum oxide (Al ₂ O ₃ ) or yttrium oxide (Y ₂ O ₃ ) in an optimum ratio to produce a boron nitride sintered body A high density and high strength boron nitride sintered body is manufactured through optimization of the sintering temperature, the sintering pressure, the sintering temperature increasing rate and the sintering holding time in the hot pressing and sintering process, and the mold for hot pressing and sintering, To thereby prevent breakage and destruction of the graphite mold due to the difference in thermal expansion coefficient between boron nitride and graphite and to prevent the damage of the sintered boron nitride, And a method of manufacturing a small sintered body.

Boron nitride, which is a nitride ceramics, has a hexagonal structure similar to that of graphite and is a very hard bond. Its chemical and physical properties are similar to graphite.

The boron nitride sintered body is suitably used for a semiconductor, an insulator, a crucible for sintering silicon nitride, a radiator plate, a jig for insulation, and a crucible for phosphor sintering. Particularly, excellent properties such as lubricity, releasability, heat resistance, corrosion resistance, electrical insulation, thermal shock resistance, mechanical properties and chemical stability of ceramics are excellent.

The sintering aids added to the boron nitride powder are used for producing high density and high strength boron nitride sintered bodies. However, when a large amount of sintering aids are added, inherent characteristics of boron nitride and a large amount of impurities are mixed, There is a problem that quality deterioration and reprocessing process must be performed.

Accordingly, development of a high-density and high-strength boron nitride sintered product manufacturing method has been demanded by adding the sintering auxiliary agent to the raw material of the boron nitride powder at an optimum ratio.

(B ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AIN), boron (B ₂ O ₃ ), and the like are added to the boron nitride powder raw material in a sintering aid B), aluminum oxide (Al ₂ O ₃ ), or yttria (Y ₂ O ₃ ) is added to a sintered body of a high-density and high-strength boron nitride.

By dividing the two or more graphite molds into pieces, breakage and destruction of the graphite mold due to the difference in thermal expansion coefficient between boron nitride and graphite mold during the hot pressing and sintering process during the production process of the boron nitride sintered body can be prevented, To thereby prevent damage and to produce a high-density and high-strength sintered body of boron nitride.

According to another aspect of the present invention, there is provided a method of manufacturing a boron nitride sintered body, comprising: preparing a mold for hot-pressing and sintering in which two or more pieces of a mold are combined to form a hollow; Boron oxide (B ₂ O ₃₎ of the boron oxide having a purity of 95% or more of boron nitride powder material, including (B ₂ O ₃₎ the removal of boron oxide (B ₂ O ₃₎ removing step; Preparing a boron nitride powder to prepare a boron nitride powder to which the sintering aid is added to the boron nitride powder raw material; Pressurizing the boron nitride powder to prepare a preliminary sintered body of boron nitride; And a step of preparing a sintered compact by placing the preliminary sintered body in the hollow of the mold and performing a hot press-sintering process to produce a sintered boron nitride body.

(B ₂ O ₃ ) in an amount of 1.0 wt.% Or less, and the amount of the boron oxide (B ₂ O ₃ ) is 100 wt.% Or less, in the mold preparation step, And in the boron nitride powder preparation step, the sintering auxiliary agent is added in an amount of 1 wt% to 5 wt% in 100 wt% of the boron nitride powder.

In the preparation of the preliminary sintered body, the boron nitride powder is uniaxially pressed at a pressure of 3 MPa to 10 MPa, and the pressure-formed boron nitride powder is isotropically pressed at a pressure of 50 MPa to 300 MPa to produce a densified preliminary sintered body .

Also, in the step of producing the sintered body, the sintering temperature at which the hot pressing and sintering is performed is 700 ° C. to 2300 ° C., the pressure is 3 MPa to 45 MPa, and the heating rate is 5 ° C./min to 30 ° C./min, The sintering holding time is from 1 hour to 5 hours.

In detail, the sintering aids have a purity of 99.5% or more, and in 100 wt% of the boron nitride powder, 3 wt% to 5 wt% of boron oxide (B ₂ O ₃ ), 2 wt% to 5 wt% nitride (Si ₃ N _4), 1% to 4% by weight of aluminum nitride (AIN), 1% to 5% by weight of boron (B), 1 weight% to 4 weight% of aluminum (Al ₂ O oxide ₃ ) and 2.5 wt% to 4 wt% yttria (Y ₂ O ₃ ).

