JP3693001B2

JP3693001B2 - Surface-coated cemented carbide cutting tool with excellent wear resistance due to high-speed cutting and hard coating layer

Info

Publication number: JP3693001B2
Application number: JP2001332805A
Authority: JP
Inventors: 和則佐藤; 暁裕近藤; 裕介田中
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2001-10-30
Filing date: 2001-10-30
Publication date: 2005-09-07
Anticipated expiration: 2021-10-30
Also published as: JP2003136302A

Description

【０００１】
【発明の属する技術分野】
この発明は、硬質被覆層がすぐれた高温特性を有し、したがって各種の鋼や鋳鉄などの高熱発生を伴う高速切削加工で、すぐれた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、切削工具には、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、前記被削材の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、さらに前記被削材の面削加工や溝加工、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、切削工具として、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、組成式：（Ｔｉ_1-YＡｌ_Y）Ｎ（ただし、原子比で、Ｙは０．４〜０．６を示す）を満足するＴｉ−Ａｌ複合窒化物［以下、（Ｔｉ，Ａｌ）Ｎで示す］層からなる硬質被覆層を２〜１５μｍの平均層厚で物理蒸着してなる被覆超硬工具が知られており、これが各種の鋼や鋳鉄などの連続切削や断続切削加工に用いられることも良く知られるところである。
【０００４】
さらに、上記の被覆超硬工具が、例えば図３に概略説明図で示される物理蒸着装置の１種であるアークイオンプレーティング装置に上記の超硬基体を装入し、ヒータで装置内を、例えば雰囲気を１．３×１０^-3Ｐａの真空として、５００℃の温度に加熱した状態で、アノード電極と所定組成を有するＴｉ−Ａｌ合金がセットされたカソード電極（蒸発源）との間に、例えば電圧：３５Ｖ、電流：９０Ａの条件でアーク放電を発生させ、同時に装置内に反応ガスとして窒素ガスを導入し、一方上記超硬基体には、例えば−２００Ｖのバイアス電圧を印加した条件で、前記超硬基体の表面に、上記（Ｔｉ，Ａｌ）Ｎ層からなる硬質被覆層を蒸着することにより製造されることも知られている。
【０００５】
【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にあるが、上記の従来被覆超硬工具においては、これを通常の切削加工条件で用いた場合には問題はないが、これを高い発熱を伴う高速切削条件用いた場合には、硬質被覆層の摩耗進行が促進され、比較的短時間で使用寿命に至るのが現状である。
【０００６】
【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、高速切削加工ですぐれた耐摩耗性を発揮する被覆超硬工具を開発すべく、特に上記の従来被覆超硬工具を構成する硬質被覆層に着目し、研究を行った結果、
（ａ）上記の従来被覆超硬工具を構成する（Ｔｉ，Ａｌ）Ｎ層からなる硬質被覆層は、Ｃｕ−Ｋα線を用いたＸ線回折装置による測定で、図２に例示される通り（２００）面に最高ピークが現われ、かつ前記最高ピークの半価幅が２θ（横軸）で０．９度以上であるＸ線回折パターンを示すが、この硬質被覆層を超硬基体表面に物理蒸着形成するに先だって、予め組成式：（Ｔｉ_1-XＡｌ_X）Ｃ（ただし、原子比で、Ｘは０．０５〜０．２０を示す）を満足するＴｉ−Ａｌ複合炭化物［以下、（Ｔｉ，Ａｌ）Ｃで示す］層をきわめて薄い０．０５〜０．５μｍの平均層厚で蒸着形成しておくと、前記（Ｔｉ，Ａｌ）Ｃ層は、（２００）面に高配向し、前記（２００）結晶面のピークの半価幅が２θで０．６度以下のＸ線回折パターンを示すので、これの上に物理蒸着された、本来Ｘ線回折パターンの（２００）面におけるピークの半価幅が２θで０．９度以上であるＸ線回折パターンを示す前記（Ｔｉ，Ａｌ）Ｎ層も、図１に例示される通り前記（Ｔｉ，Ａｌ）Ｃ層による結晶配向履歴効果によって前記（２００）面のピークの半価幅が２θで０．６度以下の高配向Ｘ線回折パターンを示すようになること。
【０００７】
（ｂ）Ｘ線回折パターンの（２００）面におけるピークの半価幅が２θで０．６度以下を示す高配向の（Ｔｉ，Ａｌ）Ｎ層は、同ピークの半価幅が同０．９度以上の（Ｔｉ，Ａｌ）Ｎ層に比して高温特性（高温耐酸化性および高温硬さ）にすぐれているので、前記高配向の（Ｔｉ，Ａｌ）Ｎ層からなる硬質被覆層を超硬基体表面に物理蒸着してなる被覆超硬工具は、高い発熱を伴う鋼や軟鋼などの高速切削加工ですぐれた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。
【０００８】
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、
（ａ）０．０５〜０．５μｍの平均層厚を有し、かつ、
組成式：（Ｔｉ_1-XＡｌ_X）Ｃ（ただし、原子比で、Ｘは０．０５〜０．２０を示す）を満足し、
さらに、Ｃｕ−Ｋα線を用いたＸ線回折装置による測定で、（２００）面に最高ピークが現われ、かつ前記最高ピークの半価幅が２θで０．６度以下であるＸ線回折パターンを示す（Ｔｉ，Ａｌ）Ｃ層からなる結晶配向履歴層を介して、
（ｂ）２〜１５μｍの平均層厚を有し、
組成式：（Ｔｉ_1-YＡｌ_Y）Ｎ（ただし、原子比で、Ｙは０．４〜０．６を示す）を満足し、
同じくＣｕ−Ｋα線を用いたＸ線回折装置による測定で、（２００）面に最高ピークが現われ、かつ前記最高ピークの半価幅が２θで０．６度以下であるＸ線回折パターンを示す（Ｔｉ，Ａｌ）Ｎ層からなる硬質被覆層を物理蒸着してなる、
高速切削加工で硬質被覆層がすぐれた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。
【０００９】
つぎに、この発明の被覆超硬工具において、これを構成する結晶配向履歴層および硬質被覆層の組成および平均層厚を上記の通りに限定した理由を説明する。
