JP2017036170A - Production method of sintered body of boron carbide - Google Patents
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- 229910052580 B4C Inorganic materials 0.000 title claims abstract description 77
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 title claims abstract description 76
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 23
- 238000005245 sintering Methods 0.000 claims abstract description 132
- 239000011230 binding agent Substances 0.000 claims abstract description 23
- 238000003754 machining Methods 0.000 claims abstract description 19
- 238000002156 mixing Methods 0.000 claims abstract description 13
- 238000000465 moulding Methods 0.000 claims description 13
- 238000002844 melting Methods 0.000 claims description 9
- 230000008018 melting Effects 0.000 claims description 9
- 239000004020 conductor Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 abstract description 27
- 230000000704 physical effect Effects 0.000 abstract description 6
- 239000000126 substance Substances 0.000 abstract description 6
- 238000000034 method Methods 0.000 description 18
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 15
- 229910052782 aluminium Inorganic materials 0.000 description 14
- 238000010438 heat treatment Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- 239000000203 mixture Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- -1 polypropylene Polymers 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000001993 wax Substances 0.000 description 7
- 238000005238 degreasing Methods 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 229910033181 TiB2 Inorganic materials 0.000 description 5
- 239000011261 inert gas Substances 0.000 description 5
- 238000001746 injection moulding Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- QYEXBYZXHDUPRC-UHFFFAOYSA-N B#[Ti]#B Chemical compound B#[Ti]#B QYEXBYZXHDUPRC-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000008188 pellet Substances 0.000 description 4
- 229920000178 Acrylic resin Polymers 0.000 description 3
- 239000004925 Acrylic resin Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 235000014113 dietary fatty acids Nutrition 0.000 description 3
- 239000000194 fatty acid Substances 0.000 description 3
- 229930195729 fatty acid Natural products 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004793 Polystyrene Substances 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000004203 carnauba wax Substances 0.000 description 2
- 235000013869 carnauba wax Nutrition 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000009760 electrical discharge machining Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000012188 paraffin wax Substances 0.000 description 2
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- 230000008016 vaporization Effects 0.000 description 2
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 229910052810 boron oxide Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000009694 cold isostatic pressing Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
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- 238000001125 extrusion Methods 0.000 description 1
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- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000004200 microcrystalline wax Substances 0.000 description 1
- 235000019808 microcrystalline wax Nutrition 0.000 description 1
- 239000012170 montan wax Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- XNGIFLGASWRNHJ-UHFFFAOYSA-N o-dicarboxybenzene Natural products OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000002006 petroleum coke Substances 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 1
- 239000010695 polyglycol Substances 0.000 description 1
- 229920000151 polyglycol Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920005990 polystyrene resin Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000011369 resultant mixture Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Landscapes
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Ceramic Products (AREA)
Abstract
Description
本発明は、放電加工性に優れた炭化ホウ素の焼結体を製造することができる炭化ホウ素の焼結体の製造方法に関するものである。 The present invention relates to a method for manufacturing a sintered body of boron carbide capable of manufacturing a sintered body of boron carbide having excellent electric discharge processability.
炭化ホウ素（例えば、B4C）は、ダイヤモンド、立方晶窒化ホウ素（cBN）に次ぐ硬度を有する工業材料として知られ、炭化ホウ素を含む材料を焼結した焼結体は超硬材料などとしてさまざまな用途に用いられている。
上述した炭化ホウ素の焼結体は、高硬度であるが故に切削加工などの機械加工を行うことが困難であり、機械的加工における加工性があまり良くない。それゆえ、炭化ホウ素の焼結体のような材料に対しては、機械加工に代えて放電加工を用いて加工が検討されてきた。
Boron carbide (for example, B4C) is known as an industrial material with hardness next to diamond and cubic boron nitride (cBN). It is used for.
Since the above-mentioned sintered body of boron carbide has high hardness, it is difficult to perform machining such as cutting, and workability in mechanical processing is not so good. Therefore, for materials such as a sintered body of boron carbide, machining has been studied using electric discharge machining instead of machining.
なお、炭化ホウ素の焼結体は、アルミナなどの焼結体に比して多少の導電性があるものの、放電加工を満足に行える程の導電性は備えていない。それゆえ、放電加工に際しては、炭化ホウ素の焼結体の導電性をさらに良くする手段を講じる必要がある。
例えば、非特許文献１には、表面に導電性膜を付与して油中で加工を行えば、炭化ホウ素の焼結体のような材料に対しても十分に放電加工が可能なことが記載されている。
Although the sintered body of boron carbide has some conductivity as compared with a sintered body such as alumina, the sintered body does not have sufficient conductivity to perform electric discharge machining satisfactorily. Therefore, it is necessary to take measures to further improve the conductivity of the sintered body of boron carbide in electric discharge machining.
For example, Non-Patent Document 1 describes that if a conductive film is provided on the surface and processing is performed in oil, sufficient electrical discharge processing can be performed even for materials such as a sintered body of boron carbide. Has been.
また、特許文献１、２には、炭化ホウ素の粉末に、二酸化チタン、炭素粉末を加えたものを、１８５０℃〜２１５０℃の温度で焼結することで、抵抗率が０．１Ω・ｃｍの炭化ホウ素−二ホウ化チタン焼結体を得る技術が開示されている。これらの文献に記載された焼結体では、導電性を備えた二ホウ化チタンを炭化ホウ素の粒子間に存在させることで、放電加工を可能としている。 Patent Documents 1 and 2 disclose that the resistivity is 0.1 Ω · cm by sintering a powder obtained by adding titanium dioxide and carbon powder to boron carbide powder at a temperature of 1850 ° C. to 2150 ° C. A technique for obtaining a boron carbide-titanium diboride sintered body is disclosed. In the sintered bodies described in these documents, electrical discharge machining is possible by allowing conductive titanium diboride to exist between boron carbide particles.