(B ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AIN), boron (B ₂ O ₃ ), and the like are added to the boron nitride powder raw material in a sintering aid B), aluminum oxide (Al ₂ O ₃ ), or yttria (Y ₂ O ₃ ) is added to the boron nitride sintered body to produce a sintered body of boron nitride of high density and high strength.

By dividing the two or more graphite molds into pieces, breakage and destruction of the graphite mold due to the difference in thermal expansion coefficient between boron nitride and graphite mold during the hot pressing and sintering process during the production process of the boron nitride sintered body can be prevented, It is possible to manufacture a high-density and high-strength sintered body of boron nitride by preventing damage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart sequentially showing a method for producing a boron nitride sintered body using the structure of a divided mold according to the present invention,
2 is a schematic view of a graphite mold inside a furnace for producing a boron nitride sintered body,
3 is a sectional view of a divided graphite mold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings, with reference to the method for producing a boron nitride sintered body to which a sintering auxiliary agent according to the present invention is added. The present invention may be better understood by the following examples, which are for the purpose of illustrating the present invention and are not intended to limit the scope of protection defined by the appended claims.

First, a method of manufacturing a sintered boron nitride using a mold for hot press-sintering according to the present invention comprises the steps of preparing a mold (S10), removing boron oxide (B ₂ O ₃ ) (S20) A powder preparation step (S30), a preliminary sintering step (S40), and a sintering step (S50).

The mold preparing step S10 is a step of preparing a mold for hot-pressing and sintering in which two or more pieces of the mold are combined with each other to form a hollow.

The mold may be composed of various materials, but is preferably made of graphite. Further, it is preferable to further include fibers on the outside of the body of the mold, more preferably, the fibers are made of carbon. This is advantageous in preventing breakage and breakage of the graphite mold due to the difference in thermal expansion coefficient between boron nitride and graphite during hot pressing and sintering, thereby preventing damage to the sintered boron nitride. By using graphite, it is more stable and can be used for a long time than other molds. The carbon fiber relaxes the elastic modulus of the graphite mold and prevents breakage and destruction of the graphite mold during hot pressing and sintering. There are advantages.

The boron oxide (B ₂ O ₃ ) removing step (S20) is a step of removing the boron oxide (B ₂ O ₃ ) of a raw material of boron nitride powder having a purity of 95% or more including boron oxide (B ₂ O ₃ ).

To use the alcohol as a way to remove the boron oxide (B ₂ O _3), it is effective for high purity of the boron oxide (B ₂ O _3). Boron oxide (B ₂ O ₃ ) is mixed with an alcohol solvent and a ball mill to produce sludge, and the resulting sludge is subjected to forced volatilization to remove the alcohol. It is possible to solve the difficulty of molding and the severe sintering shrinkage due to the electrostatic repulsion between particles having a large specific surface area by pulverizing the dried mass after the alcohol is volatilized in the boron nitride sludge and using it as the raw material of the boron nitride powder.

After the removal by the above method, boron oxide (B ₂ O ₃ ) partially remaining between the boron nitride powders serves as a sintering bridge between the particles and the particles at the time of sintering, and a new boron nitride is synthesized by the nitrogen gas, do.

It is preferable to remove 1.0 wt% or less of the boron oxide (B ₂ O ₃ ) in 100 wt% of the raw material of the boron nitride powder. When the amount of the boron oxide (B ₂ O ₃ ) exceeds 1.0% by weight, boron oxide (B ₂ O ₃ ) is present as an impurity in the boron nitride powder raw material, and the problem that the quality of the sintered body is degraded and the reprocessing step And it is difficult to obtain a high-density and high-strength sintered body of boron nitride.

The boron nitride powder preparation step (S30) is a step of preparing a boron nitride powder to which the sintering auxiliary agent is added to the boron nitride powder raw material.

