JP3879113B2

JP3879113B2 - Surface coated cemented carbide cutting tool with excellent wear resistance with hard coating layer in high speed cutting

Info

Publication number: JP3879113B2
Application number: JP2001337458A
Authority: JP
Inventors: 惠滋中村; 安彦田代; 隆史藤澤
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2001-11-02
Filing date: 2001-11-02
Publication date: 2007-02-07
Anticipated expiration: 2021-11-02
Also published as: JP2003136305A

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、したがって特に焼入れ鋼や合金鋼などの高硬度鋼、さらに高硬度を有する各種Ｔｉ合金などの被削材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、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：（Ｃｒ_1-YＶ_Y）Ｎ（ただし、原子比で、Ｙは０．４〜０．７を示す）を満足するＣｒとＶの複合窒化物［以下、（Ｃｒ，Ｖ）Ｎで示す］層からなる硬質被覆層を２〜１０μｍ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、これが特に焼入れ鋼や合金鋼などの高硬度鋼、さらに高硬度を有する各種Ｔｉ合金などの被削材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４５０℃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Ｃｒ−Ｖ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：３０Ｖ、電流：８０Ａ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て、２Ｐａの反応雰囲気とし、一方上記超硬基体には、例えば−３００Ｖ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（Ｃｒ，Ｖ）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で用いた場合には、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（Ｃｒ，Ｖ）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で１．２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-XＣｒ_X）Ｎ（ただし、原子比で、Ｘは０．０５〜０．２０を示す）を満足するＴｉ−Ｃｒ複合窒化物［以下、（Ｔｉ，Ｃｒ）Ｎ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，Ｃｒ）Ｎ層は、（２００）面に高配向し、前記（２００）面のピークの半価幅が２θで０．９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１．２度以上であるＸ線回折パターンを示す前記（Ｃｒ，Ｖ）Ｎ層も前記（Ｔｉ，Ｃｒ）Ｎ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図１に例示される通り２θで０．９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０．９度以下を示す高配向の（Ｃｒ，Ｖ）Ｎ層は、同ピークの半価幅が１．２度以上の（Ｃｒ，Ｖ）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（Ｃｒ，Ｖ）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、高い発熱を伴う高硬度鋼やＴｉ合金などの被削材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-XＣｒ_X）Ｎ（ただし、原子比で、Ｘは０．０５〜０．２０を示す）を満足満足し、
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０．９度以下であるＸ線回折パターンを示す（Ｔｉ，Ｃｒ）Ｎ層からなる結晶配向履歴層を介して、
（ｂ）０．５〜７μｍの平均層厚を有し、
組成式：（Ｃｒ_1-YＶ_Y）Ｎ（ただし、原子比で、Ｙは０．４〜０．７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０．９度以下であるＸ線回折パターンを示す（Ｃｒ，Ｖ）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，Ｃｒ）Ｎ層］
（Ｔｉ，Ｃｒ）Ｎ層におけるＣｒ成分には、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、Ｃｒの割合がＴｉとの合量に占める割合（原子比）で０．０５未満では、（２００）面への配向効果が不十分で、（２００）面に現われる最高ピークの半価幅を２θで０．９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，Ｃｒ）Ｎ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［（Ｃｒ，Ｖ）Ｎ層］
（Ｃｒ，Ｖ）Ｎ層のＶ成分には、靭性を有するＣｒＮに高硬度を付与し、もって層の耐摩耗性を向上させる作用があるが、その割合がＣｒとの合量に占める割合（原子比）で０．４未満では所望の硬さ向上効果が得られず、一方その割合が同じく０．７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０．４〜０．７と定めた。