ところで、上述した非特許文献１のように、導電性物質を用いて炭化ホウ素の焼結体の表面を被覆する技術では、焼結体が薄い場合には問題はないが、厚みのある焼結体を放電加工する際には放電加工を行うことが困難になる場合がある。
また、特許文献１、２のように放電性物質を混合した上で焼結体を成形する技術では、炭化ホウ素に対して二ホウ化チタンを混合するため、焼結体の物性が本来炭化ホウ素が持つ値に対して劣化してしまう、言い換えれば二ホウ化チタンを混合せずに焼結した場合の物性値よりも二ホウ化チタンを混合して焼結した焼結体の物性値の方が悪くなってしまう可能性がある。
By the way, as in Non-Patent Document 1 described above, the technique of coating the surface of a sintered body of boron carbide using a conductive material is not problematic when the sintered body is thin, but thick sintering is performed. When electric discharge machining is performed on the body, it may be difficult to perform electric discharge machining.
Moreover, in the technique of forming a sintered body after mixing dischargeable substances as in Patent Documents 1 and 2, since titanium diboride is mixed with boron carbide, the physical properties of the sintered body are originally boron carbide. In other words, the physical property value of a sintered body in which titanium diboride is mixed and sintered is more than the physical property value in the case of sintering without mixing titanium diboride. May get worse.
本発明は、上述の問題に鑑みてなされたものであり、炭化ホウ素の物性、特に密度を可能な限り損なうことなく放電加工性に優れた炭化ホウ素の焼結体を得ることができる炭化ホウ素の焼結体の製造方法を提供することを目的とする。 The present invention has been made in view of the above-mentioned problems, and it is possible to obtain a boron carbide sintered body excellent in electric discharge workability without damaging the physical properties of boron carbide, particularly the density as much as possible. It aims at providing the manufacturing method of a sintered compact.
上記課題を解決するため、本発明の炭化ホウ素の焼結体の製造方法は以下の技術的手段を講じている。
即ち、本発明の炭化ホウ素の焼結体の製造方法は、炭化ホウ素とバインダとを混合し且つ成形した成形体を導電性物質が気化した雰囲気下で焼結して前記炭化ホウ素の焼結体を成形するに際しては、前記成形体を焼結する際の条件を、放電加工が可能な焼結体が得られるような条件として焼結を行うことを特徴とする。
In order to solve the above problems, the method for producing a sintered body of boron carbide according to the present invention employs the following technical means.
That is, the method for producing a sintered body of boron carbide according to the present invention comprises mixing a boron carbide and a binder and sintering the molded body in an atmosphere in which a conductive substance is vaporized, thereby sintering the boron carbide sintered body. When molding is performed, the sintering is performed under the condition that the molded body is sintered so that a sintered body capable of electric discharge machining is obtained.
なお、好ましくは、炭化ホウ素とバインダとを混合し且つ成形した成形体を導電性物質が気化した雰囲気下で焼結して前記炭化ホウ素の焼結体を成形するに際しては、前記成形体を焼結する際の条件を、焼結後に最高密度が出る条件から未焼結側にシフトした条件としつつ焼結を行うことで、前記焼結体に放電加工が可能となる特性を発現させるとよい。
なお、好ましくは、前記成形体を焼結する際の条件である焼結温度が、焼結後に最高密度が出る焼結温度をＴ０℃とした場合に、（Ｔ０−５０）℃〜（Ｔ０−２０）℃とされているとよい。
Preferably, when forming the sintered body of boron carbide by sintering the molded body in which boron carbide and a binder are mixed and molded in an atmosphere in which a conductive substance is vaporized, the molded body is sintered. It is better to develop the characteristics that enable electric discharge machining to the sintered body by performing sintering while setting the conditions when the sintering is performed to the conditions in which the highest density after sintering is shifted to the unsintered condition. .
Preferably, the sintering temperature, which is a condition for sintering the molded body, is (T 0 -50) ° C. to (T 0 ° C.) when the sintering temperature at which the maximum density is obtained after sintering is T 0 ° C. T 0 -20) may have been a ° C..
なお、好ましくは、前記成形体を焼結する際の条件である焼結温度が、前記炭化ホウ素の融点をＴ１℃とした場合に、（Ｔ１×０．７６０）℃〜（Ｔ１×０．７７１）℃とされているとよい。
なお、好ましくは、前記成形体を焼結する際の条件である焼結時間が、焼結後に最高密度が出る焼結時間をｔ０（ｈｒ）とした場合に、（ｔ０−３）〜（ｔ０−１）とされているとよい。
Preferably, the sintering temperature, which is a condition for sintering the molded body, is (T 1 × 0.760) ° C. to (T 1 ×) when the melting point of the boron carbide is T 1 ° C. 0.771) C.
Preferably, the sintering time, which is a condition for sintering the molded body, is (t 0 -3) to (t 0 -3) when the sintering time at which the maximum density is obtained after sintering is t 0 (hr). It may be (t 0 −1).
本発明にかかる炭化ホウ素の焼結体の製造方法によれば、炭化ホウ素の物性、特に密度を可能な限り損なうことなく放電加工性に優れた炭化ホウ素の焼結体を得ることができる。 According to the method for producing a sintered body of boron carbide according to the present invention, it is possible to obtain a sintered body of boron carbide having excellent electric discharge workability without impairing the physical properties of boron carbide, particularly the density as much as possible.
以下、本発明にかかる炭化ホウ素の焼結体１の製造方法の実施形態を、図面に基づき説明する。
図１は、本実施形態の焼結体１の製造方法を模式的に示したものである。
図１に示すように、本実施形態の焼結体１の製造方法は、炭化ホウ素の粒子２とバインダ３とを混合すると共に成形する「成形工程」と、成形された成形体４を導電性物質５が気化した雰囲気下で焼結して炭化ホウ素の焼結体１を成形する「焼結工程」と、を備えている。
Hereinafter, an embodiment of a method for producing a sintered body 1 of boron carbide according to the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a method for producing the sintered body 1 of the present embodiment.
As shown in FIG. 1, the manufacturing method of the sintered body 1 of the present embodiment includes a “molding step” in which boron carbide particles 2 and a binder 3 are mixed and molded, and the molded body 4 is made conductive. A “sintering step” in which a sintered body 1 of boron carbide is formed by sintering in an atmosphere in which the substance 5 is vaporized.