（ａ）結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］
（Ｔｉ，Ａｌ）Ｃ層におけるＡｌには、層の（２００）面を切刃のすくい面および逃げ面に対して垂直方向に配向する作用があるが、Ａｌの割合が原子比で０．０５未満では、（２００）面への配向が不十分で、（２００）面に現われる最高ピークの半価幅を２θで０．６度以下に高配向させることができず、一方その割合が同じく０．２０を越えても、結晶配向が乱れるようになって、（２００）面を高配向させることが困難になることから、その割合を０．０５〜０．２０と定めた。
また、その平均層厚が０．０５μｍ未満では、（Ｔｉ，Ａｌ）Ｃ層の本来有する（２００）面の高配向性を硬質被覆層に転化する結晶配向履歴効果を十分に発揮させることができず、一方この結晶配向履歴効果は０．５μｍまでの平均層厚で十分であることから、その平均層厚を０．０５〜０．５μｍと定めた。
【００１０】
（ｂ）硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］
（Ｔｉ，Ａｌ）Ｎ層のＡｌは、高靭性を有するＴｉＮ層の硬さおよび耐熱性を高め、もって耐摩耗性を向上させる目的で含有するが、その割合がＴｉとの合量に占める割合（原子比）で０．４未満では所望の耐摩耗性向上効果が得られず、一方その割合が同じく０．６を越えると、切刃にチッピング（微小欠け）などが発生し易くなることから、その割合を０．４〜０．６と定めた。
また、その平均層厚が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１５μｍを越えると、切刃にチッピングが発生し易くなることから、その平均層厚を２〜１５μｍと定めた。
さらに、Ｘ線回折パターンの（２００）面に現われる最高ピークの半価幅：０．６度以下（２θ）は、試験結果に基づいて経験的に定めたものであり、したがって前記半価幅が０．６度以下の場合に、特に高速切削加工ですぐれた耐摩耗性を発揮し、前記半価幅が０．６度を越えて大きくなる、すなわち（２００）面の配向性が低下するようになると、所望の耐摩耗性を確保することができなくなる、という理由によるものである。
【００１１】
【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。
（実施例１）
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、ＺｒＣ粉末、ＶＣ粉末、ＴａＣ粉末、ＮｂＣ粉末、Ｃｒ₃Ｃ₂粉末、ＴｉＮ粉末、ＴａＮ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：０．０５のホーニング加工を施してＩＳＯ規格・ＣＮＭＧ１２０４０８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。
【００１２】
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、Ｍｏ₂Ｃ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・ＣＮＭＧ１２０４０８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。
【００１３】
ついで、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、乾燥した状態で、それぞれ図３に例示される通常のアークイオンプレーティング装置に装入し、一方カソード電極（蒸発源）として種々の成分組成をもった結晶配向履歴層形成用Ｔｉ−Ａｌ合金および硬質被覆層形成用Ｔｉ−Ａｌ合金を装着し、装置内を排気して０．５Ｐａの真空に保持しながら、ヒーターで装置内を５００℃に加熱した後、Ａｒガスを装置内に導入して１０ＰａのＡｒ雰囲気とし、この状態で超硬基体に−８００Ｖのバイアス電圧を印加して超硬基体表面をＡｒガスボンバート洗浄し、ついでＡｒガスの導入を止めた状態で、前記超硬基体に印加するバイアス電圧を−１００Ｖに下げ、かつ装置内に反応ガスとしてメタンガスを導入して３．５Ｐａの反応雰囲気とすると共に、前記カソード電極（結晶配向履歴層形成用Ｔｉ−Ａｌ合金）とアノード電極との間にアーク放電を発生させ、もって前記超硬基体Ａ１〜Ａ１０およびＢ１〜Ｂ６のそれぞれの表面に、表３，４に示される目標組成および目標層厚の結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］を形成し、引き続いて装置内に反応ガスとして窒素ガスを導入して３．５Ｐａの反応雰囲気とすると共に、前記超硬基体に印加するバイアス電圧を−３０Ｖに下げて、前記カソード電極（硬質被覆層形成用Ｔｉ−Ａｌ合金）とアノード電極との間にアーク放電を発生させ、もって同じく表３，４に示される目標組成および目標層厚の硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］を蒸着することにより、図４（ａ）に概略斜視図で、同（ｂ）に概略縦断面図で示される形状を有する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）１〜２０をそれぞれ製造した。
また、比較の目的で、表５，６に示される通り上記結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］の形成を行なわない以外は同一の条件で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）１〜２０をそれぞれ製造した。
【００１４】
つぎに、上記本発明被覆超硬チップ１〜２０および従来被覆超硬チップ１〜２０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・ＳＮＣＭ４３９の丸棒、
切削速度：３６０ｍ／ｍｉｎ．、
切り込み：１．５ｍｍ、
送り：０．２ｍｍ／ｒｅｖ．、
切削時間：１０分、
の条件での合金鋼の乾式高速連続旋削加工試験、
被削材：ＪＩＳ・Ｓ５０Ｃの長さ方向等間隔４本縦溝入り丸棒、
切削速度：２８０ｍ／ｍｉｎ．、
切り込み：１．８ｍｍ、
送り：０．３ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での炭素鋼の乾式高速断続旋削加工試験、さらに、
被削材：ＪＩＳ・ＦＣ２５０の長さ方向等間隔４本縦溝入り丸棒、
切削速度：２００ｍ／ｍｉｎ．、
切り込み：１．５ｍｍ、
送り：０．３ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での鋳鉄の乾式高速断続旋削加工試験を行い、いずれの旋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７、８に示した。
【００１５】
【表１】

