JP3922141B2 - Cutting tool made of surface-coated cemented carbide that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions. - Google Patents
Cutting tool made of surface-coated cemented carbide that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions. Download PDFInfo
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【０００１】
【発明の属する技術分野】
この発明は、硬質被覆層が高強度を有し、かつ高温硬さと耐熱性にもすぐれ、したがって特に各種の鋼や鋳鉄などの高速切削加工を、高い熱的機械的衝撃を伴う高切り込みや高送りなどの重切削条件で行なった場合にも、硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮する表面被覆超硬合金製切削工具（以下、被覆超硬工具という）に関するものである。
【０００２】
【従来の技術】
一般に、被覆超硬工具には、各種の鋼や鋳鉄などの被削材の旋削加工や平削り加工にバイトの先端部に着脱自在に取り付けて用いられるスローアウエイチップ、穴あけ切削加工などに用いられるドリルやミニチュアドリル、さらに面削加工や溝加工、肩加工などに用いられるソリッドタイプのエンドミルなどがあり、また前記スローアウエイチップを着脱自在に取り付けて前記ソリッドタイプのエンドミルと同様に切削加工を行うスローアウエイエンドミル工具などが知られている。
【０００３】
また、被覆超硬工具として、炭化タングステン（以下、ＷＣで示す）基超硬合金または炭窒化チタン（以下、ＴｉＣＮで示す）基サーメットからなる基体（以下、これらを総称して超硬基体と云う）の表面に、個々の層厚が１μm以下のＡｌ酸化物（以下、Ａｌ2Ｏ3で示す）層とＴｉ炭窒化物（以下、ＴｉＣＮで示す）層とを交互積層して、２〜２０μｍの全体平均層厚で蒸着してなる被覆超硬工具が提案され、前記硬質被覆層を構成するＡｌ2Ｏ3−ＴｉＣＮ交互積層が、Ａｌ2Ｏ3層による高温硬さおよび耐熱性と、ＴｉＣＮ層による強度を具備することから、かかる被覆超硬工具を各種の鋼や鋳鉄などの連続切削や断続切削加工に用いた場合にすぐれた切削性能を発揮することも知られている（例えば特許文献１参照）。
【０００４】
さらに、上記の被覆超硬工具が、例えば図１に概略縦断面図で示される通り、中央部にステンレス鋼製の反応ガス吹き出し管が立設され、前記反応ガス吹き出し管には、図２（ａ）に概略斜視図で、同（ｂ）に概略平面図で例示される黒鉛製の超硬基体支持パレットが串刺し積層嵌着され、かつこれらがステンレス鋼製のカバーを介してヒーターで加熱される構造を有する化学蒸着装置を用い、超硬基体を前記超硬基体支持パレットの底面に形成された多数の反応ガス通過穴位置に図示される通りに載置した状態で前記化学蒸着装置に装入し、ヒータで装置内を、例えば８００〜１１００℃の範囲内の所定の温度に加熱した後、Ａｌ2Ｏ3層形成には、反応ガスとして、容量％で（以下、反応ガスの％は容量％を示す）、
ＡｌＣｌ3：２〜７％、
ＣＯ2：２〜１０％、
ＨＣｌ：３〜７％、
Ｈ2：残り、
からなる組成を有する反応ガスを用い、また、ＴｉＣＮ層形成には、
ＴｉＣｌ4：１〜３％、
ＣＨ4：５〜２０％、
Ｎ2：４０〜６０％、
Ｈ2：残り、
からなる組成を有する反応ガスを用い、これらの反応ガスを予め真空排気された装置内に前記反応ガス吹き出し管を通して、装置内の反応ガス圧力を７〜４０ｋＰａの範囲内の所定の圧力に保持しながら、交互に導入することによりＡｌ2Ｏ3−ＴｉＣＮ交互積層からなる硬質被覆層を形成することにより製造されることも知られている（例えば特許文献２参照）。
【０００５】
【特許文献１】
特開昭５２−１０５３９６号公報
【特許文献２】
特開昭５５−１４５１６５号公報
【０００６】
【発明が解決しようとする課題】
近年の切削加工装置の高性能化はめざましく、一方で切削加工に対する省力化および省エネ化、さらに低コスト化の要求は強く、これに伴い、切削加工は高速化の傾向を強め、かつ高切り込みや高送りなどの重切削条件での切削加工を余儀なくされる傾向にあるが、上記の従来被覆超硬工具においては、これを高い熱的機械的衝撃を伴う高切り込みや高送りなどの重切削を高速で行なうのに用いると、特にＡｌ2Ｏ3−ＴｉＣＮ交互積層からなる硬質被覆層のＡｌ2Ｏ3層はすぐれた高温硬さおよび耐熱性を有するものの強度が不十分であるために、高速重切削ではこれが破壊の起点となることから、チッピング（微小割れ）発生の原因となり、また同じくＴｉＣＮ層は高強度を有するものの高温硬さおよび耐熱性の低いものであることから、高速重切削では摩耗進行が急速に促進されるようになり、この結果比較的短時間で使用寿命に至るのが現状である。
【０００７】
【課題を解決するための手段】
そこで、本発明者等は、上述のような観点から、特に高速重切削加工で硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮する被覆超硬工具を開発すべく、研究を行った結果、
（ａ）上記の図１，２に示される化学蒸着装置を用いて、上記の従来被覆超硬工具の硬質被覆層の構成成分であるＡｌ2Ｏ3とＴｉＣＮの複合化合物、すなわちＡｌとＴｉの複合炭窒酸化物（以下、Ａｌ−Ｔｉ炭窒酸化物という）層を形成するに際して、例えば図３に反応ガス組成自動制御システムが概略チャート図で示される通り、反応ガス組成および流量中央制御装置に、前記Ａｌ−Ｔｉ炭窒酸化物層からなる硬質被覆層に、層厚方向にそって、Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点とを所定間隔をおいて交互に繰り返し形成させる目的で、前記Ａｌおよび酸素の最高含有点、並びにＴｉ、炭素、および窒素の最高含有点に対応した反応ガス組成、並びに前記両点間のＡｌと酸素、およびＴｉと炭素と窒素の連続変化に対応した反応ガス組成、さらに前記両点間の間隔を、過去の実績データに基づいてインプットし、この反応ガス組成および流量中央制御装置からの制御信号にしたがって、原料ガスボンベからのＨ2ガス、ＣＯ2ガス、ＣＨ4ガス、Ｎ2ガス、ＣＨ3ＣＮガス、およびＨＣｌガスの流量、さらにＡｌＣｌ3ガスおよびＴｉＣｌ4ガスの流量をそれぞれの原料ガス流量自動制御装置にて制御しながら、化学蒸着装置の反応ガス吹き出し管に導入すると、層厚方向にそって、Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点とが所定間隔をおいて交互に繰り返し存在し、かつ前記Ａｌおよび酸素の最高含有点から前記Ｔｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点から前記Ａｌおよび酸素の最高含有点へＡｌと酸素、およびＴｉと炭素と窒素の含有量が連続的に変化する成分濃度分布構造をもつたＡｌ−Ｔｉ炭窒酸化物層からなる硬質被覆層が形成されるようになること。
【０００８】
（ｂ）上記（ａ）の繰り返し連続変化成分濃度分布構造のＡｌ−Ｔｉ炭窒酸化物層において、
上記Ａｌおよび酸素の最高含有点におけるＡｌとＴｉ、および酸素と炭素と窒素の相互含有割合を示すＡｌ／（Ａｌ＋Ｔｉ）、並びに酸素／（酸素＋炭素＋窒素）、炭素／（酸素＋炭素＋窒素）、および窒素／（酸素＋炭素＋窒素）が、それぞれ原子比で、
Ａｌ／（Ａｌ＋Ｔｉ）：０．８０〜０．９８、
酸素／（酸素＋炭素＋窒素）：０．８０〜０．９８、
炭素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
窒素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