次に、本実施形態の焼結体１の製造方法を構成する「成形工程」及び「焼結工程」について説明する。
成形工程の方法としては、例えば粉末射出成形を用いることができるが、他にも金型成形、冷間静水圧成形(CIP)、押し出し成形、鋳込み成形、シート成形、インクジェットプリンタによる成形も用いることができる。ここでは、粉末射出成形を適用する場合の実施形態について説明する。
Next, the “forming step” and the “sintering step” constituting the method for manufacturing the sintered body 1 of the present embodiment will be described.
As a method of the molding process, for example, powder injection molding can be used, but in addition, mold molding, cold isostatic pressing (CIP), extrusion molding, casting molding, sheet molding, and molding by an ink jet printer can also be used. Can do. Here, an embodiment in the case of applying powder injection molding will be described.
粉末射出成形とは、炭化ホウ素の粒子２と、バインダ３とを混合し、得られた混合物を金型６内に射出成形して、所定の形状の成形体４を成形するものである。
この成形工程に用いられる炭化ホウ素の粒子２は、平均粒径Ｄ５０（メジアン径）が０．１μｍ〜１０μｍ、好ましくは０．１μｍ〜１．０μｍとされている。また、この炭化ホウ素の粒子２には、熱炭素還元反応を用いて合成したものを用いることができる。つまり、熱炭素還元反応を用いて、ホウ素源（ホウ酸（Ｈ３ＢＯ３）や酸化ホウ素（Ｂ２Ｏ３））と炭素源（活性炭や石油コークスなど）を直接混合し、高温加熱を行えば、本実施形態の製造方法に用いることができるような炭化ホウ素の粒子２を得ることが可能となる。なお、炭化ホウ素の粒子２には、熱炭素還元反応以外の方法で合成された粒子を用いても良い。
In the powder injection molding, boron carbide particles 2 and a binder 3 are mixed, and the resultant mixture is injection-molded into a mold 6 to form a molded body 4 having a predetermined shape.
The boron carbide particles 2 used in this molding step have an average particle diameter D 50 (median diameter) of 0.1 μm to 10 μm, preferably 0.1 μm to 1.0 μm. The boron carbide particles 2 may be synthesized using a thermal carbon reduction reaction. That is, using a hot carbon reduction reaction, a boron source (boric acid (H 3 BO 3 ) or boron oxide (B 2 O 3 )) and a carbon source (such as activated carbon or petroleum coke) are directly mixed and heated at a high temperature. For example, boron carbide particles 2 that can be used in the manufacturing method of the present embodiment can be obtained. The boron carbide particles 2 may be particles synthesized by a method other than the thermal carbon reduction reaction.
バインダ３は、炭化ホウ素の粒子２同士を結着することにより、成形体４における炭化ホウ素の粒子２の保形性を向上させるものである。具体的には、バインダ３には、アクリル樹脂、ポリスチレン、またはポリプロピレンなどの母材樹脂に、ワックスなどを混合した混合物が用いられる。
このバインダ３の母材樹脂には、上述したアクリル樹脂を１０vol%〜４０vol%、ポリスチレン樹脂を０vol%〜２５vol%、ポリプロピレン樹脂を０vol%〜１０vol%を用いるのが好ましい。
The binder 3 improves the shape retention of the boron carbide particles 2 in the molded body 4 by binding the boron carbide particles 2 together. Specifically, the binder 3 is a mixture in which a base material resin such as acrylic resin, polystyrene, or polypropylene is mixed with wax or the like.
As the base resin of the binder 3, it is preferable to use 10 vol% to 40 vol% of the acrylic resin described above, 0 vol% to 25 vol% of the polystyrene resin, and 0 vol% to 10 vol% of the polypropylene resin.
また、ワックスとしては、脂肪酸エステル、脂肪酸アミド、フタル酸エステル、パラフィンワックス、マイクロクリスタリンワックス、ポリエチレンワックス、ポリプロピレンワックス、カルナバワックス、モンタン系ワックス、ウレタン化ワックス、無水マレイン酸変性ワックス、及びポリグリコール系化合物から選ばれる少なくとも１種以上を用いることができる。 As the wax, fatty acid ester, fatty acid amide, phthalic acid ester, paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, carnauba wax, montan wax, urethanized wax, maleic anhydride modified wax, and polyglycol type At least one selected from compounds can be used.
さらに、これらのワックスに加えて、炭化ホウ素の粒子２と母材樹脂との親和性（結着性）を高めるなどの目的で、ポリエチレン、アモルファスポリオレフィン、エチレン酢酸ビニル共重合体、ポリビニルブチラール樹脂、グリシジルメタクリレート樹脂などを結着補助剤として加えることもできる。
上述した炭化ホウ素の粒子２及びバインダ３を混合する混合比率は、炭化ホウ素の粒子２が４０vol%〜７０vol%、バインダ３が３０vol%〜６０vol%とするのが良い。この混合比率で炭化ホウ素の粒子２とバインダ３とを混合すれば、圧粉工程での形状保持が容易となり、さまざまな形状の焼結体１を成形することが可能となる。
Furthermore, in addition to these waxes, polyethylene, amorphous polyolefin, ethylene vinyl acetate copolymer, polyvinyl butyral resin, for the purpose of increasing the affinity (binding property) between the boron carbide particles 2 and the base resin, Glycidyl methacrylate resin or the like can also be added as a binding aid.
The mixing ratio of mixing the boron carbide particles 2 and the binder 3 is preferably 40 vol% to 70 vol% for the boron carbide particles 2 and 30 vol% to 60 vol% for the binder 3. If the boron carbide particles 2 and the binder 3 are mixed at this mixing ratio, the shape can be easily maintained in the compacting process, and various shapes of the sintered body 1 can be formed.
