JPH0461828B2 - - Google Patents
Info
- Publication number
- JPH0461828B2 JPH0461828B2 JP62244161A JP24416187A JPH0461828B2 JP H0461828 B2 JPH0461828 B2 JP H0461828B2 JP 62244161 A JP62244161 A JP 62244161A JP 24416187 A JP24416187 A JP 24416187A JP H0461828 B2 JPH0461828 B2 JP H0461828B2
- Authority
- JP
- Japan
- Prior art keywords
- sic
- mob
- sintered body
- boron
- carbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 47
- 239000002245 particle Substances 0.000 claims description 15
- 238000010304 firing Methods 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 12
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 11
- 229910052796 boron Inorganic materials 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 11
- 239000000843 powder Substances 0.000 claims description 11
- 150000001875 compounds Chemical class 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 2
- 150000002894 organic compounds Chemical class 0.000 claims description 2
- PPWPWBNSKBDSPK-UHFFFAOYSA-N [B].[C] Chemical compound [B].[C] PPWPWBNSKBDSPK-UHFFFAOYSA-N 0.000 claims 1
- 238000000465 moulding Methods 0.000 claims 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 44
- 239000000654 additive Substances 0.000 description 12
- 238000000280 densification Methods 0.000 description 8
- 238000001272 pressureless sintering Methods 0.000 description 7
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 6
- 230000000996 additive effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000002159 abnormal effect Effects 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- OHVLMTFVQDZYHP-UHFFFAOYSA-N 1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-2-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]ethanone Chemical compound N1N=NC=2CN(CCC=21)C(CN1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)=O OHVLMTFVQDZYHP-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910015173 MoB2 Inorganic materials 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000002706 hydrostatic effect Effects 0.000 description 2
- 229910052580 B4C Inorganic materials 0.000 description 1
- 229910021431 alpha silicon carbide Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 1
- 239000002775 capsule Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Description
（産業上の利用分野）
本発明は、SiC特有の高温特性を有し、かつ靭
性の高い焼結体を常圧焼結により得ることのでき
るSiC複合焼結体及びその製造方法に関するもの
である。
（従来の技術）
従来、単一相のSiC焼結体としてはその添加物
によりＢ−Ｃ系助剤SiCとAl系助剤SiCとがある。
Ｂ−Ｃ系SiCは高温特性は良好だが靭性が劣る
（K1C＝２〜3MN／m3/2）ことが、またAl系SiC
は靭性は良好だが高温特性がそれほど良好でない
ことが知られている。
Al系SiCにおいて、より高靭性化を目的とし
て、特開昭60−186468号公報においてセラミツク
ス構造材及びその製造方法が開示されている。こ
のセラミツクス構造材は、炭化ケイ素に周期表の
第Va族若しくは第VIa族元素の各ホウ化物の少
なくとも１種を含有させたものであり、所定組成
の元素を混合し、1900〜2500℃の範囲内の温度で
焼成して得られるものである。
（発明が解決しようとする問題点）
しかしながら、上述した特開昭60−186468号公
報に示されたセラミツクス構造材においては、そ
の実施例では、MoB2を添加剤とし、Alを焼結助
剤として用いホツトプレスにより緻密化を進め破
壊靭性を改善している。これはAl系SiCにMoB2
を添加した場合、常圧焼結では、緻密化できない
欠点を有するためである。しかしホツトプレスは
複雑形状の焼結体を得ることができないととも
に、量産性、製造コストの点で工業的利用価値は
低い。
また、一般にAl系助剤を用いた場合、低融点
粒界相がSiC粒界に残存し、高温での強度低下、
耐酸化性の低下等高温材料としては致命的欠点を
有している。
本発明の目的は上述した欠点を解消して、SiC
特有の高温特性を維持しつつ靭性の高い焼結体を
常圧焼結により得ることのできる高強度・高靭性
SiC複合焼結体及びその製造方法を提供しようと
するものである。
（問題点を解決するための手段）
本発明の第１発明であるSiC複合焼結体は、
