JPS6228111B2 - - Google Patents
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- JPS6228111B2 JPS6228111B2 JP55032064A JP3206480A JPS6228111B2 JP S6228111 B2 JPS6228111 B2 JP S6228111B2 JP 55032064 A JP55032064 A JP 55032064A JP 3206480 A JP3206480 A JP 3206480A JP S6228111 B2 JPS6228111 B2 JP S6228111B2
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- 239000000843 powder Substances 0.000 claims description 77
- 239000002245 particle Substances 0.000 claims description 42
- 239000000463 material Substances 0.000 claims description 33
- 238000005245 sintering Methods 0.000 claims description 26
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 12
- 229910052796 boron Inorganic materials 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 5
- 239000011812 mixed powder Substances 0.000 claims description 5
- 238000000465 moulding Methods 0.000 claims description 2
- 238000005520 cutting process Methods 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 229910000601 superalloy Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 229910052582 BN Inorganic materials 0.000 description 4
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 229910000997 High-speed steel Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 229910003460 diamond Inorganic materials 0.000 description 3
- 239000010432 diamond Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910001347 Stellite Inorganic materials 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052810 boron oxide Inorganic materials 0.000 description 1
- AHICWQREWHDHHF-UHFFFAOYSA-N chromium;cobalt;iron;manganese;methane;molybdenum;nickel;silicon;tungsten Chemical compound C.[Si].[Cr].[Mn].[Fe].[Co].[Ni].[Mo].[W] AHICWQREWHDHHF-UHFFFAOYSA-N 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- -1 iron group metals Chemical class 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
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Description
この発明は、高硬度、並びにすぐれた耐摩耗性
および靭性を有し、特にこれらの特性が要求され
る高硬度鋼やNi基あるいはCo基スーパーアロイ
などの切削に用いられる切削工具の刃先として、
また同じくダイスやノズルなどの耐摩耗工具とし
て使用するのに適した立方晶炭窒化硼素基焼結材
料の製造法に関するものである。
近年、例えば高速度鋼や、Ni基あるいはCo基
スーパーアロイのような材料の切削には、ダイヤ
モンドと並んで硬度の高い立方晶窒化硼素(以下
c−BNという)を主成分とする焼結材料が切削
工具の刃先として使用されているが、前記c−
BN基焼結材料はダイヤモンドに比して硬さが低
いために、苛酷な条件下での使用に際しては、摩
耗しやすい上に、靭性不足が原因のチツピングを
起し易いという問題点を有している。このc−
BN基焼結材料の靭性不足の原因は、c−BN粒子
と添加含有粒子間での熱膨脹係数の差が大きすぎ
ることによる残留歪、さらに異種粒子間における
著しい濃度変化による焼結性の低下、ひいては粒
子界面強度の低下にあると思われる。
一方、ダイヤモンドは、硬さがc−BN基焼結
材料より硬いものの、これを、例えば上記のよう
な高硬度鋼や、Ni基あるいはCo基スーパーアロ
イの切削に切削工具刃先として使用すると、これ
らの被削材が主として鉄族金属からなるため、非
常に大きな摩耗を生じ、実用的使用に供し得ない
のが現状である。
そこで、本発明者等は、上述のような観点か
ら、すぐれた耐摩耗性と靭性とを兼ね備え、かつ
例えば、高速度鋼やNi基あるいはCo基スーパー
アロイなどの切削に切削工具刃先として、またダ