また、炭化ホウ素の粒子２及びバインダ３の混合には、バッチ式または連続式の混練機（図示略）を用いて混練（混合）を行うのが好ましい。混練機としてバッチ式を用いる場合であれば、混練機の内部で混合物を１６０℃〜１８０℃の温度で２時間程度に亘って混練を行えば、炭化ホウ素の粒子とバインダ３とが均質な混合された混合物を得ることができる。このようにして混練が行われた混練物（混合物）はペレタイザを用いて粒径５ｍｍ程度のペレットに加工され、ペレットとして成形機（射出成形機）に送られる。 Further, the mixing of the boron carbide particles 2 and the binder 3 is preferably carried out by kneading (mixing) using a batch type or continuous type kneader (not shown). If a batch type is used as the kneader, the mixture of the boron carbide particles and the binder 3 are homogeneously mixed if the mixture is kneaded at a temperature of 160 ° C. to 180 ° C. for about 2 hours. Can be obtained. The kneaded material (mixture) thus kneaded is processed into pellets having a particle size of about 5 mm using a pelletizer, and sent to a molding machine (injection molding machine) as pellets.
成形機は、金型６内に射出された混合物に、５０ton〜１５０tonの圧力を加えて、混合物を所望の形状に成形するものである。圧粉装置の金型６は複数に分割可能となっている。また、金型６の内部には、金型６外の混練物を金型６内に射出する射出部（図示略）が形成されており、射出部を介して混練後の混練物を金型６内に射出できるようになっている。さらに、金型６の内部には、金型６内のガスを金型６外に排出するガス抜き部（図示略）が形成されているのが好ましい。 The molding machine applies a pressure of 50 to 150 tons to the mixture injected into the mold 6 to form the mixture into a desired shape. The mold 6 of the compacting device can be divided into a plurality of parts. Further, an injection part (not shown) for injecting the kneaded material outside the mold 6 into the mold 6 is formed inside the mold 6, and the kneaded material after kneading is injected into the mold through the injection part. 6 can be injected. Furthermore, it is preferable that a gas vent (not shown) for discharging the gas in the mold 6 out of the mold 6 is formed inside the mold 6.
上述した圧粉工程が終了した混練物に対しては、加熱炉７を用いて脱脂を行う。この脱脂は、成形体からバインダを除去するために実施されるが、成形工程で成形された混練物中に入り込んだ空気などのガスや成形体４中に含まれる溶剤などを除く効果も得られる。この脱脂を行うことで、焼結体１の膨れやクラックを防止することができる。
この脱脂を行う雰囲気は、窒素やアルゴンなどの不活性ガスや水素ガスのようなガスを用いて行われ、非酸化性のものとなっている。特に好ましくは、この非酸化性の雰囲気としては、大気圧に対して減圧された不活性ガスの雰囲気、大気圧に保持した不活性ガスの雰囲気、あるいは大気圧に保持した水素ガスの雰囲気を用いるのが良い。
The kneaded product after the above-described compacting process is degreased using the heating furnace 7. This degreasing is carried out in order to remove the binder from the molded body, but it is also possible to obtain the effect of removing gases such as air that has entered into the kneaded product molded in the molding process and the solvent contained in the molded body 4. . By performing this degreasing, swelling and cracks of the sintered body 1 can be prevented.
The degreasing atmosphere is performed using an inert gas such as nitrogen or argon, or a gas such as hydrogen gas, and is non-oxidizing. Particularly preferably, as the non-oxidizing atmosphere, an inert gas atmosphere depressurized with respect to atmospheric pressure, an inert gas atmosphere maintained at atmospheric pressure, or a hydrogen gas atmosphere maintained at atmospheric pressure is used. Is good.
また、脱脂は、バッチ式の加熱炉７か、ベルト式、プッシャー式、ウォーキング式などの連続式の加熱炉７を用いて行うことができ、その際の炉内温度は炭化ホウ素の焼結が起きない６００℃以下の温度域とされる。このようにして脱脂が行われた混練物に対しては、焼結工程が行われる。
焼結工程は、圧粉工程において金型６により所定の形状に成形された成形体４を高温状態に保持して、成形体４中の炭化ホウ素の粒子２同士を結合させる工程である。この焼結工程は、上述した脱脂と同じ加熱炉７を用いて行われるが、成形体４を処理する温度及び時間が脱脂とは異なっている。
In addition, degreasing can be performed using a batch-type heating furnace 7 or a continuous heating furnace 7 such as a belt type, a pusher type, or a walking type. A temperature range of 600 ° C. or less that does not occur. A sintering process is performed on the kneaded material thus degreased.
The sintering process is a process in which the molded body 4 formed into a predetermined shape by the mold 6 in the compacting process is held in a high temperature state and the boron carbide particles 2 in the molded body 4 are bonded to each other. This sintering step is performed using the same heating furnace 7 as the above-described degreasing, but the temperature and time for processing the molded body 4 are different from degreasing.
焼結工程においては、難焼結性物質である炭化ホウ素の粒子２の焼結を促進するために、焼結時の雰囲気中にアルミニウム（導電性物質５）が気化されて加えられている。このアルミニウムは、加熱炉７の炉内に成形体４から距離をあけて設けられていて、焼結時に加熱炉７の熱により気化するようになっている。つまり、２０００℃を超える焼結温度を備えた焼結工程においては、アルミニウムは融点を超える温度で加熱されることになるため、大気圧状態での飽和蒸気圧に達するまではガスとして気化し、気化したアルミニウムガスが加熱炉７内の雰囲気に含まれるようになる。 In the sintering step, aluminum (conductive material 5) is vaporized and added to the atmosphere during sintering in order to promote the sintering of the boron carbide particles 2 which are hardly sinterable materials. This aluminum is provided in the furnace of the heating furnace 7 at a distance from the molded body 4 and is vaporized by the heat of the heating furnace 7 during sintering. In other words, in a sintering process with a sintering temperature exceeding 2000 ° C., aluminum is heated at a temperature exceeding the melting point, and thus vaporizes as a gas until reaching the saturated vapor pressure at atmospheric pressure, The vaporized aluminum gas is included in the atmosphere in the heating furnace 7.
