JPH0363949B2 - - Google Patents
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- Publication number
- JPH0363949B2 JPH0363949B2 JP24543385A JP24543385A JPH0363949B2 JP H0363949 B2 JPH0363949 B2 JP H0363949B2 JP 24543385 A JP24543385 A JP 24543385A JP 24543385 A JP24543385 A JP 24543385A JP H0363949 B2 JPH0363949 B2 JP H0363949B2
- Authority
- JP
- Japan
- Prior art keywords
- cemented carbide
- intermediate layer
- binder phase
- layer
- phase
- 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
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- 239000010410 layer Substances 0.000 claims description 138
- 239000011230 binding agent Substances 0.000 claims description 45
- 239000010936 titanium Substances 0.000 claims description 19
- 229910052719 titanium Inorganic materials 0.000 claims description 17
- 150000001875 compounds Chemical class 0.000 claims description 13
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 12
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 229910052751 metal Inorganic materials 0.000 claims description 9
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 8
- 238000005229 chemical vapour deposition Methods 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 150000004767 nitrides Chemical class 0.000 claims description 5
- 230000000737 periodic effect Effects 0.000 claims description 5
- 238000005240 physical vapour deposition Methods 0.000 claims description 5
- 239000006104 solid solution Substances 0.000 claims description 5
- 230000007423 decrease Effects 0.000 claims description 4
- 150000001247 metal acetylides Chemical class 0.000 claims description 4
- 150000002739 metals Chemical class 0.000 claims description 3
- 239000002356 single layer Substances 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 claims description 2
- 239000012071 phase Substances 0.000 description 61
- 238000005520 cutting process Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 14
- 229910052799 carbon Inorganic materials 0.000 description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 10
- 239000007789 gas Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 239000000463 material Substances 0.000 description 5
- 229910052721 tungsten Inorganic materials 0.000 description 5
- 239000010730 cutting oil Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 229910052715 tantalum Inorganic materials 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 102220033831 rs145989498 Human genes 0.000 description 2
- 238000005245 sintering Methods 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
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Laminated Bodies (AREA)
- Physical Vapour Deposition (AREA)
- Chemical Vapour Deposition (AREA)
Description
（産業上の利用分野）
本発明は、切削工具及び耐摩耗工具などの工具
部品として用いられる高靭性被覆超硬合金及びそ
の製造方法に関するものである。
（従来の技術）
被覆超硬合金は、超硬合金の表面に形成させる
硬質な外層により耐摩耗性が大幅に向上するが、
外層が超硬合金に比して脆弱であるために、超硬
合金の破壊応力よりもはるかに低い応力で外層自
体にき裂が生じ、この外層に発生したき裂が超硬
