JP2004230515A

JP2004230515A - Tool for highly functional processing

Info

Publication number: JP2004230515A
Application number: JP2003022734A
Authority: JP
Inventors: Norihiro Katou; 範博加藤; Masaru Sonobe; 勝園部; Yoshio Kizawa; 敬男木沢
Original assignee: Nachi Fujikoshi Corp
Current assignee: Nachi Fujikoshi Corp
Priority date: 2003-01-30
Filing date: 2003-01-30
Publication date: 2004-08-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool for highly functional processing of a film structure which sufficiently displays resistance of oxidization of a TiAlSiN film even when a content of Si exceeds 10% on a parent material of high speed steel and a cemented carbide alloy, and secures adhesivity between the covered parent material which is a tool base body and a hard coat, and hardness. <P>SOLUTION: This tool is alternately and respectively covered with, by arc discharge ion plating, more than one layers each of of an (a) layer made of a chemical composition a component of the hard coat of which is shown as (Ti<SB>x</SB>Al<SB>l-x-y</SB>Si<SB>y</SB>)(C<SB>z</SB>N<SB>l-z</SB>), where 0.3≤x≤0.45, 0.1<y≤0.3, 0≤z≤0.4 in atomic fraction of a metallic element and a (b) layer made of a chemical composition shown as (Ti<SB>x</SB>Al<SB>l-x</SB>)(C<SB>z</SB>N<SB>l-z</SB>), where 0.3≤x≤0.7, 0≤z≤0.2 in the atomic fraction of the metallic element, and the (b) layer is on a surface of the covered parent material. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】本発明は、複層コーティングを施した金属材料などのフライス加工、切削加工、穿孔加工用の加工工具に関し、特に高能率加工でき高温下での耐酸化性、耐摩耗性及び密着性に優れた硬質被膜を被覆した工具に関する。
【０００２】