イスやノズルなどの耐摩耗工具として使用した場
合に、すぐれた性能を発揮する材料を得べく、特
に四面体構造を有する窒化硼素(BN)に炭素を
固溶したものからなり、c−BNのもつ化学的安
定性を保持しつつ、c−BNよりも高い硬さを有
する立方晶炭窒化硼素(以下c−B(CN)で示
す)に着目し研究を行なつた結果、
(a) 従来、c−B(CN)粉末は、研摩材として
使用されており、例えば特開昭53−101000号公
報に記載されるような方法、すなわち六方晶系
または無定形の炭窒化硼素化合物を、周期律表
の8族の金属であるCo、Ni、あるいはFeと、
Alとの混合物、またはこれらの合金からなる
溶媒の存在下において、圧力:50Kb(キロバ
ール)以上、温度:1300℃以上の条件で相変態
させる方法によつて製造されているが、これら
の従来方法によつて製造された研摩材用c−B
(CN)粉末を原料粉末として使用して切削工具
刃先や耐摩耗工具などを製造しても、焼結性が
著しく劣ることから、これを実用に供した場合
満足する性能を発揮しないこと。
(b) しかし、上記従来方法におけるような溶媒金
属を使用しない条件下でc−B(CN)粉末を
合成すると、この結果得られたc−B(CN)
粉末は前記溶媒金属などの混入がなく、比較的
純度の高いものとなつており、このような不純
物の少ないc−B(CN)粉末はきわめて良好
な焼結性を有すること。
(c) c−B(CN)粉末は、微粒で結晶性の悪い
ものが良好な焼結性を示すこと。
(d) 微粒で結晶性の悪いc−B(CN)粉末は、
溶媒金属を使用しない条件下で容易に合成でき
ること。
(e) 緻密なc−B(CN)基焼結材料が、c−B
(CN)粉末に、ボロン(以下Bで示す)粉末
と、六方晶炭窒化硼素(以下h−B(CN)で
示す)とを配合したものからなる混合粉末を原
料粉末として使用することによつて得られるこ
と。
(f) 焼結時の加圧、昇温に際して形成されるc−
B(CN)粒子同士のブリツジ部分は、そのま
ま焼結した場合にはブリツジ部でのくびれが成
長しないままの状態で残るので、脆い焼結材料
しか得られないが、c−B(CN)粒子表面
に、h−C(BN)粒子とB粒子とを接触存在
させた状態で焼結を行なうと、前記c−B
(CN)粒子間のブリツジ部での焼結が促進され
て、くびれがなくなることからc−B(CN)
粒子同士の接合が著しく強固になること。以上
(a)〜(f)に示される知見を得たのである。
この発明は、上記知見にもとづいてなされたも
のであつて、容量%で、
B粉末:0.1〜2%、
h−B(CN)粉末:1〜30%、
c−B(CN)粉末:残り、
からなる配合組成を有し、かつ前記c−B
(CN)粉末の80%以上が粒径3μm以下の微細で
あり、一方前記h−B(CN)粉末は、その平均
粒径が前記c−B(CN)粉末の平均粒径よりも
小さく、しかもその50%以上が粒径1μm以下の
微粉で構成された混合粉末より、通常の条件にて
圧粉体を成形し、ついで前記圧粉体を、温度
(T1):1800℃以下、圧力(P1):50Kb以上にし
て、温度(T1)と圧力(P1)の関係が、T1−10P1
>800を満足する条件下で第1段加圧焼結した
後、さらに引続いて温度(T2):1300℃以上、圧
力(P2):100Kb以下にして、温度(T2)と圧力
(P2)の関係が、T2−10P2≦800を満足する条件下
で第2段加圧焼結を行なうことによつて、
B:0.1〜2%、
c−B(CN)および不可避不純物:残り、
からなる組成を有し、耐摩耗性および靭性にすぐ
れ、かつ特に高速度鋼やNi基あるいはCo基スー
パーアロイなどの被削材の切削工具刃先や、ダイ
スおよびドリルなどの耐摩耗工具などの製造に使
用した場合に著しくすぐれた性能を発揮するc−
B(CN)基焼結材料を製造することに特徴を有
するものである。
なお、この発明のc−B(CN)基焼結材料の
製造に際して、上記の加熱加圧条件下での保持時
間は、c−B(CN)粉末およびh−B(CN)粉
末の安定性を確保する上で10分〜2時間が適当で
ある。
ついで、この発明のc−B(CN)基焼結材料
の製造条件および成分組成を上記の通りに限定し
た理由を説明する。
A 製造条件
(a) B粉末およびh−B(CN)粉末の配合量
この発明にかかる圧粉体においては、c−
B(CN)粉末同士が連続したスケルトン構
造(粉末同士が接触部をもつて形成される骨
組構造)をとり、その微小間隙にB粉末とh
−B(CN)粉末とが入り込んだ状態にある
のがよく、これによつて焼結時に、B粉末は
c−B(CN)粉末およびh−B(CN)粉末
の表面に付着している酸素分を酸化ボロンの
形で除去して、その表面を活性化し、もつて
焼結性の促進をはかると共に、前記両B
(CN)粉末におけるB成分と相互置換反応を
起して粉末相互間の結合強度を向上させ、一
方、h−B(CN)粉末は、c−B(CN)に
変換しながらc−B(CN)粒子間の接触部
のくびれをなくする形で、c−B(CN)粒
子間の接触部で焼結を促進させる方向に作用
することから、c−B(CN)粒子が強固に
結合したc−B(CN)基焼結材料が得られ
るようになるのである。
しかし、B粉末(望ましくは平均粒径3μ
m以下をもつのがよい)の配合量が0.1%未
満では、上記作用に所望の効果が得られず、
一方2%を越えて配合すると、上記のB成分
のもつ作用が強くなり過ぎて所望の特性を確
保することができなくなることから、B粉末
の配合量を0.1〜2%とした。
また、h−B(CN)粉末の配合量が1%
未満でも上記のh−B(CN)粉末によつて
もたらされる作用に所望の効果が得られず、
一方30%を越えて配合すると、相対的にh−
B(CN)粉末の配合量が多くなりすぎて、
h−B(CN)粉末自体が連続した構造をと
りやすくなり、この状態で焼結を行なうと、
体積変化が大きくなるばかりでなく、未変換
のh−B(CN)が残留してc−B(CN)粒
子相互の強固な粒子結合が損なわれるように
なることから、その配合量を1〜30%と定め
た。
(b) c−B(CN)粉末の粒径