上記Ｔｉ、炭素、および窒素の最高含有点におけるＴｉとＡｌ、および炭素と窒素と酸素の相互含有割合を示すＴｉ／（Ｔｉ＋Ａｌ）、並びに炭素／（炭素＋窒素＋酸素）、窒素／（炭素＋窒素＋酸素）、および酸素／（炭素＋窒素＋酸素）が、それぞれ原子比で、
Ｔｉ／（Ｔｉ＋Ａｌ）：０．８０〜０．９８、
炭素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
窒素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
酸素／（炭素＋窒素＋酸素）：０．０２〜０．２０、
とし、かつ隣り合う上記Ａｌおよび酸素の最高含有点と、上記Ｔｉ、炭素、および窒素の最高含有点の厚さ方向の間隔を０．０１〜０．２μmとすると、
上記Ａｌおよび酸素の最高含有点部分では、Ａｌ2Ｏ3のもつ高温硬さと耐熱性に相当するすぐれた高温硬さと耐熱性を示し、一方上記Ｔｉ、炭素、および窒素の最高含有点部分では、ＴｉＣＮのもつ強度に相当する高強度が確保され、かつこれらＡｌおよび酸素の最高含有点と、上記Ｔｉ、炭素、および窒素の最高含有点の間隔をきわめて小さくしたことから、層全体の特性としてすぐれた高温硬さと耐熱性、および高強度を具備するようになり、さらに前記両点間でＡｌと酸素、およびＴｉと炭素と窒素の含有量が連続的に変化（成分濃度分布構造）することにより、破壊の起点が存在しないことになり、したがって、硬質被覆層がかかる構成のＡｌ−Ｔｉ炭窒酸化物層からなる被覆超硬工具は、特に各種の鋼や鋳鉄などの切削加工を、高速で、かつ高い熱的機械的衝撃を伴う高切り込みや高送りなどの重切削条件で行なった場合にも、硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮するようになること。
以上（ａ）および（ｂ）に示される研究結果を得たのである。
【０００９】
この発明は、上記の研究結果に基づいてなされたものであって、超硬基体の表面に、Ａｌ−Ｔｉ炭窒酸化物層からなる硬質被覆層を２〜２０μｍの全体平均層厚で蒸着してなる被覆超硬工具において、
上記硬質被覆層が、層厚方向にそって、Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点とが所定間隔をおいて交互に繰り返し存在し、かつ前記Ａｌおよび酸素の最高含有点から前記Ｔｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点から前記Ａｌおよび酸素の最高含有点へＡｌと酸素、およびＴｉと炭素と窒素の含有量が連続的に変化する成分濃度分布構造を有し、
さらに、上記Ａｌおよび酸素の最高含有点におけるＡｌとＴｉ、および酸素と炭素と窒素の相互含有割合を示すＡｌ／（Ａｌ＋Ｔｉ）、並びに酸素／（酸素＋炭素＋窒素）、炭素／（酸素＋炭素＋窒素）、および窒素／（酸素＋炭素＋窒素）が、それぞれ原子比で、
Ａｌ／（Ａｌ＋Ｔｉ）：０．８０〜０．９８、
酸素／（酸素＋炭素＋窒素）：０．８０〜０．９８、
炭素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
窒素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
上記Ｔｉ、炭素、および窒素の最高含有点におけるＴｉとＡｌ、および炭素と窒素と酸素の相互含有割合を示すＴｉ／（Ｔｉ＋Ａｌ）、並びに炭素／（炭素＋窒素＋酸素）、窒素／（炭素＋窒素＋酸素）、および酸素／（炭素＋窒素＋酸素）が、それぞれ原子比で、
Ｔｉ／（Ｔｉ＋Ａｌ）：０．８０〜０．９８、
炭素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
窒素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
酸素／（炭素＋窒素＋酸素）：０．０２〜０．２０、
を満足し、かつ隣り合う上記Ａｌおよび酸素の最高含有点と、上記Ｔｉ、炭素、および窒素の最高含有点の間隔が、０．０１〜０．２μmである、
高速重切削条件で硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮する被覆超硬工具に特徴を有するものである。
【００１０】
つぎに、この発明の被覆超硬工具において、これを構成する硬質被覆層の構成を上記の通りに限定した理由を説明する。
（ａ）Ａｌおよび酸素の最高含有点
Ａｌ−Ｔｉ炭窒酸化物層のＴｉ、炭素、および窒素成分には強度を向上させ、同Ａｌおよび酸素成分には高温硬さおよび耐熱性を向上させる作用があり、したがってＡｌおよび酸素の最高含有点ではＡｌおよび酸素の含有割合を相対的に高くして高温硬さおよび耐熱性を向上させることにより、高熱発生を伴う高速切削に適合するものとするが、この場合ＡｌとＴｉ、および酸素と炭素と窒素の相互含有割合を示すＡｌ／（Ａｌ＋Ｔｉ）値、および酸素／（酸素＋炭素＋窒素）値がいずれも原子比で（以下、同じ）０．９８を越えると、Ｔｉ／（Ｔｉ＋Ａｌ）値：０．０２未満、並びに炭素／（酸素＋炭素＋窒素）値および窒素／（酸素＋炭素＋窒素）値がいずれも０．０１未満となってしまい、実質的にＡｌ酸化物で構成されるようになることから、高強度を有するＴｉと炭素と窒素の最高含有点が隣接して存在しても層自体の強度の低下は避けられず、この結果チッピングなどが発生し易くなり、一方同値がそれぞれ０．８０未満になると、Ｔｉ／（Ｔｉ＋Ａｌ）値が０．２０を越え、かつ炭素／（酸素＋炭素＋窒素）値および窒素／（酸素＋炭素＋窒素）値がいずれも０．１０を越えて高くなり、反面相対的にＡｌおよび酸素が少なくなり、この結果高温硬さおよび耐熱性が急激に低下し、摩耗促進の原因となることから、Ａｌ／（Ａｌ＋Ｔｉ）、および酸素／（酸素＋炭素＋窒素）の値をいずれも０．８０〜０．９８、炭素／（酸素＋炭素＋窒素）および窒素／（酸素＋炭素＋窒素）の値をいずれも０．０１〜０．１０と定めた。
【００１１】
（ｂ）Ｔｉ、炭素、および窒素の最高含有点
上記の通りＡｌおよび酸素の最高含有点は相対的にすぐれた高温硬さおよび耐熱性を有するが、反面相対的に強度が不十分であるため、このＡｌおよび酸素の最高含有点の強度不足を補う目的で、高強度を有するＴｉ、炭素、および窒素の最高含有点を厚さ方向に交互に介在させるものである。しかし、ＴｉとＡｌ、および炭素と窒素と酸素の相互含有割合を示すＴｉ／（Ｔｉ＋Ａｌ）値が０．９８を越え、かつ炭素／（酸素＋炭素＋窒素）値および窒素／（酸素＋炭素＋窒素）値が、いずれも０．４９を越えると、Ａｌ／（Ａｌ＋Ｔｉ）値が０．０２未満、並びに酸素／（炭素＋窒素＋酸素）値が０．０２未満となってしまい、実質的にＴｉ炭窒化物で構成されるようになることから、Ｔｉ、炭素、および窒素の最高含有点に所定の高温硬さおよび耐熱性を確保することができず、これが摩耗促進の原因となり、一方Ｔｉ／（Ｔｉ＋Ａｌ）値が０．８０未満、炭素／（炭素＋窒素＋酸素）値および窒素／（炭素＋窒素＋酸素）値がいずれも０．４０未満になると、Ａｌ／（Ａｌ＋Ｔｉ）値が０．２０を越え、かつ酸素／（炭素＋窒素＋酸素）値が０．２０を越えて高くなり、相対的にＴｉ、炭素、および窒素の割合が少なくなって、所望の強度を確保することができず、この結果チッピングが発生し易くなることから、Ｔｉ／（Ｔｉ＋Ａｌ）の値を０．８０〜０．９８、炭素／（炭素＋窒素＋酸素）および窒素／（炭素＋窒素＋酸素）の値をいずれも０．４０〜０．４９、酸素／（炭素＋窒素＋酸素）の値を０．０２〜０．２０と定めた。
【００１２】
（ｃ）Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点間の間隔
その間隔が０．０１μm未満ではそれぞれの点を上記の組成で明確に形成することが困難であり、この結果層に所望のすぐれた高温硬さおよび耐熱性、さらに高強度を確保することができなくなり、またその間隔が０．２μmを越えるとそれぞれの点がもつ欠点、すなわちＡｌおよび酸素の最高含有点であれば強度不足、Ｔｉ、炭素、および窒素の最高含有点であれば高温硬さおよび耐熱性不足が層内に局部的に現れ、これが原因でチッピングが発生し易くなったり、摩耗進行が促進されるようになることから、その間隔を０．０１〜０．２μmと定めた。