The boron nitride powder raw material is preferably composed of particles having a purity of 95% or more. In addition, it is preferable that the particle size of the boron nitride powder raw material is 5 탆 to 60 탆, and it is effective to have various kinds of particle sizes. When the particle size of the boron nitride powder raw material is less than 5 탆, the boron nitride powder raw material melts due to pressurization in the step of producing the preliminary boron nitride sintered body, which poses a problem in producing a preliminary boron nitride sintered body, There is a problem in manufacturing a high-density boron nitride sintered body because of the large particle size and the pores between the particles.

(B ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AIN), boron (B), and boron nitride are added as a sintering auxiliary agent having a purity of 99.5% aluminum oxide (Al ₂ O ₃₎ and yttrium oxide (Y ₂ O ₃₎ will the addition of at least one of the boron oxide (B ₂ O ₃₎ is 3% to 5% by weight, the silicon nitride (Si ₃ N ₄₎ is 2% to 5% by weight, the aluminum nitride (AIN) is 1% to 4% by weight, the boron (B) is 1% by weight to 5% by weight, of aluminum the oxide (Al ₂ O ₃₎ (Y ₂ O ₃ ) is added in an amount of 1 wt% to 4 wt%, and the amount of yttrium oxide (Y ₂ O ₃ ) is added in an amount of 2.5 wt% to 4 wt%.

When the sintering aid is added in an amount of less than 1% by weight based on 100% by weight of the boron nitride powder, the boron nitride sintered body to which the sintering aid is added has a higher density and higher strength than the sintered boron nitride , And if it is added in an amount exceeding 5% by weight, the inherent characteristics of boron nitride will be destroyed, deteriorating the heat resistance and impurities mixed therewith, resulting in deterioration of quality of the sintered body and reprocessing.

The preliminary sintered compact forming step (S40) is a step of pressing the boron nitride powder to prepare a boron nitride preliminary sintered body.

The boron nitride powder raw material in which boron oxide (B ₂ O ₃ ), which is an inevitably added impurity, is removed in an amount of not more than 1.0% by weight in 100% by weight of the boron nitride powder raw material is obtained by adding the above- And then uniaxial pressing is performed to produce a constant boron nitride preliminary shape, and then a densified boron nitride preliminary sintered body is produced by isostatic pressing.

The uniaxial pressing pressure is preferably 3 MPa to 10 MPa. If the uniaxial pressing pressure is out of this range, there is a problem in making the desired constant boron nitride preform. The isostatic pressing pressure is preferably within a range of 50 MPa to 300 MPa. If the isostatic pressing pressure is less than 50 MPa, the boron nitride preliminary form is not sufficiently pressurized and there is a problem in making the densified boron nitride pre-sintered body, and when the pressure exceeds 300 MPa, the boron nitride preliminary form There is a problem that is destroyed.

The sintered body manufacturing step (S50) is a sintered body manufacturing step in which the pre-sintered body is placed in the hollow of the mold and a sintered body of boron nitride is manufactured through a hot press sintering process.

It is effective to manufacture the sintered boron nitride using the multi-axial hot pressing. In the case of general hot pressing, when a large product is sintered using a uniaxial hot pressing, heat loss through the shaft is largely generated, and the degree of sintering of the center and side of the product is varied due to a large temperature deviation on the product to be sintered. It is not effective. In the present invention, it is possible to manufacture excellent sintered boron nitride by minimizing heat transfer by using multi-axis thermal compression.

The sintering temperature at which the hot press-sintering occurs is preferably 700 to 2300 ° C. When the sintering temperature is lower than 700 ° C, there is a problem in producing a sintered body of boron nitride that can withstand high temperatures. When the sintering temperature exceeds 2300 ° C, the boron nitride powder particles are melted to produce a high density and high strength boron nitride sintered body there is a problem.

The pressure at which the hot pressing and sintering takes place is preferably from 3 MPa to 45 MPa. When the pressure to pressurize the preliminary sintered body is less than 3 MPa, the boron nitride preliminary sintered body is not subjected to sufficient pressure, which causes problems in the manufacture of high density and high strength boron nitride sintered bodies. When the pressure exceeds 45 MPa, There is a problem that the powder particles of the boron nitride preliminary sintered body are destroyed and the shape of the boron nitride preliminary sintered body is lost.