【００１６】
【表２】

【００１７】
【表３】

【００１８】
【表４】

【００１９】
【表５】

【００２０】
【表６】

【００２１】
【表７】

【００２２】
【表８】

【００２３】
（実施例２）
原料粉末として、平均粒径：５．５μｍを有する中粗粒ＷＣ粉末、同０．８μｍの微粒ＷＣ粉末、同１．３μｍのＴａＣ粉末、同１．２μｍのＮｂＣ粉末、同１．２μｍのＺｒＣ粉末、同２．３μｍのＣｒ₃Ｃ₂粉末、同１．５μｍのＶＣ粉末、同１．０μｍの（Ｔｉ，Ｗ）Ｃ粉末、および同１．８μｍのＣｏ粉末を用意し、これら原料粉末をそれぞれ表９に示される配合組成に配合し、さらにワックスを加えてアセトン中で２４時間ボールミル混合し、減圧乾燥した後、１００ＭＰａの圧力で所定形状の各種の圧粉体にプレス成形し、これらの圧粉体を、６Ｐａの真空雰囲気中、７℃／分の昇温速度で１３７０〜１４７０℃の範囲内の所定の温度に昇温し、この温度に１時間保持後、炉冷の条件で焼結して、直径が８ｍｍ、１３ｍｍ、および２６ｍｍの３種の超硬基体形成用丸棒焼結体を形成し、さらに前記の３種の丸棒焼結体から、研削加工にて、表９に示される組合せで、切刃部の直径×長さがそれぞれ６ｍｍ×１３ｍｍ、１０ｍｍ×２２ｍｍ、および２０ｍｍ×４５ｍｍの寸法をもった超硬基体（エンドミル）ａ〜ｈをそれぞれ製造した。
【００２４】
ついで、これらの超硬基体（エンドミル）ａ〜ｈの表面に、ホーニングを施し、アセトン中で超音波洗浄し、乾燥した状態で、同じく図３に例示される通常のアークイオンプレーティング装置に装入し、上記実施例１と同一の条件で、表１０に示される目標組成および目標層厚をもった結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］および硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］を蒸着することにより、図５（ａ）に概略正面図で、同（ｂ）に切刃部の概略横断面図で示される形状を有する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エンドミル（以下、本発明被覆超硬エンドミルと云う）１〜８をそれぞれ製造した。
また、比較の目的で、表１１に示される通り上記結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］の形成を行なわない以外は同一の条件で従来被覆超硬工具としての従来表面被覆超硬合金製エンドミル（以下、従来被覆超硬エンドミルと云う）１〜８をそれぞれ製造した。
【００２５】
つぎに、上記本発明被覆超硬エンドミル１〜８および従来被覆超硬エンドミル１〜８のうち、本発明被覆超硬エンドミル１〜３および従来被覆超硬エンドミル１〜３については、
被削材：平面寸法：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍのＪＩＳ・ＳＣＭ４４０の板材、
切削速度：１６０ｍ／ｍｉｎ．、
溝深さ（切り込み）：２．５ｍｍ、
テーブル送り：７００ｍｍ／分、
の条件での合金鋼の乾式高速溝切削加工試験、本発明被覆超硬エンドミル４〜６および従来被覆超硬エンドミル４〜６については、
被削材：平面寸法：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍのＪＩＳ・Ｓ４５Ｃの板材、
切削速度：１８０ｍ／ｍｉｎ．、
溝深さ（切り込み）：５ｍｍ、
テーブル送り：５５０ｍｍ／分、
の条件での炭素鋼の乾式高速溝切削加工試験、本発明被覆超硬エンドミル７，８および従来被覆超硬エンドミル７，８については、
被削材：平面寸法：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍのＪＩＳ・ＦＣ３００の板材、
切削速度：１８０ｍ／ｍｉｎ．、
溝深さ（切り込み）：１０ｍｍ、
テーブル送り：３００ｍｍ／分、
の条件での鋳鉄の乾式高速溝切削加工試験、
をそれぞれ行い、いずれの溝切削加工試験でも外周刃の逃げ面摩耗量が使用寿命の目安とされる０．１ｍｍに至るまでの切削溝長を測定した。この測定結果を表１０、１１にそれぞれ示した。
【００２６】
【表９】