【００１３】
（ｄ）硬質被覆層の全体平均層厚
その層厚が２μｍ未満では、所望の耐摩耗性を確保することができず、一方その平均層厚が２０μｍを越えると、チッピングが発生し易くなることから、その平均層厚を２〜２０μｍと定めた。
【００１４】
【発明の実施の形態】
つぎに、この発明の被覆超硬工具を実施例により具体的に説明する。
原料粉末として、いずれも１〜３μｍの平均粒径を有するＷＣ粉末、ＴｉＣ粉末、ＶＣ粉末、ＴａＣ粉末、ＮｂＣ粉末、Ｃｒ3 Ｃ2 粉末、およびＣｏ粉末を用意し、これら原料粉末を、表１に示される配合組成に配合し、ボールミルで７２時間湿式混合し、乾燥した後、１００ＭＰａ の圧力で圧粉体にプレス成形し、この圧粉体を６Ｐａの真空中、温度：１４００℃に１時間保持の条件で焼結し、焼結後、切刃部分にＲ：０．０３のホーニング加工を施してＩＳＯ規格・ＣＮＭＧ１６０６０８のチップ形状をもったＷＣ基超硬合金製の超硬基体Ａ１〜Ａ１０を形成した。
【００１５】
また、原料粉末として、いずれも０．５〜２μｍの平均粒径を有するＴｉＣＮ（重量比でＴｉＣ／ＴｉＮ＝５０／５０）粉末、Ｍｏ2 Ｃ粉末、ＺｒＣ粉末、ＮｂＣ粉末、ＴａＣ粉末、ＷＣ粉末、Ｃｏ粉末、およびＮｉ粉末を用意し、これら原料粉末を、表２に示される配合組成に配合し、ボールミルで２４時間湿式混合し、乾燥した後、１００ＭＰａの圧力で圧粉体にプレス成形し、この圧粉体を２ｋＰａの窒素雰囲気中、温度：１５００℃に１時間保持の条件で焼結し、焼結後、切刃部分にＲ：０．０３のホーニング加工を施してＩＳＯ規格・ＣＮＭＧ１６０６１２のチップ形状をもったＴｉＣＮ系サーメット製の超硬基体Ｂ１〜Ｂ６を形成した。
【００１６】
つぎに、上記の超硬基体Ａ１〜Ａ１０およびＢ１〜Ｂ６のそれぞれを、アセトン中で超音波洗浄し、乾燥した後、図１に示される化学蒸着装置内に、第２図に示される超硬基体支持パレットの位置決め穴に載置した状態で装入し、まず、装置内をヒーターで９００℃に加熱したところで、ＴｉＣｌ4：４．２％、Ｎ2：３０％、Ｈ2：残りからなる組成を有する反応ガスを反応ガス吹き出し管を通して導入して、装置内の反応雰囲気圧力を３０ｋＰａとし、この状態で３０分間保持して下地密着層として０．３μmの平均層厚をもった窒化チタン（ＴｉＮ）層を形成し、ついで、同じく装置内の雰囲気温度をヒーターにて加熱して１０２０℃とした後、図３に示される反応ガス組成自動制御システムの反応ガス組成および流量中央制御装置に、過去の実績データにしたがって、表３、４に示されるＡｌおよび酸素の最高含有点の目標Ａｌ／（Ａｌ＋Ｔｉ）、並びに目標酸素／（酸素＋炭素＋窒素）、目標炭素／（酸素＋炭素＋窒素）、および目標窒素／（酸素＋炭素＋窒素）、さらにＴｉ、炭素、および窒素の最高含有点の目標Ｔｉ／（Ｔｉ＋Ａｌ）、、並びに目標炭素／（炭素＋窒素＋酸素）、目標窒素／（炭素＋窒素＋酸素）、および目標窒素／（炭素＋窒素＋酸素）に対応する反応ガス組成、前記Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点間のＡｌと酸素、およびＴｉと炭素と窒素の含有量の連続変化に対応する反応ガス組成、さらに表５、６に示される前記両点間の目標間隔および硬質被覆層の目標全体層厚をインプットし、この反応ガス組成および流量中央制御装置からの信号にしたがって作動するコントロールバルブ内蔵の原料ガス流量自動制御装置を通して、原料ガスであるＨ2ガス、ＣＨ4ガス、Ｎ2ガス、ＣＨ3ＣＮガス、ＣＯ2ガス、およびＨＣｌガス、さらにＡｌＣｌ3ガスおよびＴｉＣｌ4ガス（この場合、ＡｌＣｌ3ガスは、ＡｌＣｌ3ガス発生器で金属Ａｌと流量制御されたＨＣｌガスを反応させることにより形成され、また、ＴｉＣｌ4ガスは、図示の通り流量制御されたＨ2ガスをキャリアガスとしてＴｉＣｌ4ガス発生器に送り、ここで液体から気化されたＴｉＣｌ4ガスと共に原料ガス流量自動制御装置に送られ、さらにＣＨ3ＣＮガスは、ＣＨ3ＣＮ気化器で液体のＣＨ3ＣＮを加熱してガス化したものが原料ガス流量自動制御装置に送られる）を、それぞれのガス流量を制御しながら、図１の化学蒸着装置の反応ガス吹き出し管から装置内に導入し（装置内の反応雰囲気圧力は常に７ｋＰａに保持される）、もって前記超硬基体の表面に、層厚方向に沿って表５、６に示される目標Ａｌ／（Ａｌ＋Ｔｉ）、並びに目標酸素／（酸素＋炭素＋窒素）、目標炭素／（酸素＋炭素＋窒素）、および目標窒素／（酸素＋炭素＋窒素）のＡｌおよび酸素の最高含有点と、目標Ｔｉ／（Ｔｉ＋Ａｌ）、目標炭素／（炭素＋窒素＋酸素）、目標窒素／（炭素＋窒素＋酸素）、および目標窒素／（炭素＋窒素＋酸素）のＴｉ、炭素、および窒素の最高含有点とが交互に同じく表５、６に示される目標間隔で繰り返し存在し、かつ前記Ａｌおよび酸素の最高含有点から前記Ｔｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点から前記Ａｌおよび酸素の最高含有点へＡｌと酸素、およびＴｉと炭素と窒素の含有量がそれぞれ連続的に変化する成分濃度分布構造を有し、かつ同じく表５、６に示される目標全体層厚の硬質被覆層を蒸着することにより、本発明被覆超硬工具としての本発明表面被覆超硬合金製スローアウエイチップ（以下、本発明被覆超硬チップと云う）１〜１６をそれぞれ製造した。
【００１７】
また、比較の目的で、これら超硬基体Ａ１〜Ａ１０およびＢ１〜Ｂ６を、アセトン中で超音波洗浄し、乾燥した後、同じくそれぞれ図１，２に示される通常の化学蒸着装置に装入し、Ａｌ2Ｏ3層の形成条件を、
反応ガス組成：ＡｌＣｌ3：３％、ＣＯ2：７％、ＨＣｌ：３％、Ｈ2：残り、
反応雰囲気温度：１０００℃、
反応雰囲気圧力：７ｋＰａ、
とし、また、ＴｉＣＮ層の形成条件を、
反応ガス組成：ＴｉＣｌ4：２％、ＣＨ4：１２％、Ｎ2：５５％、Ｈ2：残り、
反応雰囲気温度：１０００℃、
反応雰囲気圧力：１３ｋＰａ、
として、それぞれ表７、８に示される目標層厚のＡｌ2Ｏ3層およびＴｉＣＮ層の交互積層からなる硬質被覆層を、前記超硬基体Ａ１〜Ａ１０およびＢ１〜Ｂ６のそれぞれの表面に、同じく表７、８に示される目標全体層厚で蒸着することにより、従来被覆超硬工具としての従来表面被覆超硬合金製スローアウエイチップ（以下、従来被覆超硬チップと云う）１〜１６をそれぞれ製造した。
【００１８】
つぎに、上記本発明被覆超硬チップ１〜１６および従来被覆超硬チップ１〜１６について、これを工具鋼製バイトの先端部に固定治具にてネジ止めした状態で、
被削材：ＪＩＳ・ＳＣＭ４４０の丸棒、
切削速度：３２０ｍ／ｍｉｎ．、
切り込み：４ｍｍ、
送り：０．２ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での合金鋼の乾式連続高速高切り込み切削加工試験、
被削材：ＪＩＳ・Ｓ３０Ｃの長さ方向等間隔４本縦溝入り丸棒、
切削速度：３００ｍ／ｍｉｎ．、
切り込み：２ｍｍ、
送り：０．５ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での炭素鋼の乾式断続高速高送り切削加工試験、さらに、
被削材：ＪＩＳ・ＦＣ３００の長さ方向等間隔４本縦溝入り丸棒、
切削速度：４００ｍ／ｍｉｎ．、
切り込み：４．５ｍｍ、
送り：０．１５ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での鋳鉄の乾式断続高速高切り込み切削加工試験を行い、いずれの切削加工試験でも切刃の逃げ面摩耗幅を測定した。この測定結果を表５〜８に示した。
【００１９】
【表１】
【表２】
【表３】
【表４】
【表５】
【表６】
【表７】
【表８】