The rate of temperature rise at which the hot press-sintering occurs is preferably 5 ° C / min to 30 ° C / min. When the rate of temperature rise is less than 5 캜 / min, the sintering holding time is prolonged and there is a problem in producing a sintered body having high strength and excellent insulating properties. When the temperature increase rate is more than 30 캜 / min, There is a problem that breakage and destruction of the mold occurs.

The sintering holding time at which hot pressing and sintering occurs is preferably from 1 hour to 5 hours. When the sintering holding time is less than 1 hour, sufficient sintering is not performed and there is a problem in obtaining a high density and high strength sintered body of boron nitride. When the sintering holding time exceeds 5 hours, economical problems and particles of the sintered body of the boron nitride There is a problem of losing inherent characteristics of boron nitride.

After the sintered body production step (S50), it is preferable to include a heat treatment step. It is effective to perform heat treatment in a gas atmosphere of hydrogen gas (H ₂ ) and nitrogen gas (N ₂ ), which can remove residual stress and remove impurities by heat treatment of the manufactured sintered product. More preferably, it is effective that the hydrogen gas is from 0.5 to 30% by volume, the nitrogen gas is from 70 to 95.5% by volume, more preferably the hydrogen gas is from 3 to 8% by volume and the nitrogen gas is from 92 to 97% It is most effective.

The boron nitride sintered body of the present invention produced by the above production method has a density of about 1.8 g / m ³ or more and a strength of about 35 Mpa or more, so that a high density and high strength sintered body of boron nitride can be manufactured as compared with the conventional sintered body of boron nitride have.

Hereinafter, examples and comparative examples in which the characteristics of the sintered boron nitride formed using the sintered boron nitride sintered body with the sintering aid of the present invention are tested will be described.

Table 1 below is experimental data comparing the high density and high strength of the boron nitride sintered body formed by the present invention (Example) and the boron nitride sintered body (Comparative Example) deviated from the addition amount of the sintering auxiliary of the present invention.

Example  One

4 A graphite mold for hot-pressing and sintering further comprising carbon fibers on the outer side where the pieces of the mold are bonded to each other to form a hollow are prepared, and 100% by weight of boron nitride powder material containing 95% or more of purity of boron oxide (B ₂ O ₃ ) in the boron oxide (B ₂ O ₃₎ 0.3 wherein boron oxide, so that it contains only the wt% of (B ₂ O ₃₎ to remove the boron nitride powder raw material sintering aid is 99.5% of yttrium oxide to the (Y in ₂ O ₃₎ 100% by weight of boron nitride powder added thereto, preparing the yttrium oxide (Y ₂ O ₃₎ a boron nitride powder comprising 3% by weight, the boron nitride powder was molded into a 7 MPa pressure Then, the preliminary sintered body was pressurized with isotropic pressure at a pressure of 200 MPa to prepare a preliminary sintered body, and the preliminarily sintered body was placed in a hollow formed by joining the four pieces of the mold together. The sintering temperature was 2000 캜, the sintering pressure was 30 MPa, The holding time is 3 hours, and the sintering temperature Turning through 20 ℃ / min in a hot-pressing process, to prepare a boron nitride sintered body.

Example  2

In the above embodiment 1, in the sintering aid in the silicon nitride (Si ₃ N ₄₎ 100% by weight of boron nitride powder added to changes in the purity of 99.7%, the silicon nitride (Si ₃ N ₄₎ is 5% by weight The boron nitride sintered body is changed to be the contained boron nitride powder.

Example  3

In Example 1, the sintering assistant was changed to aluminum nitride (AIN) having a purity of 99.5% and changed to be boron nitride powder containing 2 wt% of the aluminum nitride (AIN) in 100 wt% of the added boron nitride powder Thereby producing a sintered body of boron nitride.

Example  4

In the above-mentioned Example 1, the sintering assistant was changed to aluminum nitrate (AIN) having a purity of 99.5% and yttrium oxide (Y ₂ O ₃ ) having a purity of 99.5% in 100 wt.% Of boron nitride powder, ) Is contained in an amount of 1 wt%, and the boron nitride powder is changed to a boron nitride powder containing 3 wt% of yttria (Y ₂ O ₃ ).