また、その平均層厚が０．５μｍ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７μｍ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０．５〜７μｍ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：２θで０．９度以下は、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２θで０．９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、前記半価幅が同０．９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：０．０３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−Ｃｒ合金および硬質被覆層形成用Ｃｒ−Ｖ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７００℃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、ついで装置内に反応ガスとして窒素ガスを導入して４Ｐａ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，Ｃｒ］および硬質被覆層［（Ｃｒ，Ｖ）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，Ｃｒ）Ｎ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・ＳＫＤ６１（硬さ：ＨＲＣ４５）の丸棒、
切削速度：８０ｍ／ｍｉｎ．、
切り込み：１．５ｍｍ、
送り：０．２ｍｍ／ｒｅｖ．、
切削時間：３分、
の条件での焼入れ鋼の湿式高速連続旋削加工試験（水溶性切削油使用）、
被削材：ＪＩＳ・ＳＮＣＭ４３９（硬さ：ＨＢ２９５）の長さ方向等間隔４本縦溝入り丸棒、
切削速度：３３０ｍ／ｍｉｎ．、
切り込み：３．２ｍｍ、
送り：０．３８ｍｍ／ｒｅｖ．、
切削時間：５分、
の条件での合金鋼の湿式高速断続旋削加工試験（水溶性切削油使用）、さらに、
被削材：Ｔｉ−６％Ａｌ−４％Ｖ（質量％）の組成を有するＴｉ合金の丸棒、
切削速度：１００ｍ／ｍｉｎ．、
切り込み：２．８ｍｍ、
送り：０．３ｍｍ／ｒｅｖ．、
切削時間：８分、
の条件でのＴｉ合金の湿式高速連続旋削加工試験（水溶性切削油使用）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，Ｃｒ）Ｎ層］および硬質被覆層［（Ｃｒ，Ｖ）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，Ｃｒ）Ｎ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・ＳＮＣＭ４３９の板材、
切削速度：２８０ｍ／ｍｉｎ．、
軸方向切込み：６ｍｍ、
径方向切込み：０．２ｍｍ
テーブル送り：２０００ｍｍ／分、
の条件での合金鋼の湿式高速側面切削加工試験、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にして、厚さ：５０ｍｍ、組成：Ｔｉ−６％Ａｌ−４％Ｖ（質量％）の板材、
切削速度：１２０ｍ／ｍｉｎ．、
軸方向切込み：５ｍｍ、
径方向切込み：０．２ｍｍ
テーブル送り：８００ｍｍ／分、
の条件でのＴｉ合金の湿式高速側面切削加工試験、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・ＳＫＤ６１の板材、
切削速度：１００ｍ／ｍｉｎ．、
軸方向切込み：１０ｍｍ、
径方向切込み：０．２ｍｍ、
テーブル送り：３０００ｍｍ／分、
の条件での焼入れ鋼の湿式高速側面切削加工試験（いずれの試験も水溶性切削油使用）、をそれぞれ行い、いずれの溝切削加工試験でも切刃部先端面の直径が使用寿命の目安とされる０．１ｍｍ減少するまでの切削長を測定した。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，Ｃｒ）Ｎ層］および硬質被覆層［（Ｃｒ，Ｖ）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、従来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，Ｃｒ）Ｎ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×２５０ｍｍにして、厚さ：５０ｍｍ、組成：Ｔｉ−６％Ａｌ−４％Ｖ（質量％）の板材、
切削速度：３８ｍ／ｍｉｎ．、
送り：０．１１ｍｍ／ｒｅｖ、
の条件でのＴｉ合金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・ＳＫＤ６１の板材、
切削速度：４５ｍ／ｍｉｎ．、
送り：０．１５ｍｍ／ｒｅｖ、
の条件での焼入れ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・ＳＮＣＭ４３９の板材、
切削速度：１５０ｍ／ｍｉｎ．、
送り：０．２５ｍｍ／ｒｅｖ、
の条件での合金鋼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，Ｃｒ）Ｎ層］および硬質被覆層［（Ｃｒ，Ｖ）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［（Ｃｒ，Ｖ）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線回折装置にて切刃のすくい面および／または逃げ面を観察し、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、いずれも高硬度鋼やＴｉ合金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、特に焼入れ鋼や高炭素鋼などの高硬度鋼、さらに高硬度を有する各種Ｔｉ合金などの被削材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３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３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 in which the hard coating layer has an excellent high temperature, and therefore, high-speed cutting with high heat generation particularly in high-hardness steel such as hardened steel and alloy steel, and various Ti alloys having high hardness. Thus, the present invention relates to a surface-coated cemented carbide cutting tool that exhibits excellent wear resistance (hereinafter referred to as a coated carbide tool).