一般に、原料粉末の粒径は小さい方が焼結
が進行しやすく、かつ製造された焼結材料に
おいても個々の結晶粒の劈開強度が高いので
靭性に富んだ焼結材料が得られるものであ
り、したがつて、c−B(CN)粉末の粒径
が3μmを越えると、粗い粉末同士でブリツ
ジ(粉末同士が均一に圧縮されない、あるい
は同じく均一に焼結されない結果生ずる棚吊
り現象)を作つて大きな隙間空間ができやす
くなり、この空間内では相対的に圧力が低い
ために均一な焼結の進行が困難になることか
ら、3μmを越えた粒径にしてはならない。
ただし、3μm以下の粒径のc−B(CN)
粉末を80%以上配合してあると、残りに3μ
mを越えた粗粒のc−B(CN)粉末が含ま
れていても、上記のブリツジを組まず、この
結果均一な焼結が行なわれるようになること
から、粒径3μm以下のc−B(CN)粉末
を80%以上配合する必要があるのである。
(c) h−B(CN)粉末の粒径
h−B(CN)粉末の平均粒径がc−B
(CN)粉末の平均粒径より大きいと、混合粉
末中にh−B(CN)粉末が局在しやすくな
ると共に、焼結後においても、焼結材料中に
未変換のh−B(CN)が残存しやすくなる
ことから、h−B(CN)粉末の平均粒径を
c−B(CN)粉末の平均粒径より大きくし
てはならない。
また、h−B(CN)粉末の50%以上が1
μmより大きい粒径をもつようになると、h
−B(CN)粉末とc−B(CN)粉末相互間
に大きな形状的および寸法的差異がなくな
り、c−B(CN)粒子相互のスケルトン形
成頻度が低下するようになつて強固な粒子結
合を確保することができなくなることから、
h−B(CN)粉末の50%以上を1μm以下
の粒径をもつ微粉としなければならない。
(d) 加圧焼結時の温度および圧力
焼結にあたつて、原料混合粉末をまず、h
−B(CN)粉末の安定条件下で、かつc−
B(CN)粉末の安定条件に遠すぎない条件
下におくことにより、c−B(CN)粉末の
表面付近の一部を、h−B(CN)に相変換
しておき、ついでc−B(CN)粉末の安定
条件下で焼結を行なうと、c−B(CN)粒
子同士の強固な接合が得られるようになるの
である。しかし、第1段加圧焼結時に、圧力
が50Kb未満で、温度が1300℃未満では、c
−B(CN)粉末の表面付近部の相変換がほ
とんど生ぜず、一方圧力が100Kbを越えた
り、温度が1800℃を越えて高い場合には焼結
の進行が早くなりすぎて、局部的に焼結が進
行しやすく、この結果一部に焼結完了後もh
−B(CN)が残存したり、粒成長が大きく
なつたりして組織的に不均一になりやすくな
ることから、上記の不都合な温度範囲および
圧力範囲を除いた温度−圧力範囲にしなけれ
ばならない。しかし、上記の不都合な温度−
圧力範囲を除いた温度−圧力範囲には、さら
にh−B(CN)の不安定域を含むので、こ
れをも除いた温度−圧力範囲にしなければな
らない。すなわち、縦軸に圧力P1、横軸に温
度T1を取つた第1図に示すグラフにおい
て、圧力:50Kbで温度:1300℃の点と、圧
力:100Kbで温度:1800℃の点とを結ぶ直線
よりも高温で低圧の側、すなわち、不等式:
T1−10P1>800を満足する温度−圧力範囲、
つまり第1図の斜線を付した範囲の焼結条件
を、第1段加圧焼結において守らなければな
らないのである。
また、第2段加圧焼結時に、圧力が50Kb
未満で、温度が1300℃未満の場合には、h−
B(CN)のc−B(CN)への相変換がほと
んど生ぜず、一方圧力が100Kbを越え、温度
が1800℃を越えた場合には、やはり粒成長が
大きくなつて組織的に不均一になりやすい。
そして、この場合も温度と圧力が上記の不都
合な範囲を除いた範囲内にあつても、c−B
(CN)の安定域からはずれてはいけないの
で、第2図において斜線を付した範囲、すな
わち、1300℃以上の温度で、100Kb以下の圧
力の範囲のうちの、さらに不等式:T2−
10P2≦800の条件を満足する温度−圧力範囲
での焼結を行なう必要がある。
つぎに、この発明を実施例により比較例と対比
しながら具体的に説明する。
原料粉末として、それぞれ第1表に示される粒
径分布を有するc−B(CN)粉末およびh−B
(CN)粉末、さらに平均粒径2μmのB粉末を用
意し、同じく第1表に示される割合にこれらの原
料粉末を配合し、混合した後、この混合粉末より
通常の圧縮条件にて圧粉体を成形し、ついでこれ
らの圧粉体を同じく第1表に示される加圧焼結条
件にて第1段および第2段加圧焼結を行なうこと
によつて本発明焼結材料1〜4および比較焼結材
料1〜6をそれぞれ製造した。
なお、上記比較焼結材料1〜6は、第1表に示
される諸条件のうち、※印の付された条件がこの
発明の範囲から外れた条件で製造したものであ
る。
この結果得られた比較焼結材料1〜6は、いず
れも市配のc−BN基焼結材料によつて容易に引
つかき傷がつくものであり、耐摩耗性の著しく劣
るものであつた。しかも比較焼結材料1〜3には
微量、また比較焼結材料4〜6にはかなり大量の
h−
This invention has high hardness as well as excellent wear resistance and toughness, and is particularly useful as a cutting tool edge used for cutting high-hardness steel, Ni-based or Co-based super alloys, etc., which require these properties.