合金の内部にまで容易に進展して被覆超硬合金を
欠損させるという問題がある。また、外層の形成
方法として一般に行なわれている化学蒸着法
（CVD法）又は物理蒸着法（PVD法）の内、特
にCVD法は、900℃〜1100℃の高温で処理される
ために、その冷却過程において、超硬合金と外層
との熱膨張率の差によつて外層の中にき裂が生じ
易く、このき裂に応力が加らると、それが超硬合
金の破壊応力よりもはるかに低いものであつて
も、応力集中により超硬合金の内部にき裂が容易
に進展して被覆超硬合金を欠損させるという問題
がある。
これらの問題を解決するために、超硬合金と外
層との間の中間層を介在させてなる被覆超硬合金
の提案が種々行なわれている。これらの中間層の
内、代表的なものとして、同様な構成で開示され
ている特開昭54−87719号公報及び日本金属学会
誌45、（1981）、95（鈴木ら）があり、他の構成で
開示されているのに特開昭53−131909号公報があ
る。
（発明が解決しようとする問題点）
特開昭54−87719号公報などに開示の被覆超硬
合金は、WC相、立方晶系化合物及びCo相の３層
からなる超硬合金と外層との間なWC相とCo相の
２相からなる中間層を介在させたもので、同時
に、中間層中のCo相は超硬合金中のCo相よりも
富化しているものである。しかしながら、このよ
うな中間層を設けた場合、耐欠損性は改善される
ものの、摩耗の進行と共に、あるいは外層が剥離
して超硬合金又は中間層が１部でも露出してしま
うと、中間層内に立方晶系化合別が存在しないた
めに、耐酸化抵抗が低くなるのと、被削材の切粉
への炭素の拡散流出が激しくなつて、摩耗が急速
に進行し、被覆超硬合金の寿命を短くするという
問題がある。
特開昭53−131909号公報に開示の被覆超硬合金
は、超硬合金と外層との間に、靭性に富み、しか
も超硬合金側に向かつて硬さが連続的に増加する
硬さ勾配をもつた中間層を介在させてなるもので
ある。ここで記載されている中間層とは、具体的
にどのような組織的構造になつているのか確認し
てみると、同公報に、中間層は、超硬合金の表
面に結合相をメツキした後加熱する方法、超硬
合金中の結合相をその表面部にしみ出させる方法
又は超硬合金を液相が発生する温度以上に加熱
して、その表面に炭素を浸入させる方法によつて
作製されている。この中間層を更に、同公報の実
施で確認してみると又はによつて作製される
中間層は、新たに加えた結合相となる金属又は超
硬合金中の結合相が移動して多く存在することに
よつて靭性に富み、しかもそれによつて連続的な
硬さ勾配を有しているものである。しかしなが
ら、及びによる中間層は、外層側の中間層表
面に結合相の金属のみの層が形成されているため
に耐摩耗性及び耐塑性変形性が低下するという問
題がある。また、及びによる中間層は、浸炭
雰囲気中で加熱して作製する方法であるために、
その調整が困難であるのと、中間層中に遊離カー
ボンを生じさせているために外層との耐剥離性を
低下させるという問題がある。
本発明は、上述のような問題点を解決したもの
で、具体的には、超硬合金と外層との間に遊離カ
ーボンの存在なく、炭化タングステン相、立方晶
系化合物相及び結合相の３相構造からなり、しか
も超硬合金よりも結合相の富化してなる中間層を
介在させることによつて靭性、耐摩耗性、耐塑性
変形性及び耐剥離性にすぐれる被覆超硬合金の提
供を目的とするものである。
（問題点を解決するための手段）
本発明者らは、被覆超硬合金の靭性を高めるた
めには超硬合金と外層との間に結合相を富化した
中間層を介在させることが効果的であるというこ
とを確認し、次いで、その中間層がどのような構
成になつているときが被覆超硬合金の靭性及びそ
の他の諸特性を最適にできるかについて鋭意研究
した結果、本発明を完成するに至つたものであ
る。
すなわち、本発明の高靭性被覆超硬合金は、炭
化タングステン相と、周期律表4a，5a，6a族金
属の炭化物、窒化物及びこれらの相互固溶体の中
の少なくとも１種でなる立方晶系化合物相と、
Fe、Ni、Coの中の少なくとも１種でなる結合相
とからなる超硬合金の表面に、この超硬合金より
も結合相の富化してなる中間層と、この中間層の
表面に単層もしくは多重層の外層を形成してなる
被覆超硬合金において、下記(a)、(b)及び(c)、を具
備していることを特徴とするものである。
(a) 前記中間層は、前記炭化タングステン相と前
記立方晶系化合物相と前記結合相とからなる
5μｍ以上〜40μｍ以下の層厚を有しているこ
と。
(b) 該中間層中の結合相の量は、前記外層に接す
る中間層面で最大となり、前記超硬合金に接す
る中間層面で最小となるように連続的に減少
し、かつ最大の結合相量が前記超硬合金の結合
相量の120％以上〜500％以下であり、最小の結
合相量が前記超硬合金の結合相量と同等である
こと。
(c) 前記外層は、前記中間層に隣接する外層が窒
化チタン、炭窒化チタン、窒酸化チタン又は炭
窒酸化チタンであること。
この本発明の高靭性被覆超硬合金における超硬
合金は、炭化タングステン相としてのWCと立方
晶系化合物相としての、例えば、（Ti、Ｗ）Ｃ、
（Ti、Ta、Ｗ）Ｃ、（Ti、Ta、Nb、Ｗ）Ｃ、
（Ti、Ｗ）（Ｃ、Ｎ）、（（Ti、Ta、Ｗ）（Ｃ、Ｎ）
などの少なくとも１種の結合相としてのFe、Ni、
Coの少なくとも１種からなるものである。
中間層は、超硬合金に含有しているのと同じ炭
化タングステン相と立方晶系化合物相と結合相と
からなるので超硬合金との密着性を高めており、
中間層中に存在する立方晶系化合物相は、外層が
一部摩耗して中間層を露出させた場合でも耐酸化
性にすぐれるのと、被削材などの相手材への炭素
の拡散流出を生じ難くして、耐摩耗性の急速な低
下を防止させているものである。この中間層中の
結合相量は、外層に接する中間層の面が最大の結
合相量で、この最大の結合相量が超硬合金中の結
合相量の120％未満になると耐欠損性に対する効
果が低く、500％を超えて多くなると耐塑性変形
性に対する効果が低いために、中間層中の最大の
結合相量を超硬合金中の結合相量の120％以上〜
500％以下と定めたものである。また、中間層の
厚みは、5μｍ未満では外層に生ずるき裂の進展
を抑止できなくて耐欠損性が低くなり、40μｍを
超えて厚くなると耐塑性変形が低下することから
5μｍ以上〜40μｍ以下と定めたものである。
外層は、中間層に隣接する外層が窒化チタン、
炭窒化チタン、窒酸化チタン又は炭窒酸化チタン
の中の１種からなるもので、具体的には、窒化チ
タン、炭窒化チタン、窒酸化チタン又は炭窒酸化
チタンの中の１種からなる単層もしくは窒化チタ
ン、炭窒化チタン、達酸化チタン又は炭窒酸化チ
