JP2018144224A - Surface-coated cutting tool - Google Patents

Surface-coated cutting tool Download PDF

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JP2018144224A
JP2018144224A JP2018018809A JP2018018809A JP2018144224A JP 2018144224 A JP2018144224 A JP 2018144224A JP 2018018809 A JP2018018809 A JP 2018018809A JP 2018018809 A JP2018018809 A JP 2018018809A JP 2018144224 A JP2018144224 A JP 2018144224A
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強 大上
Tsutomu Ogami
強 大上
健志 山口
Kenji Yamaguchi
健志 山口
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Mitsubishi Materials Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool which exhibits excellent chipping resistance and abrasion resistance in intermittent cutting.SOLUTION: A surface-coated cutting tool comprises a hard coating layer containing a TiAlN layer on a tool base surface. The TiAlN layer, when represented by a composition formula (TiAl)N, has an average composition satisfying 0.10≤x≤0.35 (where x is an atomic ratio). In the TiAlN layer, compared to the average composition x of a Ti component, high Ti strip regions with a relatively high composition of the Ti component exist at least in a direction where an angle formed with a normal line of the tool base surface is 35-70 degrees. Preferably, in the high Ti strip regions, an average composition Y of the Ti component satisfies (x+0.01)≤Y≤(x+0.05), an average width W of the high Ti strip regions is 30-500 nm, and an average area ratio St of the high Ti strip regions is 3-50 area%.SELECTED DRAWING: Figure 1

Description

この発明は、合金鋼などの断続切削加工において、硬質被覆層がすぐれた耐チッピング性と耐摩耗性を発揮し、長期の使用にわたってすぐれた切削性能を発揮する表面被覆切削工具(以下、被覆工具という)に関するものである。   The present invention provides a surface-coated cutting tool (hereinafter referred to as a coated tool) that exhibits excellent chipping resistance and wear resistance in a hard coating layer in intermittent cutting of alloy steel and the like, and exhibits excellent cutting performance over a long period of use. )).

一般に、被覆工具として、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、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エンドミル、前記被削材の歯形の歯切加工などに用いられるソリッドホブ、ピニオンカッタなどが知られている。
そして、被覆工具の切削性能改善を目的として、従来から、数多くの提案がなされている。
In general, as a coated tool, for throwing inserts that can be used detachably attached to the tip of a cutting tool for turning and planing of various materials such as steel and cast iron, and for drilling and cutting the work material Known drills and miniature drills, end mills used for chamfering and grooving, shoulder processing, etc. of the work material, solid hob, pinion cutter used for gear cutting of the tooth profile of the work material, etc. Yes.
Many proposals have been made for the purpose of improving the cutting performance of the coated tool.

例えば、特許文献1に示すように、工具基体表面に、物理蒸着によって堆積された耐火性層を含むコーティングを含む被覆工具であって、 前記耐火性層がM1−xAlN(式中、x≧0.68であり、MがTi、CrまたはZrである)を含み、前記耐火性層が立方晶結晶相を含有し、少なくとも25GPaの硬度を有する厚膜、高硬度および低残留応力の耐摩耗性被覆工具が提案されている。 For example, as shown in Patent Document 1, a coated tool including a coating including a refractory layer deposited by physical vapor deposition on the surface of a tool base, wherein the refractory layer is M 1-x Al x N (wherein X ≧ 0.68, and M is Ti, Cr or Zr), and the refractory layer contains a cubic crystal phase and has a hardness of at least 25 GPa, high hardness and low residual stress Abrasion-resistant coated tools have been proposed.

また、特許文献2には、工具基体表面にTiAlN層からなる硬質被覆層を被覆した被覆工具において、上記硬質被覆層が、層厚方向にそって、Al最高含有点(Ti最低含有点)とAl最低含有点(Ti最高含有点)とが所定間隔をおいて交互に繰り返し存在し、かつ前記Al最高含有点から前記Al最低含有点、前記Al最低含有点から前記Al最高含有点へAl(Ti)含有量が連続的に変化する成分濃度分布構造を有し、さらに、上記Al最高含有点が、組成式:(Ti1−XAl)N(ただし、原子比で、Xは0.70〜0.95を示す)、上記Al最低含有点が、組成式:(Ti1−YAl )N(ただし、原子比で、Yは0.40〜0.65を示す)、をそれぞれ満足し、かつ隣り合う上記Al最高含有点とAl最低含有点の間隔が、0.01〜0.1μmである耐摩耗性にすぐれた被覆工具が提案されている。 Further, in Patent Document 2, in a coated tool in which a hard coating layer composed of a TiAlN layer is coated on the surface of a tool base, the hard coating layer has an Al maximum content point (Ti minimum content point) along the layer thickness direction. Al lowest content points (Ti highest content points) are alternately present at predetermined intervals, and the Al highest content point to the Al lowest content point, the Al lowest content point to the Al highest content point Al ( Ti) It has a component concentration distribution structure in which the content changes continuously, and the Al highest content point is the composition formula: (Ti 1-X Al X ) N (wherein the atomic ratio, X is 0. 70 to 0.95), and the above-mentioned lowest Al content point is a composition formula: (Ti 1-Y Al Y ) N (wherein Y represents 0.40 to 0.65 in atomic ratio), respectively. Satisfied and adjacent Al highest content point and Al lowest Distance Yu points, coated tool having excellent wear resistance is 0.01~0.1μm have been proposed.

特開2015−36189号公報Japanese Patent Laying-Open No. 2015-36189 特開2003−211304号公報JP 2003-211304 A

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、切削加工はますます高速化・高能率化の傾向にあるが、上記従来の被覆工具においては、これを鋼や鋳鉄などの通常の切削条件での切削加工に用いた場合には、特段の問題は生じないが、これを、例えば、合金鋼等の断続切削加工のような、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷がかかる切削加工に用いた場合には、クラックの発生・伝播を十分に抑制することができず、また、摩耗進行も促進されるため、比較的短時間で使用寿命に至ることが現状である。   In recent years, the performance of cutting machines has been dramatically improved, while there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and as a result, cutting has become a trend toward higher speed and higher efficiency. However, in the above-mentioned conventional coated tool, when this is used for cutting under normal cutting conditions such as steel and cast iron, no particular problem occurs. When used for cutting that involves high heat generation, such as intermittent cutting, and that imposes an impact and intermittent high load on the cutting edge, the generation and propagation of cracks should be sufficiently suppressed. In addition, since the progress of wear is not promoted, the service life is reached in a relatively short time.

例えば、特許文献1に示される従来被覆工具においては、M1−xAlNの一つの形態であるTiAlN層は高硬度で耐摩耗性にすぐれる層であり、Al含有量が多いほど耐摩耗性にすぐれるが、その一方で、格子歪が大きくなるため、耐チッピング性が低下するという問題がある。
また、特許文献2に示される従来被覆工具においては、層厚方向に組成変化を形成することで高温硬さと耐熱性、靱性を両立せしめることができるが、層内の異方性によって、層厚に垂直方向のクラックの発生・伝播を十分に防止することはできないという問題がある。
For example, in the conventional coated tool shown in Patent Document 1, a TiAlN layer which is one form of M 1-x Al x N is a layer having high hardness and excellent wear resistance, and the higher the Al content, the more resistant it is. Although it is excellent in wearability, on the other hand, there is a problem that chipping resistance is lowered because lattice strain increases.
Moreover, in the conventional coated tool shown in Patent Document 2, it is possible to achieve both high-temperature hardness, heat resistance, and toughness by forming a composition change in the layer thickness direction. However, there is a problem that the generation and propagation of vertical cracks cannot be sufficiently prevented.

そこで、本発明者等は、上述の観点から、合金鋼などの断続切削加工のような、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷が作用する切削加工条件下で、硬質被覆層がすぐれた耐チッピング性と耐摩耗性を両立し得る被覆工具を開発すべく、硬質被覆層の成分組成、結晶構造および層構造等に着目し研究を行った結果、以下のような知見を得た。   Therefore, the present inventors, from the above-mentioned viewpoint, are accompanied by high heat generation, such as intermittent cutting of alloy steel, and the cutting conditions under which a shocking and intermittent high load acts on the cutting blade. Below, as a result of conducting research focusing on the component composition, crystal structure and layer structure of the hard coating layer in order to develop a coated tool that can achieve both chipping resistance and wear resistance with excellent hard coating layer, The following knowledge was obtained.