The present invention also relates to a method for producing a cubic boron carbonitride-based sintered material suitable for use as wear-resistant tools such as dies and nozzles. In recent years, sintered materials whose main component is cubic boron nitride (hereinafter referred to as c-BN), which has a high hardness comparable to diamond, have been used for cutting materials such as high-speed steel and Ni-based or Co-based superalloys. is used as the cutting edge of cutting tools, but the c-
BN-based sintered materials have lower hardness than diamond, so when used under harsh conditions, they are prone to wear and chipping due to lack of toughness. ing. This c-
The causes of the lack of toughness in BN-based sintered materials are residual strain due to an excessively large difference in coefficient of thermal expansion between c-BN particles and additive particles, and a decrease in sinterability due to significant concentration changes between different types of particles. This is thought to be due to a decrease in particle interface strength. On the other hand, although diamond is harder than c-BN-based sintered material, when it is used as a cutting tool edge to cut high-hardness steel, Ni-based or Co-based superalloy, for example, Currently, the workpiece material of this method is mainly composed of iron group metals, which causes extremely large wear and cannot be used for practical use. Therefore, from the above-mentioned viewpoints, the present inventors have developed a material that has both excellent wear resistance and toughness, and that can be used as a cutting tool tip for cutting high-speed steel, Ni-based or Co-based super alloys, etc. In order to obtain a material that exhibits excellent performance when used as wear-resistant tools such as dies and nozzles, we developed c-BN, which is made of boron nitride (BN) with a tetrahedral structure and carbon dissolved in it. As a result of research focusing on cubic boron carbonitride (hereinafter referred to as c-B (CN)), which has higher hardness than c-BN while maintaining chemical stability, we found that (a) conventional , c-B(CN) powder is used as an abrasive, for example, by the method described in JP-A-53-101000, that is, hexagonal or amorphous boron carbonitride compound is cyclically polished. Co, Ni, or Fe, which are metals in Group 8 of the Table of Laws,
It is manufactured by a method of phase transformation in the presence of a mixture with Al or a solvent consisting of an alloy thereof at a pressure of 50 Kb (kilobar) or higher and a temperature of 1300°C or higher, but these conventional methods c-B for abrasives manufactured by