Comparative Example  One

4 A graphite mold for hot-pressing and sintering further comprising carbon fibers on the outer side where the pieces of the mold are bonded to each other to form a hollow are prepared, and 100% by weight of boron nitride powder material containing 95% or more of purity of boron oxide (B ₂ O ₃ ) The boron nitride powder was molded at a pressure of 7 MPa and was isotropically pressed at a pressure of 200 MPa in 100 wt% of boron nitride powder composed only of a boron nitride powder raw material to which no sintering aid was added, The pre-sintered body was put into a hollow formed by joining the four pieces of the mold together. The sintering temperature was 2000 ° C, the sintering pressure was 30 MPa, the sintering holding time was 3 hours, the sintering temperature increasing rate was 20 ° C / min, a sintered body of boron nitride is produced.

Comparative Example  2

4 A graphite mold for hot-pressing and sintering further comprising carbon fibers on the outer side where the pieces of the mold are bonded to each other to form a hollow are prepared, and 100% by weight of boron nitride powder material containing 95% or more of purity of boron oxide (B ₂ O ₃ ) in the boron oxide (B ₂ O ₃₎ 0.3 wherein boron oxide, so that it contains only the wt% of (B ₂ O ₃₎ to remove the boron nitride powder raw material sintering aid is 99.5% of yttrium oxide to the (Y in ₂ O ₃₎ 100% by weight of boron nitride powder added thereto, preparing the yttrium oxide (Y ₂ O ₃₎ a boron nitride powder containing 7% by weight, the boron nitride powder was molded into a 7 MPa pressure Then, the preliminary sintered body was pressurized with isotropic pressure at a pressure of 200 MPa to prepare a preliminary sintered body, and the preliminarily sintered body was placed in a hollow formed by joining the four pieces of the mold together. The sintering temperature was 2000 캜, the sintering pressure was 30 MPa, The holding time is 3 hours, and the sintering temperature Turning through 20 ℃ / min in a hot-pressing process, to prepare a boron nitride sintered body.

Comparative Example  3

In the comparative example 2, a boron nitride sintered body in which the silicon nitride (Si ₃ N ₄ ) content is 6% by weight and the boron nitride powder is 100% by weight is prepared.

Comparative Example  4

In Comparative Example 2, a boron nitride sintered body in which the boron nitride powder was changed to 100 wt% of the boron nitride powder was changed to a boron nitride powder containing 8 wt% of aluminum nitride (AIN).

Comparative Example  5

In Comparative Example 2, it was changed to a boron nitride powder containing 3 wt% of aluminum nitride (AIN) and 5 wt% of yttrium oxide (Y ₂ O ₃ ) in 100 wt% of the boron nitride powder Thereby producing a sintered body of boron nitride.

density burglar Example 1 1.9 g / cm < 3 > 33 MPa Example 2 2.0 g / cm3 34 MPa Example 3 1.7 g / cm3 33 MPa Example 4 2.0 g / cm3 35 MPa Comparative Example 1 1.5 g / cm3 29 MPa Comparative Example 2 1.3 g / cm3 29 MPa Comparative Example 3 1.3 g / cm3 27 MPa Comparative Example 4 1.3 g / cm3 29 MPa Comparative Example 5 1.2 g / cm3 28 MPa

As shown in Table 1, Examples 1 to 4 of the present invention have a density of 1.6 g / cm3 to 2.0 g / cm3 and a strength of 33 MPa or more, so that compared with Comparative Example 1, A sintered body of boron nitride having a high density and a high strength can be produced by adding the sintering aid to the sintered body of the sintered body of the sintered body. In comparison with the density of 1.3 g / cm 3 or less and the strength of 29 MPa or less in Comparative Examples 2 to 5, , It is difficult to obtain a high-density and high-strength sintered body of boron nitride because the hard bonds inherent in boron nitride are lost. Further, the inherent characteristics of boron nitride are deteriorated by the deterioration of the lubricity and the sinterability, so that a sintered body of boron nitride having a high density and a high strength can not be produced, the quality of the sintered body is lowered, and a reprocessing step is required.