【００２７】
【表１０】

【００２８】
【表１１】

【００２９】
（実施例３）
上記の実施例２で製造した直径が８ｍｍ（超硬基体ａ〜ｃ形成用）、１３ｍｍ（超硬基体ｄ〜ｆ形成用）、および２６ｍｍ（超硬基体ｇ、ｈ形成用）の３種の丸棒焼結体を用い、この３種の丸棒焼結体から、研削加工にて、溝形成部の直径×長さがそれぞれ４ｍｍ×１３ｍｍ（超硬基体ａ´〜ｃ´）、８ｍｍ×２２ｍｍ（超硬基体ｄ´〜ｆ´）、および１６ｍｍ×４５ｍｍ（超硬基体ｇ´、ｈ´）の寸法をもった超硬基体（ドリル）ａ´〜ｈ´をそれぞれ製造した。
【００３０】
ついで、これらの超硬基体（ドリル）ａ´〜ｈ´の表面に、ホーニングを施し、アセトン中で超音波洗浄し、乾燥した状態で、同じく図３に例示される通常のアークイオンプレーティング装置に装入し、上記実施例１と同一の条件で、表１２に示される目標組成および目標層厚をもった結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］および硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］を蒸着することにより、図６（ａ）に概略正面図で、同（ｂ）に溝形成部の概略横断面図で示される形状を有する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ドリル（以下、本発明被覆超硬ドリルと云う）１〜８をそれぞれ製造した。
また、比較の目的で、表１３に示される通り上記結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］の形成を行なわない以外は同一の条件で従来被覆超硬工具としての従来表面被覆超硬合金製ドリル（以下、従来被覆超硬ドリルと云う）１〜８をそれぞれ製造した。
【００３１】
つぎに、上記本発明被覆超硬ドリル１〜８および従来被覆超硬ドリル１〜８のうち、本発明被覆超硬ドリル１〜３および従来被覆超硬ドリル１〜３については、
被削材：平面寸法：１００ｍｍ×２５０、厚さ：５０ｍｍのＪＩＳ・ＳＮＣＭ４３９の板材、
切削速度：１２０ｍ／ｍｉｎ．、
送り：０．１２ｍｍ／ｒｅｖ、
の条件での合金鋼の湿式高速穴あけ切削加工試験、本発明被覆超硬ドリル４〜６および従来被覆超硬ドリル４〜６については、
被削材：平面寸法：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍのＪＩＳ・Ｓ５５Ｃの板材、
切削速度：１００ｍ／ｍｉｎ．、
送り：０．２５ｍｍ／ｒｅｖ、
の条件での炭素鋼の湿式高速穴あけ切削加工試験、本発明被覆超硬ドリル７，８および従来被覆超硬ドリル７，８については、
被削材：平面寸法：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍのＪＩＳ・ＦＣ２５０の板材、
切削速度：１００ｍ／ｍｉｎ．、
送り：０．２５ｍｍ／ｒｅｖ、
の条件での鋳鉄の湿式高速穴あけ切削加工試験、をそれぞれ行い、いずれの湿式高速穴あけ切削加工試験（水溶性切削油使用）でも先端切刃面の逃げ面摩耗幅が０．３ｍｍに至るまでの穴あけ加工数を測定した。この測定結果を表１２、１３にそれぞれ示した。
【００３２】
【表１２】