すなわち、本発明者は、工具基体表面に、TiとAlの複合窒化物(以下、「TiAlN」で示す場合がある。)層からなる硬質被覆層を形成した被覆工具において、該層におけるAlのTiとAlとの合量に占める組成割合を比較的高くし、もって、硬質被覆層全体としての耐摩耗性を確保するとともに、該層内には、少なくとも、工具基体表面の法線とのなす角度が30度以下の方向に、Ti成分の組成が相対的に高い帯状領域(以下、「高Ti帯状領域」という場合がある。)を形成することによって、前記特許文献2に示されるような異方性を有する硬質被覆層によってもたらされる剥離発生という問題点を解消するとともに、靱性を有する高Ti帯状領域が切削加工時の衝撃的、断続的な負荷を吸収・緩和することによって、硬質被覆層中のクラックの発生・伝播を抑制し、これらを原因とするチッピング発生を抑制し得る、という知見を得た。
したがって、この知見に基づいて作成された被覆工具は、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷が作用する断続切削加工条件下で、すぐれた耐チッピング性と耐摩耗性を両立することができるのである。
That is, the present inventor, in a coated tool in which a hard coating layer composed of a composite nitride of Ti and Al (hereinafter sometimes referred to as “TiAlN”) layer is formed on the tool base surface, The composition ratio in the total amount of Ti and Al is made relatively high, so that the wear resistance of the hard coating layer as a whole is ensured, and at least the normal of the tool substrate surface is formed in the layer. By forming a band-like region having a relatively high Ti component composition (hereinafter sometimes referred to as a “high Ti band-like region”) in a direction with an angle of 30 degrees or less, as shown in Patent Document 2 above. While eliminating the problem of exfoliation caused by the hard coating layer having anisotropy, the high Ti band-like region having toughness absorbs and relieves shocking and intermittent loads during cutting, thereby making it hard Suppressing crack generation and propagation in Kutsugaeso can suppress chipping occurrence caused them to obtain a finding that.
Therefore, the coated tool created based on this knowledge has high heat generation and excellent chipping resistance under intermittent cutting conditions in which impact and intermittent high loads act on the cutting edge. It is possible to achieve both wear resistance.

本発明者は、上記知見を基にして、硬質被覆層に形成する高Ti帯状領域の工具基体の法線方向に対する角度について、更に研究を行ったところ、新たに、以下の知見を得た。   Based on the above knowledge, the present inventor conducted further research on the angle of the high Ti band-shaped region formed in the hard coating layer with respect to the normal direction of the tool substrate, and newly obtained the following knowledge.

すなわち、TiAlN層からなる硬質被覆層を形成した被覆工具において、該層内に工具基体表面の法線とのなす角が35度以上70度以下の方向に高Ti帯状領域を形成することによっても、前記特許文献2に示されるような異方性を有する硬質被覆層によってもたらされる剥離発生という問題点を解消するとともに、靱性を有する高Ti帯状領域が切削加工時の衝撃的、断続的な負荷を吸収・緩和することによって、硬質被覆層中のクラックの発生・伝播を抑制し、これらを原因とするチッピング発生を抑制し得ることを知見した。さらに、該層内に工具基体表面の法線とのなす角が35度以上70度以下の方向に高Ti帯状領域を形成されることにより、硬質被覆層表面から基材方向に伸展するクラックの伝播を抑制することが分かった。
したがって、これら知見に基づいて作製された被覆工具も、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷が作用する断続切削加工条件下で、すぐれた耐チッピング性と耐摩耗性を両立することができるのである。
That is, in a coated tool in which a hard coating layer made of a TiAlN layer is formed, a high Ti band-shaped region is formed in the direction in which the angle formed with the normal line of the tool base surface is not less than 35 degrees and not more than 70 degrees. In addition to solving the problem of occurrence of delamination caused by the hard coating layer having anisotropy as shown in Patent Document 2, the high Ti band-like region having toughness has an impact and intermittent load during cutting. It has been found that by absorbing and mitigating, the generation and propagation of cracks in the hard coating layer can be suppressed, and the occurrence of chipping caused by these can be suppressed. Furthermore, by forming a high Ti band-shaped region in the direction in which the angle between the normal to the tool substrate surface is not less than 35 degrees and not more than 70 degrees in the layer, cracks extending from the surface of the hard coating layer toward the base material are formed. It was found to suppress propagation.
Therefore, the coated tool produced based on these findings also has excellent chipping resistance under intermittent cutting conditions where high heat is generated and impact / intermittent high load acts on the cutting edge. It is possible to achieve both wear resistance.

この発明は、上記の新たな知見に基づいてなされたものであって、
「(1)WC基超硬合金、TiCN基サーメットおよびcBN焼結体のいずれかからなる工具基体の表面に、0.5〜8.0μmの平均層厚のTiとAlの複合窒化物層を少なくとも含む硬質被覆層が設けられた表面被覆切削工具において、
前記TiとAlの複合窒化物層は、その組成を、組成式:(TiAl1−x)Nで表した場合、0.10≦x≦0.35(ただし、xは原子比)を満足する平均組成を有し、
前記TiとAlの複合窒化物層中には、前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域が、少なくとも、工具基体表面の法線とのなす角度が35度以上70度以下の方向に存在していることを特徴とする表面被覆切削工具。
(2)前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域のTi成分の平均組成をYとした場合、前記TiとAlの複合窒化物層におけるTi成分の平均組成xと前記Yは、(x+0.01)≦Y≦(x+0.05)の関係を満足することを特徴とする上記(1)に記載の表面被覆切削工具。
(3)前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域の平均幅Wは、30〜500nmであることを特徴とする上記(2)に記載の表面被覆切削工具。
(4)前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域が前記TiとAlの複合窒化物層の縦断面に占める、平均面積割合Stは3〜50面積%であることを特徴とする上記(1)乃至(3)のいずれかに記載の表面被覆切削工具。
(5)前記TiとAlの複合窒化物層は、立方晶構造の結晶粒と六方晶構造の結晶粒の混合組織からなり、前記TiとAlの複合窒化物層の縦断面に占める立方晶構造の結晶粒の平均面積割合Sは30面積%以上であることを特徴とする上記(1)乃至(4)のいずれかに記載の表面被覆切削工具。」
を特徴とするものである。
This invention has been made based on the above-mentioned new knowledge,
“(1) A composite nitride layer of Ti and Al having an average layer thickness of 0.5 to 8.0 μm is formed on the surface of a tool base made of any one of a WC-based cemented carbide, a TiCN-based cermet and a cBN sintered body. In a surface-coated cutting tool provided with a hard coating layer containing at least,
The composite nitride layer of Ti and Al has a composition expressed by a composition formula: (Ti x Al 1-x ) N, where 0.10 ≦ x ≦ 0.35 (where x is an atomic ratio). Having a satisfactory average composition,
In the composite nitride layer of Ti and Al, at least an angle formed by a belt-like region having a relatively high Ti component composition as compared to the average composition of the Ti component with the normal of the tool base surface is 35. A surface-coated cutting tool characterized by existing in a direction of not less than 70 degrees and not more than 70 degrees.
(2) When the average composition of the Ti component in the belt-like region where the composition of the Ti component is relatively higher than the average composition of the Ti component is Y, the average of the Ti components in the composite nitride layer of Ti and Al The surface-coated cutting tool according to (1), wherein the composition x and the Y satisfy a relationship of (x + 0.01) ≦ Y ≦ (x + 0.05).
(3) The surface-coated cutting according to (2) above, wherein the average width W of the band-shaped region having a relatively high Ti component composition as compared with the average composition of the Ti component is 30 to 500 nm. tool.
(4) An average area ratio St in which a strip-like region having a relatively high Ti component composition as compared to the average composition of the Ti component occupies the longitudinal section of the composite nitride layer of Ti and Al is 3 to 50 area% The surface-coated cutting tool according to any one of (1) to (3) above, wherein
(5) The Ti and Al composite nitride layer is composed of a mixed structure of cubic crystal grains and hexagonal crystal grains, and occupies a cubic structure in the longitudinal section of the Ti and Al composite nitride layer. The surface-coated cutting tool according to any one of (1) to (4) above, wherein the average area ratio S of the crystal grains is 30 area% or more. "
It is characterized by.