この結果得られた本発明被覆超硬チップ１〜１６および従来被覆超硬チップ１〜１６を構成する硬質被覆層について、厚さ方向に沿ってＡｌ、Ｔｉ、酸素、炭素、および窒素の含有量をオージェ分光分析装置を用いて測定し、この測定結果から各測定点におけるＡｌ／（Ａｌ＋Ｔｉ）およびＴｉ／（Ｔｉ＋Ａｌ）の値、さらに酸素／（酸素＋炭素＋窒素）、炭素／（酸素＋炭素＋窒素）、および窒素／（酸素＋炭素＋窒素）の値を算出したところ、本発明被覆超硬チップ１〜１６の硬質被覆層では、Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点とがそれぞれ目標値と実質的に同じ組成および間隔で交互に繰り返し存在し、かつＡｌおよび酸素の最高含有点からＴｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点からＡｌおよび酸素の最高含有点へＡｌとＴｉ、および酸素と炭素と窒素の含有量が連続的に変化する成分濃度分布構造を有することが確認され、硬質被覆層の平均層厚も目標全体層厚と実質的に同じ値を示した。また、従来被覆超硬チップ１〜１６の硬質被覆層においても目標層厚と実質的に同じ平均層厚のＡｌ2Ｏ3層とＴｉＣＮ層とが交互に、かつ目標全体層厚と実質的に同じ平均層厚で形成されていることが確認された。
【００２８】
【発明の効果】
表５〜８に示される結果から、硬質被覆層が層厚方向に、相対的にすぐれた高温硬さと耐熱性を有するＡｌおよび酸素の最高含有点と，相対的に高強度を有するＴｉ、炭素、および窒素の最高含有点とが交互に所定間隔をおいて繰り返し存在し、かつ前記Ａｌおよび酸素の最高含有点から前記Ｔｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点から前記Ａｌおよび酸素の最高含有点へＡｌと酸素、およびＴｉと炭素と窒素の含有量が連続的に変化する成分濃度分布構造を有する本発明被覆超硬チップ１〜１６は、いずれも各種の鋼や鋳鉄などの切削加工を、高速で、かつ高い熱的機械的衝撃を伴う高切り込みや高送りなどの重切削条件で行なった場合にも、硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮するのに対して、硬質被覆層がＡｌ2Ｏ3層とＴｉＣＮ層の交互積層からなる従来被覆超硬チップ１〜１６においては、前記硬質被覆層のＡｌ2Ｏ3層が特に高速重切削条件ではチッピング発生の起点となり、また前記ＴｉＣＮ層の摩耗進行が切削時の高熱発熱により促進されることから、比較的短時間で使用寿命に至ることが明らかである。
上述のように、この発明の被覆超硬工具は、通常の条件での切削加工は勿論のこと、特に各種の鋼や鋳鉄などの切削加工を、高速で、かつ高い熱的機械的衝撃を伴う高切り込みや高送りなどの重切削条件で行なった場合にも、すぐれた耐チッピング性と耐摩耗性を発揮し、長期に亘ってすぐれた切削性能を示すものであるから、切削加工の省力化および省エネ化、さらに低コスト化に十分満足に対応できるものである。
【図面の簡単な説明】
【図１】被覆超硬工具を構成する硬質被覆層を形成するのに用いた化学蒸着装置を例示する概略縦断面図である。
【図２】化学蒸着装置の構造部材である超硬基体支持パレットを示し、（ａ）が概略斜視図、（ｂ）が概略平面図である。
【図３】この発明の被覆超硬工具を構成する硬質被覆層の形成に用いられる反応ガス組成自動制御システムの概略チャート図である。[0001]
BACKGROUND OF THE INVENTION
In the present invention, the hard coating layer has high strength and is excellent in high-temperature hardness and heat resistance. Therefore, high-speed cutting such as various types of steel and cast iron is particularly suitable for high cutting and high cutting with high thermal mechanical impact. The present invention relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a coated carbide tool) that exhibits excellent chipping resistance and wear resistance even when performed under heavy cutting conditions such as feeding. .
[0002]
[Prior art]
In general, coated carbide tools are used for throwaway inserts that are detachably attached to the tip of a cutting tool for drilling and cutting of various materials such as steel and cast iron, and for flat cutting. There are drills, miniature drills, solid type end mills used for chamfering, grooving, shoulder processing, etc. Also, the throwaway tip is detachably attached and cutting is performed in the same way as the solid type end mill Throwaway end mill tools are known.
[0003]
Further, as a coated carbide tool, a substrate made of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet (hereinafter collectively referred to as a cemented carbide substrate). ), An Al oxide (hereinafter referred to as Al 2 O 3 ) layer and a Ti carbonitride (hereinafter referred to as TiCN) layer having an individual layer thickness of 1 μm or less are alternately laminated to have a thickness of 2 to 20 μm. overall average layer coated cemented carbide formed by deposition to a thickness have been proposed in, Al 2 O 3 -TiCN alternate lamination constituting the hard coating layer, and the high-temperature hardness and heat resistance by the Al 2 O 3 layer, TiCN It is also known to exhibit excellent cutting performance when such coated carbide tools are used for continuous cutting and intermittent cutting of various steels and cast irons because of the strength of the layers (for example, patent documents) 1).