SiCが20〜99wt％、MoB2が80〜0.5wt％、硼素、
炭素、炭化硼素のうち少なくとも１種類が0.5〜
5wt％からなり、破壊靭性K1Cが４以上であるこ
とを特徴とするものである。
本発明の第２発明であるSiC複合焼結体の製造
方法は、平均粒径5μｍ以下のSiC粉末20〜99wt
％、MoB2又はMoB2を生成する化合物をMoB2
に換算して80〜0.5％、硼素又は硼素を含有する
化合物を硼素に換算して0.1〜5wt％、炭素又は炭
素を生成する有機化合物を炭素に換算して0.1〜
5wt％からなる調合粉末を混合成形し、次いで
1500℃まで真空中でその後不活性雰囲気中1900〜
2500℃の温度下で焼成することにより破壊靭性
K1Cが４以上の焼結体を得ることを特徴とするも
のである。
（作用）
上述した構成において、Ｂ−Ｃ系SiCに所定量
のMoB2を含有させることにより、Ｂ−Ｃ系SiC
の欠点であつた靭性を高めることができ、高温で
も高強度で高靭性のSiC複合焼結体を常圧焼結に
より得ることができる。すなわち、MoB2は熱的
に安定なため優れた高温特性を発揮するととも
に、SiCとの硬度差が大きく、焼結体中を進展す
るクラツクがMoB2粒子とSiC粒子の界面で反跳
されるクラツクデイフレクト作用が有効に発揮さ
れ靭性が向上する。またＢ、Ｃ系Sicの場合、焼
結の終期、即ち2100℃以上の焼成温度で、数
100μｍにまでSiCが異常粒子成長し、緻密化を阻
害するとともに焼結体特性を著しく劣化させるこ
とが知られており、実質的に焼成温度を2100℃以
下にする必要があつた。MoB2はこの異常粒子成
長を効果的に抑制するため、2100℃を越える焼成
温度での焼結が可能となり従来のSiC焼結体では
得られない高密度を常圧焼結法で達成できるとと
もに所望の粒子形状からなる焼結体を作製するこ
とができる。各種硼化物、及びSiCの硬度、融点
を第１表にまとめて示す。本データは、サムソノ
フ著高融点化合物便覧及びエル・ベ・カテリニコ
フ著超高融点材料便覧より抜すいした。
(Field of Industrial Application) The present invention relates to a SiC composite sintered body that has high temperature characteristics unique to SiC and can obtain a highly tough sintered body by pressureless sintering, and a method for manufacturing the same. . (Prior Art) Conventionally, single-phase SiC sintered bodies include B--C type auxiliary SiC and Al-based auxiliary SiC, depending on their additives.
B-C-based SiC has good high-temperature properties but poor toughness (K 1C = 2~3MN/m 3/2 ), and Al-based SiC
Although it has good toughness, it is known that its high temperature properties are not so good. In order to improve the toughness of Al-based SiC, Japanese Patent Laid-Open No. 186468/1983 discloses a ceramic structural material and a method for producing the same. This ceramic structural material is made by making silicon carbide contain at least one type of each boride of Group Va or Group VIa elements of the periodic table, and is made by mixing elements of a predetermined composition and heating it at a temperature in the range of 1900 to 2500℃. It is obtained by firing at a temperature within (Problems to be Solved by the Invention) However, in the ceramic structural material disclosed in JP-A-60-186468 mentioned above, in the example, MoB 2 is used as an additive and Al is used as a sintering aid. It is used as a hot press to increase densification and improve fracture toughness. This is Al-based SiC with MoB 2
This is because if sintering is added, densification cannot be achieved by pressureless sintering. However, hot pressing cannot produce sintered bodies with complex shapes, and its industrial utility value is low in terms of mass productivity and manufacturing costs. Additionally, when Al-based auxiliary agents are used, low melting point grain boundary phases remain at SiC grain boundaries, resulting in a decrease in strength at high temperatures and
It has fatal drawbacks as a high-temperature material, such as reduced oxidation resistance. The purpose of the present invention is to eliminate the above-mentioned drawbacks and to
High strength and high toughness that can be obtained by pressureless sintering to produce a sintered body with high toughness while maintaining unique high-temperature properties.