このような気化したアルミニウムガスの雰囲気中で成形体４を焼結すると、気化したアルミニウムが成形体４の表面に存在するホウ素の酸化物に作用して、炭化ホウ素の焼結反応が促進される。
ところで、本発明の焼結体１の製造方法は、成形体４を焼結する際の条件を、放電加工が可能な焼結体１が得られるような条件として焼結を行う、例えば、焼結体１の焼結を未焼結状態または過焼結状態となる側に変更しつつ焼結を行うことで、焼結体１に放電加工が可能となる特性を発現させることを特徴としている。この「焼結体の焼結が未焼結状態となる」とは、焼結が完全に完了していない状態、つまり「半焼け状態」を意味している。例えば、本来ならば焼結が完全に行われて焼結体１として最高密度が得られる焼結温度や焼結時間に対して、この焼結温度や焼結時間を下回る温度や時間で成形体４を焼結することが、「焼結後に最高密度が出る条件から未焼結側にシフトした条件」に他ならない。
When the molded body 4 is sintered in the atmosphere of the vaporized aluminum gas, the vaporized aluminum acts on the boron oxide existing on the surface of the molded body 4 to promote the boron carbide sintering reaction. .
By the way, in the method for producing the sintered body 1 of the present invention, the sintering is performed with the conditions for sintering the molded body 4 being such that the sintered body 1 capable of electric discharge machining is obtained. By performing sintering while changing the sintering of the bonded body 1 to an unsintered state or an oversintered state, the sintered body 1 is characterized in that it can exhibit electric discharge machining characteristics. . This “sintering of the sintered body is in an unsintered state” means a state where the sintering is not completely completed, that is, a “semi-burned state”. For example, if the sintering is performed completely and the sintering temperature and the sintering time at which the highest density can be obtained as the sintered body 1, the molded body is formed at a temperature and time lower than the sintering temperature and the sintering time. Sintering No. 4 is nothing but “a condition shifted from the condition of maximum density after sintering to the unsintered side”.
例えば、焼結体１を焼結する際に最低でも２１５０℃という焼結温度が必要な場合であれば、２１５０℃に対して５０℃低い２１００℃から、２１５０℃に対して２０℃低い２１３０℃までの範囲で焼結を行うことが「焼結後に最高密度が出る条件から未焼結側にシフトした条件」ということになる。
なお、炭化ホウ素の焼結体を焼結する場合には焼結温度をある程度まで大きくすると焼結体の密度がそれ以上大きくならないようになる。このように焼結体の密度に変化がなくなった温度を最高焼結温度とした場合に、上述した「最高密度が出る焼結温度（条件）」とは、最高焼結温度に対して９８％以上となるような温度を選択するとよい。
For example, if a sintering temperature of at least 2150 ° C. is required when sintering the sintered body 1, 2130 ° C., which is 20 ° C. lower than 2150 ° C. Sintering in the range up to this is "the condition shifted from the condition of maximum density after sintering to the unsintered side".
When sintering a sintered body of boron carbide, if the sintering temperature is increased to some extent, the density of the sintered body will not increase any further. In this way, when the temperature at which the density of the sintered body has ceased to be the maximum sintering temperature, the above-mentioned “sintering temperature (condition) at which the maximum density is obtained” is 98% of the maximum sintering temperature. It is advisable to select such a temperature.
このような条件で焼結体１を焼結すれば、焼結体１の密度を下げて内部に微小な空孔を残留させることにより、焼結後の冷却過程において気化した金属アルミニウムが空孔内で析出して残留する。それによって焼結体の電気的な体積抵抗率が減少し、放電加工に適した状態となる。
具体的には、本発明の焼結体１の製造方法では、成形体４を焼結する際の条件の一つである焼結温度Ｔに対して、焼結後に最高密度が出る焼結温度をＴ０℃とした場合に、焼結温度Ｔが（Ｔ０−５０）℃〜（Ｔ０−２０）℃、より好ましくは（Ｔ０−５０）℃〜（Ｔ０−３０）℃とされている。例えば、本実施形態の組成の焼結体を焼結する場合であれば、焼結後の密度が最大となる焼結温度Ｔ０＝２１５０℃となるので、焼結温度を２１３０℃（＝Ｔ０−２０℃）としている。
If the sintered body 1 is sintered under such conditions, the density of the sintered body 1 is reduced and minute pores remain inside, so that the metal aluminum vaporized in the cooling process after the sintering becomes voids. It precipitates and remains inside. As a result, the electrical volume resistivity of the sintered body is reduced, and it becomes a state suitable for electric discharge machining.
Specifically, in the manufacturing method of the sintered body 1 of the present invention, the sintering temperature at which the highest density is obtained after sintering with respect to the sintering temperature T, which is one of the conditions when the molded body 4 is sintered. Is set to T 0 ° C, the sintering temperature T is (T 0 -50) ° C to (T 0 -20) ° C, more preferably (T 0 -50) ° C to (T 0 -30) ° C. ing. For example, in the case of sintering a sintered body having the composition of the present embodiment, the sintering temperature T 0 = 2150 ° C. at which the density after sintering becomes maximum is set to 2130 ° C. (= T It is set to 0 -20 ℃).
また、本発明の焼結体１の製造方法では、成形体４を焼結する際の条件の一つである焼結温度Ｔに対して、炭化ホウ素の融点をＴ１℃とした場合に、焼結温度Ｔが（Ｔ１×０．７６０）℃〜（Ｔ１×０．７７１）℃、より好ましくは（Ｔ１×０．７６０）℃〜（Ｔ１×０．７６７）℃とされている。例えば、本実施形態の組成の焼結体を焼結する場合であれば、炭化ホウ素の融点はＴ１＝２７６３℃となり、本実施形態の焼結温度である２１３０℃は（＝Ｔ１×０．７７１）と示すことができる。つまり、本実施形態の焼結温度は、上述した（Ｔ１×０．７６０）℃〜（Ｔ１×０．７７１）℃の範囲に含まれている。 Further, in the sintered body 1 of the production method of the present invention, the molded body 4 with respect to the sintering temperature T, which is one of the conditions for sintering, the melting point of boron carbide in the case of the T 1 ° C., The sintering temperature T is (T 1 × 0.760) ° C. to (T 1 × 0.771) ° C., more preferably (T 1 × 0.760) ° C. to (T 1 × 0.767) ° C. Yes. For example, when the sintered body having the composition of the present embodiment is sintered, the melting point of boron carbide is T 1 = 2763 ° C., and the sintering temperature of the present embodiment is 2130 ° C. (= T 1 × 0 .771). That is, the sintering temperature of this embodiment is included in the range of (T 1 × 0.760) ° C. to (T 1 × 0.771) ° C. described above.