Therefore, by using the mold for hot press-sintering of the present invention and the method for producing a boron nitride sintered body using the same, breakage of the mold for hot-pressing and sintering due to difference in thermal expansion coefficient between boron nitride and hot- The boron nitride sintered body having high density and high strength of the sintered body of boron nitride was produced by preventing the breakdown of the sintered body and preventing damage to the sintered body of the boron nitride by adding the sintering aid to the boron nitride powder.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

10: hollow of the graphite mold into which the preliminary boron nitride sintered body is put
20: upper punch
30: Lower punch
40: Graphite mold sleeve
50: Graphite mold division part
51: one mold in which the divided molds are combined
60: Carbon fiber winding layer

Claims (16)

A mold preparing step of preparing a hot press sintering mold in which two or more pieces of a mold are joined to each other to form a hollow;
Boron oxide (B ₂ O _3), including the purity of the boron oxide at least 95% of boron nitride powder raw material (B ₂ O ₃₎ the removal of boron oxide (B ₂ O ₃₎ removing step;
Preparing a boron nitride powder to prepare a boron nitride powder to which the sintering aid is added to the boron nitride powder raw material;
Pressurizing the boron nitride powder to prepare a preliminary sintered body of boron nitride; And
And sintering the sintered compact by placing the preliminary sintered body in the hollow of the mold to produce a sintered body of boron nitride through a hot press sintering process,
In the boron nitride powder preparation step, wherein the sintering aid is has a purity of at least 99.5%, boron oxide (B ₂ O in 100% by weight of the boron nitride powder, 1% to 5 addition of% by weight, the sintering aid ₃ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AIN) or boron (B), wherein the boron oxide (B ₂ O ₃ ) (Si ₃ N ₄ ) is added in an amount of 2 wt% to 5 wt% in 100 wt% of the boron nitride powder, and the aluminum nitride (AIN ) Is added in an amount of 1 wt% to 4 wt% in 100 wt% of the boron nitride powder, and the boron (B) is added in an amount of 1 wt% to 5 wt% in 100 wt% of the boron nitride powder And,
Wherein the preliminary sintered compact is uniaxially pressurized with the boron nitride powder at a pressure of 3 MPa to 10 MPa and isotropically pressurized at a pressure of 50 MPa to 300 MPa to produce a sintered boron nitride sintered body
The method according to claim 1,
In the mold preparation step, the mold is characterized in that it comprises graphite, further comprising fibers on the outside of the mold, the fibers comprising carbon A method for producing a boron nitride sintered body to which a sintering auxiliary agent is added
The method according to claim 1,
In the boron oxide (B ₂ O ₃₎ stripping step, in the boron nitride powder raw materials of 100% by weight, the addition of a sintering aid it characterized in that the boron oxide (B ₂ O ₃₎ contains less than 1.0% by weight Manufacturing method of boron nitride sintered body
The method according to claim 1,
Wherein the sintering temperature at which the hot press sintering is performed in the sintering step is 700 ° C. to 2300 ° C. 3. A sintered body according to claim 1,
The method according to claim 1,
Wherein the pressure at which the hot press sintering is performed is 3 MPa to 45 MPa in the step of manufacturing the sintered body,
The method according to claim 1,
Wherein a temperature increase rate at which the hot press sintering is performed is 5 ° C / min to 30 ° C / min in the sintered body manufacturing step, wherein the sintering aid is added to the boron nitride sintered body
The method according to claim 1,
Wherein the sintering holding time of the hot press is 1 hour to 5 hours in the step of manufacturing the sintered body,
The method according to claim 1,
Characterized in that in the boron nitride powder preparation step, the particle size of the boron nitride powder raw material is from 5 탆 to 60 탆, wherein the sintering aid is added to the boron nitride sintered product
The method according to claim 1,
After the sintered body is manufactured, the boron nitride sintered body is subjected to a heat treatment in a gas atmosphere of hydrogen gas (H ₂ ) and nitrogen gas (N ₂ ), wherein the hydrogen gas is 0.5 to 30% by volume, 95.5% by volume, based on the total amount of the boron nitride sintered body delete delete delete delete delete delete delete

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