【従来の技術】従来の硬質被膜を被覆した工具として、ＴｉＮ、ＴｉＣ、ＴｉＣＮなどなどのセラミックスを単層又は複層にコーティングしたものが開発され、実用に供されてきた。これらの硬質被膜では切削工具の寿命延長を図る目的で耐摩耗性に優れた高硬度の硬質被膜が求められてきた。そして金属加工の高能率化と共に切削工具に要求される機能も従来の工具寿命から高能率加工時の刃先保護へと変化して来た。高能率加工では切削速度の増加に従って加工時の発熱量も増大しており、それに伴って硬質被膜も従来のＴｉＣ、ＴｉＣＮ被膜から例えば特開平２−１９４１５９号公報に開示するような耐熱性に優れたＴｉＡｌＮ被膜へと変遷して来た。ところが、近年の加工機械の能力向上に伴って切削速度がさらに向上し、ＴｉＡｌＮ被膜でも耐熱性が不十分になってきた。これに対してＴｉＡｌＮ膜の耐熱性を向上させる添加元素についての研究が行われ、特許文献１に記述されているＳｉの添加が耐熱性の向上に対して有効であることが分かった。しかしながら、金属元素の原子分率でＳｉの含有量が１０％を越えると耐熱性自身は向上するものの被膜自身の密着性が低下し、かつ被膜の硬度が低下するため、十分な耐摩耗性が得られなかった。このためＳｉの含有量が１０％を越えても被膜の密着性と硬度が確保されている硬質被膜の開発が期待されていた。
【０００３】
【特許文献１】特許２７９３７７３請求項１、〔００１０〕
【特許文献２】特許３０８９２６２請求項２、〔００１４〕表１
【特許文献３】特開２００２−９６２０５請求項１、〔００２９〕表３
【特許文献４】特開２００２−３３７００２請求項１、〔００１８〕表１
【特許文献５】特開２００２−３３７００６請求項１、〔００２２〕表１
【０００４】
この他にも金属加工の高能率化を目的としてＴｉＡｌＮ被膜にＳｉを添加した例がいくつかあるが、それぞれ次の様な問題があった。特許文献２ではＴｉＡｌＳｉ合金をターゲット材料として用いスパッタリング法によりＴｉＡｌＳｉＮ膜を成膜しているが、スパッタリング法ではターゲット材料に用いている材料元素のスパッタ収率の相違により成分が継続的に変化しやすいため、この変化を見込んだ組成のターゲットを要する。また、被膜の密着性が必ずしも良好でなく、複雑な形状の基材を被覆する場合の生産性も低い。さらにスパッタ粒子のイオン化率が低いため、基板に突入するイオンの量が少なく、従って十分な膜硬さが得られないという欠点があった。さらに成膜速度が遅く量産化が困難である。
【０００５】
さらに、特許文献３では、工具基体に直接にＴｉ、Ａｌ、Ｓｉからなる金属元素と、Ｂ、Ｃ、Ｎ、Ｏから選択される少なくとも１種以上の元素から構成される硬質層を１層以上被覆した硬質被覆工具において、該硬質層にＳｉの窒化物層を介在させたものが開示され、その〔００２９〕表３では、ＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものが開示されている。しかしながら工具基体に直接にＴｉＡｌＳｉＮ膜、又はＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものでは、工具基体とＴｉＡｌＳｉＮ膜との密着性が悪く、硬質被膜の硬度が低下するため、十分な耐摩耗性が得られなかった。
【０００６】
また、特許文献４では、工具基体表面に直接にＴｉ、Ａｌ、Ｓｉからなる金属元素と、Ｂ、Ｃ、Ｎ、Ｏから選択される少なくとも１種以上の元素から構成される硬質層を１層以上被覆した硬質被覆工具において、該硬質層にＳｉを含有し、相対的にＳｉに富みアモルファスであるＴｉとＡｌとＳｉとＣ、Ｎ、Ｏ、Ｂ、から選択されるすくなくとも１種以上の化合物相と、相対的にＳｉに乏しい結晶質のＴｉとＡｌとＳｉとＣ、Ｎ、Ｏ、Ｂ、から選択されるすくなくとも１種以上の化合物相と、から構成されたものが開示され、その〔００１８〕表１では、Ｓｉに富む化合物相とＳｉに乏しい化合物相とから構成されたＴｉＡｌＳｉＮ膜と、比較例として被覆条件により均一な（ＴｉＡｌＳｉ）Ｎ固溶体被膜であるＴｉＡｌＳｉＮ膜と、かかる各ＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものが開示されている。相対的にＳｉに富む化合物相と相対的にＳｉに乏しい化合物相とから構成されたＴｉＡｌＳｉＮ膜は製造が複雑で極めて厳格な工程管理を行なわないと所望の構成の被膜を形成することが難しく、多くの手間とコストを要するだけでなく、工具基体に直接にＴｉＡｌＳｉＮ膜、又はＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものでは、工具基体とＴｉＡｌＳｉＮ膜との密着性が悪く、硬質被膜の硬度が低下するため、十分な耐摩耗性が得られなかった。