上述した焼結温度Ｔで成形体４の焼結を行えば、焼結温度Ｔが低い分だけ焼結を促進するために加えられたアルミニウムが焼結体１中に残留しやすくなり、残留したアルミニウムにより焼結体１の導電性が高くなり、焼結体１に対して良好な放電加工性を発現させることが可能となる。
さらに、本発明の焼結体１の製造方法では、成形体４を焼結する際の条件の一つである成形体４を焼結する際の条件である焼結時間ｔに対して、焼結後の密度が最大となる焼結時間をｔ０（ｈｒ）とした場合に、焼結時間ｔが（ｔ０−３）〜（ｔ０−１）、より好ましくは（ｔ０−３）〜（ｔ０−２）とされている。
If the molded body 4 is sintered at the sintering temperature T described above, the aluminum added to promote the sintering by the amount of the lower sintering temperature T tends to remain in the sintered body 1 and remains. The electrical conductivity of the sintered body 1 is increased by aluminum, and it becomes possible to develop good electric discharge processability for the sintered body 1.
Furthermore, in the manufacturing method of the sintered body 1 of the present invention, the sintering time t is a condition for sintering the molded body 4, which is one of the conditions for sintering the molded body 4. Sintering time t is (t 0 -3) to (t 0 -1), more preferably (t 0 -3), where t 0 (hr) is the sintering time at which the density after sintering is maximum. To (t 0 -2).
このように焼結体１の焼結が未焼結状態となる条件、言い換えれば上述した焼結温度Ｔや焼結時間ｔで成形体４の焼結を行えば、焼結を促進するために加えられたアルミニウムが焼結体１中に残留しやすくなり、残留したアルミニウムにより焼結体１の導電性を高めて、良好な放電加工性を発現することが可能となる。
なお、「焼結体１の焼結が未焼結状態となる条件」には、焼結温度Ｔや焼結時間ｔ以外にも、昇温スピードや冷却スピードを用いることもできる。例えば、昇温スピードや冷却スピードを小さくすれば、焼結温度Ｔや焼結時間ｔの場合と同様に、焼結体１の焼結が未焼結状態となり、アルミニウム（導電性物質５）が焼結体１中に残留しやすくなって、焼結体１に対して良好な放電加工性を発現させることが可能となる。
In this way, if the molded body 4 is sintered at the condition where the sintered body 1 is sintered in the unsintered state, in other words, the sintering temperature T and the sintering time t described above, the sintering is promoted. The added aluminum is likely to remain in the sintered body 1, and the electrical conductivity of the sintered body 1 can be increased by the remaining aluminum, and good electric discharge processability can be expressed.
In addition, in addition to the sintering temperature T and the sintering time t, the temperature raising speed and the cooling speed can also be used as the “conditions for sintering the sintered body 1 to be in an unsintered state”. For example, if the temperature raising speed or the cooling speed is reduced, the sintered body 1 is sintered in the unsintered state as in the case of the sintering temperature T and the sintering time t, and aluminum (the conductive material 5) is replaced. It becomes easy to remain in the sintered body 1, and it becomes possible to express good electric discharge processability to the sintered body 1.
さらに、焼結体内部に残留させるために気化させる金属として、融点が炭化ホウ素焼結温度よりも低く、気化した気体の蒸気圧を容易に上げることができ、且つ体積抵抗率が炭化ホウ素よりも十分に低い材料、例えば亜鉛、銀、クロム、銅、金も用いることができる。これらの金属を気化材料として用いる場合、焼結を促進させる目的で気化させるアルミニウムと併用される必要がある。 Furthermore, as a metal to be vaporized to remain inside the sintered body, the melting point is lower than the boron carbide sintering temperature, the vapor pressure of the vaporized gas can be easily increased, and the volume resistivity is higher than that of boron carbide. Sufficiently low materials such as zinc, silver, chromium, copper, gold can also be used. When these metals are used as vaporizing materials, it is necessary to use them together with aluminum that is vaporized for the purpose of promoting sintering.
次に、実施例及び比較例を用いて、本願発明の作用効果をさらに詳しく説明する。
実施例及び比較例に用いた炭化ホウ素の粒子２は、平均粒径Ｄ５０が１．３μｍのものである。この炭化ホウ素の粒子２に、バインダ３を加えた。炭化ホウ素の粒子２とバインダ３との混合比率は、混合後のバインダ３及び炭化ホウ素の総量を１００vol%とした場合に、炭化ホウ素が５６vol%及びバインダ３が４４vol%となっている。また、バインダ３中には、アクリル樹脂が２８vol%、ポリスチレンが１２vol%、脂肪酸アミド、フタル酸エステル、パラフィンワックス、カルナバワックスが合わせて４vol%含まれている。
Next, the function and effect of the present invention will be described in more detail using Examples and Comparative Examples.
Particles 2 of boron carbide used in Examples and Comparative Examples, the average particle diameter D 50 is of 1.3 .mu.m. A binder 3 was added to the boron carbide particles 2. The mixing ratio of the boron carbide particles 2 and the binder 3 is 56 vol% for boron carbide and 44 vol% for the binder 3 when the total amount of the binder 3 and boron carbide after mixing is 100 vol%. The binder 3 contains 28 vol% of acrylic resin, 12 vol% of polystyrene, 4 vol% of fatty acid amide, phthalate ester, paraffin wax and carnauba wax.
上述した炭化ホウ素の粒子２とバインダ３との混合物については、混練装置を用いて１８０℃、２時間混練を行い、混練済みの混練物を５ｍｍ程度のペレットに加工した。
このようにして得られたペレットを金型６内に射出し、金型６間に５０ｔの圧力を加えて粉末射出成形加工を行い、成形体４を成形した。
成形された成形体４を、不活性ガス（窒素ガス）が充填されたバッチ式の加熱炉７に入れ、減圧状態とされた８００℃の炉内で脱脂を行った。次に、同じバッチ式の加熱炉７に対して、不活性ガス（アルゴンガス）を充填して、成形体４の焼結を行った。なお、焼結に際しては、加熱炉７内に金属のアルミニウムを配置し、アルミニウムを気化させながら焼結を行った。
The mixture of the boron carbide particles 2 and the binder 3 described above was kneaded at 180 ° C. for 2 hours using a kneader, and the kneaded kneaded material was processed into pellets of about 5 mm.