タンの中の１種からなる外層とこの外層の表面に
周期律表4a，5a，6a族金属の炭化物、窒化物、
酸化物、ホウ化物、硫化物又はこれらの相互固溶
体並びに酸化アルミニウム、窒化アルミニウム、
散窒化アルミニウム、窒化ケイ素、炭化ケイ素、
立方晶窒化ホウ素又はダイヤモンドの中の１種以
上の外層とからなる多重層にすることもできる。
このように、中間層に隣接する外層を窒化チタ
ン、炭窒化チタン、窒酸化チタン又は炭窒酸化チ
タンの中の１種にすると、中間層中の結合相が外
層中へ拡散侵入するのを抑制できるものである。
このために、中間層内に係合相の流出による孔が
生じなく緻密で靭性の高い中間層になつているも
のである。
以上、中間層と外層を形成してなる本発明の高
靭性被覆超硬合金における層の構成は、例えば、
第１図又は第２図に示すような断面層の構成から
なり、この断面層における結合相の相対濃度分布
の代表例としては第３図の実線もしくは破線で示
すような状態でなるものである。
本発明の高靭性被覆超硬合金の製造方法は、炭
化タングステン相と、周期律表4a，5a，6a族金
属の炭化物、窒化物及びこれらの相互固溶体の中
の少なくとも１種でなる立方晶系化合物相と、
Fe、Ni、Coの中の少なくとも１種でなる結合相
とからなる超硬合金を真空又はガス雰囲気中で処
理して、前記超硬合金の表面に該超硬合金よりも
結合相の富化してなる中間層と、該中間層の表面
にCVD法又はPVD法によつて単層又は多重層の
外層とを形成させる被覆超硬合金の製造方法にお
いて、前記中間層は前記超硬合金を該超硬合金に
含有する結合相の固液共存温度域に保持しながら
該超硬合金の表面を脱炭させることによつて生成
させることを特徴とするものである。
本発明の高靭性被覆超硬合金の製造方法におけ
る超硬合金は、市販の超硬合金を用いることもで
きるが、超硬合金の表面に中間層を生成するに
は、超硬合金中の含有炭素量が大きく影響するこ
とから含有炭素量を調整した超硬合金を用いるの
が好ましい。
超硬合金の表面に中間層を生成する場合は、超
硬合金の表面を必要に応じて研摩加工又は洗浄
後、反応炉内にセツトし、次いで反応炉内を真空
に保持して、結合相の固液共存温度域とする。こ
の結合相の固液共存温度域は超硬合金の組成によ
つて異なるが、特に1290℃〜1360℃が好ましく、
この結合相の固液共存温度域に保持しながら炉内
を、例えばH2とCO2の混合ガス、CO2ガス、CO
とCO2の混合ガス、H2とCO2とCOの混合ガス又
はH2とH2Oの混合ガスなどの脱炭性のガス雰囲
気にするか、又は高真空に保持すると、超硬合金
の表面部は脱炭されて焼結後には、脱炭された表
面部が中間層となる。このとき、超硬合金を脱炭
性雰囲気中で脱炭する時間は、超硬合金中の含有
炭素量、処理温度及び脱炭性雰囲気により異なる
が、20秒以上〜３分以下に保持するのが好まし
い。脱炭時間が長くなると脱炭量が多くなつて超
硬合金の表面にη相（W3Co3C）のような異相が
生じて好ましくない。その他、超硬合金の表面を
脱炭する方法としては、脱炭作用する粉末、例え
ば酸化アルミニウム粉末の中に超硬合金を埋めて
加熱することも可能であるが、中間層の均一性及
び作業性から高真空又はガス雰囲気性が好ましい
ものである。
中間層の表面に外層を形成する場合は、従来の
CVD法、プラズマCVD法又はイオンプレーテイ
ング、スパツタリングなどのPVD法によつて行
なうことができる。
（作用）
本発明の高靭性被覆超硬合金は、超硬合金と外
層との間に介在させる中間層が脱炭性雰囲気によ
つて生成される靭性の高い層からなり、その中間
層には、遊離カーボンが生じてなく、結合相
のみの層が生じてなく、立方晶系化合物相を含
む３相構造からなつているために、耐欠損性、耐
塑性変形性、耐摩耗性及び被覆層の耐剥離性が著
しくすぐれているものである。
また、その製造方法は、低温で非常に短時間の
処理によつて中間層を生成させることができるの
で中間層中の合金組織の変動が殆んど生じない安
定性のある方法であり、しかも簡易に行なうこと
ができる方法である。
（実施例）
実施例 １
市販の平均粒径0.7μｍ〜3.0μｍの各種出発原料
粉末を用いて、83％WC−４％ TiC−１％
TiN−６％ TaC−６％Co（重量％）組成に配合
し、これを常法の製法によつて成形した後1400
℃、50分保持にて真空焼結した。こうして得た超
硬合金をJIS規格のTNP332形状に研摩加工した
後、反応炉に設置してH2とCO2の混合ガス雰囲
気中、1330℃で３分間保持にて処理し中間層を生
成させ、次いで常法のCVD法によつて中間層の
表面に4μｍ厚さのTi（Ｃ、Ｎ）層とTi（Ｃ、Ｎ）
層の表面に2μｍ厚さのAl2O3層からなる外層を形
成させて本発明品を得た。
比較として、上述の本発明品の工程の内、中間
層の生成工程として、超硬合金の表面にCoを25μ
ｍの層厚でメツキし、水素ガス雰囲気中、温度
1430℃に30分間保持した後、本発明品と同様にし
て外層を形成させることによつて比較品１を得
た。上述の本発明品の工程の内、中間層の生成工
程として超硬合金の表面にグラフアイトを塗布
し、1490℃、30分間保持した後、本発明品と同様
にして外層を形成させることによつて比較品２を
得た。上述の本発明品で中間層の生成工程まで同
じで、外層が中間層の表面に4μｍ厚さのTiC層と
TiC層の表面に2μｍ厚さのAl2O3層からなる比較
品３を得た。上述の本発明品の工程の内、中間層
の生成工程がH2とCO2の混合ガス雰囲気中、
1350℃で１分間保持にて処理した以外は本発明品
と同様に行なつて比較品４を得た。上述の本発明
品の工程の内、研摩加工及び中間層の生成工程を
省略した超硬合金の表面に直接外層を形成させて
比較品５を得た。
こうして得た本発明品と比較品１〜５の中間層
をＸ線マイクロアナライザーにて調べ、その結果
を第１表に示した。
(Industrial Application Field) The present invention relates to a high-toughness coated cemented carbide used as tool parts such as cutting tools and wear-resistant tools, and a method for manufacturing the same. (Prior art) Coated cemented carbide has greatly improved wear resistance due to the hard outer layer formed on the surface of the cemented carbide.