The present invention aims to provide a SiC composite sintered body and a method for manufacturing the same. (Means for solving the problem) The SiC composite sintered body, which is the first invention of the present invention, has the following features:
SiC 20~99wt%, MoB2 80~0.5wt%, boron,
At least one of carbon and boron carbide is 0.5~
5wt%, and has a fracture toughness K1C of 4 or more. The method for producing a SiC composite sintered body, which is the second invention of the present invention, uses 20 to 99 wt of SiC powder with an average particle size of 5 μm or less.
%, MoB 2 or compound that produces MoB 2
80-0.5% in terms of boron, 0.1-5wt% in terms of boron for boron or boron-containing compounds, 0.1-5% in terms of carbon for carbon or organic compounds that generate carbon.
A blended powder consisting of 5wt% was mixed and molded, and then
In vacuum to 1500℃ then in inert atmosphere to 1900℃
Fracture toughness improved by firing at a temperature of 2500℃
This method is characterized in that a sintered body with K 1C of 4 or more is obtained. (Function) In the above-mentioned configuration, by containing a predetermined amount of MoB 2 in B-C system SiC, B-C system SiC
It is possible to improve the toughness, which was a drawback in the previous method, and it is possible to obtain a SiC composite sintered body with high strength and high toughness even at high temperatures by pressureless sintering. In other words, MoB 2 is thermally stable and exhibits excellent high-temperature properties, and also has a large hardness difference with SiC, meaning that cracks that propagate in the sintered body are rebounded at the interface between MoB 2 particles and SiC particles. The crack deflection effect is effectively exerted and toughness is improved. In addition, in the case of B and C-based Sic, several
It is known that SiC particles grow abnormally to a size of 100 μm, inhibiting densification and significantly deteriorating the properties of the sintered body, so it was essentially necessary to reduce the firing temperature to 2100°C or lower. Since MoB 2 effectively suppresses this abnormal particle growth, it is possible to sinter at a firing temperature of over 2100℃, and it is possible to achieve high densities that cannot be obtained with conventional SiC sintered bodies using the pressureless sintering method. A sintered body having a desired particle shape can be produced. The hardness and melting point of various borides and SiC are summarized in Table 1. This data was extracted from the Handbook of High Melting Point Compounds by Samsonov and the Handbook of Ultrahigh Melting Point Materials by L.B. Katelinnikov.
【表】
これらの効果はＢ，Ｃを焼結助剤としたSiCと
MoB2の複合焼結体においてのみ得られるもので
あり、従来全く知られていない。
原料となるSiC粉末の平均粒径を5μｍ以下と限
定したのは、SiC粉末の平均粒径が5μｍを超える
と常圧焼結で緻密化が不可能なためである。
SiCの組成範囲を20〜99wt％と限定したのは、
他の添加物との関係で他の添加物の総量が80wt
％を超えると基礎となるSiCの特性を十分に発揮
することができないとともに、1wt％未満である
と添加物の性質改善効果がないためである。な
お、このSiCの組成範囲は30〜99wt％であると好
ましく、40〜99wt％であるとさらに好ましい。
添加物として、MoB2が80〜0.5wt％と限定し
たのは、80wt％を超えると高温特性が劣化し、
0.5wt％未満であると靭性の向上がないとともに
異常粒子成長抑制効果がないためである。この添
加量は70〜0.5wt％であると好ましく、60〜0.5wt
％であるとさらに好ましい。
また、Ｂ化合物を0.1〜5wt％と限定したのは、
0.1wt％未満であるとその添加効果が認められず、
緻密化に寄与しないとともに、5wt％を超えると