Even if (CN) powder is used as a raw material powder to manufacture cutting tool edges, wear-resistant tools, etc., the sinterability is extremely poor, so if it is put into practical use, it will not exhibit satisfactory performance. (b) However, when c-B(CN) powder is synthesized under conditions without using a solvent metal as in the conventional method, the resulting c-B(CN)
The powder has relatively high purity without contamination with the solvent metal, etc., and the c-B(CN) powder containing few impurities has extremely good sinterability. (c) The c-B(CN) powder should have fine particles and poor crystallinity and exhibit good sinterability. (d) Fine-grained c-B(CN) powder with poor crystallinity is
Easily synthesized under conditions that do not use solvent metals. (e) The dense c-B(CN)-based sintered material
(CN) powder mixed with boron (hereinafter referred to as B) powder and hexagonal boron carbonitride (hereinafter referred to as h-B(CN)) as a raw material powder. What you can get from it. (f) c- formed during pressurization and temperature rise during sintering
If the bridge parts between B(CN) particles are sintered as they are, the constrictions at the bridge parts will remain in a state without growth, so only a brittle sintered material will be obtained, but c-B(CN) particles When sintering is performed with h-C (BN) particles and B particles present in contact with each other on the surface, the c-B
c-B(CN) because sintering at the bridge between particles is promoted and the constriction is eliminated.
Bonds between particles become significantly stronger. that's all
The findings shown in (a) to (f) were obtained. This invention was made based on the above knowledge, and in terms of volume %, B powder: 0.1 to 2%, h-B(CN) powder: 1 to 30%, c-B(CN) powder: the remainder. , and the c-B
80% or more of the (CN) powder is fine with a particle size of 3 μm or less, while the average particle size of the h-B(CN) powder is smaller than the average particle size of the c-B(CN) powder, Moreover, a green compact is formed from a mixed powder of which 50% or more is composed of fine powder with a particle size of 1 μm or less under normal conditions, and then the green compact is heated at a temperature (T 1 ) of 1800°C or less and a pressure of (P 1 ): 50Kb or more, the relationship between temperature (T 1 ) and pressure (P 1 ) is T 1 −10P 1
After the first stage pressure sintering under conditions satisfying >800 , the temperature (T 2 ) and the pressure By performing the second stage pressure sintering under conditions where the relationship (P 2 ) satisfies T 2 −10P 2 ≦800, B: 0.1 to 2%, c-B(CN) and unavoidable Impurities: The remainder has a composition of c-, which exhibits outstanding performance when used in the manufacture of tools, etc.