Because the outer layer is weaker than the cemented carbide, cracks occur in the outer layer itself at a stress much lower than the fracture stress of the cemented carbide, and the cracks generated in the outer layer cause damage to the interior of the cemented carbide. There is a problem in that it easily progresses to the point where it damages the coated cemented carbide. Furthermore, among the chemical vapor deposition (CVD) and physical vapor deposition (PVD) methods that are generally used to form the outer layer, the CVD method in particular is difficult to use because it is processed at a high temperature of 900°C to 1100°C. During the cooling process, cracks are likely to occur in the outer layer due to the difference in thermal expansion coefficient between the cemented carbide and the outer layer, and when stress is applied to this crack, the stress is greater than the fracture stress of the cemented carbide. Even if the stress concentration is much lower, there is a problem that cracks can easily propagate inside the cemented carbide due to stress concentration, causing damage to the coated cemented carbide. In order to solve these problems, various proposals have been made for coated cemented carbide in which an intermediate layer is interposed between the cemented carbide and the outer layer. Representative examples of these intermediate layers include Japanese Patent Application Laid-open No. 54-87719 and Japanese Institute of Metals 45, (1981), 95 (Suzuki et al.), which disclose similar structures; JP-A No. 53-131909 discloses the structure. (Problems to be Solved by the Invention) The coated cemented carbide disclosed in JP-A No. 54-87719 etc. consists of a cemented carbide consisting of three layers of a WC phase, a cubic compound, and a Co phase, and an outer layer. An intermediate layer consisting of two phases, a WC phase and a Co phase, is interposed, and at the same time, the Co phase in the intermediate layer is more enriched than the Co phase in the cemented carbide. However, when such an intermediate layer is provided, although fracture resistance is improved, as wear progresses or the outer layer peels off and even a part of the cemented carbide or the intermediate layer is exposed, the intermediate layer Because there is no cubic crystal compound in the coated cemented carbide, the oxidation resistance is low, and the diffusion and outflow of carbon into the chips of the work material becomes intense, causing rapid wear and tear. There is a problem of shortening the lifespan of The coated cemented carbide disclosed in JP-A No. 53-131909 has a hardness gradient between the cemented carbide and the outer layer that is rich in toughness and in which the hardness continuously increases toward the cemented carbide side. It is formed by interposing an intermediate layer with When we check the specific structural structure of the intermediate layer described here, we find that the same publication states that the intermediate layer is made by plating the surface of cemented carbide with a binder phase. Produced by a method of post-heating, a method of exuding the binder phase in the cemented carbide onto its surface, or a method of heating the cemented carbide to a temperature higher than that at which a liquid phase occurs and infiltrating carbon into its surface. has been done. When this intermediate layer was further confirmed by implementing the same publication, it was found that the intermediate layer created by or is due to the movement of the newly added binder phase in the metal or cemented carbide, and the presence of a large amount of the binder phase in the metal or cemented carbide. Due to this, it has high toughness and also has a continuous hardness gradient. However, the intermediate layer formed by and has a problem in that wear resistance and plastic deformation resistance are reduced because a layer containing only the metal of the binder phase is formed on the surface of the intermediate layer on the outer layer side. In addition, since the intermediate layer by and is produced by heating in a carburizing atmosphere,
There are problems in that it is difficult to adjust and that the presence of free carbon in the intermediate layer reduces the peeling resistance from the outer layer. The present invention solves the above-mentioned problems, and specifically, there is no free carbon between the cemented carbide and the outer layer, and the three phases of the tungsten carbide phase, the cubic compound phase, and the binder phase are formed. To provide a coated cemented carbide having excellent toughness, wear resistance, plastic deformation resistance, and peeling resistance by interposing an intermediate layer having a phase structure and having a binder phase richer than that of the cemented carbide. The purpose is to (Means for Solving the Problems) The present inventors have found that it is effective to interpose an intermediate layer enriched with a binder phase between the cemented carbide and the outer layer in order to increase the toughness of the coated cemented carbide. As a result of intensive research into what kind of structure the intermediate layer should have in order to optimize the toughness and other properties of the coated cemented carbide, we have developed the present invention. It has come to completion. That is, the high-toughness coated cemented carbide of the present invention comprises a tungsten carbide phase and a cubic compound consisting of at least one of carbides, nitrides, and mutual solid solutions of metals of groups 4a, 5a, and 6a of the periodic table. phase and
On the surface of a cemented carbide consisting of a binder phase made of at least one of Fe, Ni, and Co, there is an intermediate layer with a binder phase richer than that of the cemented carbide, and a single layer on the surface of this intermediate layer. Alternatively, a coated cemented carbide formed by forming a multilayer outer layer is characterized by comprising the following (a), (b), and (c). (a) The intermediate layer is composed of the tungsten carbide phase, the cubic compound phase, and the binder phase.