【００３３】
【表１３】

【００３４】
なお、この結果得られた本発明被覆超硬工具としての本発明被覆超硬チップ１〜２０、本発明被覆超硬エンドミル１〜８、および本発明被覆超硬ドリル１〜８の結晶配向履歴層［（Ｔｉ，Ａｌ）Ｃ層］および硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］、並びに従来被覆超硬工具としての従来被覆超硬チップ１〜２０、従来被覆超硬エンドミル１〜８、および従来被覆超硬ドリル１〜８の硬質被覆層［（Ｔｉ，Ａｌ）Ｎ層］の組成について、その厚さ方向中央部をオージェ分光分析装置を用いて測定したところ、それぞれ目標組成と実質的に同じ組成を示した。
また、これらの本発明被覆超硬工具、並びに従来被覆超硬工具の上記構成層の厚さを、走査型電子顕微鏡を用いて断面測定したところ、いずれも目標層厚と実質的に同じ平均層厚（５点測定の平均値）を示した。
さらに、これらの本発明被覆超硬工具、並びに従来被覆超硬工具の上記構成層をＣｕ−Ｋα線を用いたＸ線回折装置を用いて切刃のすくい面および／または逃げ面で観察し、この結果得られたＸ線回折パターンから（２００）面に現われたピークの半価幅を測定し（この場合正確な測定が困難な場合には、上記の実施例時にアークイオンプレーティング装置に同時に装入した測定ピースのＸ線回折パターンを用いて測定した）、この測定結果を表３〜６および表１０〜１３にそれぞれ示した。
【００３５】
【発明の効果】
表３〜１３に示される結果から、結晶配向履歴層の介在によって硬質被覆層の（２００）面が高配向し、これによってすぐれた高温特性（高温耐酸化性および高温硬さ）を具備すようになる本発明被覆超硬工具は、いずれも鋼や鋳鉄の切削加工を高い発熱を伴う高速で行っても、すぐれた耐摩耗性を発揮するのに対して、硬質被覆層の（２００）面の配向性の低い従来被覆超硬工具においては、高温を伴う高速切削加工では切刃の摩耗進行が速く、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、特に各種の鋼や鋳鉄などの高速切削加工でもすぐれた耐摩耗性を発揮し、長期に亘ってすぐれた切削性能を示すものであるから、切削加工装置の高性能化、並びに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】本発明被覆超硬チップ１５の硬質被覆層が示すＸ線回折パターンである。
【図２】従来被覆超硬チップ１５の硬質被覆層が示すＸ線回折パターンである。
【図３】アークイオンプレーティング装置の概略説明図である。
【図４】（ａ）は被覆超硬チップの概略斜視図、（ｂ）は被覆超硬チップの概略縦断面図である。
【図５】（ａ）は被覆超硬エンドミル概略正面図、（ｂ）は同切刃部の概略横断面図である。
【図６】（ａ）は被覆超硬ドリルの概略正面図、（ｂ）は同溝形成部の概略横断面図である。[0001]
BACKGROUND OF THE INVENTION
The present invention has a high temperature characteristic with a hard coating layer, and thus a surface-coated cemented carbide cutting tool that exhibits excellent wear resistance in high-speed cutting with high heat generation such as various steels and cast iron ( Hereinafter, it is related to a coated carbide tool.
[0002]
[Prior art]
In general, for cutting tools, a throw-away tip that is used by attaching to the tip of a cutting tool for turning and planing of various steels and cast irons, drilling of the work material, etc. Drills and miniature drills, and solid type end mills used for chamfering, grooving and shouldering of the work material, etc. A slow-away end mill tool that performs cutting work in the same manner as an end mill is known.
[0003]
Further, as a cutting 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). On the surface, a Ti—Al composite nitride satisfying the composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.4 to 0.6 by atomic ratio) [hereinafter referred to as (Ti, Al ) N is a coated carbide tool formed by physically vapor-depositing a hard coating layer with an average layer thickness of 2 to 15 μm. This is used for continuous cutting and intermittent cutting of various steels and cast irons. It is well known that it is used.
[0004]
Furthermore, the above-mentioned coated carbide tool is, for example, the above-mentioned carbide substrate is loaded into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. For example, with the atmosphere set to a vacuum of 1.3 × 10 ⁻³ Pa and heated to a temperature of 500 ° C., between the anode electrode and the cathode electrode (evaporation source) on which a Ti—Al alloy having a predetermined composition is set For example, arc discharge is generated under the conditions of voltage: 35 V and current: 90 A, and simultaneously, nitrogen gas is introduced into the apparatus as a reaction gas, while a bias voltage of, for example, −200 V is applied to the carbide substrate. It is also known that it is produced by vapor-depositing a hard coating layer composed of the (Ti, Al) N layer on the surface of the cemented carbide substrate.
[0005]
[Problems to be solved by the invention]
In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and with this, cutting tends to be faster. In the coated carbide tool, there is no problem when it is used under normal cutting conditions, but when this is used at high speed cutting conditions with high heat generation, the progress of wear of the hard coating layer is promoted, At present, the service life is reached in a relatively short time.
[0006]
[Means for Solving the Problems]
In view of the above, the present inventors have developed a hard coating layer that constitutes the above conventional coated carbide tool, in particular, in order to develop a coated carbide tool that exhibits excellent wear resistance in high-speed cutting. As a result of conducting research with a focus on
(A) The hard coating layer composed of the (Ti, Al) N layer constituting the conventional coated carbide tool is measured by an X-ray diffractometer using Cu-Kα rays as illustrated in FIG. The X-ray diffraction pattern in which the highest peak appears on the (200) plane and the half-width of the highest peak is 0.9 degrees or more at 2θ (horizontal axis) is shown on the surface of the carbide substrate. Prior to vapor deposition, a Ti—Al composite carbide satisfying the composition formula: (Ti _1-X Al _X ) C (wherein X is 0.05 to 0.20 in atomic ratio) [hereinafter, ( (Ti, Al) C] layer is deposited with a very thin average layer thickness of 0.05 to 0.5 μm, the (Ti, Al) C layer is highly oriented in the (200) plane, Since the half width of the peak of the (200) crystal plane is 2θ, it shows an X-ray diffraction pattern of 0.6 degrees or less. The (Ti, Al) N layer that is physically vapor-deposited thereon and exhibits an X-ray diffraction pattern with a half-width of a peak on the (200) plane of the X-ray diffraction pattern being 0.9 or more at 2θ 1 shows a highly oriented X-ray diffraction pattern in which the half width of the peak of the (200) plane is 2θ and 0.6 degrees or less due to the crystal orientation history effect by the (Ti, Al) C layer as illustrated in FIG. To be like that.
[0007]
(B) A highly oriented (Ti, Al) N layer in which the half-value width of the peak in the (200) plane of the X-ray diffraction pattern is 0.6 or less at 2θ is the same. Since it has excellent high-temperature characteristics (high-temperature oxidation resistance and high-temperature hardness) compared to a (Ti, Al) N layer of 9 degrees or more, a hard coating layer composed of the highly-oriented (Ti, Al) N layer is used. Coated carbide tools that are physically vapor-deposited on the surface of a cemented carbide substrate should exhibit excellent wear resistance in high-speed cutting such as steel and mild steel with high heat generation.
The research results shown in (a) and (b) above were obtained.
[0008]
This invention was made based on the above research results, and on the surface of the carbide substrate,
(A) having an average layer thickness of 0.05 to 0.5 μm, and
Composition formula: (Ti _1-X Al _X ) C (wherein X is 0.05 to 0.20 in atomic ratio) is satisfied,
Furthermore, an X-ray diffraction pattern in which the highest peak appears on the (200) plane and the half width of the highest peak is 2θ at 0.6 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. Through the crystal orientation history layer consisting of the (Ti, Al) C layer shown,
(B) having an average layer thickness of 2-15 μm;
Composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.4 to 0.6 in atomic ratio) is satisfied,