The pellets thus obtained were injected into the mold 6, and a powder injection molding process was performed by applying a pressure of 50 t between the molds 6 to form the molded body 4.
The molded body 4 thus formed was put into a batch-type heating furnace 7 filled with an inert gas (nitrogen gas), and degreased in an oven at 800 ° C. under reduced pressure. Next, the same batch type heating furnace 7 was filled with an inert gas (argon gas), and the compact 4 was sintered. In the sintering, metallic aluminum was placed in the heating furnace 7 and sintering was performed while vaporizing the aluminum.
表１に示すように、比較例は、焼結温度を２１５０℃として焼結を行ったものである。上述した組成の焼結体１では、比較例の２１５０℃という焼結温度で焼結を行った場合に、最高密度が得られる。つまり、比較例は焼結体の密度が最大となる最高焼結温度Ｔ０℃で焼結を行ったものである。また、炭化ホウ素の融点２７６３℃（Ｔ１）を基準にした場合には、比較例の焼結温度Ｔは、（Ｔ１×０．７７８）℃としても示される。 As shown in Table 1, the comparative example was sintered at a sintering temperature of 2150 ° C. In the sintered body 1 having the above-described composition, the highest density is obtained when sintering is performed at the sintering temperature of 2150 ° C. in the comparative example. That is, in the comparative example, the sintering was performed at the maximum sintering temperature T 0 ° C. at which the density of the sintered body is maximized. Moreover, when the melting point of boron carbide is based on 2763 ° C. (T 1 ), the sintering temperature T of the comparative example is also shown as (T 1 × 0.778) ° C.
一方、実施例は、焼結温度を２１３０℃として焼結を行ったものである。上述した組成の焼結体では、最高焼結温度Ｔ０は２１５０℃である。それゆえ、実施例の焼結温度Ｔは、（Ｔ０−２０）℃と示すこともできる。また、炭化ホウ素の融点２７６３℃（Ｔ１）を基準にした場合には、実施例の焼結温度Ｔは、（Ｔ１×０．７７１）℃と示してもよい。
上述のようにして焼結を行った実施例及び比較例の焼結体１に対して、体積抵抗率を計測した。結果を表１に示す。
On the other hand, in the example, sintering was performed at a sintering temperature of 2130 ° C. In the sintered body having the above composition, the maximum sintering temperature T 0 is 2150 ° C. Therefore, the sintering temperature T of the examples can also be expressed as (T 0 -20) ° C. In addition, when the melting point of boron carbide is 2766 ° C. (T 1 ), the sintering temperature T of the example may be expressed as (T 1 × 0.771) ° C.
Volume resistivity was measured with respect to the sintered bodies 1 of Examples and Comparative Examples in which sintering was performed as described above. The results are shown in Table 1.
比較例の焼結体１の体積抵抗率である３．２８Ω・ｃｍに比して、実施例の焼結体１の体積抵抗率は、０．３３Ω・ｃｍとなっており、導通性については実施例の方が比較例のものより導電しやすくなっており、実施例の焼結体１では導電性物質５のコーティングなどを行わなくても放電加工が十分に可能であることがわかる。
このことから、焼結後に最高密度が得られる最高焼結温度をＴ０℃とした場合に、成形体４を実際に焼結する際の焼結温度Ｔを（Ｔ０−５０）℃〜（Ｔ０−２０）℃の範囲内として焼結を行うか、あるいは炭化ホウ素の融点をＴ１℃とした場合に、成形体４を実際に焼結する際の焼結温度Ｔを（Ｔ１×０．７６０）℃〜（Ｔ１×０．７７１）℃として焼結を行うことで、導電性に優れ、放電加工が可能な焼結体１を得ることが可能になることが分かる。
Compared to 3.28 Ω · cm which is the volume resistivity of the sintered body 1 of the comparative example, the volume resistivity of the sintered body 1 of the example is 0.33 Ω · cm. The example is easier to conduct than the comparative example, and it can be seen that the sintered body 1 of the example can sufficiently perform electric discharge machining without coating the conductive material 5 or the like.
From this, when the maximum sintering temperature at which the maximum density is obtained after sintering is T 0 ° C., the sintering temperature T when actually sintering the molded body 4 is (T 0 −50) ° C. to ( When sintering is performed within the range of T 0 -20) ° C., or when the melting point of boron carbide is T 1 ° C., the sintering temperature T when the molded body 4 is actually sintered is (T 1 × It can be seen that by performing the sintering at 0.760) ° C. to (T 1 × 0.771) ° C., it is possible to obtain a sintered body 1 having excellent conductivity and capable of electric discharge machining.
また、成形体４を焼結する際の条件である焼結時間ｔが、焼結後に最高密度が得られる焼結時間（ｈｒ）をｔ０した場合に、（ｔ０−３）〜（ｔ０−１）として焼結を行うことで、導電性に優れ、放電加工が可能な焼結体１を得ることが可能になることも分かる。
なお、今回開示された実施形態はすべての点で例示であって制限的なものではないと考えられるべきである。特に、今回開示された実施形態において、明示的に開示されていない事項、例えば、運転条件や操業条件、各種パラメータ、構成物の寸法、重量、体積などは、当業者が通常実施する範囲を逸脱するものではなく、通常の当業者であれば、容易に想定することが可能な値を採用している。
In addition, when the sintering time t, which is a condition for sintering the compact 4, is t 0, the sintering time (hr) at which the highest density is obtained after sintering, (t 0 −3) to (t It can also be seen that by performing sintering as 0-1 ), it is possible to obtain a sintered body 1 that is excellent in electrical conductivity and capable of electric discharge machining.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. In particular, in the embodiment disclosed this time, matters that are not explicitly disclosed, for example, operating conditions and operating conditions, various parameters, dimensions, weights, volumes, and the like of a component deviate from a range that a person skilled in the art normally performs. Instead, values that can be easily assumed by those skilled in the art are employed.