It must have a layer thickness of 5 μm or more and 40 μm or less. (b) The amount of the binder phase in the intermediate layer is maximum on the surface of the intermediate layer in contact with the outer layer, and decreases continuously so as to be minimum on the surface of the intermediate layer in contact with the cemented carbide, and the amount of binder phase is the maximum. is from 120% to 500% of the binder phase amount of the cemented carbide, and the minimum binder phase amount is equivalent to the binder phase amount of the cemented carbide. (c) The outer layer adjacent to the intermediate layer is made of titanium nitride, titanium carbonitride, titanium nitride oxide, or titanium carbonitoxide. The cemented carbide in the high-toughness coated cemented carbide of the present invention includes WC as a tungsten carbide phase and (Ti, W)C as a cubic compound phase, for example.
(Ti, Ta, W)C, (Ti, Ta, Nb, W)C,
(Ti, W) (C, N), ((Ti, Ta, W) (C, N)
Fe, Ni as at least one binder phase such as
It consists of at least one type of Co. The intermediate layer is composed of the same tungsten carbide phase, cubic compound phase, and binder phase that are contained in the cemented carbide, so it improves its adhesion to the cemented carbide.
The cubic compound phase that exists in the intermediate layer has excellent oxidation resistance even when the outer layer is partially worn away and the intermediate layer is exposed, and it also prevents carbon from diffusing and flowing into the other material such as the workpiece. This prevents a rapid decline in wear resistance. The amount of binder phase in this intermediate layer is the maximum amount of binder phase on the surface of the intermediate layer in contact with the outer layer, and if this maximum amount of binder phase is less than 120% of the amount of binder phase in the cemented carbide, the fracture resistance will be affected. The maximum amount of binder phase in the intermediate layer should be set to 120% or more of the amount of binder phase in the cemented carbide because the effect on plastic deformation resistance is low when the amount exceeds 500%.
It is set as 500% or less. In addition, if the thickness of the intermediate layer is less than 5 μm, it will not be able to suppress the propagation of cracks that occur in the outer layer, resulting in low fracture resistance, and if it becomes thicker than 40 μm, the plastic deformation resistance will decrease.
It is defined as 5 μm or more and 40 μm or less. The outer layer adjacent to the middle layer is made of titanium nitride,
It is made of one of titanium carbonitride, titanium nitride, or titanium carbonitoxide. Specifically, it is made of one of titanium nitride, titanium carbonitride, titanium nitride, or titanium carbonitoxide. A layer or an outer layer made of one of titanium nitride, titanium carbonitride, titanium oxide, or titanium carbonitride, and a carbide or nitride of a metal from group 4a, 5a, or 6a of the periodic table on the surface of this outer layer.
Oxides, borides, sulfides or mutual solid solutions thereof, as well as aluminum oxide, aluminum nitride,
Dispersed aluminum nitride, silicon nitride, silicon carbide,
It can also be multilayered with one or more outer layers of cubic boron nitride or diamond.
In this way, when the outer layer adjacent to the intermediate layer is made of one type of titanium nitride, titanium carbonitride, titanium nitride, or titanium carbonitride, the binder phase in the intermediate layer is suppressed from diffusing into the outer layer. It is possible.