【０００７】
同様に、特許文献５では、その〔００２２〕表１では特許文献４と同様な、Ｓｉに富む化合物相とＳｉに乏しい化合物相とから構成されたＴｉＡｌＳｉＮ膜と、かかるＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものが開示されている。相対的にＳｉに富む化合物相と相対的にＳｉに乏しい化合物相とから構成されたＴｉＡｌＳｉＮ膜は製造が複雑で極めて厳格な工程管理を行なわないと所望の構成の被膜を形成することが難しく、多くの手間とコストを要するだけでなく、工具基体に直接にＴｉＡｌＳｉＮ膜、又はＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものでは、工具基体とＴｉＡｌＳｉＮ膜との密着性が悪く、硬質被膜の硬度が低下するため、十分な耐摩耗性が得られなかった。
【０００８】
【発明が解決しようとする課題】本発明の課題は、ＴｉＡｌＳｉＮ系膜の優れた耐酸化性に注目し、金属元素の原子分率でＳｉの含有量が１０％を越えてもＴｉＡｌＳｉＮ系膜の耐酸化性を充分に発揮することのでき、工具基体である被覆母材と硬質被膜との密着性と硬度が確保された膜構造を提供することにある。
【０００９】
【課題を解決するための手段】このため本発明は、高速度鋼、超硬合金のいずれかを母材質とし、アーク放電イオンプレーティング法により硬質被膜を被覆してなる工具であって、前記硬質被膜の成分が、
（Ｔｉ_ｘＡｌ_{１−ｘ−ｙ}Ｓｉ_ｙ）（Ｃ_ｚＮ_１−ｚ）、ただし金属元素の原子分率で
０．３≦ｘ≦０．４５，０．１＜ｙ≦０．３，０≦ｚ≦０．４で示される化学組成からなるａ層と、
（Ｔｉ_ｘＡｌ_１−ｘ）（Ｃ_ｚＮ_１−ｚ）、ただし金属元素の原子分率で、
０．３≦ｘ≦１．０，０≦ｚ≦０．２で示される化学組成からなるｂ層と、
がそれぞれ１層以上交互に被覆されたものであり、
かつ、ｂ層が被覆母材表面上にあることを特徴とする高機能加工工具を提供することによって上述した課題を解決した。
【００１０】
より望ましくは、前記ａ層のｘ、ｙ、ｚは金属元素の原子分率で、
０．３１≦ｘ≦０．３９，０．１１＜ｙ≦０．２１，０≦ｚ≦０．４，そして
前記ｂ層のｘ、ｙ、ｚは金属元素の原子分率で、０．４≦ｘ≦０．６，
０≦ｚ≦０．２である
【００１１】
【発明の効果】本発明者らはＴｉＡｌＳｉＮ系膜の耐熱性をより一層向上させることを目的として大気中での耐酸化性を向上させることのできるＳｉ添加量の範囲を調査した。その結果表１に示す様にＳｉの添加量が金属元素の原子分率で１０％を越えた場合に耐酸化性向上の効果が高くＳｉ添加量の増加に伴ってその効果が高くなることを見出した。しかしながら、特許文献１にも記載があるようにＳｉ添加量の増加は結晶系が立方晶から六法晶に変化してしまい、被膜硬さが低下して十分な耐摩耗性を得ることが出来なくなる。一般に物理気相蒸着法により成膜された被覆膜は成膜される下地の結晶構造および結晶方位の影響を受け、結晶構造が等しく格子定数が近い結晶系では特にその傾向は顕著になることが一般的に知られている。本発明者らは気相合成法のこのような特性を利用し、上述した本発明の構成の、被覆母材とＴｉＡｌＳｉＮ系膜との界面に結晶学的に格子定数が近い立方晶系のＴｉＡｌＮ被膜を被覆することで、被覆母材上に直接にＴｉＡｌＳｉＮ膜、又はＴｉＡｌＳｉＮ膜の上にＴｉＡｌＮ膜を被覆したものに比べて、工具基体である被覆母材とＴｉＡｌＮ膜との密着性を良くし、ＴｉＡｌＮ膜の上に被覆されたＴｉＡｌＳｉＮ膜とＴｉＡｌＮ膜との密着性を良くし、被覆母材上の硬質被膜の硬度の低下を防止して、ＴｉＡｌＮ膜よりも優れた硬度と高い密着性を有する硬質被膜を得た。本発明における硬質被膜の構成を図１に示す。
【００１２】
【表１】