１ 焼結体
２ 炭化ホウ素の粒子
３ バインダ
４ 成形体
５ 導電性物質
６ 金型
７ 加熱炉
DESCRIPTION OF SYMBOLS 1 Sintered body 2 Boron carbide particle 3 Binder 4 Molded body 5 Conductive substance 6 Mold 7 Heating furnace
Claims (5)
前記成形体を焼結する際の条件を、放電加工が可能な焼結体が得られるような条件として焼結を行うことを特徴とする炭化ホウ素の焼結体の製造方法。 When molding the boron carbide sintered body by mixing the boron carbide and the binder and sintering the molded body in an atmosphere where the conductive material is vaporized,
A method for producing a sintered body of boron carbide, characterized in that sintering is performed under the conditions for sintering the formed body so that a sintered body capable of electric discharge machining is obtained.
前記成形体を焼結する際の条件を、焼結後に最高密度が出る条件から未焼結側にシフトした条件としつつ焼結を行うことで、前記焼結体に放電加工が可能となる特性を発現させることを特徴とする請求項１に記載の炭化ホウ素の焼結体の製造方法。 When molding the boron carbide sintered body by mixing the boron carbide and the binder and sintering the molded body in an atmosphere where the conductive material is vaporized,
By performing the sintering while changing the conditions for sintering the molded body from the condition where the highest density is obtained after sintering to the unsintered side, characteristics that enable electric discharge machining to the sintered body The method for producing a sintered body of boron carbide according to claim 1, wherein:
The sintering time, which is a condition for sintering the molded body, is (t 0 -3) to (t 0 -1), where t 0 (hr) is the sintering time at which the highest density is obtained after sintering. The method for producing a sintered body of boron carbide according to any one of claims 2 to 4, wherein:
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113345615A (en) * | 2021-05-31 | 2021-09-03 | 中国工程物理研究院材料研究所 | Paraffin/boron carbide neutron protection composite material and preparation method thereof |
| JP7116234B1 (en) | 2021-09-24 | 2022-08-09 | 美濃窯業株式会社 | Manufacturing method of composite ceramics |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6212663A (en) * | 1985-07-09 | 1987-01-21 | 株式会社ノリタケカンパニーリミテド | Method of sintering b4c base fine body |
| JPH0812434A (en) * | 1993-11-01 | 1996-01-16 | Noritake Co Ltd | Production of sintered b4c material and sintered b4c compact |
| JP2005089268A (en) * | 2003-09-18 | 2005-04-07 | Japan Nuclear Cycle Development Inst States Of Projects | Method and apparatus for sintering boron carbide ceramic |
| JP2008524108A (en) * | 2004-12-20 | 2008-07-10 | ジョージア・テック・リサーチ・コーポレーション | B4C with improved density and hardness after pressureless sintering and post-HIP |
| JP2008273753A (en) * | 2007-04-25 | 2008-11-13 | Kyocera Corp | Boron carbide-based sintered compact and protective member |
| JP2008273752A (en) * | 2007-04-25 | 2008-11-13 | Kyocera Corp | Boron carbide-based sintered compact and protective member |
| WO2008153177A1 (en) * | 2007-06-15 | 2008-12-18 | Mino Ceramic Co., Ltd. | Dense boron carbide ceramic and process for producing the same |
| JP2009143777A (en) * | 2007-12-17 | 2009-07-02 | Denki Kagaku Kogyo Kk | Boron carbide-titanium diboride sintered compact, and production method therefor |
| JP2011063453A (en) * | 2009-09-15 | 2011-03-31 | Mino Ceramic Co Ltd | Boron carbide-silicon carbide composite ceramic and method for producing the same |
-
2015
- 2015-08-07 JP JP2015157272A patent/JP6346593B2/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6212663A (en) * | 1985-07-09 | 1987-01-21 | 株式会社ノリタケカンパニーリミテド | Method of sintering b4c base fine body |
| JPH0812434A (en) * | 1993-11-01 | 1996-01-16 | Noritake Co Ltd | Production of sintered b4c material and sintered b4c compact |
| JP2005089268A (en) * | 2003-09-18 | 2005-04-07 | Japan Nuclear Cycle Development Inst States Of Projects | Method and apparatus for sintering boron carbide ceramic |
| JP2008524108A (en) * | 2004-12-20 | 2008-07-10 | ジョージア・テック・リサーチ・コーポレーション | B4C with improved density and hardness after pressureless sintering and post-HIP |
| JP2008273753A (en) * | 2007-04-25 | 2008-11-13 | Kyocera Corp | Boron carbide-based sintered compact and protective member |
| JP2008273752A (en) * | 2007-04-25 | 2008-11-13 | Kyocera Corp | Boron carbide-based sintered compact and protective member |
| WO2008153177A1 (en) * | 2007-06-15 | 2008-12-18 | Mino Ceramic Co., Ltd. | Dense boron carbide ceramic and process for producing the same |
| JP2009143777A (en) * | 2007-12-17 | 2009-07-02 | Denki Kagaku Kogyo Kk | Boron carbide-titanium diboride sintered compact, and production method therefor |
| JP2011063453A (en) * | 2009-09-15 | 2011-03-31 | Mino Ceramic Co Ltd | Boron carbide-silicon carbide composite ceramic and method for producing the same |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113345615A (en) * | 2021-05-31 | 2021-09-03 | 中国工程物理研究院材料研究所 | Paraffin/boron carbide neutron protection composite material and preparation method thereof |
| CN113345615B (en) * | 2021-05-31 | 2022-12-27 | 中国工程物理研究院材料研究所 | Paraffin/boron carbide neutron protection composite material and preparation method thereof |
| JP7116234B1 (en) | 2021-09-24 | 2022-08-09 | 美濃窯業株式会社 | Manufacturing method of composite ceramics |
| JP2023046932A (en) * | 2021-09-24 | 2023-04-05 | 美濃窯業株式会社 | Manufacturing method of composite ceramic |
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