[0002]
[Prior art]
Generally, for cutting tools, a throw-away tip that is detachably attached to the tip of a cutting tool for turning and planing of various work materials, drills and miniature drills used for drilling and cutting work materials, etc. In addition, there are solid type end mills that are used for chamfering, grooving, shoulder processing, etc. of work materials, and the throwaway tip is detachably attached and cutting is performed in the same manner as the solid type end mill. Throwaway end mill tools are 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 composite nitride of Cr and V satisfying the composition formula: (Cr _1-Y V _Y ) N (wherein Y represents 0.4 to 0.7 in atomic ratio) [hereinafter referred to as (Cr, V) a coated carbide tool formed by physically vapor-depositing a hard coating layer composed of a layer with an average layer thickness of 2 to 10 μm, which is particularly known as a high-hardness steel such as hardened steel or alloy steel, It is also well known that it is used for continuous cutting and intermittent cutting of work materials such as various Ti alloys having high hardness.
[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, arc discharge is performed between the anode electrode and the cathode electrode (evaporation source) on which a Cr-V alloy having a predetermined composition is set in a state heated to 450 ° C., for example, under a voltage of 30 V and a current of 80 A. At the same time, nitrogen gas is introduced as a reactive gas into the apparatus to form a reaction atmosphere of 2 Pa. On the other hand, the surface of the cemented carbide substrate is applied to the cemented carbide substrate under a condition that, for example, a bias voltage of −300 V is applied. In addition, it is also known to be produced by vapor-depositing a hard coating layer composed of the (Cr, V) N layer.
[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 are strong demands for labor saving and energy saving and further cost reduction for cutting, and with this, cutting tends to be faster. In coated carbide tools, there is no problem when used under normal cutting conditions, but when this is used under 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 (Cr, V) N layer constituting the conventional coated carbide tool is measured by an X-ray diffractometer using Cu-Kα rays as illustrated in FIG. 200) shows an X-ray diffraction pattern in which the highest peak appears and the half width of the highest peak is 1.2 degrees or more at 2θ, and this hard coating layer is formed by physical vapor deposition on the surface of a carbide substrate. Prior to this, a Ti—Cr composite nitride satisfying the composition formula: (Ti _1-X Cr _X ) N (wherein X is 0.05 to 0.20 in atomic ratio) [hereinafter referred to as (Ti, Cr ) N]], the (Ti, Cr) N layer is highly oriented on the (200) plane, and the (200) plane is formed by vapor deposition with a very thin average layer thickness of 0.05 to 0.5 μm. ) An X-ray diffraction pattern with a half-value width of the surface peak of 2θ and 0.9 degrees or less is shown. The (Cr, V) N layer, which shows an X-ray diffraction pattern with a half-width of a peak at the (200) plane of the originally X-ray diffraction pattern being 1.2 degrees or more, is also deposited (Ti, Cr) N. Due to the crystal orientation history effect due to the layer, the half width of the peak of the (200) plane shows a high orientation X-ray diffraction pattern of 0.9 degrees or less at 2θ as illustrated in FIG.
[0007]
(B) A highly oriented (Cr, V) N layer in which the half-value width of the peak in the (200) plane of the X-ray diffraction pattern is 0.9 or less at 2θ is 1.2. The high temperature characteristics (high temperature oxidation resistance and high temperature hardness) are superior to those of the (Cr, V) N layer at a higher degree, so that the hard coating layer composed of the highly oriented (Cr, V) N layer is superb. Coated carbide tools that are physically vapor-deposited on the surface of a hard substrate should exhibit excellent wear resistance in high-speed cutting of work materials such as high-hardness steel and Ti alloys 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
The compositional formula: (Ti _1-X Cr _X ) N (wherein X is 0.05 to 0.20 in terms of atomic ratio) is satisfied and 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 0.9 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. Through the crystal orientation history layer consisting of the (Ti, Cr) N layer shown,
(B) having an average layer thickness of 0.5 to 7 μm;
Composition formula: (Cr _1-Y V _Y ) N (wherein Y represents 0.4 to 0.7 in atomic ratio),
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 0.9 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. This is characterized by a coated cemented carbide tool that exhibits physical wear resistance with a hard coating layer excellent in high-speed cutting, which is formed by physical vapor deposition of a hard coating layer composed of a (Cr, V) N layer.