[0004]
Furthermore, as shown in the schematic longitudinal sectional view of FIG. 1, for example, the coated carbide tool has a stainless steel reaction gas blowing pipe standing at the center thereof. A graphite cemented carbide substrate support pallet illustrated in a schematic perspective view in (a) and a schematic plan view in (b) is skewered and laminated, and these are heated by a heater through a stainless steel cover. A chemical vapor deposition apparatus having a structure is used, and the cemented carbide substrate is mounted on the chemical vapor deposition apparatus in a state where the carbide substrate is placed as illustrated in a number of reaction gas passage hole positions formed on the bottom surface of the carbide substrate support pallet. Then, after heating the inside of the apparatus to a predetermined temperature within a range of 800 to 1100 ° C. with a heater, for the formation of the Al 2 O 3 layer, the reaction gas is in volume% (hereinafter,% of reaction gas is Capacity%),
AlCl 3 : 2 to 7%,
CO 2 : 2 to 10%
HCl: 3-7%
H 2 : Remaining
For forming a TiCN layer, a reactive gas having a composition consisting of:
TiCl 4: 1~3%,
CH 4: 5~20%,
N 2 : 40-60%
H 2 : Remaining
The reaction gas pressure in the apparatus is maintained at a predetermined pressure within a range of 7 to 40 kPa through the reaction gas blowing pipe into the apparatus that has been evacuated in advance. However, it is also known that it is manufactured by forming a hard coating layer composed of Al 2 O 3 —TiCN alternating layers by introducing them alternately (see, for example, Patent Document 2).
[0005]
[Patent Document 1]
JP 52-105396 A [Patent Document 2]
JP-A-55-145165 [0006]
[Problems to be solved by the invention]
In recent years, there has been a remarkable increase in the performance of cutting equipment, while there has been a strong demand for labor saving and energy saving and further cost reduction for cutting work. Although there is a tendency to be forced to perform cutting under heavy cutting conditions such as high feed, the above-mentioned conventional coated carbide tools are used for heavy cutting such as high cutting and high feed with high thermal mechanical impact. When used for high-speed operation, the Al 2 O 3 layer, which is a hard coating layer composed of Al 2 O 3 -TiCN alternating layers in particular, has excellent high-temperature hardness and heat resistance, but has insufficient strength. Since this is the starting point of fracture in heavy cutting, it causes chipping (microcracking), and similarly, the TiCN layer has high strength but low hardness at high temperatures and low heat resistance. Now wear progress is rapidly accelerated as fast heavy cutting, from reaching this result relatively short time service life at present.
[0007]
[Means for Solving the Problems]
In view of the above, the present inventors conducted research in order to develop a coated carbide tool that exhibits excellent chipping resistance and wear resistance with a hard coating layer particularly excellent in high speed heavy cutting. result,
(A) Using the chemical vapor deposition apparatus shown in FIGS. 1 and 2 above, a composite compound of Al 2 O 3 and TiCN which is a constituent component of the hard coating layer of the conventional coated carbide tool, that is, Al and Ti When forming a composite oxycarbonitride (hereinafter referred to as Al-Ti oxycarbonitride) layer, for example, as shown in a schematic chart of a reaction gas composition automatic control system in FIG. In addition, along the thickness direction, the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen are spaced from the hard coating layer made of the Al-Ti oxycarbonitride layer at a predetermined interval. For the purpose of alternately and repeatedly forming, the highest content point of Al and oxygen, and the reaction gas composition corresponding to the highest content point of Ti, carbon, and nitrogen, and Al and oxygen, and Ti and carbon between the two points. And nitrogen H of the reaction gas composition corresponding to the continuous variation, the further the distance between two points, and inputs based on historical data, according to a control signal from the reaction gas composition and flow rates central control unit, from the raw material gas cylinders While controlling the flow rates of 2 gas, CO 2 gas, CH 4 gas, N 2 gas, CH 3 CN gas, and HCl gas, and further the flow rates of AlCl 3 gas and TiCl 4 gas with the respective raw material gas flow rate automatic control devices When introduced into the reaction gas blowing tube of a chemical vapor deposition apparatus, the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen exist alternately at predetermined intervals along the layer thickness direction. And from the highest content point of Al and oxygen, the highest content point of Ti, carbon, and nitrogen, and from the highest content point of Ti, carbon, and nitrogen, A hard coating layer composed of an Al—Ti oxynitride layer having a component concentration distribution structure in which the contents of Al, oxygen, and Ti, carbon, and nitrogen continuously change to the highest content point of oxygen and oxygen is formed. To be like that.
[0008]
(B) In the Al—Ti oxynitride layer having the repeated continuous change component concentration distribution structure of (a) above,
Al / Ti and Al / (Al + Ti) indicating the mutual content of oxygen, carbon, and nitrogen at the highest content point of Al and oxygen, and oxygen / (oxygen + carbon + nitrogen), carbon / (oxygen + carbon + nitrogen) ), And nitrogen / (oxygen + carbon + nitrogen), respectively, in atomic ratios,
Al / (Al + Ti): 0.80 to 0.98,
Oxygen / (oxygen + carbon + nitrogen): 0.80 to 0.98,
Carbon / (oxygen + carbon + nitrogen): 0.01 to 0.10,
Nitrogen / (oxygen + carbon + nitrogen): 0.01-0.10,
Ti / Al at the highest content point of Ti, carbon, and nitrogen, and Ti / (Ti + Al) indicating the mutual content ratio of carbon, nitrogen, and oxygen, and carbon / (carbon + nitrogen + oxygen), nitrogen / (carbon + Nitrogen + oxygen) and oxygen / (carbon + nitrogen + oxygen) in atomic ratios, respectively
Ti / (Ti + Al): 0.80 to 0.98,
Carbon / (carbon + nitrogen + oxygen): 0.40-0.49,
Nitrogen / (carbon + nitrogen + oxygen): 0.40-0.49,
Oxygen / (carbon + nitrogen + oxygen): 0.02 to 0.20,
And the distance in the thickness direction between the highest Al and oxygen content points adjacent to each other and the highest content point of Ti, carbon, and nitrogen is 0.01 to 0.2 μm,
The highest content point portion of Al and oxygen shows excellent high temperature hardness and heat resistance corresponding to the high temperature hardness and heat resistance of Al 2 O 3 , while the highest content point portion of Ti, carbon, and nitrogen, High strength corresponding to the strength of TiCN is secured, and the distance between the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen is extremely small. High-temperature hardness, heat resistance, and high strength, and the content of Al, oxygen, Ti, carbon, and nitrogen continuously changes (component concentration distribution structure) between the two points. Therefore, there is no starting point of fracture, and therefore, the coated carbide tool composed of the Al-Ti oxycarbonitride layer with the configuration in which the hard coating layer is applied, particularly cutting processing such as various steels and cast iron, A fast, and even when conducted in heavy cutting conditions such as high cut and high feed with high thermal mechanical shock, the chipping resistance of the hard coating layer has excellent and so exhibits wear resistance.
The research results shown in (a) and (b) above were obtained.