For this reason, no pores are formed in the intermediate layer due to outflow of the engaging phase, resulting in a dense and highly tough intermediate layer. As described above, the structure of the layer in the high toughness coated cemented carbide of the present invention formed by forming the intermediate layer and the outer layer is, for example,
It consists of a cross-sectional layer configuration as shown in FIG. 1 or FIG. 2, and a typical example of the relative concentration distribution of the binder phase in this cross-sectional layer is as shown by the solid line or broken line in FIG. 3. . The method for producing a high-toughness coated cemented carbide of the present invention comprises a cubic crystal system consisting of a tungsten carbide phase and at least one of carbides, nitrides, and mutual solid solutions of metals of groups 4a, 5a, and 6a of the periodic table. a compound phase;
A cemented carbide comprising a binder phase made of at least one of Fe, Ni, and Co is treated in a vacuum or gas atmosphere to make the surface of the cemented carbide enriched in the binder phase compared to the cemented carbide. In the method for manufacturing a coated cemented carbide, the intermediate layer comprises a single layer or a multilayer outer layer formed on the surface of the intermediate layer by a CVD method or a PVD method. It is characterized in that it is produced by decarburizing the surface of the cemented carbide while maintaining the solid-liquid coexistence temperature range of the binder phase contained in the cemented carbide. A commercially available cemented carbide may be used as the cemented carbide in the method for producing a high-toughness coated cemented carbide of the present invention, but in order to form an intermediate layer on the surface of the cemented carbide, it is necessary to Since the amount of carbon has a large effect, it is preferable to use a cemented carbide whose carbon content is adjusted. When producing an intermediate layer on the surface of a cemented carbide, the surface of the cemented carbide is polished or cleaned as necessary, and then set in a reaction furnace.Then, the interior of the reactor is kept in vacuum, and the binder phase is removed. solid-liquid coexistence temperature range. The solid-liquid coexistence temperature range of this binder phase varies depending on the composition of the cemented carbide, but is particularly preferably 1290°C to 1360°C.
While maintaining the solid-liquid coexistence temperature range of this bonded phase, the inside of the furnace is filled with, for example, a mixed gas of H 2 and CO 2 , CO 2 gas, CO
When placed in a decarburizing gas atmosphere such as a mixed gas of H2 and CO2, a mixed gas of H2 and CO2 and CO, or a mixed gas of H2 and H2O , or kept in a high vacuum, the cemented carbide The surface portion is decarburized and after sintering, the decarburized surface portion becomes an intermediate layer. At this time, the time for decarburizing the cemented carbide in a decarburizing atmosphere varies depending on the amount of carbon contained in the cemented carbide, the treatment temperature, and the decarburizing atmosphere, but it should be kept between 20 seconds and 3 minutes. is preferred. If the decarburization time becomes longer, the amount of decarburization increases and a foreign phase such as η phase (W 3 Co 3 C) occurs on the surface of the cemented carbide, which is not preferable. Another way to decarburize the surface of cemented carbide is to bury the cemented carbide in decarburizing powder, such as aluminum oxide powder, and heat it, but the uniformity of the intermediate layer and the workability High vacuum or gas atmosphere is preferred from the viewpoint of properties. When forming an outer layer on the surface of the intermediate layer, use the conventional
This can be carried out by a CVD method, a plasma CVD method, or a PVD method such as ion plating or sputtering. (Function) In the high-toughness coated cemented carbide of the present invention, the intermediate layer interposed between the cemented carbide and the outer layer is a high-toughness layer generated by a decarburizing atmosphere. , there is no free carbon, no layer of only binder phase is formed, and it has a three-phase structure including a cubic compound phase, so it has excellent chipping resistance, plastic deformation resistance, wear resistance, and coating layer. It has extremely good peeling resistance. In addition, the manufacturing method is a stable method in which the intermediate layer can be generated in a very short time at low temperatures, and there is almost no change in the alloy structure in the intermediate layer. This is an easy method to perform. (Example) Example 1 Using various starting material powders with an average particle size of 0.7 μm to 3.0 μm, 83% WC-4% TiC-1%
After blending TiN-6% TaC-6%Co (wt%) composition and molding it by a conventional manufacturing method,
Vacuum sintering was performed at ℃ for 50 minutes. After polishing the thus obtained cemented carbide into the JIS standard TNP332 shape, it was placed in a reaction furnace and treated at 1330°C for 3 minutes in a mixed gas atmosphere of H 2 and CO 2 to form an intermediate layer. Then, a 4 μm thick Ti(C,N) layer and a Ti(C,N) layer are deposited on the surface of the intermediate layer by a conventional CVD method.
A product of the present invention was obtained by forming an outer layer consisting of three Al 2 O layers with a thickness of 2 μm on the surface of the layer. For comparison, 25μ of Co was applied to the surface of the cemented carbide as an intermediate layer generation step in the process of the product of the present invention described above.
Plated with a layer thickness of m, in a hydrogen gas atmosphere, at a temperature of
After holding at 1430° C. for 30 minutes, an outer layer was formed in the same manner as the product of the present invention to obtain Comparative Product 1. In the process of producing the product of the present invention described above, graphite was applied to the surface of the cemented carbide as the intermediate layer generation step, and after holding at 1490°C for 30 minutes, the outer layer was formed in the same manner as the product of the present invention. Comparative product 2 was thus obtained. The production process of the intermediate layer is the same as that of the above-mentioned product of the present invention, and the outer layer is a 4 μm thick TiC layer on the surface of the intermediate layer.
Comparative product 3 was obtained, which consisted of three Al 2 O layers with a thickness of 2 μm on the surface of the TiC layer. Among the steps of the product of the present invention described above, the intermediate layer generation step is performed in a mixed gas atmosphere of H 2 and CO 2 ,
Comparative product 4 was obtained in the same manner as the product of the present invention, except that the product was held at 1350° C. for 1 minute. Comparative product 5 was obtained by forming an outer layer directly on the surface of the cemented carbide by omitting the polishing and intermediate layer forming steps of the above-mentioned steps for the product of the present invention. The intermediate layers of the thus obtained products of the present invention and comparative products 1 to 5 were examined using an X-ray microanalyzer, and the results are shown in Table 1.