【００１３】
本発明の硬質被膜ａ層を構成する金属元素中のＴｉの原子比率は、図２に示した膜硬度の測定結果から、金属元素の原子分率で３０％以上、４５％以下、より望ましくは３１％以上、３９％以下を満足することが必要である。図２において左端のものは比較例である。同じく硬質被膜ａ層におけるＳｉの添加量は、耐酸化性の観点から金属元素の原子分率で１０％以上で多ければ多いほど効果が高いが、３０％を越えると密着性が低下し、切削に耐えることが出来ない。より望ましくは１１％以上、２１％以下である。
【００１４】
本発明において硬質被膜ａ層の密着性を向上し、被膜の硬度低下を抑制する下地の硬質被膜ｂ層ＴｉＡｌＣＮ膜としてはａ層と結晶構造の等しいＴｉＡｌＮ系の被膜である必要がある。従って硬質被膜ｂ層における金属元素中のＴｉの原子比率は金属元素の原子分率で７０％以下を満足する必要があり、０％、すなわちＴｉＮでもかまわないが、より望ましくは同４０％以上６０％以下である。
【００１５】
又、本発明では硬質被膜ａ層およびｂ層の窒素の一部を炭素で置き換えることが可能であるが、硬質被膜ａ層においては炭素の添加量が増えると耐酸化性が低下することから金属元素の原子分率で４０％以下、より望ましくは２０％以下である必要があり、硬質被膜ｂ層においては炭素の添加量が増えると密着性が低下するため２０％以下である必要がある。
【００１６】
切削工具としての適用する場合の硬質被膜ａ層の厚さとしては０．３μｍ以上１０μｍ以下、より望ましくは２．１μｍ以上３．２μｍ以下であることが望ましいく、硬質被膜ｂ層の厚さとしては０．２μｍ以上５μｍ以下、より望ましくは０．３μｍ以上０．６μｍ以下であることが望ましく、それぞれ下限値未満では膜自体の強度が不足し、また上限値以上では切削時の衝撃によって被膜にきれつが生じ、膜厚が薄い場合と同様に母材を保護することができない。そして全体の硬質被膜の厚さとしては０．５μｍ以上１０μｍ以下、より望ましくは２．４μｍ以上３．７μｍ以下であることが望ましく、膜の厚さが０．５μｍ未満であると膜自体の強度が不足し、被膜に容易に亀裂が入るため、母材を発熱から保護することができない。また、被膜の厚さが１０μｍを越えると切削時の衝撃によって被膜にきれつが生じ、膜厚が薄い場合と同様に母材を保護することができない。
【００１７】
【発明の実施の形態】〔実施例１〕図３に示すアーク方式イオンプレーティング装置に、１２．７ｍｍ角の超硬合金チップ素材を装着して真空ポンプにて０．１３３Ｐａ以下まで排気し、ヒータにより４００〜５００℃に加熱した。所定の温度に達した後、アルゴンガスによってイオンボンバードを施した上、０．６６６〜０．４Ｐａの窒素ガスを導入して硬質被膜ｂ層としてＴｉＮ膜又はＴｉＣＮ膜を０．３μｍ成膜した。その後、硬質被膜ｂ層の上にＴｉ_０．４Ａｌ_０．４Ｓｉ_０．２，Ｔｉ_０．３Ａｌ_０．５Ｓｉ_０．２またはＴｉ_０．５Ａｌ_０．５ターゲットを組み合わせて、基板電圧５０Ｖを印加して、表１に示す金属元素の原子分率で示す種々の組成の硬質被膜ａ層を得た。電子プローブマイクロアナリシスにより得られた硬質被膜ｂの金属成分の構成比とマイクロビッカース硬度計で測定した被膜の硬度を表１に示す。表１からＳｉの添加により膜硬度が向上していること、ならびにＳｉ含有量が１０％を越えた場合においても被膜の硬度低下が生じていないことがわかる。
【００１８】
〔実施例２〕実施例１で作製した被覆超硬チップを大気中で１０００℃、１時間加熱保持し、鋼球による擦過痕を利用したカロテスト法により酸化物層の膜厚を測定した結果を表１中に併記した。従来例１，２，３及び比較例２ではＳｉ含有量が１０％より少ないために耐酸化性が本発明品よりも劣っていた。
【００１９】
〔実施例３〕実施例１に示したコーティング条件にて超硬製のエンドミルφ１０に、表２に示す金属元素の原子分率で示す当該硬質被膜を被覆し、下記の切削条件にて切削試験を実施した。切削試験結果を表２に示す。