本発明の被覆工具は、硬質被覆層を構成するTiAlN層中に、TiAlN層のTi成分の平均組成xに比して、Ti成分の組成が相対的に高い高Ti帯状領域が、工具基体表面の法線とのなす角度が35度以上70度以下の方向に存在することによって、硬質被覆層の層厚方向に特性、特に靱性に富む高Ti帯状領域が連続して存在することとなり、これによって硬質被覆層全体の特性の異方性が解消されて耐剥離性が向上し、またさらに、靱性を有する高Ti帯状領域が切削加工時の衝撃的、断続的な負荷を吸収・緩和することによって、硬質被覆層中のクラックの発生・伝播が抑制され、さらに、これらを原因とするチッピング発生が抑制されることによって、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷が作用する断続切削加工条件に供された場合であっても、すぐれた耐チッピング性と耐摩耗性を両立することができる。   In the coated tool of the present invention, the TiAlN layer constituting the hard coating layer has a high Ti band-like region having a relatively high Ti component composition compared to the average composition x of the Ti component of the TiAlN layer. When the angle formed with the normal line is in the direction of not less than 35 degrees and not more than 70 degrees, a high Ti band-like region rich in characteristics, particularly toughness, is continuously present in the layer thickness direction of the hard coating layer. This eliminates the anisotropy of the properties of the entire hard coating layer and improves the peel resistance, and furthermore, the tough high Ti band region absorbs and relieves shocking and intermittent loads during cutting. This suppresses the generation and propagation of cracks in the hard coating layer, and further suppresses the generation of chipping caused by these, resulting in high heat generation and impact / intermittent on the cutting edge. High load acts Even when subjected to intermittent cutting conditions, it is possible to achieve both excellent chipping resistance and wear resistance.

本発明被覆工具のTiAlN層の縦断面模式図を示す。The longitudinal cross-sectional schematic diagram of the TiAlN layer of this invention coated tool is shown. 本発明被覆工具のTiAlN層を成膜するのに用いるアークイオンプレーティング(AIP)装置を示し、(a)は概略平面図、(b)は概略正面図である。The arc ion plating (AIP) apparatus used for forming the TiAlN layer of the coated tool of the present invention is shown, (a) is a schematic plan view, and (b) is a schematic front view.

次に、本発明の被覆工具について、詳細に説明する。   Next, the coated tool of the present invention will be described in detail.

TiAlN層の平均層厚:
硬質被覆層は、少なくともTiAlN層を含むが、該TiAlN層の平均層厚が0.5μm未満では、TiAlN層によって付与される長期の耐摩耗性向上効果が十分に得られず、一方、平均層厚が8.0μmを超えると、欠損やチッピングが発生しやすくなることがあるため、TiAlN層の平均層厚を0.5〜8.0μmとする。
Average thickness of the TiAlN layer:
The hard coating layer includes at least a TiAlN layer, but if the average thickness of the TiAlN layer is less than 0.5 μm, the long-term wear resistance improving effect imparted by the TiAlN layer cannot be sufficiently obtained, while the average layer If the thickness exceeds 8.0 μm, defects and chipping may easily occur. Therefore, the average thickness of the TiAlN layer is set to 0.5 to 8.0 μm.

TiAlN層の平均組成:
TiAlN層を、
組成式:(TiAl1−x)N
で表した場合、0.10≦x≦0.35(ただし、xは原子比)を満足する平均組成を有することが必要である。
Ti成分の平均組成を表すxが0.10未満である場合には、六方晶構造のTiAlN結晶粒が形成されやすくなり、TiAlN層の硬度が低下し高速切削において十分な耐摩耗性を得ることができない。
一方、Ti成分の平均組成を表すxが0.35を超える場合には、Al成分の組成割合が減少するため、TiAlN層の高温硬さおよび高温耐酸化性が低下する。
したがって、Ti成分の平均組成xは、0.10≦x≦0.35とする。
なお、工具基体表面の汚染の影響などで不可避的に検出される炭素や酸素などの元素を除いてTi、Al、Nの含有割合の原子比を定量し、TiとAlとNの含有割合の原子比の合計に対するNの含有割合が0.45以上0.65以下の範囲であれば、上記xの範囲が満足される限り、同等の効果が得られ特に問題は無い。
Average composition of TiAlN layer:
TiAlN layer,
Composition formula: (Ti x Al 1-x ) N
It is necessary to have an average composition that satisfies 0.10 ≦ x ≦ 0.35 (where x is an atomic ratio).
When x representing the average composition of the Ti component is less than 0.10, TiAlN crystal grains having a hexagonal crystal structure are easily formed, the hardness of the TiAlN layer is lowered, and sufficient wear resistance is obtained in high-speed cutting. I can't.
On the other hand, when x representing the average composition of the Ti component exceeds 0.35, the composition ratio of the Al component decreases, so that the high-temperature hardness and high-temperature oxidation resistance of the TiAlN layer decrease.
Accordingly, the average composition x of the Ti component is 0.10 ≦ x ≦ 0.35.
The atomic ratio of the content ratio of Ti, Al, and N is quantified excluding elements such as carbon and oxygen that are inevitably detected due to the contamination of the tool base surface, and the content ratio of Ti, Al, and N is determined. If the content ratio of N with respect to the total atomic ratio is in the range of 0.45 or more and 0.65 or less, the same effect can be obtained as long as the range of x is satisfied, and there is no particular problem.

TiAlN層中の立方晶構造の結晶粒の平均面積割合S:
本発明のTiAlN層では、Al成分の平均組成割合1−x(ただし、1−xは原子比)を0.65〜0.90と高くしているため、TiAlN層は、立方晶構造の結晶粒と六方晶構造の結晶粒の混合組織からなるが、TiAlN層の縦断面に占める立方晶構造の結晶粒の平均面積割合S(面積%)は30面積%以上とすることが望ましい。
これは、立方晶構造の結晶粒の平均面積割合Sが30面積%未満では、相対的に、六方晶構造の結晶粒の面積割合が増加するためTiAlN層の硬さが低下し、その結果、耐摩耗性が低下することがあるためである。
なお、立方晶構造の結晶粒の平均面積割合Sは、例えば、電界放出型走査電子顕微鏡と電子線後方散乱回折装置を用いて、TiAlN層の工具基体表面に垂直な方向の断面(縦断面)を測定することにより求めることができる。
Average area ratio S of cubic structure crystal grains in the TiAlN layer:
In the TiAlN layer of the present invention, since the average composition ratio 1-x (where 1-x is an atomic ratio) of the Al component is as high as 0.65 to 0.90, the TiAlN layer is a crystal having a cubic structure. Although it is composed of a mixed structure of grains and hexagonal crystal grains, the average area ratio S (area%) of cubic crystal grains in the longitudinal section of the TiAlN layer is preferably 30 area% or more.
This is because when the average area ratio S of the cubic structure crystal grains is less than 30% by area, the area ratio of the hexagonal crystal grains is relatively increased, so that the hardness of the TiAlN layer is decreased. This is because the wear resistance may decrease.
Note that the average area ratio S of crystal grains having a cubic crystal structure is, for example, a cross section (longitudinal section) in a direction perpendicular to the tool base surface of the TiAlN layer using a field emission scanning electron microscope and an electron beam backscatter diffraction apparatus. Can be determined by measuring.

高Ti帯状領域:
TiAlN層中に、Ti成分の平均組成xに比して、Ti成分の平均組成xが相対的に高い高Ti帯状領域は、次の(1)〜(5)のとおりである。
High Ti strip region:
In the TiAlN layer, the high Ti band-like regions in which the average composition x of the Ti component is relatively higher than the average composition x of the Ti component are as follows (1) to (5).