【表】
以上の本発明品と比較品１〜５を用いて、下記
に示す条件で外周旋削による切削試験を行ない、
その結果を第２表に示した。
(A) 耐欠損性試験
被削材 S48C（HB250）等間隔４本スロツト入
切削速度 100ｍ／min
切込み量 1.5mm
送り速度 0.30mm／rev
切削油 なし（乾式切削）
(B) 耐塑性変形性試験
被削材 SNCM439（HB280）
切削速度 150ｍ／min
切込み量 1.5mm
送り速度 0.4mm／rev
切削時間 3min
切削油 なし（乾式切削）[Table] Using the above-mentioned products of the present invention and comparative products 1 to 5, a cutting test was conducted by peripheral turning under the conditions shown below.
The results are shown in Table 2. (A) Fracture resistance test workpiece material S48C (HB250) with 4 equally spaced slots Cutting speed 100m/min Depth of cut 1.5mm Feed rate 0.30mm/rev Cutting oil None (dry cutting) (B) Plastic deformation resistance test Work material SNCM439 (HB280) Cutting speed 150m/min Depth of cut 1.5mm Feed rate 0.4mm/rev Cutting time 3min Cutting oil None (dry cutting)
【表】【table】
【表】
実施例 ２
実施例１で作製した本発明品と比較品１と比較
品５を用いて、下記に示す切削条件により耐摩耗
試験を行ない、その結果を第３表に示した。
(C) 耐摩耗試験
被削材 S48C（HB255）
切削速度 180ｍ／min
切込み量 1.5mm
送り速度 0.30mm／rev
切削油 なし（乾式切削）[Table] Example 2 Using the product of the present invention prepared in Example 1, Comparative Product 1, and Comparative Product 5, a wear resistance test was conducted under the cutting conditions shown below, and the results are shown in Table 3. (C) Wear resistance test work material S48C (HB255) Cutting speed 180m/min Depth of cut 1.5mm Feed rate 0.30mm/rev Cutting oil None (dry cutting)
【表】
（発明の効果）
以上の結果、本発明の高靭性被覆超硬合金は、
外層自体の有する耐摩耗性及び耐食性は勿論のこ
と、中間層の存在により耐塑性変形性の低下を生
ずることなく、耐欠損性及び耐剥離性を著しく高
めることができたので、その製造方法も簡易な方
法であることから工業化が容易である。このこと
から、従来の被覆超硬合金の用途範囲である旋削
用切削工具やメカニカルシール、ノズル、バル
ブ、ゲージなどの耐摩耗工具の他に、更に耐衝撃
性を必要とするような切削工具、例えばフライス
用切削工具、ドリル、リーマ、エンドミルなどの
回転用切削工具にも利用できる産業上有用な被覆
超硬合金及びその製造方法である。[Table] (Effects of the invention) As a result of the above, the high toughness coated cemented carbide of the present invention has the following properties:
Not only the wear resistance and corrosion resistance of the outer layer itself, but also the presence of the intermediate layer has significantly improved chipping resistance and peeling resistance without reducing plastic deformation resistance. Since it is a simple method, it is easy to industrialize. For this reason, in addition to wear-resistant tools such as turning cutting tools, mechanical seals, nozzles, valves, and gauges, which are the range of applications for conventional coated cemented carbide, cutting tools that require even more impact resistance, The present invention provides an industrially useful coated cemented carbide that can be used for rotary cutting tools such as milling cutting tools, drills, reamers, and end mills, and a method for producing the same.
第１図は、超硬合金の一面に中間層と外層を形
成してなる本発明品の断面層構成図。第２図は、
超硬合金の全面に中間層と外層を形成してなる本
発明品の断面層構成図。第３図は、本発明品の表
面から内部の断面層における結合相の相対濃度分
布を示すブラフ。
図中、１：外層、２：中間層、３：超硬合金。
FIG. 1 is a cross-sectional layer configuration diagram of a product of the present invention in which an intermediate layer and an outer layer are formed on one side of cemented carbide. Figure 2 shows
FIG. 2 is a cross-sectional layer configuration diagram of a product of the present invention in which an intermediate layer and an outer layer are formed on the entire surface of a cemented carbide. FIG. 3 is a bluff showing the relative concentration distribution of the binder phase in the cross-sectional layer from the surface to the inside of the product of the present invention. In the figure, 1: outer layer, 2: intermediate layer, 3: cemented carbide.