【００２０】
【表２】

【図面の簡単な説明】
【図１】本発明の実施の形態の膜構成を示す説明図。
【図２】本発明の実施例１によって得られた被膜の硬度分布を示すグラフ。
【図３】本発明の実施例実施例１〜３に使用したアーク方式イオンプレーティング装置のブロック図。
【符号の説明】
１・・真空装置２・・電子銃３・・工具取り付け治具
４・・アノード５・・金属蒸発源６・・アルゴンガス導入口
７・・窒素ガス導入口８・・金属蒸発源用直流電源９・・電子銃用直流電源
１０・・基板用直流電源１１・・真空排気口１２・・加熱用ヒータ[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining tool for milling, cutting, and drilling a metal material having a multi-layer coating, and more particularly to a high-efficiency machining, oxidation resistance and abrasion resistance at high temperatures. The present invention relates to a tool coated with a hard coating having excellent properties and adhesion.
[0002]
2. Description of the Related Art As a conventional tool coated with a hard film, a tool coated with ceramics such as TiN, TiC, TiCN or the like in a single layer or a plurality of layers has been developed and put to practical use. For these hard coatings, high hardness hard coatings having excellent wear resistance have been demanded in order to extend the life of cutting tools. The functions required for cutting tools have been changing from the conventional tool life to the protection of the cutting edge during high-efficiency machining with the increase in metal machining efficiency. In high-efficiency machining, the calorific value at the time of machining increases as the cutting speed increases. Accordingly, the hard coating is also superior to conventional TiC and TiCN coatings in heat resistance as disclosed in, for example, JP-A-2-194159. Has changed to a TiAlN coating. However, the cutting speed has been further improved with the recent improvement in processing machine performance, and even with a TiAlN film, the heat resistance has become insufficient. On the other hand, a study has been conducted on an additive element for improving the heat resistance of the TiAlN film, and it has been found that the addition of Si described in Patent Document 1 is effective for improving the heat resistance. However, when the content of Si exceeds 10% in terms of the atomic ratio of the metal element, the heat resistance itself is improved, but the adhesion of the film itself is reduced, and the hardness of the film is reduced. Could not be obtained. For this reason, the development of a hard coating in which the adhesion and hardness of the coating are ensured even when the content of Si exceeds 10% has been expected.
[0003]
[Patent Document 1] Japanese Patent 2793773 Claim 1, [0010]
[Patent Document 2] Japanese Patent No. 3089262 Claim 2, [0014] Table 1
[Patent Document 3] JP-A-2002-96205 Claim 1, [0029] Table 3
[Patent Document 4] JP-A-2002-337002 Claim 1, [0018] Table 1
[Patent Document 5] JP-A-2002-337006 Claim 1, [0022] Table 1
[0004]
In addition to these, there are some examples in which Si is added to a TiAlN film for the purpose of improving the efficiency of metal working, but each has the following problems. In Patent Document 2, a TiAlSiN film is formed by a sputtering method using a TiAlSi alloy as a target material. However, in the sputtering method, components continuously change due to a difference in a sputtering yield of a material element used in the target material. Therefore, a target having a composition that allows for this change is required. Further, the adhesion of the coating is not always good, and the productivity when coating a substrate having a complicated shape is low. Furthermore, since the ionization rate of sputtered particles is low, the amount of ions rushing into the substrate is small, so that there is a disadvantage that sufficient film hardness cannot be obtained. Furthermore, the film formation rate is low and mass production is difficult.
[0005]
Further, in Patent Document 3, one or more hard layers composed of a metal element composed of Ti, Al, and Si and at least one element selected from B, C, N, and O are directly provided on a tool base. A coated hard-coated tool in which a silicon nitride layer is interposed in the hard layer is disclosed. [0029] Table 3 discloses a tool in which a TiAlN film is coated on a TiAlSiN film. However, if the tool base is directly coated with a TiAlSiN film or a TiAlSiN film coated with a TiAlN film, the adhesion between the tool base and the TiAlSiN film is poor, and the hardness of the hard coating is reduced. Could not be obtained.
[0006]