This method is characterized by producing a B(CN)-based sintered material. In addition, when manufacturing the c-B(CN)-based sintered material of this invention, the holding time under the above heating and pressurizing conditions is determined based on the stability of the c-B(CN) powder and h-B(CN) powder. 10 minutes to 2 hours is appropriate to ensure that. Next, the reason why the manufacturing conditions and component composition of the c-B(CN)-based sintered material of the present invention are limited as described above will be explained. A. Manufacturing conditions (a) Amounts of B powder and h-B(CN) powder In the green compact according to the present invention, c-
The B (CN) powder forms a continuous skeleton structure (a framework structure formed by the powders having contact parts), and the B powder and h
-B(CN) powder is preferably mixed with the powder, so that during sintering, B powder adheres to the surfaces of c-B(CN) powder and h-B(CN) powder. By removing oxygen in the form of boron oxide, the surface is activated and sinterability is promoted, and both of the above-mentioned B
A mutual substitution reaction occurs with the B component in the (CN) powder to improve the bonding strength between the powders. On the other hand, the h-B(CN) powder is converted to c-B(CN) while c-B( The c-B(CN) particles are strongly bonded by eliminating the constriction at the contact area between the c-B(CN) particles and promoting sintering at the contact area between the c-B(CN) particles. This makes it possible to obtain a c-B(CN)-based sintered material. However, B powder (preferably average particle size 3μ)
If the amount of (preferably less than m) is less than 0.1%, the desired effect cannot be obtained from the above action,
On the other hand, if the amount exceeds 2%, the effect of the above-mentioned B component becomes too strong, making it impossible to secure the desired properties, so the amount of B powder blended is set at 0.1 to 2%. In addition, the blending amount of h-B (CN) powder is 1%.
Even if it is less than that, the desired effect cannot be obtained from the action brought about by the h-B(CN) powder, and
On the other hand, if it is blended in excess of 30%, the relative h-
The amount of B(CN) powder blended is too large,
The h-B(CN) powder itself tends to take on a continuous structure, and when sintered in this state,
Not only will the volume change become large, but unconverted h-B(CN) will remain and the strong particle bond between the c-B(CN) particles will be impaired, so the blending amount should be increased from 1 to 1. It was set at 30%. (b) Particle size of c-B(CN) powder In general, the smaller the particle size of the raw material powder, the easier sintering will progress, and the cleavage strength of individual crystal grains will be higher in the manufactured sintered material. A sintered material with high toughness can be obtained. Therefore, if the particle size of c-B(CN) powder exceeds 3 μm, bridging occurs between coarse powders (powders are not compressed uniformly, or If the thickness exceeds 3 μm, it is easy to create a large gap space (shelf hanging phenomenon that occurs as a result of not being sintered uniformly), and the pressure within this space is relatively low, making it difficult to proceed with uniform sintering. The particle size shall not be too large.
However, c-B(CN) with a particle size of 3 μm or less
If more than 80% powder is mixed, the remaining 3μ
Even if c-B (CN) powder with coarse grains exceeding m is included, the above-mentioned bridges are not formed, and as a result, uniform sintering is performed. It is necessary to mix 80% or more of B(CN) powder. (c) Particle size of h-B(CN) powder The average particle size of h-B(CN) powder is c-B
If the particle size is larger than the average particle size of the (CN) powder, h-B(CN) powder tends to be localized in the mixed powder, and even after sintering, unconverted h-B(CN) powder remains in the sintered material. ) tends to remain, so the average particle size of the h-B(CN) powder should not be made larger than the average particle size of the c-B(CN) powder. In addition, more than 50% of h-B(CN) powder is 1
When the particle size becomes larger than μm, h
- There is no large shape and dimensional difference between B(CN) powder and c-B(CN) powder, and the frequency of skeleton formation between c-B(CN) particles is reduced, resulting in strong particle bonding. Because it becomes impossible to secure
At least 50% of the h-B(CN) powder must be fine powder with a particle size of 1 μm or less. (d) Temperature and pressure during pressure sintering For sintering, the raw material mixed powder is first
- Under stable conditions of B(CN) powder, and c-
By placing the c-B(CN) powder under conditions that are not too far from the stable conditions, a part of the c-B(CN) powder near the surface undergoes a phase transformation to h-B(CN), and then c- When sintering is performed under stable conditions for B(CN) powder, strong bonding between c-B(CN) particles can be obtained. However, during the first stage pressure sintering, if the pressure is less than 50Kb and the temperature is less than 1300℃, c
- There is almost no phase transformation near the surface of the B(CN) powder.On the other hand, if the pressure exceeds 100Kb or the temperature exceeds 1800℃, sintering progresses too quickly, resulting in localized Sintering progresses easily, and as a result, some h
- Since B(CN) may remain or grain growth may increase, resulting in a non-uniform structure, the temperature-pressure range must be set excluding the above-mentioned disadvantageous temperature and pressure ranges. . However, the above unfavorable temperature −
Since the temperature-pressure range excluding the pressure range further includes the unstable region of h-B(CN), the temperature-pressure range must also exclude this range. In other words, in the graph shown in Figure 1 with pressure P 1 on the vertical axis and temperature T 1 on the horizontal axis, a point at pressure: 50 Kb and temperature: 1300°C, and a point at pressure: 100 Kb and temperature: 1800°C. The side with higher temperature and lower pressure than the connecting straight line, that is, the inequality:
Temperature-pressure range that satisfies T 1 −10P 1 >800,
In other words, the sintering conditions within the shaded range in FIG. 1 must be observed in the first stage pressure sintering. In addition, during the second stage pressure sintering, the pressure is 50Kb.