(1)工具基体表面の法線とのなす角
本発明では、工具基体表面の法線とのなす角度が35度以上70度以下の方向となるように形成する(図1を参照)。
この角度範囲とした理由は、35度未満であると、高切込み等の切れ刃に高負荷が掛かる切削において硬質被覆層の表面のクラック発生・進展が生じやすく、一方、70度を超えると硬質被覆層が積層膜であるときと同様の層厚方向の剥離が生じやすくなるためである。
なお、本発明の知見に先行する知見において、30度以下であれば、層厚方向の異方性がないためTiAlN層の剥離が生じることはなく、しかも、高Ti帯状領域の存在によって靱性が向上し、切削加工時に断続的・衝撃的負荷が作用しても、TiAlN層のチッピング発生、欠損発生が抑制されることがわかっている。しかし、後述する切削試験2の結果が示すように、より高負荷の切削性能は、30度以下の範囲では、35度以上70度以下には及ばず、70度を超える範囲の切削条件よりもすぐれ、さらには、高Ti帯状組織の存在しないものよりも一層すぐれていることがわかった。
この角度の測定は、高Ti帯状領域の特定がなされた後に行うものであるから、後述する「高Ti帯状領域の特定」の欄で説明する。
(1) Angle formed with the normal line on the tool base surface In the present invention, the angle formed with the normal line on the tool base surface is set to be in the direction of 35 degrees or more and 70 degrees or less (see FIG. 1).
The reason for this angle range is that if it is less than 35 degrees, cracks on the surface of the hard coating layer are likely to occur and progress in cutting where a high load is applied to the cutting edge such as a high depth of cut, while if it exceeds 70 degrees, it is hard. This is because peeling in the layer thickness direction is likely to occur as in the case where the coating layer is a laminated film.
In addition, in the knowledge preceding the knowledge of the present invention, if it is 30 degrees or less, there is no anisotropy in the layer thickness direction, so that the TiAlN layer does not peel off, and the toughness is obtained due to the presence of the high Ti band region. It has been found that even when intermittent / impact loads are applied during cutting, chipping and chipping of the TiAlN layer are suppressed. However, as shown in the results of the cutting test 2 to be described later, the higher-load cutting performance does not reach 35 degrees or more and 70 degrees or less in the range of 30 degrees or less, but more than the cutting conditions in the range exceeding 70 degrees. It was found to be superior and even better than the absence of a high Ti band structure.
The measurement of the angle is performed after the high Ti band-shaped region is specified, and will be described in the section “Specifying the high Ti band-shaped region” described later.

(2)Ti成分の平均組成
高Ti帯状領域のTi成分の平均組成をYとした場合、TiとAlの複合窒化物層におけるTi成分の平均組成xとYは、(x+0.01)≦Y≦(x+0.05)の関係を満足することが好ましい。
これは、Yが(x+0.01)未満であると、TiAlN層全体に対して高Ti帯状領域の靱性が十分ではないため衝撃の吸収・緩和が不十分なときがあり、(x+0.05)を超えると、高Ti帯状領域が必要な硬度を得ることができず、TiAlN層全体の耐摩耗性が低下してしまうことがあるためである。
(2) Average composition of Ti component When the average composition of the Ti component in the high Ti band region is Y, the average composition x and Y of the Ti component in the composite nitride layer of Ti and Al is (x + 0.01) ≦ Y It is preferable to satisfy the relationship of ≦ (x + 0.05).
This is because when Y is less than (x + 0.01), the toughness of the high Ti band-like region is not sufficient with respect to the entire TiAlN layer, so that absorption / relaxation of impact may be insufficient, and (x + 0.05) This is because the hardness required for the high Ti band-like region cannot be obtained and the wear resistance of the entire TiAlN layer may be deteriorated.

(3)平均幅W
高Ti帯状領域の幅とは、図1に示すように、高Ti帯状領域が傾斜している角度に対して垂直な方向における幅をいい、一例として、その平均幅Wは30〜500nmであることが望ましい。
これは、前記Wが30nm未満では、TiAlN層が全体としてほぼ均質な組成となるため、靱性向上効果、衝撃の吸収・緩和効果を期待することができないことがあり、一方、前記Wが500nmを超えると、TiAlN層中に部分的な低硬度領域が形成され、偏摩耗発生等により耐摩耗性が低下することがあるという理由による。
なお、高Ti帯状領域の幅とは、後記するように、例えば、透過型電子顕微鏡(TEM)を用いたエネルギー分散型X線分析法(EDS)(以下、「TEM−EDS」という。)によりTiAlN層の縦断面のTi成分の組成を測定した場合に、Ti成分の平均組成Yが、前記した(x+0.01)≦Y≦(x+0.05)の関係を満たすTi帯状領域の幅である。
(3) Average width W
As shown in FIG. 1, the width of the high Ti strip region refers to the width in a direction perpendicular to the angle at which the high Ti strip region is inclined. As an example, the average width W is 30 to 500 nm. It is desirable.
This is because when the W is less than 30 nm, the TiAlN layer has a substantially homogeneous composition as a whole, and therefore it may not be possible to expect a toughness improving effect and an impact absorbing / relaxing effect, while the W is less than 500 nm. If it exceeds the upper limit, a partial low hardness region is formed in the TiAlN layer, and wear resistance may be lowered due to occurrence of uneven wear or the like.
Note that the width of the high Ti band-shaped region is, for example, by energy dispersive X-ray analysis (EDS) (hereinafter referred to as “TEM-EDS”) using a transmission electron microscope (TEM), as will be described later. When the composition of the Ti component in the longitudinal section of the TiAlN layer is measured, the average composition Y of the Ti component is the width of the Ti strip region that satisfies the relationship (x + 0.01) ≦ Y ≦ (x + 0.05) described above. .

(4)平均面積割合St
高Ti帯状領域がTiAlN層に占める平均面積割合Stは、3〜50面積%であることが望ましい。
これは、Stが3面積%未満の場合には、高Ti帯状領域を形成したことによる靱性向上効果、衝撃の吸収・緩和効果が少ないため、耐チッピング性の改善度合いが低いことがあり、一方、Stが50面積%を超える場合には、高Ti帯状領域が低硬度領域として形成され、その結果、偏摩耗発生等により耐摩耗性が低下することがある、という理由による。
(4) Average area ratio St
The average area ratio St occupied by the high Ti strip region in the TiAlN layer is desirably 3 to 50 area%.
This is because when St is less than 3% by area, the toughness improving effect and impact absorbing / relaxing effect due to the formation of the high Ti band-like region are small, and the improvement degree of chipping resistance may be low. When St exceeds 50 area%, the high Ti band-like region is formed as a low hardness region, and as a result, wear resistance may be reduced due to the occurrence of uneven wear or the like.