Claims (1)
6a族金属の炭化物、窒化物及びこれらの相互固
溶体の中の少なくとも１種でなる立方晶系化合物
相と、Fe、Ni、Coの中の少なくとも１種でなる
結合相とからなる超硬合金の表面に、該超硬合金
よりも結合相の富化してなる中間層と、該中間層
の表面に単層もしくは多重層の外層を形成してな
る被覆超硬合金において、下記(a)、(b)及び(c)を具
備していることを特徴とする高靭性被覆超硬合
金。 (a) 前記中間層は、前記炭化タングステン相と前
記立方晶系化合物相と前記結合相とからなる
5μｍ以上〜40μｍ以下の層厚を有しているこ
と。 (b) 該中間層中の結合相の量は、前記外層に接す
る中間層面で最大となり、前記超硬合金に接す
る中間層面で最小となるように連続的に減少
し、かつ最大の結合相量が前記超硬合金の結合
相量の120％以上〜500％以下であり、最小の結
合相量が前記超硬合金の結合相量と同等である
こと。 (c) 前記外層は、前記中間層に隣接する外層が窒
化チタン、炭窒化チタン、窒酸化チタン又は炭
窒酸化チタンであること。 ２ 炭化タングステンと、周期律表4a，5a，6a
族金属の炭化物、窒化物及びこれらの相互固溶体
の中の少なくとも１種でなる立方晶系化合物相
と、Fe、Ni、Coの中の少なくとも１種でなる結
合相とからなる超硬合金を真空又はガス雰囲気中
で処理して、前記超硬合金の表面に該超硬合金よ
りも結合相の富化してなる中間層と、該中間層の
表面に化学蒸着法又は物理蒸着法によつて単層も
しくは多重層の外層とを形成させる被覆超硬合金
の製造方法において、前記中間層は、超硬合金を
該超硬合金に含有する結合相の固液共存温度域に
保持しながら該超硬合金の表面を脱炭させること
によつて生成させることを特徴とする高靭性被覆
超硬合金の製造方法。 ３ 上記結合相の固液共存温度域は、1290℃以上
〜1360℃以下であることを特徴とする特許請求の
範囲第２項記載の高靭性被覆超硬合金の製造方
法。[Claims] 1. Tungsten carbide phase and periodic table 4a, 5a,
A cemented carbide comprising a cubic compound phase consisting of at least one of carbides, nitrides, and mutual solid solutions of group 6a metals, and a binder phase consisting of at least one of Fe, Ni, and Co. A coated cemented carbide comprising an intermediate layer having a binder phase enriched more than the cemented carbide, and a single layer or multilayer outer layer formed on the surface of the intermediate layer, the following (a), ( A high toughness coated cemented carbide characterized by comprising b) and (c). (a) The intermediate layer is composed of the tungsten carbide phase, the cubic compound phase, and the binder phase.
It must have a layer thickness of 5 μm or more and 40 μm or less. (b) The amount of the binder phase in the intermediate layer is maximum on the surface of the intermediate layer in contact with the outer layer, and decreases continuously so as to be minimum on the surface of the intermediate layer in contact with the cemented carbide, and the amount of binder phase is the maximum. is from 120% to 500% of the binder phase amount of the cemented carbide, and the minimum binder phase amount is equivalent to the binder phase amount of the cemented carbide. (c) The outer layer adjacent to the intermediate layer is made of titanium nitride, titanium carbonitride, titanium nitride oxide, or titanium carbonitoxide. 2 Tungsten carbide and the periodic table 4a, 5a, 6a
A cemented carbide consisting of a cubic compound phase consisting of at least one of group metal carbides, nitrides, and their mutual solid solutions, and a binder phase consisting of at least one of Fe, Ni, and Co is heated in a vacuum. Alternatively, the cemented carbide may be treated in a gas atmosphere to form an intermediate layer having a binder phase richer than that of the cemented carbide on the surface of the cemented carbide, and the surface of the intermediate layer may be coated by chemical vapor deposition or physical vapor deposition. In the method for producing a coated cemented carbide in which a layer or an outer layer of multiple layers is formed, the intermediate layer maintains the cemented carbide in the solid-liquid coexistence temperature range of the binder phase contained in the cemented carbide. A method for producing a high-toughness coated cemented carbide, which is produced by decarburizing the surface of the alloy. 3. The method for producing a high-toughness coated cemented carbide according to claim 2, wherein the solid-liquid coexistence temperature range of the binder phase is from 1290°C to 1360°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24543385A JPS62105628A (en) | 1985-11-01 | 1985-11-01 | High-tenacity coated cemented carbide and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24543385A JPS62105628A (en) | 1985-11-01 | 1985-11-01 | High-tenacity coated cemented carbide and manufacture thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62105628A JPS62105628A (en) | 1987-05-16 |
| JPH0363949B2 true JPH0363949B2 (en) | 1991-10-03 |
Family
ID=17133584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24543385A Granted JPS62105628A (en) | 1985-11-01 | 1985-11-01 | High-tenacity coated cemented carbide and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62105628A (en) |
Cited By (1)
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|---|---|---|---|---|
| WO2022059679A1 (en) | 2020-09-18 | 2022-03-24 | ヤマハ発動機株式会社 | Straddled vehicle |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2819648B2 (en) * | 1989-08-24 | 1998-10-30 | 住友電気工業株式会社 | Coated cemented carbide for wear-resistant tools |
-
1985
- 1985-11-01 JP JP24543385A patent/JPS62105628A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022059679A1 (en) | 2020-09-18 | 2022-03-24 | ヤマハ発動機株式会社 | Straddled vehicle |
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| Publication number | Publication date |
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| JPS62105628A (en) | 1987-05-16 |
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