[0009]
The present invention was made based on the above research results, and a hard coating layer made of an Al-Ti carbonitride oxide layer was deposited on the surface of a cemented carbide substrate with an overall average layer thickness of 2 to 20 μm. In the coated carbide tool
In the hard coating layer, the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen are alternately present at predetermined intervals along the layer thickness direction, and the Al and oxygen From the highest content point of Ti to carbon, and nitrogen, from the highest content point of Ti, carbon, and nitrogen to the highest content point of Al and oxygen, Al and oxygen, and Ti, carbon, and nitrogen It has a component concentration distribution structure whose amount changes continuously,
Furthermore, Al / (Al + Ti) indicating the mutual content ratio of Al and Ti and oxygen, carbon, and nitrogen at the highest content point of Al and oxygen, and oxygen / (oxygen + carbon + nitrogen), carbon / (oxygen + carbon). + Nitrogen) and nitrogen / (oxygen + carbon + nitrogen), respectively, in atomic ratios
Al / (Al + Ti): 0.80 to 0.98,
Oxygen / (oxygen + carbon + nitrogen): 0.80 to 0.98,
Carbon / (oxygen + carbon + nitrogen): 0.01 to 0.10,
Nitrogen / (oxygen + carbon + nitrogen): 0.01-0.10,
Ti / Al at the highest content point of Ti, carbon, and nitrogen, and Ti / (Ti + Al) indicating the mutual content ratio of carbon, nitrogen, and oxygen, and carbon / (carbon + nitrogen + oxygen), nitrogen / (carbon + Nitrogen + oxygen) and oxygen / (carbon + nitrogen + oxygen) in atomic ratios, respectively
Ti / (Ti + Al): 0.80 to 0.98,
Carbon / (carbon + nitrogen + oxygen): 0.40-0.49,
Nitrogen / (carbon + nitrogen + oxygen): 0.40-0.49,
Oxygen / (carbon + nitrogen + oxygen): 0.02 to 0.20,
And the distance between the highest content point of Al and oxygen adjacent to each other and the highest content point of Ti, carbon, and nitrogen is 0.01 to 0.2 μm.
This is characterized by a coated carbide tool that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions.
[0010]
Next, in the coated carbide tool of the present invention, the reason why the structure of the hard coating layer constituting the tool is limited as described above will be described.
(A) Al and oxygen highest content point Al-Ti carbon nitride oxide layer of Ti, carbon, and nitrogen component to improve the strength, Al and oxygen component to improve the high temperature hardness and heat resistance Therefore, at the highest content point of Al and oxygen, the content ratio of Al and oxygen is relatively increased to improve high-temperature hardness and heat resistance, so that it is suitable for high-speed cutting with high heat generation. In this case, the Al / (Al + Ti) value and the oxygen / (oxygen + carbon + nitrogen) value indicating the mutual content ratio of Al and Ti, and oxygen, carbon and nitrogen are all in atomic ratio (hereinafter the same). When it exceeds 98, Ti / (Ti + Al) value: less than 0.02, and carbon / (oxygen + carbon + nitrogen) value and nitrogen / (oxygen + carbon + nitrogen) value are both less than 0.01. , Virtually Therefore, even if the highest content points of Ti, carbon, and nitrogen having high strength exist adjacent to each other, a decrease in strength of the layer itself is inevitable, resulting in chipping and the like. When the same value is less than 0.80, Ti / (Ti + Al) value exceeds 0.20, and carbon / (oxygen + carbon + nitrogen) value and nitrogen / (oxygen + carbon + nitrogen) Both values are higher than 0.10, while Al and oxygen are relatively decreased. As a result, the high-temperature hardness and heat resistance are drastically reduced, which causes accelerated wear. Al + Ti) and oxygen / (oxygen + carbon + nitrogen) values of 0.80 to 0.98, and carbon / (oxygen + carbon + nitrogen) and nitrogen / (oxygen + carbon + nitrogen) values It was set as 0.01-0.10.
[0011]
(B) Maximum content point of Ti, carbon, and nitrogen As described above, the maximum content point of Al and oxygen has relatively excellent high-temperature hardness and heat resistance, but on the other hand, the strength is relatively insufficient. In order to make up for the insufficient strength of the highest content point of Al and oxygen, the highest content points of Ti, carbon, and nitrogen having high strength are alternately interposed in the thickness direction. However, the Ti / (Ti + Al) value indicating the mutual content ratio of Ti and Al, and carbon, nitrogen and oxygen exceeds 0.98, and the carbon / (oxygen + carbon + nitrogen) value and nitrogen / (oxygen + carbon + When both nitrogen) values exceed 0.49, the Al / (Al + Ti) value is less than 0.02 and the oxygen / (carbon + nitrogen + oxygen) value is less than 0.02, Since it will be composed of Ti carbonitrides, the predetermined high temperature hardness and heat resistance cannot be ensured at the highest content point of Ti, carbon, and nitrogen, which causes wear acceleration, while Ti When the / (Ti + Al) value is less than 0.80, and the carbon / (carbon + nitrogen + oxygen) value and the nitrogen / (carbon + nitrogen + oxygen) value are both less than 0.40, the Al / (Al + Ti) value is 0. .20 and oxygen / (carbon + nitrogen (Oxygen) value becomes higher than 0.20, the proportion of Ti, carbon, and nitrogen is relatively reduced, and the desired strength cannot be ensured, and as a result, chipping is likely to occur. Ti / (Ti + Al) is 0.80 to 0.98, carbon / (carbon + nitrogen + oxygen) and nitrogen / (carbon + nitrogen + oxygen) are both 0.40 to 0.49, oxygen The value of / (carbon + nitrogen + oxygen) was determined to be 0.02 to 0.20.
[0012]
(C) Interval between the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen If the distance is less than 0.01 μm, it is difficult to clearly form each point with the above composition. As a result, it is impossible to ensure the desired excellent high-temperature hardness and heat resistance and further high strength in the layer, and when the distance exceeds 0.2 μm, the disadvantages of the respective points, that is, the highest of Al and oxygen Insufficient strength if included, high temperature hardness and insufficient heat resistance appear locally in the layer if the highest content point of Ti, carbon, and nitrogen. Therefore, the interval was set to 0.01 to 0.2 μm.
[0013]
(D) Overall average layer thickness of hard coating layer If the layer thickness is less than 2 μm, desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 20 μm, chipping tends to occur. Therefore, the average layer thickness was determined to be 2 to 20 μm.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, the coated carbide tool of the present invention will be specifically described with reference to examples.
As raw material powders, WC powder, TiC powder, VC powder, TaC powder, NbC powder, Cr 3 C 2 powder, and Co powder, all having an average particle diameter of 1 to 3 μm, were prepared. And then wet-mixed with a ball mill for 72 hours, dried, and press-molded into a green compact at a pressure of 100 MPa. The green compact was vacuumed at 6 Pa at a temperature of 1400 ° C. for 1 hour. Sintered under the holding conditions, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03, and the carbide bases A1 to A10 made of WC-based cemented carbide having a chip shape of ISO standard CNMG160608 Formed.
[0015]
In addition, as raw material powders, all are TiCN (weight ratio TiC / TiN = 50/50) powder, Mo 2 C powder, ZrC powder, NbC powder, TaC powder, WC powder having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then pressed into a compact at a pressure of 100 MPa. The green compact was sintered in a 2 kPa nitrogen atmosphere at a temperature of 1500 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03, and ISO standard / CNMG160612. TiCN-based cermet carbide substrates B1 to B6 having the following chip shape were formed.