If the temperature is less than 1300℃, h-
Almost no phase transformation of B(CN) to c-B(CN) occurs, and on the other hand, when the pressure exceeds 100 Kb and the temperature exceeds 1800°C, grain growth increases and the structure becomes non-uniform. easy to become.
In this case as well, even if the temperature and pressure are within the range excluding the above disadvantageous range, c-B
Since it is important not to deviate from the stability region of (CN), the inequality in the shaded range in Figure 2, that is, the range of temperatures above 1300℃ and pressures below 100Kb: T 2 −
It is necessary to perform sintering in a temperature-pressure range that satisfies the condition of 10P 2 ≦800. Next, the present invention will be specifically explained using examples and comparing with comparative examples. As raw material powders, c-B (CN) powder and h-B powder each having a particle size distribution shown in Table 1 were used.
(CN) powder and B powder with an average particle size of 2 μm are prepared, and these raw material powders are blended in the proportions shown in Table 1. After mixing, this mixed powder is compacted under normal compression conditions. The sintered materials 1 to 1 of the present invention are obtained by molding the compacts and then subjecting these green compacts to first and second stage pressure sintering under the same pressure sintering conditions shown in Table 1. 4 and Comparative Sintered Materials 1 to 6 were produced, respectively. The comparative sintered materials 1 to 6 were manufactured under the conditions shown in Table 1, where the conditions marked with an asterisk (*) were outside the scope of the present invention. Comparative sintered materials 1 to 6 obtained as a result were all easily scratched and scratched by commercially available c-BN-based sintered materials, and had significantly inferior wear resistance. Ta. Moreover, comparative sintered materials 1 to 3 contained a small amount of h-, and comparative sintered materials 4 to 6 contained a considerably large amount of h-.
【表】
B(CN)がそれぞれ観察された。
これに対して、上記本発明焼結材料1〜4は、
いずれも実質的に配合量と同じ含有量のB成分
と、c−B(CN)および不可避不純物からな
り、市販のc−BN基焼結材料でこすつても全く
傷のつかないものであつた。
つぎに、上記本発明焼結材料1、3から切刃を
切出し、炭化タングステン基超硬材料製台金上に
ろう付けし、研削加工を施すことによつて本発明
焼結材料1、3を刃先として使用した切削工具
A,Bを製造した。
この切削工具A,Bと、市販のc−BN基焼結
材料より同一の条件で製造した従来切削工具とを
用いて、Co基スーパーアロイであるヘインズア
ロイステライトNo.6の切削を行なつたところ、従
来切削工具は400個の加工数で寿命に達したのに
対して、上記切削工具Aは1800個、上記切削工具
Bは2700個でそれぞれ寿命に至るものであつた。
上述のように、この発明によれば、高硬度を有
し、かつ耐摩耗性および靭性にすぐれたc−B
(CN)基焼結材料を製造することができ、しかも
このc−B(CN)基焼結材料を、例えば高速度
鋼やNi基あるいはCo基スーパーアロイなどの切
削に切削工具切刃として、さらにダイスやノズル
などの耐摩耗工具の製造に使用した場合に、著し
くすぐれた性能を発揮するなど工業上有用な効果
がもたらされるのである。[Table] B (CN) was observed. On the other hand, the above-mentioned sintered materials 1 to 4 of the present invention are
All of them consisted of component B in substantially the same amount as the blended amount, c-B(CN), and inevitable impurities, and were completely free of scratches even when rubbed with a commercially available c-BN-based sintered material. . Next, a cutting edge is cut out from the sintered materials 1 and 3 of the present invention, brazed onto a base metal made of tungsten carbide-based carbide material, and ground. Cutting tools A and B used as cutting edges were manufactured. Haynes Alloy Stellite No. 6, a Co-based superalloy, was cut using these cutting tools A and B and a conventional cutting tool manufactured from a commercially available c-BN-based sintered material under the same conditions. However, while the conventional cutting tool reached the end of its life after machining 400 pieces, the cutting tool A and the cutting tool B reached the end of their life after machining 1800 pieces and 2700 pieces, respectively. As described above, according to the present invention, c-B has high hardness and excellent wear resistance and toughness.