(5)高Ti帯状領域の特定
少なくとも500nmの帯状の幅が入る視野で測定したTEM−EDSによる測定像において、基体表面の法線とのなす角が35度以上70度以下である直線上の複数の測定点におけるTi成分の組成Yが、所定のTiの濃度の高い領域、例えば、(x+0.01)以上(x+0.05)以下の範囲内(なお、xは、既述したTiAlN層全体におけるTi成分の平均組成)にあるか否かによって、該直線が高Ti帯状領域に属するか直線であるか否かを判定する。
ついで、前記直線が高Ti帯状領域に属する場合には、該直線に直交する方向にTi成分の組成を測定し、測定したTi成分の組成が、当該所定のTiの濃度の高い領域、例えば、(x+0.01)≦Y≦(x+0.05)の関係から外れる位置を、高Ti帯状領域の境界として特定する。
それから、前記で特定された高Ti帯状領域の複数位置においてTi成分の組成を測定し、これらを平均することによって、高Ti帯状領域におけるTi成分の平均組成Yを求めることができる。
また、前記で特定された高Ti帯状領域の輪郭を確定し、複数位置における幅を測定し、これらを平均することによって、高Ti帯状領域の平均幅Wを求めることができる。
そして、この確定された高Ti帯状領域の輪郭を、当該高Ti帯状領域の境界線として、工具基体表面の法線となす角度を測定し、この測定した角度を各高Ti帯状領域ごとに平均したものを工具基体の法線となす角とする。
(5) Identification of high Ti band-like region In a measurement image by TEM-EDS measured in a field of view where a band width of at least 500 nm enters, on a straight line whose angle formed with the normal of the substrate surface is not less than 35 degrees and not more than 70 degrees The composition Y of the Ti component at a plurality of measurement points is within a predetermined high Ti concentration region, for example, in the range of (x + 0.01) to (x + 0.05) (where x is the entire TiAlN layer described above) It is determined whether the straight line belongs to the high Ti band-like region or is a straight line depending on whether or not it is in the average composition of the Ti component.
Next, when the straight line belongs to the high Ti band-shaped region, the composition of the Ti component is measured in a direction orthogonal to the straight line, and the measured Ti component composition is a region having a high concentration of the predetermined Ti, for example, A position deviating from the relationship of (x + 0.01) ≦ Y ≦ (x + 0.05) is specified as the boundary of the high Ti band-shaped region.
Then, the average composition Y of the Ti component in the high Ti strip region can be obtained by measuring the composition of the Ti component at a plurality of positions of the high Ti strip region specified above and averaging them.
Moreover, the average width W of the high Ti strip region can be obtained by determining the outline of the high Ti strip region specified above, measuring the widths at a plurality of positions, and averaging these.
Then, the angle between the determined contour of the high Ti strip region and the normal of the tool base surface is measured as the boundary line of the high Ti strip region, and the measured angle is averaged for each high Ti strip region. This is the angle between the tool base and the normal.

結晶構造と面積割合の測定:
本発明のTiAlN層は、立方晶構造の結晶粒と六方晶構造の結晶粒の混合組織からなるが、結晶構造と面積割合は、例えば、電界放出型走査電子顕微鏡と電子線後方散乱回折装置を用いて、TiAlN層の工具基体表面に垂直な方向の断面(縦断面)を測定することにより求めることができる。
より具体的に言えば、TiAlN層の工具基体表面に垂直な方向の断面を研磨面とした状態で、電界放出型走査電子顕微鏡の鏡筒内にセットし、前記研磨面に70度の入射角度で15kVの加速電圧の電子線を1nAの照射電流で、前記断面研磨面の測定範囲内に存在する結晶粒個々に照射し、工具基体と水平方向に長さ100μm、工具基体表面と垂直な方向の断面に沿って層厚以下の距離の測定範囲内について0.01μm/stepの間隔で、電子線後方散乱回折像を測定し、個々の結晶粒の結晶構造を解析することで、立方晶構造の結晶粒の面積割合を測定することができる。
上記測定を5箇所の測定範囲で行い、これらの平均値として、立方晶構造の結晶粒の平均面積割合Sを算出する。なお、0.01μm/stepの間隔とした測定点は、より詳細には、測定範囲内を充填するように一辺が0.01μmの正三角形を配置して、その各々の正三角形の頂点を測定点としており、一つの測定点での測定結果はこの正三角形一つの面積の測定結果を代表する測定結果となっている。従って、上記に示したように、測定点数の割合から面積割合が求められる。
Measurement of crystal structure and area ratio:
The TiAlN layer of the present invention is composed of a mixed structure of cubic crystal grains and hexagonal crystal grains. The crystal structure and area ratio can be determined by, for example, using a field emission scanning electron microscope and an electron beam backscatter diffraction apparatus. It can be obtained by measuring the cross section (longitudinal section) of the TiAlN layer in the direction perpendicular to the surface of the tool substrate.
More specifically, the TiAlN layer is set in a lens barrel of a field emission scanning electron microscope in a state where the cross section in a direction perpendicular to the surface of the tool substrate is a polished surface, and an incident angle of 70 degrees on the polished surface. An electron beam with an acceleration voltage of 15 kV is irradiated at an irradiation current of 1 nA to individual crystal grains existing within the measurement range of the cross-section polished surface, and the length is 100 μm in the horizontal direction with respect to the tool base, and the direction perpendicular to the tool base surface. A cubic structure is obtained by measuring an electron beam backscatter diffraction image at an interval of 0.01 μm / step and analyzing a crystal structure of each crystal grain within a measurement range of a distance equal to or less than the layer thickness along the cross section of The area ratio of crystal grains can be measured.
The said measurement is performed in the measurement range of five places, and average area ratio S of the crystal grain of a cubic structure is computed as these average values. More specifically, the measurement points with an interval of 0.01 μm / step are arranged in more detail by arranging equilateral triangles with a side of 0.01 μm so as to fill the measurement range and measuring the apexes of the equilateral triangles. The measurement result at one measurement point is a measurement result representing the measurement result of the area of one equilateral triangle. Therefore, as shown above, the area ratio is obtained from the ratio of the number of measurement points.

TiAlN層の成膜方法:
前記特徴を備える本発明のTiAlN層は、例えば、以下の方法によって成膜することができる。
図2(a)、(b)に、本発明のTiAlN層を成膜するための、アークイオンプレーティング(以下、「AIP」という)装置の概略図を示す。
図2(a)、(b)に示すAIP装置内に、所定組成のTi−Al合金ターゲットを配置するとともに、WC基超硬合金、TiCN基サーメットおよびcBN焼結体のいずれかからなる工具基体をAIP装置の回転テーブル上に載置し、工具基体に対するボンバード前処理および工具基体の温度(成膜温度)、Nガス圧、成膜時のバイアス電圧、バイアス電圧上昇速度を制御してアーク放電を発生させることにより、本発明のTiAlN層を成膜することができる。
特に、低バイアス電圧による処理から高バイアス電圧の処理に漸次変化させることで、自発的にTi成分の組成分布を形成させ、さらに、工具基体の温度(成膜温度)とNガス圧、バイアス電圧、バイアス電圧上昇速度の制御により、工具基体表面の法線とのなす角度が35度以上70度以下の方向に平行な結晶方位に沿う原子の積層関係を制御し、本発明に規定する高Ti帯状領域を形成することができる。
Method for forming TiAlN layer:
The TiAlN layer of the present invention having the above characteristics can be formed by, for example, the following method.
2A and 2B are schematic views of an arc ion plating (hereinafter referred to as “AIP”) apparatus for forming a TiAlN layer of the present invention.
A tool base comprising either a WC-based cemented carbide alloy, a TiCN-based cermet, or a cBN sintered body, with a Ti-Al alloy target having a predetermined composition disposed in the AIP apparatus shown in FIGS. Is mounted on the rotary table of the AIP apparatus, and the arc is controlled by controlling the bombarding pretreatment for the tool base, the temperature of the tool base (film formation temperature), the N 2 gas pressure, the bias voltage during film formation, and the bias voltage increase rate. By generating the discharge, the TiAlN layer of the present invention can be formed.
In particular, by gradually changing from low bias voltage processing to high bias voltage processing, the Ti component composition distribution is spontaneously formed, and the tool base temperature (film formation temperature), N 2 gas pressure, bias By controlling the voltage and bias voltage increase rate, the stacking relationship of atoms along the crystal orientation parallel to the direction in which the angle formed with the normal to the tool base surface is not less than 35 degrees and not more than 70 degrees is controlled. Ti band-like regions can be formed.

なお、本発明において、TiAlNを含む硬質被覆層と工具基体との間に、TiN等の介在層を設けたり、該硬質被覆層の表面にAl等の被覆層を更に設けてもよい。 In the present invention, an intermediate layer such as TiN may be provided between the hard coating layer containing TiAlN and the tool base, or a coating layer such as Al 2 O 3 may be further provided on the surface of the hard coating layer. .

次に、この発明の被覆工具を実施例により具体的に説明する。
なお、具体的な説明としては、WC基超硬合金を工具基体とする被覆工具について説明するが、TiCN基サーメットあるいはcBN焼結体を工具基体とする被覆工具についても同様である。
Next, the coated tool of the present invention will be specifically described with reference to examples.
As a specific description, a coated tool using a WC-based cemented carbide as a tool base will be described, but the same applies to a coated tool using a TiCN-based cermet or a cBN sintered body as a tool base.