[0016]
Next, each of the above-mentioned carbide substrates A1 to A10 and B1 to B6 is ultrasonically cleaned in acetone and dried, and then the carbide shown in FIG. 2 is placed in the chemical vapor deposition apparatus shown in FIG. First, when the inside of the apparatus was heated to 900 ° C. with a heater, it was loaded with TiCl 4 : 4.2%, N 2 : 30%, H 2 : remaining. A reactive gas having a composition is introduced through a reactive gas blowing tube, the reaction atmosphere pressure in the apparatus is set to 30 kPa, and this state is maintained for 30 minutes, and the titanium nitride having an average layer thickness of 0.3 μm as a base adhesion layer ( TiN) layer is formed, and the atmospheric temperature in the apparatus is then heated to 1020 ° C. with a heater, and then the reaction gas composition and flow rate central control apparatus of the reaction gas composition automatic control system shown in FIG. According to the past performance data, the target Al / (Al + Ti) of the highest content point of Al and oxygen shown in Tables 3 and 4, and target oxygen / (oxygen + carbon + nitrogen), target carbon / (oxygen + carbon + nitrogen) ), And target nitrogen / (oxygen + carbon + nitrogen), target Ti / (Ti + Al) at the highest content point of Ti, carbon, and nitrogen, and target carbon / (carbon + nitrogen + oxygen), target nitrogen / ( Carbon + nitrogen + oxygen), and reaction gas composition corresponding to target nitrogen / (carbon + nitrogen + oxygen), Al and oxygen between the highest content points of Al and oxygen and the highest content points of Ti, carbon, and nitrogen And the reaction gas composition corresponding to the continuous change in the contents of Ti, carbon, and nitrogen, and the target distance between the two points shown in Tables 5 and 6 and the target total layer thickness of the hard coating layer were input, and this reaction Gas composition Through the raw material gas flow automatic control of the control valve built which operate in accordance with a signal from the fine flow central controller, H 2 gas as a source gas, CH 4 gas, N 2 gas, CH 3 CN gas, CO 2 gas, and HCl gas, further AlCl 3 gas and TiCl 4 gas (in this case, AlCl 3 gas is formed by reacting metal Al with HCl gas whose flow rate is controlled by an AlCl 3 gas generator, and TiCl 4 gas is As shown in the figure, the H 2 gas whose flow rate is controlled is sent as a carrier gas to a TiCl 4 gas generator, where it is sent together with the TiCl 4 gas vaporized from the liquid to the raw material gas flow rate automatic control device, and the CH 3 CN gas is The liquid CH 3 CN heated and gasified with the CH 3 CN vaporizer is sent to the raw material gas flow rate automatic control device). 1 is introduced into the apparatus from the reaction gas blowing tube of the chemical vapor deposition apparatus of FIG. 1 (the reaction atmosphere pressure in the apparatus is always maintained at 7 kPa), and a layer is formed on the surface of the carbide substrate. Target Al / (Al + Ti) shown in Tables 5 and 6 along the thickness direction, and target oxygen / (oxygen + carbon + nitrogen), target carbon / (oxygen + carbon + nitrogen), and target nitrogen / (oxygen + carbon) + Nitrogen) maximum content point of Al and oxygen and target Ti / (Ti + Al), target carbon / (carbon + nitrogen + oxygen), target nitrogen / (carbon + nitrogen + oxygen), and target nitrogen / (carbon + nitrogen) + Oxygen) Ti, carbon, and nitrogen maximum content points alternately and repeatedly at the target intervals shown in Tables 5 and 6, and from the Al and oxygen maximum content points, the Ti, carbon, and nitrogen The highest content point of Ti, said Ti It has a component concentration distribution structure in which the contents of Al and oxygen, and Ti, carbon and nitrogen continuously change from the highest content point of carbon and nitrogen to the highest content point of Al and oxygen, respectively. , 6 to deposit a hard coating layer having a target total layer thickness, the present invention is a surface coated cemented carbide throwaway tip (hereinafter referred to as the present coated carbide tip) as a coated carbide tool of the present invention. 1 to 16 were produced.
[0017]
For comparison purposes, these carbide substrates A1 to A10 and B1 to B6 were ultrasonically cleaned in acetone and dried, and then charged into the normal chemical vapor deposition apparatus shown in FIGS. The conditions for forming the Al 2 O 3 layer are as follows:
Reaction gas composition: AlCl 3 : 3%, CO 2 : 7%, HCl: 3%, H 2 : remaining,
Reaction atmosphere temperature: 1000 ° C.
Reaction atmosphere pressure: 7 kPa,
And the conditions for forming the TiCN layer are as follows:
Reaction gas composition: TiCl 4 : 2%, CH 4 : 12%, N 2 : 55%, H 2 : remaining,
Reaction atmosphere temperature: 1000 ° C.
Reaction atmosphere pressure: 13 kPa,
As shown in Tables 7 and 8, hard coating layers composed of alternating layers of Al 2 O 3 layers and TiCN layers having target layer thicknesses are respectively applied to the surfaces of the superhard substrates A1 to A10 and B1 to B6. By depositing with the target total layer thicknesses shown in Tables 7 and 8, conventional surface-coated cemented carbide throwaway tips (hereinafter referred to as conventional coated carbide tips) 1 to 16 as conventional coated carbide tools, respectively. Manufactured.
[0018]
Next, with the present invention coated carbide tips 1-16 and conventional coated carbide tips 1-16, in a state where this is screwed to the tip of the tool steel tool with a fixing jig,
Work material: JIS / SCM440 round bar,
Cutting speed: 320 m / min. ,
Incision: 4mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
Dry-type continuous high-speed high-cut cutting test of alloy steel under the conditions of
Work material: JIS / S30C lengthwise equidistant 4 round grooved round bars,
Cutting speed: 300 m / min. ,
Cutting depth: 2mm,
Feed: 0.5 mm / rev. ,
Cutting time: 5 minutes
Dry intermittent high-speed high-feed cutting test of carbon steel under the conditions of
Work material: JIS / FC300 lengthwise equidistant 4 bars with vertical grooves,
Cutting speed: 400 m / min. ,
Cutting depth: 4.5mm,
Feed: 0.15 mm / rev. ,
Cutting time: 5 minutes
A dry interrupted high-speed high-cut cutting test of cast iron was performed under the conditions described above, and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Tables 5-8.
[0019]
[Table 1]
[Table 2]
[Table 3]
[Table 4]
[Table 5]
[Table 6]
[Table 7]
[Table 8]
About the hard coating layer which comprises this invention coated carbide | carbonized_material chip | tips 1-16 obtained as a result, and conventional coated carbide | carbonized_material chip | tips 1-16, content of Al, Ti, oxygen, carbon, and nitrogen along a thickness direction Was measured using an Auger spectroscopic analyzer, and from the measurement results, the values of Al / (Al + Ti) and Ti / (Ti + Al) at each measurement point, oxygen / (oxygen + carbon + nitrogen), carbon / (oxygen + carbon) were measured. + Nitrogen), and nitrogen / (oxygen + carbon + nitrogen) values were calculated. In the hard coating layers of the present coated carbide chips 1 to 16, the highest content point of Al and oxygen, Ti, carbon, and The highest content point of nitrogen alternately and repeatedly exists at substantially the same composition and interval as the target value, and the highest content point of Ti, carbon, and nitrogen from the highest content point of Al and oxygen, said Ti, carbon It is confirmed that it has a component concentration distribution structure in which the contents of Al and Ti, and oxygen, carbon and nitrogen continuously change from the highest content point of nitrogen and nitrogen to the highest content point of Al and oxygen, and the average of the hard coating layer The layer thickness also showed substantially the same value as the target overall layer thickness. Further, in the hard coating layers of the conventional coated carbide chips 1 to 16, Al 2 O 3 layers and TiCN layers having an average layer thickness substantially the same as the target layer thickness are alternately arranged, and substantially the target total layer thickness. It was confirmed that they were formed with the same average layer thickness.
[0028]
【The invention's effect】
From the results shown in Tables 5 to 8, the hard coating layer has, in the layer thickness direction, the highest content points of Al and oxygen having relatively high temperature hardness and heat resistance, and Ti and carbon having relatively high strength. And the highest content point of nitrogen alternately and at predetermined intervals, and from the highest content point of Al and oxygen, the highest content point of Ti, carbon, and nitrogen, the content of Ti, carbon, and nitrogen The coated carbide chips 1 to 16 of the present invention having a component concentration distribution structure in which the contents of Al and oxygen, and Ti, carbon and nitrogen continuously change from the highest content point to the highest content point of Al and oxygen are: Even when cutting various steels and cast irons at high speeds and under heavy cutting conditions such as high cutting and high feed with high thermal mechanical impact, the hard coating layer has excellent chipping resistance. And wear resistance Relative to exert, in the conventional coated carbide inserts 1 through 16 hard layer is composed of alternate lamination of the Al 2 O 3 layer and the TiCN layer, the Al 2 O 3 layer of the hard coating layer is especially high speed heavy cutting Under these conditions, it becomes the starting point of occurrence of chipping, and since the progress of wear of the TiCN layer is promoted by high heat generation during cutting, it is clear that the service life is reached in a relatively short time.