緻密化が阻害されるとともにＢが粒界に多量に残
り高温特性が劣化するためである。
さらに、Ｃ化合物を0.1〜5wt％と限定したの
は、0.1wt％未満ではSiC表面のSiO2膜を十分に
除去できないとともに5wt％を超えると焼成体に
free−Ｃが多量に残り特性が劣化するためであ
る。
（実施例）
第１図は本発明製造方法の製造工程の一例を示
す図である。まず、SiC原料粉末の平均粒径を5μ
ｍ以下となるように準備するとともに、添加剤と
してMoB2、Ｂ、Ｃを準備する。本実施例に用い
たSiC原料粉末はβ−SiC：93wt％を含み残部が
α−SiCよりなり、平均粒径0.42μｍ、比表面積
20.0m2／ｇであり、第２表に示す化学組成を有し
ている。 第２表 （wt％）
Total−Si 69.13
Free−SiO2 0.47
Free−Si 0.010
Free−Ｃ 0.51
Ｏ 0.90
Al 0.056
Fe 0.060
Ca 0.016
Mg 0.001
Ｋ ＜0.001
Na 0.001
Cu −
Ti 0.007 Ｎ 0.27
次に準備したSiC原料粉末およびMoB2、Ｂ、
Ｃの添加剤の所定量を、イソプロピルアルコール
を使用した湿式ボールミルにより粉砕・混合す
る。粉砕・混合後の原料は一旦乾燥した後造粒す
る。その後、造粒した粉末を予備成形し、さらに
静水圧プレスにより所定形状に成形する。最後に
1900〜2500℃真空中又は不活性ガス中で焼成して
焼結体を得ている。
なお。上述した製造方法において、MoB2の添
加を、MoB2以外の硼化物、酸化物、単体及び硼
素含有添加剤として別々に添加し、焼成初期又は
焼成前の別な熱処理等によりMoB2を成形体内又
は混合粉末内で合成することも可能である。この
場合、MoB2を合成させるに十分な量のＢの添加
が必要となる。また形成体を焼成後、カプセル
HIP又はカプセルフリーHIPによりさらに緻密化
を行ない特性をさらに向上することも可能であ
る。
以下、実際の例について説明する。
実施例 １
平均粒度5μｍ以下のSiC粉末、添加剤として
MoB2、焼結助剤としてＢ（金属硼素）、Ｃ（カー
ボンブラツク）を第３表に示す割合でイソプロピ
ルアルコールを使用した湿式ボールミルで混合、
乾燥後造粒し、さらに予備成形後3ton／cm2の静水
圧プレスにより60×60×６mmの角板を作製した。
作製した角板を1500℃までは真空中でその後アル
ゴン１気圧中2200℃で１時間焼成してそれぞれ本
発明実施例および比較例の焼結体を得た。なお実
施例４−２は実施例４の焼結体に対して2000℃、
2000気圧のHIP処理を行なつたものである。
得られたそれぞれの焼結体に対して、焼結体を
鏡面研磨し気孔分布より焼結体の相対密度を測定
して緻密性を評価するとともに、室温および1500
℃の温度でJIS Ｒ−1601（フアインセラミツクス
の曲げ強さ試験法）に従つた四点曲げ試験を実施
して室温、高温強度を評価した。さらに、室温に
おけるシユブロンノツチ法によりそれぞれのK1C
を求めて靭性を評価するとともに、CuKαを用い
たＸ線回折法により、焼結体中のMo化合物を同
定した。結果を第３表に示す。[Table] These effects are similar to those of SiC using B and C as sintering aids.
This can only be obtained from a composite sintered body of MoB 2 , and is completely unknown in the past. The reason why the average particle size of the SiC powder used as a raw material was limited to 5 μm or less is because if the average particle size of the SiC powder exceeds 5 μm, it is impossible to densify it by pressureless sintering. The composition range of SiC was limited to 20-99wt% because
In relation to other additives, the total amount of other additives is 80wt
This is because if it exceeds 1%, the properties of the basic SiC cannot be fully exhibited, and if it is less than 1wt%, there is no effect of improving the properties of the additive. The composition range of this SiC is preferably 30 to 99 wt%, more preferably 40 to 99 wt%. As an additive, MoB 2 was limited to 80 to 0.5 wt% because if it exceeds 80 wt%, the high temperature properties deteriorate.
This is because if it is less than 0.5 wt%, there is no improvement in toughness and there is no effect of suppressing abnormal particle growth. The amount added is preferably 70-0.5wt%, and 60-0.5wt%
% is more preferable. In addition, the reason why compound B was limited to 0.1 to 5 wt% was that
If it is less than 0.1wt%, the effect of its addition will not be recognized,
This is because B does not contribute to densification, and if it exceeds 5 wt%, densification is inhibited and a large amount of B remains at grain boundaries, deteriorating high-temperature properties. Furthermore, the reason why we limited the C compound to 0.1 to 5wt% is that if it is less than 0.1wt%, the SiO 2 film on the SiC surface cannot be removed sufficiently, and if it exceeds 5wt%, it will not be possible to remove the SiO 2 film on the SiC surface.