In Patent Document 4, one hard layer composed of a metal element composed of Ti, Al, and Si and at least one or more elements selected from B, C, N, and O is directly provided on a tool base surface. In the hard-coated tool coated as described above, at least one compound selected from Ti, Al, Si, and C, N, O, and B, which contains Si in the hard layer and is relatively rich and amorphous. A phase comprising at least one phase selected from the group consisting of crystalline Ti, Al, Si and C, N, O, and B, which are relatively low in Si, and at least one compound phase selected from the group consisting of C, N, O, and B. Table 1 shows that a TiAlSiN film composed of a compound phase rich in Si and a compound phase poor in Si, and a TiAlSiN film which is a uniform (TiAlSi) N solid solution film under coating conditions as a comparative example. Those coated with a TiAlN film on the TiAlSiN film is disclosed. The production of a TiAlSiN film composed of a relatively Si-rich compound phase and a relatively Si-poor compound phase is difficult, and it is difficult to form a film having a desired structure unless extremely strict process control is performed. Not only requires much labor and cost, but also in the case where a TiAlSiN film is directly coated on a tool base or a TiAlN film is coated on a TiAlSiN film, the adhesion between the tool base and the TiAlSiN film is poor, and the hardness of the hard coating is low. As a result, sufficient wear resistance was not obtained.
[0007]
Similarly, Patent Literature 5 discloses a TiAlSiN film composed of a Si-rich compound phase and a Si-poor compound phase in Table 1 as in Patent Literature 4, and a TiAlN film on the TiAlSiN film. Are disclosed. The production of a TiAlSiN film composed of a relatively Si-rich compound phase and a relatively Si-poor compound phase is difficult, and it is difficult to form a film having a desired structure unless extremely strict process control is performed. Not only requires much labor and cost, but also in the case where a TiAlSiN film is directly coated on a tool base or a TiAlN film is coated on a TiAlSiN film, the adhesion between the tool base and the TiAlSiN film is poor, and the hardness of the hard coating is low. As a result, sufficient wear resistance was not obtained.
[0008]
An object of the present invention is to focus on the excellent oxidation resistance of a TiAlSiN-based film, and even if the content of Si exceeds 10% by atomic ratio of a metal element, the TiAlSiN-based film has It is an object of the present invention to provide a film structure that can sufficiently exhibit oxidation resistance and that ensures the adhesion and hardness between a coating base material as a tool base and a hard coating.
[0009]
Accordingly, the present invention provides a tool comprising a high-speed steel or a cemented carbide as a base material and coated with a hard coating by an arc discharge ion plating method. The component of the hard coating is
_{_{_{(Ti x Al 1-x-}}} y Si y) (C z N 1-z), except in atomic percent of metallic elements 0.3 ≦ x ≦ 0.45,0.1 <y ≦ 0.3, 0 A layer having a chemical composition represented by ≦ z ≦ 0.4,
_{_{_{(Ti x Al 1-x)}}} (C z N 1-z), except in atomic percent of metallic elements,
A b layer having a chemical composition represented by 0.3 ≦ x ≦ 1.0 and 0 ≦ z ≦ 0.2;
Are alternately coated by at least one layer,
In addition, the above-mentioned problem has been solved by providing a high-performance machining tool characterized in that the layer b is on the surface of the coated base material.
[0010]
More preferably, x, y, and z of the a layer are atomic percentages of a metal element,
0.31 ≦ x ≦ 0.39, 0.11 <y ≦ 0.21, 0 ≦ z ≦ 0.4, and x, y, and z of the b layer are the atomic fractions of the metal elements, and 0.4 ≦ x ≦ 0.6,
0 ≦ z ≦ 0.2
The present inventors have investigated the range of the amount of Si that can improve the oxidation resistance in air for the purpose of further improving the heat resistance of the TiAlSiN-based film. As a result, as shown in Table 1, when the addition amount of Si exceeds 10% in the atomic fraction of the metal element, the effect of improving the oxidation resistance is high, and the effect increases as the addition amount of Si increases. I found it. However, as described in Patent Document 1, an increase in the amount of added Si changes the crystal system from a cubic system to a hexagonal system, and reduces the hardness of the coating, making it impossible to obtain sufficient wear resistance. . In general, coating films formed by physical vapor deposition are affected by the underlying crystal structure and crystal orientation, and this tendency is particularly pronounced in crystal systems with the same crystal structure and similar lattice constants. Is generally known. The present inventors take advantage of such characteristics of the vapor phase synthesis method, and have a cubic TiAlN having a crystallographically close lattice constant to the interface between the coating base material and the TiAlSiN-based film of the above-described configuration of the present invention. By coating the coating, the adhesion between the coating base material as the tool base and the TiAlN film is improved as compared with a TiAlSiN film directly on the coating base material or a TiAlN film coated on the TiAlSiN film. , To improve the adhesion between the TiAlN film and the TiAlSiN film coated on the TiAlN film, prevent the hardness of the hard coating on the coating base material from decreasing, and achieve a higher hardness and higher adhesion than the TiAlN film. To obtain a hard coating. FIG. 1 shows the configuration of the hard coating according to the present invention.
[0012]
[Table 1]