As described above, the coated cemented carbide tool of the present invention is not only for cutting under normal conditions, but particularly for cutting of various steels and cast irons at high speed and with high thermal mechanical impact. Even under heavy cutting conditions such as high depth of cut and high feed, it exhibits excellent chipping resistance and wear resistance, and exhibits excellent cutting performance over a long period of time. And it can cope with energy saving and cost reduction sufficiently satisfactorily.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view illustrating a chemical vapor deposition apparatus used for forming a hard coating layer constituting a coated carbide tool.
2A and 2B show a cemented carbide substrate support pallet that is a structural member of a chemical vapor deposition apparatus, in which FIG. 2A is a schematic perspective view, and FIG. 2B is a schematic plan view.
FIG. 3 is a schematic chart of a reaction gas composition automatic control system used for forming a hard coating layer constituting the coated carbide tool of the present invention.
Claims (1)
上記硬質被覆層が、層厚方向にそって、Ａｌおよび酸素の最高含有点と、Ｔｉ、炭素、および窒素の最高含有点とが所定間隔をおいて交互に繰り返し存在し、かつ前記Ａｌおよび酸素の最高含有点から前記Ｔｉ、炭素、および窒素の最高含有点、前記Ｔｉ、炭素、および窒素の最高含有点から前記Ａｌおよび酸素の最高含有点へＡｌと酸素、およびＴｉと炭素と窒素の含有量が連続的に変化する成分濃度分布構造を有し、
さらに、上記Ａｌおよび酸素の最高含有点におけるＡｌとＴｉ、および酸素と炭素と窒素の相互含有割合を示すＡｌ／（Ａｌ＋Ｔｉ）、並びに酸素／（酸素＋炭素＋窒素）、炭素／（酸素＋炭素＋窒素）、および窒素／（酸素＋炭素＋窒素）が、それぞれ原子比で、
Ａｌ／（Ａｌ＋Ｔｉ）：０．８０〜０．９８、
酸素／（酸素＋炭素＋窒素）：０．８０〜０．９８、
炭素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
窒素／（酸素＋炭素＋窒素）：０．０１〜０．１０、
上記Ｔｉ、炭素、および窒素の最高含有点におけるＴｉとＡｌ、および炭素と窒素と酸素の相互含有割合を示すＴｉ／（Ｔｉ＋Ａｌ）、並びに炭素／（炭素＋窒素＋酸素）、窒素／（炭素＋窒素＋酸素）、および酸素／（炭素＋窒素＋酸素）が、それぞれ原子比で、
Ｔｉ／（Ｔｉ＋Ａｌ）：０．８０〜０．９８、
炭素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
窒素／（炭素＋窒素＋酸素）：０．４０〜０．４９、
酸素／（炭素＋窒素＋酸素）：０．０２〜０．２０、
を満足し、かつ隣り合う上記Ａｌおよび酸素の最高含有点と、上記Ｔｉ、炭素、および窒素の最高含有点の間隔が、０．０１〜０．２μmであること、
を特徴とする高速重切削条件で硬質被覆層がすぐれた耐チッピング性および耐摩耗性を発揮する表面被覆超硬合金製切削工具。Surface-coated ultra-coating formed by depositing a hard coating layer composed of a composite carbonitride oxide layer of Al and Ti on the surface of a tungsten carbide base cemented carbide substrate or a titanium carbonitride cermet substrate with an overall average layer thickness of 2 to 20 μm. In hard alloy cutting tools,
In the hard coating layer, the highest content point of Al and oxygen and the highest content point of Ti, carbon, and nitrogen are alternately present at predetermined intervals along the thickness direction, and the Al and oxygen From the highest content point of Ti, carbon, and nitrogen to the highest content point of Ti, carbon, and nitrogen, from the highest content point of Ti, carbon, and nitrogen, to the highest content point of Al and oxygen, the content of Al, oxygen, and Ti, carbon, and nitrogen It has a component concentration distribution structure whose amount changes continuously,
Further, Al / (Al + Ti) indicating the mutual content ratio of Al and Ti, and oxygen / carbon / nitrogen at the highest content point of Al and oxygen, and oxygen / (oxygen + carbon + nitrogen), carbon / (oxygen + carbon). + Nitrogen) and nitrogen / (oxygen + carbon + nitrogen), respectively, in atomic ratios
Al / (Al + Ti): 0.80 to 0.98,
Oxygen / (oxygen + carbon + nitrogen): 0.80 to 0.98,
Carbon / (oxygen + carbon + nitrogen): 0.01 to 0.10,
Nitrogen / (oxygen + carbon + nitrogen): 0.01-0.10,
Ti / Al at the highest content point of Ti, carbon, and nitrogen, and Ti / (Ti + Al) indicating the mutual content ratio of carbon, nitrogen, and oxygen, and carbon / (carbon + nitrogen + oxygen), nitrogen / (carbon + Nitrogen + oxygen) and oxygen / (carbon + nitrogen + oxygen), respectively, in atomic ratios
Ti / (Ti + Al): 0.80 to 0.98,
Carbon / (carbon + nitrogen + oxygen): 0.40-0.49,
Nitrogen / (carbon + nitrogen + oxygen): 0.40-0.49,
Oxygen / (carbon + nitrogen + oxygen): 0.02 to 0.20,
And the interval between the highest content point of Al and oxygen adjacent to each other and the highest content point of Ti, carbon, and nitrogen is 0.01 to 0.2 μm,
A surface-coated cemented carbide cutting tool that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002271297A JP3922141B2 (en) | 2002-09-18 | 2002-09-18 | Cutting tool made of surface-coated cemented carbide that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002271297A JP3922141B2 (en) | 2002-09-18 | 2002-09-18 | Cutting tool made of surface-coated cemented carbide that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2004106107A JP2004106107A (en) | 2004-04-08 |
| JP3922141B2 true JP3922141B2 (en) | 2007-05-30 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002271297A Expired - Fee Related JP3922141B2 (en) | 2002-09-18 | 2002-09-18 | Cutting tool made of surface-coated cemented carbide that exhibits excellent chipping resistance and wear resistance under high-speed heavy cutting conditions. |
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| Country | Link |
|---|---|
| JP (1) | JP3922141B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012091312A (en) * | 2010-09-27 | 2012-05-17 | Mitsubishi Materials Corp | Surface-coated cutting tool having hard coat layer exhibiting excellent chipping resistance and wear resistance |
| JP2012091313A (en) * | 2010-09-29 | 2012-05-17 | Mitsubishi Materials Corp | Surface-coated cutting tool having hard coat layer exhibiting excellent in wear resistance |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7025727B2 (en) * | 2017-07-18 | 2022-02-25 | 三菱マテリアル株式会社 | Surface cutting tool with excellent chipping resistance and wear resistance with a hard coating layer |
| WO2019017201A1 (en) * | 2017-07-18 | 2019-01-24 | 三菱マテリアル株式会社 | Surface cutting tool with hard coating layer exhibiting excellent anti-chipping properties and wear-resistance properties |
-
2002
- 2002-09-18 JP JP2002271297A patent/JP3922141B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012091312A (en) * | 2010-09-27 | 2012-05-17 | Mitsubishi Materials Corp | Surface-coated cutting tool having hard coat layer exhibiting excellent chipping resistance and wear resistance |
| JP2012091313A (en) * | 2010-09-29 | 2012-05-17 | Mitsubishi Materials Corp | Surface-coated cutting tool having hard coat layer exhibiting excellent in wear resistance |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004106107A (en) | 2004-04-08 |
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