This is because a large amount of free-C remains and the characteristics deteriorate. (Example) FIG. 1 is a diagram showing an example of the manufacturing process of the manufacturing method of the present invention. First, the average particle size of the SiC raw material powder was set to 5μ.
In addition, MoB 2 , B, and C are prepared as additives. The SiC raw material powder used in this example contained 93 wt% of β-SiC and the remainder was α-SiC, with an average particle size of 0.42 μm and a specific surface area.
20.0 m 2 /g, and has the chemical composition shown in Table 2. Table 2 (wt%) Total−Si 69.13 Free−SiO 2 0.47 Free−Si 0.010 Free−C 0.51 O 0.90 Al 0.056 Fe 0.060 Ca 0.016 Mg 0.001 K <0.001 Na 0.001 Cu − Ti 0.007 N 0.27Next prepared SiC Raw material powder and MoB 2 , B,
A predetermined amount of additive C is ground and mixed using a wet ball mill using isopropyl alcohol. The raw materials after being crushed and mixed are once dried and then granulated. Thereafter, the granulated powder is preformed and further molded into a predetermined shape using a hydrostatic press. lastly
A sintered body is obtained by firing at 1900-2500°C in vacuum or in an inert gas. In addition. In the above manufacturing method, MoB 2 is added separately as a boride other than MoB 2 , an oxide, a simple substance, and a boron-containing additive, and MoB 2 is added into the molded body by another heat treatment at the beginning of firing or before firing. Alternatively, it is also possible to synthesize in a mixed powder. In this case, it is necessary to add a sufficient amount of B to synthesize MoB2 . In addition, after firing the formed body, the capsule
It is also possible to further improve the properties by further densification using HIP or capsule-free HIP. An actual example will be explained below. Example 1 SiC powder with an average particle size of 5 μm or less, as an additive
MoB 2 , B (metallic boron) and C (carbon black) as sintering aids were mixed in a wet ball mill using isopropyl alcohol in the proportions shown in Table 3.
After drying, the mixture was granulated, and after preforming, a square plate of 60 x 60 x 6 mm was produced by hydrostatic pressing at 3 tons/cm 2 .
The produced square plates were fired in a vacuum up to 1500°C and then at 2200°C in 1 atm of argon for 1 hour to obtain sintered bodies of examples of the present invention and comparative examples, respectively. In addition, in Example 4-2, the sintered body of Example 4 was heated at 2000℃,
It was subjected to HIP treatment at 2000 atmospheres. For each of the obtained sintered bodies, the sintered body was polished to a mirror surface, the relative density of the sintered body was measured from the pore distribution, and the compactness was evaluated.
A four-point bending test according to JIS R-1601 (Fine Ceramics Bending Strength Test Method) was conducted at a temperature of .degree. C. to evaluate room temperature and high temperature strength. Furthermore, each K 1C was determined by the Shubron Notch method at room temperature.
In addition to evaluating the toughness by determining , the Mo compound in the sintered body was identified by X-ray diffraction using CuKα. The results are shown in Table 3.
【表】【table】
【表】
第３表の結果から、本発明の組成範囲を満足す
る実施例１〜10は比較例１〜６と比べて緻密かつ
高温強度が良好であるとともに従来のSiC単味の
K1C（２〜３）に比べて高いK1C値を示し靭性が向
上していることがわかる。またMoB2無添加の比
較例１では、SiCの異常粒子成長が認められた
が、その他のものは、異常粒子成長が認められな
かつた。さらに、焼成後HIP処理を行なつた実施
例４−２では、すべての点がさらに良好な性質が
得られた。
焼結体中のMo化合物はJCPDSカードNo.６−
682に示されるMoB2であることが確認された。
第３表中実施例３のCuKα線によるＸ線回折線
図を第２図に示す。
また本実施例の焼結体を化学分析した結果、
SiC原料及び添加剤に含まれる不可避の金属不純
物（Al、Fe、Ca、Mg、Ti、Mn等）が0.01〜
0.08wt％検出された。
実施例 ２
本発明における必須成分であるMoB2をMoB2
以外の硼化物、炭化物、酸化物単体で添加し、粉
砕、混合後、実施例１と同様の方法でそれぞれの
焼結体を得た。
その後、得られた焼結体の相対密度とMo化合
物を実施例１と同様の方法で求めた。結果を第４
表に示す。[Table] From the results in Table 3, Examples 1 to 10 that satisfy the composition range of the present invention are denser and have better high-temperature strength than Comparative Examples 1 to 6.