[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, Cr) N layer]
The Cr component in the (Ti, Cr) N layer has the effect of orienting the (200) plane of the layer in a direction perpendicular to the rake face and flank face of the cutting edge, but the Cr ratio is the total amount of Ti. If the ratio (atomic ratio) to less than 0.05 is insufficient, the orientation effect on the (200) plane is insufficient, and the full width at half maximum of the maximum peak appearing on the (200) plane is 0.9 or less at 2θ. On the other hand, even if the ratio exceeds 0.20, the crystal orientation is disturbed and it becomes difficult to highly orient the (200) plane. It was set to ~ 0.20.
In addition, 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, Cr) N 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 [(Cr, V) N layer]
The V component of the (Cr, V) N layer has the effect of imparting high hardness to CrN having toughness and thereby improving the wear resistance of the layer, but the proportion of the proportion to the total amount of Cr ( If the atomic ratio is less than 0.4, the desired hardness improvement effect cannot be obtained. On the other hand, if the ratio exceeds 0.7, chipping (minute chipping) is likely to occur on the cutting edge. The ratio was set to 0.4 to 0.7.
Also, if the average layer thickness is less than 0.5 μm, the desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 7 μm, chipping tends to occur on the cutting edge. The average layer thickness was set to 0.5-7 μm.
Furthermore, the half-value width of the highest peak appearing on the (200) plane of the X-ray diffraction pattern: 2θ of 0.9 degrees or less is determined empirically based on the test results, and therefore the half-value width is 2θ. In the case of 0.9 degrees or less, excellent wear resistance is exhibited particularly in high-speed cutting, and the half width increases beyond 0.9 degrees, that is, the orientation of the (200) plane decreases. 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, after sintering, WC-based carbide with honing of R: 0.03 on the cutting edge and chip shape of ISO standard CNMG120408 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, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to obtain 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. As the (evaporation source), a Ti-Cr alloy for forming a crystal orientation history layer and a Cr-V alloy for forming a hard coating layer having various component compositions are mounted, and the inside of the apparatus is evacuated and maintained at a vacuum of 0.5 Pa. However, after heating the inside of the apparatus to 700 ° 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 cemented carbide substrate, and the surface of the cemented carbide substrate was applied. After cleaning with Ar gas bombardment, nitrogen gas was introduced into the apparatus as a reaction gas to make a reaction atmosphere of 4 Pa, and the bias voltage applied to the carbide substrate was lowered to −30 V, An arc discharge is generated between the cathode electrode and the anode electrode, and thus the crystal orientation history of the target compositions and target layer thicknesses shown in Tables 3 and 4 is formed on the surfaces of the carbide substrates A1 to A10 and B1 to B6. By depositing the layer [(Ti, Cr] and the hard coating layer [(Cr, V) N layer], the shape shown in the schematic perspective view in FIG. The present invention surface-coated cemented carbide throwaway tips (hereinafter referred to as the present invention coated carbide tips) 1 to 20 as the coated carbide tools of the present invention were produced.
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, Cr) N 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 · SKD61 (Hardness: HRC45) round bar,
Cutting speed: 80 m / min. ,
Incision: 1.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 3 minutes
Wet high-speed continuous turning test of hardened steel under the conditions (using water-soluble cutting oil),
Work material: JIS / SNCM439 (Hardness: HB295) in the longitudinal direction with four equally spaced round bars,
Cutting speed: 330 m / min. ,
Incision: 3.2 mm,
Feed: 0.38 mm / rev. ,
Cutting time: 5 minutes
Wet high-speed intermittent turning test (using water-soluble cutting oil) of alloy steel under the conditions of
Work material: Ti alloy round bar having a composition of Ti-6% Al-4% V (mass%),
Cutting speed: 100 m / min. ,
Cutting depth: 2.8 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 8 minutes
The wet high-speed continuous turning test (using water-soluble cutting oil) of Ti alloy under the above conditions was performed, 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, Cr) N layer] and the hard coating layer [(Cr, V) 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, Cr) N 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 / SNCM439 plate material,
Cutting speed: 280 m / min. ,
Axial cut: 6mm,
Radial depth of cut: 0.2mm
Table feed: 2000mm / min,
About the wet high-speed side cutting 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 size: 100 mm × 250 mm, thickness: 50 mm, composition: Ti-6% Al-4% V (mass%) plate material,
Cutting speed: 120 m / min. ,
Axial cut: 5mm,
Radial depth of cut: 0.2mm
Table feed: 800mm / min,
For the wet high-speed side cutting test of Ti alloy under the conditions of the present invention, the coated carbide end mills 7 and 8 of the present invention and the conventional coated carbide end mills 7 and 8,
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 100 m / min. ,
Axial cut: 10 mm,
Radial depth of cut: 0.2 mm,
Table feed: 3000 mm / min,
The wet high-speed side cutting test of hardened steel under the above conditions (both tests use water-soluble cutting oil) was conducted, and the diameter of the tip surface of the cutting edge was used as a guide for the service life in both groove cutting tests. The cutting length until it was reduced by 0.1 mm was measured. 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, Cr) N layer] and the hard coating layer [(Cr, Cr) having the target composition and target layer thickness shown in Table 12 under the same conditions as in Example 1 above. V) N layer] is vapor-deposited, and the book as a coated carbide tool of the present invention having the shape shown in the schematic front view of FIG. 6A and the schematic cross-sectional view of the groove forming portion in FIG. Invention surface-coated cemented carbide drills (hereinafter referred to as conventional coated carbide drills) 1 to 8 were produced.