工具基体の作製:
原料粉末として、いずれも0.5〜5μmの平均粒径を有する、Co粉末、TaC粉末、NbC粉末、VC粉末、Cr粉末、WC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、さらにワックスを加えてボールミルで72時間湿式混合し、減圧乾燥し後、100MPaの圧力でプレス成形し、これらの圧粉成形体を焼結し、所定寸法となるように加工して、ISO規格SEEN1203AFENのインサート形状をもったWC基超硬合金工具基体1〜2を製造した。
Tool substrate production:
As raw material powders, Co powder, TaC powder, NbC powder, VC powder, Cr 3 C 2 powder and WC powder, all having an average particle diameter of 0.5 to 5 μm, were prepared. Blended into the composition shown, further added with wax, wet mixed in a ball mill for 72 hours, dried under reduced pressure, press-molded at a pressure of 100 MPa, and sintered these compacts to a predetermined size. WC-based cemented carbide tool bases 1 and 2 having an ISO standard SEEN1203AFEN insert shape were produced.

Figure 2018144224
Figure 2018144224

前記の工具基体1〜2のそれぞれを、アセトン中で超音波洗浄し、乾燥した状態で、図2に示すAIP装置の回転テーブル上の中心軸から半径方向に所定距離離れた位置に外周部にそって装着し、AIP装置内に、所定組成のTi−Al合金ターゲット(カソード電極)を配置し、
まず、装置内を排気して真空に保持しながら、ヒータで工具基体を表2に示す温度に加熱した後、前記回転テーブル上で自転しながら回転する工具基体に表2に示す直流バイアス電圧を印加し、かつ、Ti−Al合金ターゲット(カソード電極)に表2に示すアーク電流を流してアーク放電を発生させ、もって工具基体表面をボンバード洗浄し、
ついで、装置内に反応ガスとして窒素ガスを導入して表2に示すNガス圧とすると共に、前記回転テーブル上で自転しながら回転する工具基体の温度を表2に示す温度範囲内に維持し、Ti−Al合金ターゲット(カソード電極)に表2に示すアーク電流を流してアーク放電を発生させ、表2に示す直流の低バイアス電圧を工具基体に対して表2に示す所定時間印加して、それから表2に示す上昇速度に沿うように、横軸を時間、縦軸をバイアス電圧(−V)としたグラフに表した際に直線状もしくは階段状に順次バイアス電圧を上昇させ、表2に示す直流の高バイアス電圧を印加して、TiAlN層を成膜することにより、表4に示す目標平均層厚、Ti成分の平均組成x、立方晶構造の結晶粒の平均面積割合S、所定の高Ti帯状領域(Ti成分の平均組成Y、平均幅W、平均面積割合St)を有する本発明被覆工具1〜10(以下、本発明工具1〜10という)をそれぞれ製造した。
Each of the tool bases 1 and 2 is ultrasonically cleaned in acetone and dried, and is placed on the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table of the AIP apparatus shown in FIG. Along with this, a Ti-Al alloy target (cathode electrode) having a predetermined composition is arranged in the AIP apparatus,
First, while evacuating the inside of the apparatus and maintaining the vacuum, the tool base is heated to the temperature shown in Table 2 with a heater, and then the DC bias voltage shown in Table 2 is applied to the tool base that rotates while rotating on the rotary table. And applying an arc current shown in Table 2 to a Ti-Al alloy target (cathode electrode) to generate an arc discharge, thereby bombard cleaning the tool base surface,
Next, nitrogen gas is introduced as a reaction gas into the apparatus to obtain the N 2 gas pressure shown in Table 2, and the temperature of the tool base rotating while rotating on the rotary table is maintained within the temperature range shown in Table 2. Then, an arc current shown in Table 2 is passed through the Ti—Al alloy target (cathode electrode) to generate arc discharge, and a DC low bias voltage shown in Table 2 is applied to the tool base for a predetermined time shown in Table 2. Then, along the rising speed shown in Table 2, when the horizontal axis is time and the vertical axis is the bias voltage (-V), the bias voltage is increased in a linear or stepwise manner. By applying a DC high bias voltage shown in FIG. 2 to form a TiAlN layer, the target average layer thickness, the Ti component average composition x, the average area ratio S of cubic crystal grains shown in Table 4, Predetermined high Ti strip area Invention coated tools 1 to 10 (hereinafter referred to as present invention tools 1 to 10) having (average composition Y of Ti component, average width W, average area ratio St) were produced, respectively.

比較の目的で、図2に示すAIP装置を用いて、表3に示すボンバード条件、同じく表3に示す成膜条件でTiAlN層を形成することにより、表5に示す比較例被覆工具1〜13(以下、比較例工具1〜13という)をそれぞれ製造した。   For the purpose of comparison, by using the AIP apparatus shown in FIG. 2, a TiAlN layer is formed under the bombardment conditions shown in Table 3 and the film formation conditions shown in Table 3 to thereby produce comparative example coated tools 1 to 13 shown in Table 5. (Hereinafter referred to as Comparative Examples Tools 1 to 13) were produced.

前記で作製した本発明工具1〜10および比較例工具1〜13のTiAlN層について、走査型電子顕微鏡を用いて断面測定し、5ヶ所の測定値の平均値から、平均層厚を算出した。
また、TiAlN層におけるTi成分の組成を、TEM−EDSにより3箇所の膜厚方向に0.4μm以上、基体表面に平行な方向に1μm以上の視野範囲で測定し、その測定値の平均値を、TiAlN層のTi成分の平均組成xとして求めた。
表4、表5に、それぞれの値を示す。
For the TiAlN layers of the inventive tools 1 to 10 and comparative example tools 1 to 13 prepared above, the cross-section was measured using a scanning electron microscope, and the average layer thickness was calculated from the average value of the five measured values.
Further, the composition of the Ti component in the TiAlN layer was measured by a TEM-EDS in a visual field range of 0.4 μm or more in three film thickness directions and 1 μm or more in a direction parallel to the substrate surface, and the average value of the measured values was calculated. The average composition x of the Ti component of the TiAlN layer was obtained.
Tables 4 and 5 show the respective values.

また、本発明工具1〜10および比較例工具1〜13のTiAlN層について、TEM−EDSにより、TiAlN層における高Ti帯状領域の存在の有無を確認するとともに、高Ti帯状領域が存在する場合には、該領域におけるTi成分の平均組成Y、該領域の平均幅W、該領域がTiAlN層の縦断面に占める平均面積割合Stを求めた。
具体的には、図1に示すようなTiAlN層の縦断面について、少なくとも500nmの帯状の幅が入る視野で測定したTEM−EDSによる測定像において、基体表面の法線とのなす角が35度以上70度以下である直線上の複数の測定点におけるTi成分の組成を測定し、該測定値が(x+0.01)以上(x+0.05)以下の範囲内にあるか否かによって、該直線が高Ti帯状領域に属するか直線であるか否かを判定する。
次に、前記直線が高Ti帯状領域に属する直線であると判定された場合には、該直線に直交する方向にTi成分の組成を測定し、測定したTi成分の組成が、(x+0.01)≦Y≦(x+0.05)の関係から外れる位置を、高Ti帯状領域の境界として特定する。
ついで、前記で特定された高Ti帯状領域の複数位置においてTi成分の組成を測定し、これらを平均することによって、高Ti帯状領域におけるTi成分の平均組成Yを求める。
つづいて、前記で特定された高Ti帯状領域の輪郭を確定し、複数位置における幅を測定し、これらを平均することによって、高Ti帯状領域の平均幅Wを求める。
さらに、前記で求めた高Ti帯状領域の輪郭から、測定視野の面積中に存在する高Ti帯状領域の合計面積を求めることにより、TiAlN層の縦断面に占める高Ti帯状領域の平均面積割合Stを算出する。
表4、表5に、それぞれの値を示す。
Moreover, about TiAlN layer of this invention tool 1-10 and comparative example tools 1-13, while confirming the presence or absence of the high Ti strip | belt area | region in a TiAlN layer by TEM-EDS, when a high Ti strip | belt area | region exists Obtained the average composition Y of the Ti component in the region, the average width W of the region, and the average area ratio St occupied by the region in the longitudinal section of the TiAlN layer.
Specifically, with respect to the longitudinal section of the TiAlN layer as shown in FIG. 1, in the measurement image by TEM-EDS measured in the field of view having a band width of at least 500 nm, the angle formed with the normal of the substrate surface is 35 degrees. The composition of the Ti component at a plurality of measurement points on the straight line that is 70 degrees or less is measured, and the straight line depends on whether or not the measured value is in the range of (x + 0.01) to (x + 0.05). Whether or not belongs to the high Ti band-like region or is a straight line.
Next, when it is determined that the straight line belongs to the high Ti band-like region, the composition of the Ti component is measured in a direction orthogonal to the straight line, and the measured composition of the Ti component is (x + 0.01). ) ≦ Y ≦ (x + 0.05) A position deviating from the relationship is specified as the boundary of the high Ti band-like region.
Next, the composition of the Ti component is measured at a plurality of positions of the high Ti strip region specified above, and these are averaged to obtain the average composition Y of the Ti component in the high Ti strip region.
Subsequently, the outline of the high Ti band-shaped region specified above is determined, the widths at a plurality of positions are measured, and these are averaged to obtain the average width W of the high Ti band-shaped region.
Further, the average area ratio St of the high Ti strip region in the longitudinal section of the TiAlN layer is obtained by obtaining the total area of the high Ti strip region existing in the area of the measurement visual field from the contour of the high Ti strip region determined above. Is calculated.
Tables 4 and 5 show the respective values.