It can be seen that the K 1C value is higher than that of K 1C (2 to 3), and the toughness is improved. Further, in Comparative Example 1 without the addition of MoB 2 , abnormal particle growth of SiC was observed, but no abnormal particle growth was observed in the other samples. Furthermore, in Example 4-2, in which HIP treatment was performed after firing, even better properties were obtained in all respects. The Mo compound in the sintered body is JCPDS card No. 6-
It was confirmed to be MoB 2 shown in 682. The X-ray diffraction diagram of Example 3 in Table 3 using CuKα rays is shown in FIG. Furthermore, as a result of chemical analysis of the sintered body of this example,
Unavoidable metal impurities (Al, Fe, Ca, Mg, Ti, Mn, etc.) contained in SiC raw materials and additives are 0.01~
0.08wt% detected. Example 2 MoB 2 , which is an essential component in the present invention, is converted into MoB 2
Other borides, carbides, and oxides were added alone, pulverized, and mixed, and then sintered bodies were obtained in the same manner as in Example 1. Thereafter, the relative density and Mo compound of the obtained sintered body were determined in the same manner as in Example 1. 4th result
Shown in the table.
【表】【table】
【表】
第４表の結果から、比較例７〜12に示すように
MoB2以外の添加剤の場合、従来知られているＢ
量（1wt％添加）では焼結体の高い相対密度すな
わち緻密化を達成することができないことがわか
る。また比較例13、14に示すようにＢの量を増加
したものであつても焼結体中でMoB2になつてい
ないと、同様に高い相対密度を達成できないこと
がわかる。
実施例11、12に示すようにＢの量を更に増加
し、Ｂの量のモル数がMo添加量のモル数の２倍
（Mo：30wt％の場合、Ｂ：6.8wt％）以上添加し
た場合、MoB2が焼成初期に成形体中で形成さ
れ、実施例１で示したMoB2で添加した場合と同
様に緻密化を達成することができることがわか
る。
（発明の効果）
以上詳細に説明したところから明らかなよう
に、本発明のSiC複合焼結体およびその製造方法
によれば、Ｂ−Ｃ系SiCに所定量のMoB2を含有
させることにより、高温焼成が可能となり、高温
強度を保つたままＢ−Ｃ系SiCの欠点であつた靭
性を高めることができ、高温でも高強度で高靭性
のSiC複合焼結体を常圧焼結により得ることがで
きる。
本発明のSiC複合焼結体の特徴を従来技術と比
較して第５表に示す。[Table] From the results in Table 4, as shown in Comparative Examples 7 to 12
In the case of additives other than MoB 2 , conventionally known B
It can be seen that a high relative density, that is, densification of the sintered body cannot be achieved with the addition of 1 wt%. Furthermore, as shown in Comparative Examples 13 and 14, it can be seen that even if the amount of B is increased, unless it is converted into MoB 2 in the sintered body, a similarly high relative density cannot be achieved. As shown in Examples 11 and 12, the amount of B was further increased, and the number of moles of B was added at least twice the number of moles of Mo added (in the case of Mo: 30 wt%, B: 6.8 wt%). In this case, it can be seen that MoB 2 is formed in the compact at the early stage of firing, and densification can be achieved in the same way as when MoB 2 is added as shown in Example 1. (Effects of the Invention) As is clear from the detailed explanation above, according to the SiC composite sintered body and the manufacturing method thereof of the present invention, by containing a predetermined amount of MoB 2 in B-C system SiC, High-temperature firing is now possible, and toughness, which was a drawback of B-C SiC, can be improved while maintaining high-temperature strength. A SiC composite sintered body with high strength and high toughness even at high temperatures can be obtained by pressureless sintering. I can do it. Table 5 shows the characteristics of the SiC composite sintered body of the present invention in comparison with the conventional technology.