[0013]
From the measurement results of the film hardness shown in FIG. 2, the atomic ratio of Ti in the metal element constituting the hard coating a layer of the present invention is 30% or more and 45% or less in terms of the atomic ratio of the metal element, and more desirably. It is necessary to satisfy 31% or more and 39% or less. In FIG. 2, the one on the left is a comparative example. Similarly, from the viewpoint of oxidation resistance, the more the amount of Si added to the hard coating a layer is 10% or more in terms of the atomic ratio of the metal element, the more the effect is increased. I can not stand it. More preferably, it is 11% or more and 21% or less.
[0014]
In the present invention, the TiAlCN film having the same crystal structure as the a layer needs to be a TiAlN-based film as the underlying hard film b layer TiAlCN film which improves the adhesion of the hard film a layer and suppresses the decrease in hardness of the film. Therefore, the atomic ratio of Ti in the metal element in the hard coating b layer must satisfy 70% or less in terms of the atomic fraction of the metal element, and may be 0%, that is, TiN, but more preferably 40% or more. % Or less.
[0015]
Further, in the present invention, it is possible to replace a part of nitrogen in the hard coating a layer and the b layer with carbon. However, in the hard coating a layer, the oxidation resistance decreases as the amount of added carbon increases. The atomic fraction of the element must be 40% or less, more desirably 20% or less. In the hard coating b layer, if the amount of carbon added increases, the adhesion decreases, and therefore it needs to be 20% or less.
[0016]
When applied as a cutting tool, the thickness of the hard coating a layer is preferably not less than 0.3 μm and not more than 10 μm, more preferably not less than 2.1 μm and not more than 3.2 μm. Is preferably 0.2 μm or more and 5 μm or less, more preferably 0.3 μm or more and 0.6 μm or less. If the value is less than the lower limit, the strength of the film itself is insufficient. Cracks occur and the base material cannot be protected as in the case where the film thickness is small. The thickness of the entire hard coating is preferably 0.5 μm or more and 10 μm or less, more preferably 2.4 μm or more and 3.7 μm or less. If the thickness of the film is less than 0.5 μm, the strength of the film itself is reduced. Is insufficient and the coating is easily cracked, so that the base material cannot be protected from heat generation. On the other hand, if the thickness of the coating exceeds 10 μm, cracks occur in the coating due to impact during cutting, and the base material cannot be protected as in the case of a thin film.
[0017]
[Embodiment 1] A cemented carbide chip material of 12.7 mm square is mounted on an arc type ion plating apparatus shown in FIG. 3 and evacuated to 0.133 Pa or less by a vacuum pump. It heated to 400-500 degreeC with the heater. After reaching a predetermined temperature, ion bombardment was performed with an argon gas, and a nitrogen gas of 0.666 to 0.4 Pa was introduced to form a TiN film or a TiCN film of 0.3 μm as a hard coating b layer. Then, a Ti _0.4 Al _0.4 Si _0.2 , Ti _0.3 Al _0.5 Si _0.2 or a Ti _0.5 Al _0.5 target is combined on the hard coating b layer, and a substrate voltage is applied. A voltage of 50 V was applied to obtain hard coating layers a of various compositions represented by the atomic percentages of the metal elements shown in Table 1. Table 1 shows the composition ratio of the metal component of the hard coating b obtained by the electron probe microanalysis and the hardness of the coating measured by a micro Vickers hardness meter. It can be seen from Table 1 that the film hardness was improved by the addition of Si, and that the hardness of the film did not decrease even when the Si content exceeded 10%.
[0018]
Example 2 The coated carbide tip prepared in Example 1 was heated and held in the air at 1000 ° C. for 1 hour, and the result of measuring the thickness of the oxide layer by a calotest method using scratches caused by steel balls was used. Also shown in Table 1. In Conventional Examples 1, 2, 3, and Comparative Example 2, the oxidation resistance was inferior to that of the product of the present invention because the Si content was less than 10%.
[0019]
[Example 3] Under the coating conditions shown in Example 1, an end mill φ10 made of carbide was coated with the hard coating indicated by the atomic fraction of the metal element shown in Table 2, and a cutting test was performed under the following cutting conditions. Was carried out. Table 2 shows the cutting test results.