Similarly, an X-ray diffraction pattern in which the highest peak appears on the (200) plane and the half-value width of the highest peak is 2θ at 0.6 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. A physical coating of a hard coating layer made of a (Ti, Al) N layer,
It is characterized by a coated carbide tool that exhibits excellent wear resistance with a hard coating layer in high-speed cutting.
[0009]
Next, the reason why the composition and the average layer thickness of the crystal orientation history layer and the hard coating layer constituting the coated carbide tool of the present invention are limited as described above will be described.
(A) Crystal orientation history layer [(Ti, Al) C layer]
Al in the (Ti, Al) C layer has the effect of orienting the (200) plane of the layer in the direction perpendicular to the rake face and flank face of the cutting edge, but the Al ratio is 0.05 by atomic ratio. If it is less than 1, the orientation to the (200) plane is insufficient, and the half-value width of the highest peak appearing on the (200) plane cannot be highly oriented to 2 degrees or less at 0.6 degrees, while the ratio is also 0 Even if .20 is exceeded, the crystal orientation becomes disordered and it becomes difficult to highly orient the (200) plane, so the ratio was set to 0.05 to 0.20.
Moreover, when the average layer thickness is less than 0.05 μm, the crystal orientation history effect that converts the high orientation of the (200) plane originally possessed by the (Ti, Al) C layer into a hard coating layer can be sufficiently exhibited. On the other hand, since the average layer thickness up to 0.5 μm is sufficient for this crystal orientation history effect, the average layer thickness was set to 0.05 to 0.5 μm.
[0010]
(B) Hard coating layer [(Ti, Al) N layer]
Al in the (Ti, Al) N layer is contained for the purpose of increasing the hardness and heat resistance of the TiN layer having high toughness and thereby improving the wear resistance. If the (atomic ratio) is less than 0.4, the desired effect of improving wear resistance cannot be obtained. On the other hand, if the ratio exceeds 0.6, chipping (minute chipping) is likely to occur on the cutting edge. The ratio was determined to be 0.4 to 0.6.
Further, if the average layer thickness is less than 2 μm, the desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 15 μm, chipping tends to occur on the cutting edge. The thickness was set to 2 to 15 μm.
Furthermore, the half-value width of the highest peak appearing on the (200) plane of the X-ray diffraction pattern: 0.6 degrees or less (2θ) is determined empirically based on the test results. In the case of 0.6 degrees or less, excellent wear resistance is exhibited particularly in high-speed cutting, so that the half width exceeds 0.6 degrees, that is, the orientation of the (200) plane is lowered. This is because the desired wear resistance cannot be ensured.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, the coated carbide tool of the present invention will be specifically described with reference to examples.
(Example 1)
WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders are blended in the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. Medium, sintered at 1400 ° C. for 1 hour, WC-based carbide with ISO standard / CNMG120408 chip shape after honed to R: 0.05 after cutting Alloy carbide substrates A1 to A10 were formed.
[0012]
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 nitrogen atmosphere of 2 kPa 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 / CNMG120408. TiCN-based cermet carbide substrates B1 to B6 having the following chip shape were formed.
[0013]
Next, these superhard substrates A1 to A10 and B1 to B6 were ultrasonically cleaned in acetone and dried, and each was then loaded into a normal arc ion plating apparatus illustrated in FIG. Attach Ti-Al alloy for crystal orientation history layer formation and Ti-Al alloy for hard coating layer formation with various component compositions as (evaporation source), evacuate the inside of the apparatus and keep it at 0.5 Pa vacuum However, after heating the inside of the apparatus to 500 ° C. with a heater, Ar gas was introduced into the apparatus to form an Ar atmosphere of 10 Pa, and in this state, a bias voltage of −800 V was applied to the carbide base to In a state where Ar gas bombard cleaning is performed, and then the introduction of Ar gas is stopped, the bias voltage applied to the carbide substrate is lowered to −100 V, and methane gas is introduced into the apparatus as a reaction gas. The reaction atmosphere is 3.5 Pa, and arc discharge is generated between the cathode electrode (Ti-Al alloy for forming a crystal orientation history layer) and the anode electrode, so that the carbide substrates A1 to A10 and B1 to B1 are generated. A crystal orientation history layer [(Ti, Al) C layer] having the target composition and target layer thickness shown in Tables 3 and 4 is formed on each surface of B6, and then nitrogen gas is introduced as a reaction gas into the apparatus. And the bias voltage applied to the cemented carbide substrate is lowered to -30V, and an arc is formed between the cathode electrode (Ti-Al alloy for forming the hard coating layer) and the anode electrode. By generating a discharge and depositing a hard coating layer [(Ti, Al) N layer] having a target composition and a target layer thickness similarly shown in Tables 3 and 4, a schematic perspective view in FIG. (B Schematic longitudinal sectional view in the present invention cover the invention as cemented carbide surface coating cemented carbide throw-away tip having a shape shown in (hereinafter, the present invention refers to the coating hard tip) 20 was prepared, respectively.
For comparison purposes, conventional surface coating as a conventional coated carbide tool under the same conditions except that the above crystal orientation history layer [(Ti, Al) C layer] is not formed as shown in Tables 5 and 6. Cemented carbide alloy throwaway tips (hereinafter referred to as conventional coated carbide tips) 1 to 20 were produced, respectively.
[0014]
Next, with the present invention coated carbide chips 1-20 and the conventional coated carbide chips 1-20, this is screwed to the tip of the tool steel tool with a fixing jig,
Work material: JIS / SNCM439 round bar,
Cutting speed: 360 m / min. ,
Incision: 1.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 10 minutes,
Dry high-speed continuous turning test of alloy steel under the conditions of
Work material: JIS / S50C lengthwise equal 4 round grooved round bars,
Cutting speed: 280 m / min. ,
Cutting depth: 1.8mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
Carbon steel dry high-speed intermittent turning test,
Work material: JIS / FC250 lengthwise equidistant round bars with 4 vertical grooves,
Cutting speed: 200 m / min. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
A dry high-speed intermittent turning test of cast iron was performed under the conditions described above, and the flank wear width of the cutting edge was measured in any turning test. The measurement results are shown in Tables 7 and 8.
[0015]
[Table 1]