(CN)-based sintered material can be produced, and this c-B(CN)-based sintered material can be used as a cutting tool cutting edge for cutting high-speed steel, Ni-based or Co-based superalloy, etc. Furthermore, when used in the manufacture of wear-resistant tools such as dies and nozzles, it provides industrially useful effects such as extremely superior performance.
第1図および第2図は第1段および第2段加圧
焼結条件に関して、この発明の範囲を示すグラフ
である。
FIGS. 1 and 2 are graphs showing the scope of the present invention with respect to first-stage and second-stage pressure sintering conditions.
Claims (1)
硼素粉末の80容量%以上が粒径3μm以下の微粉
であり、一方前記六方晶炭窒化硼素粉末は、その
平均粒径が前記立方晶炭窒化硼素粉末の平均粒径
よりも小さく、しかもその50容量%以上が粒径1
μm以下の微粉で構成された混合粉末より、通常
の成形条件にて圧粉体を成形し、ついで前記圧粉
体を、温度(T1):1800℃以下、圧力(P1):50
キロバール以上にして、温度(T1)と圧力(P1)
の関係が、T1−10P1>800を満足する条件にて第
1段加圧焼結した後、引続いて、温度(T2):
1300℃以上、圧力(P2):100キロバール以下にし
て、しかも温度(T2)と圧力(P2)の関係が、T2
−10P2≦800を満足する条件にて第2段加圧焼結
を施すことを特徴とする靭性および耐摩耗性を具
備した立方晶炭窒化硼素基焼結材料の製造法。[Scope of Claims] 1 Boron powder: 0.1 to 2% by volume, hexagonal boron carbonitride powder: 1 to 30% by volume, cubic boron carbonitride powder: the remainder; At least 80% by volume of the boron carbonitride powder is fine powder with a particle size of 3 μm or less, while the hexagonal boron carbonitride powder has an average particle size smaller than the average particle size of the cubic boron carbonitride powder, and More than 50% by volume of the particle size is 1.
A green compact is formed from a mixed powder composed of fine powder of μm or less under normal molding conditions, and then the green compact is heated at a temperature (T 1 ) of 1800°C or less and a pressure (P 1 ) of 50.
Above kilobar, temperature (T 1 ) and pressure (P 1 )
After the first stage pressure sintering under conditions that satisfy the relationship T 1 −10P 1 > 800, the temperature (T 2 ):
1300℃ or more, pressure (P 2 ): 100 kilobar or less, and the relationship between temperature (T 2 ) and pressure (P 2 ) is T 2
A method for producing a cubic boron carbonitride-based sintered material having toughness and wear resistance, the method comprising performing a second stage pressure sintering under conditions satisfying −10P 2 ≦800.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3206480A JPS56129669A (en) | 1980-03-13 | 1980-03-13 | Tenacious antiabrasive cubic boron carbonitride base sintered material and manufacture |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3206480A JPS56129669A (en) | 1980-03-13 | 1980-03-13 | Tenacious antiabrasive cubic boron carbonitride base sintered material and manufacture |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS56129669A JPS56129669A (en) | 1981-10-09 |
JPS6228111B2 true JPS6228111B2 (en) | 1987-06-18 |
Family
ID=12348445
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3206480A Granted JPS56129669A (en) | 1980-03-13 | 1980-03-13 | Tenacious antiabrasive cubic boron carbonitride base sintered material and manufacture |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS56129669A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01144812U (en) * | 1988-03-29 | 1989-10-04 |
-
1980
- 1980-03-13 JP JP3206480A patent/JPS56129669A/en active Granted
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01144812U (en) * | 1988-03-29 | 1989-10-04 |
Also Published As
Publication number | Publication date |
---|---|
JPS56129669A (en) | 1981-10-09 |
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