また、本発明工具1〜10および比較例工具1〜13のTiAlN層について、電界放出型走査電子顕微鏡と電子線後方散乱回折装置を用いて、TiAlN層全体に占める立方晶構造の結晶粒の平均面積割合Sを求めた。
具体的には、工具基体表面に垂直な方向のTiAlN層の断面を研磨面とした状態で、電界放出型走査電子顕微鏡の鏡筒内にセットし、前記研磨面に70度の入射角度で15kVの加速電圧の電子線を1nAの照射電流で、前記断面研磨面の測定範囲内に存在する結晶粒個々に照射し、工具基体と水平方向に長さ100μm、工具基体表面と垂直な方向の断面に沿って層厚以下の距離の測定範囲内について0.01μm/stepの間隔で、電子線後方散乱回折像を測定し、個々の結晶粒の結晶構造を解析することで、立方晶構造の結晶粒の面積割合を測定した。
上記測定を5箇所の測定範囲で行い、これらの平均値として、TiAlN層全体に占める立方晶構造の結晶粒の平均面積割合Sを算出した。
表4、表5に、その値を示す。
Moreover, about the TiAlN layer of this invention tools 1-10 and comparative example tools 1-13, the average of the crystal grain of the cubic structure which occupies the whole TiAlN layer using a field emission scanning electron microscope and an electron beam backscattering diffraction apparatus The area ratio S was determined.
Specifically, in a state where the cross section of the TiAlN layer in a direction perpendicular to the surface of the tool base is a polished surface, it is set in a lens barrel of a field emission scanning electron microscope, and 15 kV is incident on the polished surface at an incident angle of 70 degrees. An electron beam with an acceleration voltage of 1 nA is irradiated to each crystal grain existing within the measurement range of the cross-section polished surface with an irradiation current of 1 nA, and the cross section in the direction perpendicular to the tool substrate surface is 100 μm long in the horizontal direction. A cubic structure crystal is obtained by measuring an electron beam backscatter diffraction image at an interval of 0.01 μm / step within a measurement range of a distance less than or equal to the layer thickness and analyzing the crystal structure of each crystal grain. The area ratio of the grains was measured.
The above measurement was performed in five measurement ranges, and an average area ratio S of cubic crystal grains in the entire TiAlN layer was calculated as an average value of these measurements.
Tables 4 and 5 show the values.

Figure 2018144224
Figure 2018144224

Figure 2018144224
Figure 2018144224

Figure 2018144224
Figure 2018144224

Figure 2018144224
Figure 2018144224

次いで、本発明工具1〜10および比較例工具1〜13について、以下の条件で、高速断続切削の一種である乾式高速正面フライス、センターカット切削加工試験を実施し、切刃の逃げ面摩耗幅を測定した。
切削試験1
切削試験:乾式高速正面フライス、センターカット切削加工、
カッタ径: 125 mm、
被削材: JIS・SCM445幅100mm、長さ365mmのブロック材、
切削速度: 300 m/min、
切り込み: 2.5 mm、
一刃送り量: 0.25mm/刃、
切削時間: 9.5分、
表6に、試験結果を示す。
切削試験2
切削試験:乾式高速正面フライス、センターカット切削加工、
カッタ径: 125 mm、
被削材: JIS・SCM445幅100mm、長さ365mmのブロック材、
切削速度: 280 m/min、
切り込み: 2.8 mm、
一刃送り量: 0.3mm/刃、
切削時間: 8分
表7に、試験結果を示す。
Next, with respect to the inventive tools 1 to 10 and the comparative tools 1 to 13, a dry high-speed face milling, which is a kind of high-speed intermittent cutting, and a center cut cutting test are performed under the following conditions, and the flank wear width of the cutting edge Was measured.
Cutting test 1
Cutting test: dry high-speed face milling, center cutting,
Cutter diameter: 125 mm,
Work material: Block material of JIS / SCM445 width 100mm, length 365mm,
Cutting speed: 300 m / min,
Cutting depth: 2.5 mm,
Single-blade feed amount: 0.25 mm / tooth,
Cutting time: 9.5 minutes
Table 6 shows the test results.
Cutting test 2
Cutting test: dry high-speed face milling, center cutting,
Cutter diameter: 125 mm,
Work material: Block material of JIS / SCM445 width 100mm, length 365mm,
Cutting speed: 280 m / min,
Cutting depth: 2.8 mm,
Single blade feed rate: 0.3 mm / tooth,
Cutting time: 8 minutes Table 7 shows the test results.

Figure 2018144224
Figure 2018144224

Figure 2018144224
Figure 2018144224

表6および表7に示される結果から、本発明の被覆工具は、硬質被覆層としてTiAlN層を含み、該TiAlN層には、高Ti帯状領域が、工具基体表面の法線とのなす角度が35度以上70度以下の方向に存在していることから、これによって、靱性が向上し、かつ、層中の層厚方向の異方性がないために、高熱発生を伴い、しかも、切刃に対して衝撃的・断続的な高負荷が作用する合金鋼の断続切削加工において、すぐれた耐チッピング性と耐摩耗性を発揮する。   From the results shown in Tables 6 and 7, the coated tool of the present invention includes a TiAlN layer as a hard coating layer, and the TiAlN layer has an angle formed between the high Ti band-shaped region and the normal of the tool substrate surface. Since it exists in the direction of 35 degrees or more and 70 degrees or less, this improves the toughness, and there is no anisotropy in the layer thickness direction in the layer. It exhibits excellent chipping resistance and wear resistance in intermittent cutting of alloy steel that is subjected to shock and intermittent high loads.

これに対して、TiAlN層中に、高Ti帯状領域が形成されていない比較例の被覆工具は、切削条件が余り厳しくない切削試験1の結果が示すように、また、高Ti帯状領域が形成されていたとしても工具基体表面の法線とのなす角度が35度以上70度以下にない比較例の被覆工具は、切削条件がより厳しい切削試験2の結果が示すように、比較的短時間で使用寿命に至ることが明らかである。   On the other hand, in the coated tool of the comparative example in which the high Ti band-shaped region is not formed in the TiAlN layer, as shown by the result of the cutting test 1 in which the cutting conditions are not so severe, the high Ti band-shaped region is formed. Even if it is made, the coated tool of the comparative example in which the angle formed with the normal line of the tool base surface is not more than 35 degrees and less than 70 degrees is relatively short as shown in the result of the cutting test 2 in which cutting conditions are more severe. It is clear that the service life is reached.