[0016]
[Table 2]

[0017]
[Table 3]

[0018]
[Table 4]

[0019]
[Table 5]

[0020]
[Table 6]

[0021]
[Table 7]

[0022]
[Table 8]

[0023]
(Example 2)
As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Prepare a powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C powder, and 1.8 μm Co powder. Each was blended in the blending composition shown in Table 9, further added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then pressed into various compacts of a predetermined shape at a pressure of 100 MPa. The green compact is heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a 6 Pa vacuum atmosphere, held at this temperature for 1 hour, and then fired under furnace cooling conditions. Finally, the diameters are 8mm, 13mm, and 26 m of three kinds of sintered carbide rod forming bodies for forming a carbide substrate, and from the above three kinds of round bar sintered bodies, the diameter of the cutting edge portion in the combination shown in Table 9 by grinding. X Carbide substrates (end mills) a to h having lengths of 6 mm x 13 mm, 10 mm x 22 mm, and 20 mm x 45 mm, respectively, were manufactured.
[0024]
Next, the surfaces of these carbide substrates (end mills) a to h are subjected to honing, ultrasonically cleaned in acetone, and dried, and then mounted on the ordinary arc ion plating apparatus illustrated in FIG. The crystal orientation history layer [(Ti, Al) C layer] and the hard coating layer [(Ti, Al) having the target composition and target layer thickness shown in Table 10 under the same conditions as in Example 1 above. The surface of the present invention as a coated carbide tool of the present invention having the shape shown in the schematic front view of FIG. 5A and the schematic cross-sectional view of the cutting edge portion in FIG. Coated cemented carbide end mills (hereinafter referred to as the present invention coated carbide end mills) 1 to 8 were produced, respectively.
For comparison purposes, a conventional surface-coated carbide as a conventional coated carbide tool under the same conditions except that the crystal orientation history layer [(Ti, Al) C layer] is not formed as shown in Table 11. Alloy end mills (hereinafter referred to as conventional coated carbide end mills) 1 to 8 were produced.
[0025]
Next, of the present invention coated carbide end mills 1-8 and conventional coated carbide end mills 1-8, the present invention coated carbide end mills 1-3 and conventional coated carbide end mills 1-3 are as follows:
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 160 m / min. ,
Groove depth (cut): 2.5 mm,
Table feed: 700mm / min,
The dry high-speed grooving test of alloy steel under the conditions of the present invention, the coated carbide end mills 4-6 of the present invention and the conventional coated carbide end mills 4-6,
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / S45C plate,
Cutting speed: 180 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 550 mm / min,
With respect to the dry high-speed grooving test of carbon steel under the following conditions, the coated carbide end mills 7 and 8 according to the present invention and the conventional coated carbide end mills 7 and 8:
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / FC300 plate material,
Cutting speed: 180 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 300mm / min,
Cast iron dry high-speed grooving test under the conditions of
In each groove cutting test, the cutting groove length was measured until the flank wear amount of the outer peripheral blade reached 0.1 mm, which is a guide for the service life. The measurement results are shown in Tables 10 and 11, respectively.
[0026]
[Table 9]

[0027]
[Table 10]

[0028]
[Table 11]

[0029]
(Example 3)
Three types of diameters manufactured in Example 2 were 8 mm (for forming carbide substrates a to c), 13 mm (for forming carbide substrates d to f), and 26 mm (for forming carbide substrates g and h). Using a round bar sintered body, from these three kinds of round bar sintered bodies, the diameter x length of the groove forming portion is 4 mm x 13 mm (carbide bases a 'to c') and 8 mm x by grinding. Carbide substrates (drills) a ′ to h ′ having dimensions of 22 mm (carbide substrates d ′ to f ′) and 16 mm × 45 mm (carbide substrates g ′ and h ′) were produced, respectively.
[0030]
Next, the surface of these carbide substrates (drills) a ′ to h ′ is subjected to honing, ultrasonically cleaned in acetone, and dried, and then the ordinary arc ion plating apparatus also exemplified in FIG. The crystal orientation history layer [(Ti, Al) C layer] and the hard coating layer [(Ti, Al) having the target composition and target layer thickness shown in Table 12 under the same conditions as in Example 1 above. A book as a coated carbide tool of the present invention having a shape shown in a schematic front view in FIG. 6A and a schematic cross-sectional view of a groove forming portion in FIG. Invention surface-coated cemented carbide drills (hereinafter referred to as the present invention coated carbide drills) 1 to 8 were produced, respectively.
For comparison purposes, a conventional surface-coated carbide as a conventional coated carbide tool under the same conditions except that the crystal orientation history layer [(Ti, Al) C layer] is not formed as shown in Table 13. Alloy drills (hereinafter referred to as conventional coated carbide drills) 1 to 8 were produced, respectively.
[0031]
Next, of the present invention coated carbide drills 1-8 and conventional coated carbide drills 1-8, the present invention coated carbide drills 1-3 and conventional coated carbide drills 1-3,
Work material: Plane dimension: 100 mm × 250, thickness: 50 mm JIS / SNCM439 plate material,
Cutting speed: 120 m / min. ,
Feed: 0.12 mm / rev,
About the wet high-speed drilling test of alloy steel under the conditions of the present invention, the coated carbide drills 4-6 of the present invention and the conventional coated carbide drills 4-6,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S55C plate material,
Cutting speed: 100 m / min. ,
Feed: 0.25mm / rev,
With respect to the carbon steel wet high speed drilling test, the present invention coated carbide drills 7 and 8 and the conventional coated carbide drills 7 and 8,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / FC250 plate material,
Cutting speed: 100 m / min. ,
Feed: 0.25mm / rev,
Wet cast high-speed drilling test of cast iron under the conditions of each, and any wet high-speed drilling cutting test (using water-soluble cutting oil) until the flank wear width of the cutting edge surface reaches 0.3mm The number of drilling operations was measured. The measurement results are shown in Tables 12 and 13, respectively.
[0032]
[Table 12]