第１図は本発明製造方法の製造工程の一例を示
す図、第２図は本発明により得られた焼結体実施
例３のCuKα線によるＸ線回折結果の回折線を示
す線図である。
FIG. 1 is a diagram showing an example of the manufacturing process of the manufacturing method of the present invention, and FIG. 2 is a diagram showing the diffraction lines of the X-ray diffraction results using CuKα rays of the sintered body Example 3 obtained by the present invention. .
Claims (1)
素、炭素、炭素硼素のうち少なくとも１種類が
0.5〜5wt％からなり、破壊靭性K1Cが４以上であ
ることを特徴とするSiC複合焼結体。 ２ 平均粒径5μｍ以下のSiC粉末20〜99wt％、
MoB2又はMoB2を生成する化合物をMoB2に換
算して80〜0.5％、硼素又は硼素を含有する化合
物を硼素に換算して0.1〜5wt％、炭素又は炭素を
生成する有機化合物を炭素に換算して0.1〜5wt％
からなる調合粉末を混合成形し、次いで1500℃ま
で真空中でその後不活性雰囲気中1900〜2500℃の
温度下で焼成することにより破壊靭性K1Cが４以
上の焼結体を得ることを特徴とするSiC複合焼結
体の製造方法。[Claims] 1 SiC is 20 to 99 wt%, MoB 2 is 80 to 0.5 wt%, and at least one of boron, carbon, and carbon-boron is present.
A SiC composite sintered body comprising 0.5 to 5 wt% and having a fracture toughness K1C of 4 or more. 2 20 to 99 wt% SiC powder with an average particle size of 5 μm or less,
MoB 2 or a compound that produces MoB 2 is 80 to 0.5% in terms of MoB 2 , boron or a compound containing boron is 0.1 to 5 wt% in terms of boron, and carbon or an organic compound that produces carbon is converted to carbon. Converted to 0.1-5wt%
A sintered body with a fracture toughness K 1C of 4 or more is obtained by mixing and molding a blended powder consisting of the following, and then firing it in a vacuum up to 1500°C, and then firing it in an inert atmosphere at a temperature of 1900 to 2500°C. A method for manufacturing a SiC composite sintered body.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62244161A JPS6487561A (en) | 1987-09-30 | 1987-09-30 | Sic-based composite sintered body and production thereof |
| US07/222,554 US4963516A (en) | 1987-07-28 | 1988-07-21 | SiC complex sintered bodies and production thereof |
| EP88306863A EP0301802B1 (en) | 1987-07-28 | 1988-07-26 | Sic complex sintered bodies and production thereof |
| DE88306863T DE3881777T2 (en) | 1987-07-28 | 1988-07-26 | Sintered silicon carbide composites and process for their manufacture. |
| CA000573126A CA1314295C (en) | 1987-07-28 | 1988-07-27 | Sic complex sintered bodies and production thereof |
| KR1019880009535A KR900005510B1 (en) | 1987-07-28 | 1988-07-28 | Method for producing siliconcarbide-sinteringbody |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62244161A JPS6487561A (en) | 1987-09-30 | 1987-09-30 | Sic-based composite sintered body and production thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6487561A JPS6487561A (en) | 1989-03-31 |
| JPH0461828B2 true JPH0461828B2 (en) | 1992-10-02 |
Family
ID=17114675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62244161A Granted JPS6487561A (en) | 1987-07-28 | 1987-09-30 | Sic-based composite sintered body and production thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6487561A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010026168A (en) | 2008-07-17 | 2010-02-04 | Toshiba Mobile Display Co Ltd | Liquid crystal display |
| CN105913888B (en) * | 2016-05-10 | 2018-01-30 | 中国核动力研究设计院 | A kind of HTGR control rod core level boron carbide core preparation method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6340766A (en) * | 1986-08-01 | 1988-02-22 | 旭硝子株式会社 | High temperature steel contacting member |
-
1987
- 1987-09-30 JP JP62244161A patent/JPS6487561A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6340766A (en) * | 1986-08-01 | 1988-02-22 | 旭硝子株式会社 | High temperature steel contacting member |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6487561A (en) | 1989-03-31 |
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