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, Cr) N 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 size: 100 mm × 250 mm, thickness: 50 mm, composition: Ti-6% Al-4% V (mass%) plate material,
Cutting speed: 38 m / min. ,
Feed: 0.11 mm / rev,
About the wet high-speed drilling machining test of Ti alloy 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 dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 45 m / min. ,
Feed: 0.15mm / rev,
For the wet high speed drilling cutting test of hardened steel under the conditions of the present invention, the coated carbide drills 7 and 8 of the present invention and the conventional coated carbide drills 7 and 8,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / SNCM439 plate material,
Cutting speed: 150 m / min. ,
Feed: 0.25mm / rev,
Wet high-speed drilling machining test of alloy steel under the above conditions, and in any wet high-speed drilling machining test (using water-soluble cutting oil), until the flank wear width of the tip cutting edge surface reaches 0.3 mm The number of holes drilled 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, Cr) N layer] and hard coating layer [(Cr, V) N layer], as well as conventionally coated carbide tips 1 to 20 as conventionally coated carbide tools, conventionally coated carbide end mills 1 to 8, and About the composition of the hard coating layer [(Cr, V) 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 rake face and / or the flank face of the cutting blade were observed with an X-ray diffractometer using Cu-Kα rays for the above-mentioned constituent layers of the coated carbide tool of the present invention and the conventional coated carbide tool. 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, when accurate measurement was difficult, the arc ion plating apparatus was simultaneously installed in the above embodiment. 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 of the present invention is excellent in wear resistance even when high-hardness steel or Ti alloy is machined at high speed with high heat generation, whereas the hard coating layer ( In the conventional coated carbide tool having a low orientation of the (200) plane, it is apparent that the wear progress of the cutting edge is high 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 has excellent wear resistance even in high-speed cutting of work materials such as hard steels such as hardened steel and high carbon steel, and various Ti alloys having high hardness. Since it exhibits excellent cutting performance over a long period of time, it can fully satisfactorily respond to higher performance of 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 chip 3 of the present invention.
FIG. 2 is an X-ray diffraction pattern shown by a hard coating layer of a conventional coated carbide chip 3;
FIG. 3 is a schematic explanatory diagram of an arc ion plating apparatus.
4A is a schematic perspective view of a coated carbide chip, and FIG. 4B is a schematic longitudinal sectional view of the coated carbide chip.
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 Cr _X ) N (wherein X is 0.05 to 0.20 in atomic ratio),
Furthermore, 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 0.9 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. Through the crystal orientation history layer consisting of the Ti-Cr composite nitride layer shown,
(B) having an average layer thickness of 0.5 to 7 μm;
Composition formula: (Cr _1-Y V _Y ) N (wherein Y represents 0.4 to 0.7 in atomic ratio),
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 0.9 degrees or less as measured by an X-ray diffractometer using Cu-Kα rays. It is formed by physical vapor deposition of a hard coating layer composed of a composite nitride layer of Cr and V.
A surface-coated cemented carbide cutting tool that exhibits high wear resistance with a hard coating layer in high-speed cutting.