[0033]
[Table 13]

[0034]
In addition, the crystal orientation history layer of this invention coated carbide tips 1-20, this invention coated carbide end mills 1-8, and this invention coated carbide drills 1-8 as this invention coated carbide tool obtained as a result of this [(Ti, Al) C layer] and hard coating layer [(Ti, Al) N layer], as well as conventional coated carbide tips 1-20 as conventional coated carbide tools, conventionally coated carbide end mills 1-8, and About the composition of the hard coating layer [(Ti, Al) N layer] of the conventional coated carbide drills 1 to 8, the central portion in the thickness direction was measured using an Auger spectroscopic analyzer. It showed the same composition.
Further, when the thicknesses of the above constituent layers of the coated carbide tool of the present invention and the conventional coated carbide tool were subjected to cross-sectional measurement using a scanning electron microscope, the average layer was substantially the same as the target layer thickness. The thickness (average value of 5-point measurement) was shown.
Furthermore, the above-mentioned constituent layers of these coated carbide tools of the present invention and the conventional coated carbide tools are observed on the rake face and / or flank face of the cutting edge using an X-ray diffractometer using Cu-Kα rays, The full width at half maximum of the peak appearing on the (200) plane was measured from the X-ray diffraction pattern obtained as a result (in this case, if accurate measurement was difficult, the arc ion plating apparatus was The measurement result was measured using the X-ray diffraction pattern of the inserted measurement piece), and the measurement results are shown in Tables 3 to 6 and Tables 10 to 13, respectively.
[0035]
【The invention's effect】
From the results shown in Tables 3 to 13, the (200) plane of the hard coating layer is highly oriented due to the interposition of the crystal orientation history layer, so that it has excellent high temperature characteristics (high temperature oxidation resistance and high temperature hardness). The coated carbide tool according to the present invention exhibits excellent wear resistance even when cutting steel or cast iron at a high speed with high heat generation, whereas the (200) surface of the hard coating layer. In the conventional coated carbide tool with low orientation, it is clear that the wear of the cutting edge proceeds rapidly in high-speed cutting with high temperature, and the service life is reached in a relatively short time.
As described above, the coated carbide tool of the present invention exhibits excellent wear resistance even in high-speed cutting such as various types of steel and cast iron, and exhibits excellent cutting performance over a long period of time. It is possible to satisfactorily meet the demands for high performance cutting equipment, labor saving and energy saving of cutting, and cost reduction.
[Brief description of the drawings]
FIG. 1 is an X-ray diffraction pattern shown by a hard coating layer of a coated carbide tip 15 of the present invention.
FIG. 2 is an X-ray diffraction pattern shown by a hard coating layer of a conventional coated carbide tip 15;
FIG. 3 is a schematic explanatory diagram of an arc ion plating apparatus.
4A is a schematic perspective view of a coated carbide tip, and FIG. 4B is a schematic longitudinal sectional view of the coated carbide tip.
5A is a schematic front view of a coated carbide end mill, and FIG. 5B is a schematic cross-sectional view of the cutting edge portion.
6A is a schematic front view of a coated carbide drill, and FIG. 6B is a schematic cross-sectional view of the groove forming portion.

Claims

On the surface of a tungsten carbide base cemented carbide substrate or a titanium carbonitride cermet substrate,
(A) having an average layer thickness of 0.05 to 0.5 μm;
Composition formula: (Ti _1-X Al _X ) C (wherein X is 0.05 to 0.20 in atomic ratio) is satisfied,
Furthermore, an X-ray diffraction pattern in which the highest peak appears on the (200) plane and the half width of the highest peak is 2θ at 0.6 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. Through the crystal orientation history layer consisting of the Ti-Al composite carbide layer shown,
(B) having an average layer thickness of 2-15 μm;
Composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.4 to 0.6 in atomic ratio) is satisfied,
Similarly, an X-ray diffraction pattern in which the highest peak appears on the (200) plane and the half-value width of the highest peak is 2θ at 0.6 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. A hard coating layer made of a Ti-Al composite nitride layer is physically vapor-deposited.
A surface-coated cemented carbide cutting tool that exhibits high wear resistance with a hard coating layer in high-speed cutting.