[0020]
[Table 2]

[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a film configuration according to an embodiment of the present invention.
FIG. 2 is a graph showing a hardness distribution of a coating obtained according to Example 1 of the present invention.
FIG. 3 is a block diagram of an arc-type ion plating apparatus used in Examples 1 to 3 of the present invention.
[Explanation of symbols]
1. Vacuum device 2. Electron gun 3. Tool mounting jig 4. Anode 5. Metal evaporation source 6. Argon gas inlet 7. Nitrogen gas inlet 8. DC power supply for metal evaporation source 9 DC power supply for electron gun 10 DC power supply for substrate 11 Vacuum exhaust port 12 Heater for heating

Claims

High speed steel, one of the cemented carbide as a base material, a tool formed by coating a hard coating by arc discharge ion plating method, components of the hard _{coating, (Ti x Al 1-x} -y Si _y ) (C _z N _1-z ), where 0.3 ≦ x ≦ 0.45, 0.1 <y ≦ 0.3, 0 ≦ z ≦ 0.4 in atomic fraction of the metal element
A layer having a chemical composition represented by:
(Ti _x Al _1-x ) (C _z N _1-z ), where the chemical composition is represented by 0.3 ≦ x ≦ 1.0 and 0 ≦ z ≦ 0.2 in terms of the atomic fraction of the metal element. b layer,
Are alternately coated by at least one layer,
A high-performance machining tool, wherein the b layer is on the surface of the coated base material.

High speed steel, one of the cemented carbide as a base material, a tool formed by coating a hard coating by arc discharge ion plating method, components of the hard _{coating, (Ti x Al 1-x} -y Si _y ) (C _z N _1-z ), where 0.31 ≦ x ≦ 0.39, 0.11 <y ≦ 0.21, and 0 ≦ z ≦ 0.4 in terms of the atomic fraction of the metal element. A layer comprising a chemical composition
(Ti _x Al _1-x ) (C _z N _1-z ), where the chemical composition is represented by 0.4 ≦ x ≦ 0.6 and 0 ≦ z ≦ 0.2 in terms of the atomic fraction of the metal element. b layer,
Are alternately coated by at least one layer,
A high-performance machining tool, wherein the b layer is on the surface of the coated base material.

3. The high-performance machining tool according to claim 1, wherein the thickness of the a-layer is 0.3 to 5 [mu] m.

4. The high-performance machining tool according to claim 3, wherein the thickness of the b layer is 0.3 to 5 [mu] m.

3. The high-performance machining tool according to claim 1, wherein the thickness of the a-layer is 2.1 to 3.2 [mu] m.

The high-performance machining tool according to claim 1, wherein the thickness of the b-layer is 0.3 to 0.6 μm.

7. The high-performance machining tool according to claim 3, wherein a thickness of the hard coating including the a-layer and the b-layer is 0.5 to 10 μm. 8.

The high-performance machining tool according to any one of claims 3 to 6, wherein a thickness of the hard coating including the a layer and the b layer is 2.4 to 3.7 µm.