この発明の被覆工具は、合金鋼などの断続切削加工に供した場合に、すぐれた耐チッピング性とともに長期の使用に亘ってすぐれた耐摩耗性を発揮するものであるから、切削加工装置のFA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。   The coated tool of the present invention exhibits excellent chipping resistance and excellent wear resistance over a long period of use when subjected to intermittent cutting of alloy steel and the like. It is possible to sufficiently satisfy the demands for energy saving, cutting labor saving, energy saving, and cost reduction.

Claims (5)

WC基超硬合金、TiCN基サーメットおよびcBN焼結体のいずれかからなる工具基体の表面に、0.5〜8.0μmの平均層厚のTiとAlの複合窒化物層を少なくとも含む硬質被覆層が設けられた表面被覆切削工具において、
前記TiとAlの複合窒化物層は、その組成を、組成式:(TiAl1−x)Nで表した場合、0.10≦x≦0.35(ただし、xは原子比)を満足する平均組成を有し、
前記TiとAlの複合窒化物層中には、前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域が、少なくとも、工具基体表面の法線とのなす角度が35度以上70度以下の方向に存在していることを特徴とする表面被覆切削工具。
Hard coating comprising at least a composite nitride layer of Ti and Al having an average layer thickness of 0.5 to 8.0 μm on the surface of a tool base made of any one of a WC-based cemented carbide, a TiCN-based cermet and a cBN sintered body In a surface-coated cutting tool provided with a layer,
The composite nitride layer of Ti and Al has a composition expressed by a composition formula: (Ti x Al 1-x ) N, where 0.10 ≦ x ≦ 0.35 (where x is an atomic ratio). Having a satisfactory average composition,
In the composite nitride layer of Ti and Al, at least an angle formed by a belt-like region having a relatively high Ti component composition as compared to the average composition of the Ti component with the normal of the tool base surface is 35. A surface-coated cutting tool characterized by existing in a direction of not less than 70 degrees and not more than 70 degrees.
前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域のTi成分の平均組成をYとした場合、前記TiとAlの複合窒化物層におけるTi成分の平均組成xと前記Yは、(x+0.01)≦Y≦(x+0.05)の関係を満足することを特徴とする請求項1に記載の表面被覆切削工具。   When the average composition of the Ti component in the band-like region where the composition of the Ti component is relatively higher than the average composition of the Ti component is Y, the average composition x of the Ti component in the composite nitride layer of Ti and Al 2. The surface-coated cutting tool according to claim 1, wherein Y satisfies a relationship of (x + 0.01) ≦ Y ≦ (x + 0.05). 前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域の平均幅Wは、30〜500nmであることを特徴とする請求項2に記載の表面被覆切削工具。   3. The surface-coated cutting tool according to claim 2, wherein an average width W of the band-like region having a relatively high Ti component composition as compared with the average composition of the Ti component is 30 to 500 nm. 前記Ti成分の平均組成に比してTi成分の組成が相対的に高い帯状領域が前記TiとAlの複合窒化物層の縦断面に占める、平均面積割合Stは3〜50面積%であることを特徴とする請求項1乃至3のいずれか一項に記載の表面被覆切削工具。   An average area ratio St in which a strip-like region having a relatively high Ti component composition as compared to the average composition of the Ti component occupies the longitudinal section of the composite nitride layer of Ti and Al is 3 to 50 area% The surface-coated cutting tool according to any one of claims 1 to 3, wherein: 前記TiとAlの複合窒化物層は、立方晶構造の結晶粒と六方晶構造の結晶粒の混合組織からなり、前記TiとAlの複合窒化物層の縦断面に占める立方晶構造の結晶粒の平均面積割合Sは30面積%以上であることを特徴とする請求項1乃至4のいずれか一項に記載の表面被覆切削工具。   The Ti and Al composite nitride layer comprises a mixed structure of cubic crystal grains and hexagonal crystal grains, and the cubic crystal grains occupy the longitudinal section of the Ti and Al composite nitride layer. The surface-coated cutting tool according to any one of claims 1 to 4, wherein the average area ratio S is 30 area% or more.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019072838A (en) * 2017-10-12 2019-05-16 三菱マテリアル株式会社 Surface coating cutting tool
JP2020121378A (en) * 2019-01-31 2020-08-13 三菱マテリアル株式会社 Surface coated cutting tool
JP2020131360A (en) * 2019-02-20 2020-08-31 三菱マテリアル株式会社 Surface-coated cutting tool
CN114502774A (en) * 2019-10-11 2022-05-13 山高刀具公司 Coated cutting tool
WO2022239139A1 (en) * 2021-05-12 2022-11-17 住友電工ハードメタル株式会社 Cutting tool

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003211304A (en) * 2002-01-21 2003-07-29 Mitsubishi Materials Kobe Tools Corp Surface coating cemented carbide cutting tool having hard coating layer showing excellent wear resistance at high speed cutting
US20080317998A1 (en) * 2006-01-13 2008-12-25 Wolfgang Eichmann Wear-resistant coating
US20090060669A1 (en) * 2007-09-05 2009-03-05 Sandvik Intellectual Property Ab Coated drill and a method of making the same
JP2013139619A (en) * 2011-12-28 2013-07-18 Research Inst Of Industrial Science & Technology Hard coating layer and method for forming the same
JP2013211304A (en) * 2012-03-30 2013-10-10 Hitachi Zosen Corp Three dimensional heterojunction cnt solar cell
JP2015030061A (en) * 2013-08-02 2015-02-16 三菱マテリアル株式会社 Surface-coated cutting tool superior in chipping resistance
JP2015036189A (en) * 2013-08-16 2015-02-23 ケンナメタル インコーポレイテッドKennametal Inc. Low stress hard coatings and applications thereof
JP2016030319A (en) * 2014-07-30 2016-03-07 三菱マテリアル株式会社 Surface coated cutting tool having hard coating layer exhibiting superior chipping resistance
JP2016064485A (en) * 2014-09-25 2016-04-28 三菱マテリアル株式会社 Surface coat cutting tool having hard coat layer exhibiting superior chipping resistance
JP2016137549A (en) * 2015-01-28 2016-08-04 三菱マテリアル株式会社 Surface-coated cutting tool with hard coating layer exerting excellent chipping resistance
JP2016221672A (en) * 2015-05-26 2016-12-28 三菱マテリアル株式会社 Surface-coated cutting tool having hard coating layer exerting excellent chipping resistance
JP2017030076A (en) * 2015-07-30 2017-02-09 三菱マテリアル株式会社 Surface-coated cutting tool with hard coated layer exhibiting superior chipping resistance

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003211304A (en) * 2002-01-21 2003-07-29 Mitsubishi Materials Kobe Tools Corp Surface coating cemented carbide cutting tool having hard coating layer showing excellent wear resistance at high speed cutting
US20080317998A1 (en) * 2006-01-13 2008-12-25 Wolfgang Eichmann Wear-resistant coating
US20090060669A1 (en) * 2007-09-05 2009-03-05 Sandvik Intellectual Property Ab Coated drill and a method of making the same
JP2013139619A (en) * 2011-12-28 2013-07-18 Research Inst Of Industrial Science & Technology Hard coating layer and method for forming the same
JP2013211304A (en) * 2012-03-30 2013-10-10 Hitachi Zosen Corp Three dimensional heterojunction cnt solar cell
JP2015030061A (en) * 2013-08-02 2015-02-16 三菱マテリアル株式会社 Surface-coated cutting tool superior in chipping resistance
JP2015036189A (en) * 2013-08-16 2015-02-23 ケンナメタル インコーポレイテッドKennametal Inc. Low stress hard coatings and applications thereof
JP2016030319A (en) * 2014-07-30 2016-03-07 三菱マテリアル株式会社 Surface coated cutting tool having hard coating layer exhibiting superior chipping resistance
JP2016064485A (en) * 2014-09-25 2016-04-28 三菱マテリアル株式会社 Surface coat cutting tool having hard coat layer exhibiting superior chipping resistance
JP2016137549A (en) * 2015-01-28 2016-08-04 三菱マテリアル株式会社 Surface-coated cutting tool with hard coating layer exerting excellent chipping resistance
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