JP2007290090A - Surface coated cutting tool having hard coating layer exhibiting excellent chipping resistance in high-speed heavy cutting difficult-to-cut material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having a hard coating layer exhibiting excellent chipping resistance in high-speed heavy cutting a difficult-to-cut material. <P>SOLUTION: In this surface coated cutting tool, the following hard coating layer is formed on the surface of a tool base made of WC-base cemented carbide alloy or titanium carbonitride base cermet. The hard coating layer includes: a lower layer; and an upper layer. The lower layer is formed of a composition change (Ti, Al, Si)N layer, wherein it has a component concentration distribution structure in which from the Al highest content point (hereinafter referred to as point A) to the Al lowest content point (hereinafter referred to as point B), and from the point B to the point A, Al and Ti contents respectively continuously change. The point A satisfies a specific composition formula (Ti<SB>1-X</SB>Al<SB>X</SB>Si<SB>Y</SB>)N, the point B satisfies a specific composition formula (Ti<SB>1-A-B</SB>Al<SB>A</SB>Si<SB>B</SB>)N, and the interval between the adjacent points A and B is 0.03 to 0.1μm. The upper layer has an alternately stacked structure of a vanadium nitride layer and a vanadium oxide layer respectively having a required average layer thickness per layer, in which an acidic nitride vanadium layer is interposed between the respective layers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  This invention is especially suitable for cutting difficult-to-cut materials such as stainless steel, high manganese steel, and even mild steel under high speed with high heat generation and high cutting depth and high feed that require a high load locally on the cutting edge. The present invention also relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a coated tool) that exhibits excellent chipping resistance even when performed under high-speed heavy cutting conditions.

  In general, for coated tools, throwaway inserts that are detachably attached to the tip of the cutting tool for turning and planing of various steel and cast iron materials, drilling of the work material, etc. Drills and miniature drills, and solid type end mills used for chamfering, grooving and shouldering of the work material, etc. A slow-away end mill tool that performs cutting work in the same manner as an end mill is known.

In addition, as a coated tool, on the surface of a tool base composed of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet,
And having an average layer thickness of 1 to 5 μm, and along the layer thickness direction, Al highest content points and Al lowest content points are alternately present at predetermined intervals, and from the Al highest content point Al lowest content point, having a component concentration distribution structure in which the Al and Ti content continuously change from the Al lowest content point to the Al highest content point, respectively,
Furthermore, the Al highest content point is the composition formula: (Ti _1-XY Al _X Si _Y ) N (wherein the atomic ratio, X is 0.60 to 0.85, and Y is 0.01 to 0.00. 1),
The Al minimum content point is a composition formula: (Ti _{1-A B} Al _A Si _B ) N (where A is 0.40 to 0.55 and B is 0.01 to 0.1 in terms of atomic ratio). Show),
And a distance between the adjacent Al highest content point and Al minimum content point adjacent to each other is 0.03 to 0.1 μm, a composite nitride layer of Ti, Al, and Si [hereinafter, composition change (Ti, Al , Si) N layer] is known, and a coating tool formed by physical vapor deposition of a hard coating layer is known, and a composition change (Ti, Al, Si) N layer, which is a hard coating layer of the coating tool, It has excellent high-temperature hardness and heat resistance due to the Al of the component concentration distribution change structure, excellent high-temperature strength due to the Ti, and further combined with a further improvement in heat resistance due to the Si component content, It is known not only when it is used for continuous cutting and intermittent cutting of ordinary cast iron under normal conditions, but also when it is used for high speed cutting conditions. It has been.

Further, the above conventional coated tool is, for example, an arc ion plating apparatus having a structure shown in a schematic plan view in FIG. 2A and a schematic front view in FIG. A Ti-Al-Si alloy with a relatively high Al content on one side (low Ti content) and a relatively high Ti content on the other side (Al-containing) Using an arc ion plating apparatus in which a Ti—Al—Si alloy (low amount) is disposed as a cathode electrode (evaporation source), a predetermined distance in the radial direction is separated from the central axis on the rotary table of the apparatus. At this position, a plurality of tool bases are mounted in a ring shape, and in this state, the rotary table is rotated with the atmosphere inside the apparatus being a nitrogen atmosphere, and the layer thickness of the hard coating layer formed by vapor deposition is made uniform. While rotating the tool base itself, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode on both sides to change the composition (Ti, Al, Si) N on the surface of the tool base. In the composition change (Ti, Al, Si) N layer formed as a result, the tool base arranged in a ring shape on the rotary table is formed on the one side described above. At the point closest to the cathode electrode (evaporation source) of a Ti-Al-Si alloy having a relatively high Al content (low Ti content), the highest Al content point is formed in the layer. At the point of closest approach to the cathode electrode of the Ti—Al—Si alloy having a relatively high Ti content (low Al content) on the other side, an Al minimum content point is formed in the layer. By rotation In the layer thickness direction, the Al highest content point and the Al lowest content point appear alternately with a predetermined interval, and the Al highest content point to the Al lowest content point, the Al lowest content point to the Al highest content point. A component concentration distribution structure in which the content of Al and Ti continuously changes to the content point is formed.
Japanese Patent No. 3669334

  In recent years, the use of FA for cutting devices has been remarkable. On the other hand, there is a strong demand for labor saving and energy saving and further cost reduction for cutting processing. As a result, coated tools are affected as much as possible by the grade of work material. There is a tendency not to be versatile, that is, there is a tendency to require a coated tool capable of cutting as many kinds of work materials as possible. However, in the conventional coated tools described above, this is generally applied to low alloy steel, carbon steel, etc. There is no problem when used for high-speed cutting of normal cast iron such as steel, ductile cast iron and gray cast iron, but stainless steel and high manganese steel, which have high chip viscosity and are easy to weld to the tool surface. When cutting difficult-to-cut materials such as mild steel at high speeds and high-speed heavy cutting conditions such as high cutting and high feed that apply a high load locally to the cutting edge, it is difficult due to high heat generated during cutting. From the cutting material The material to be cut and its chips are heated to a high temperature and the viscosity is further increased. As a result, the adhesiveness and reactivity to the surface of the hard coating layer are further increased. As a result, chipping ( The occurrence of minute chipping) has increased rapidly, and this is the reason why the service life is reached in a relatively short time.

In view of the above, the present inventors have developed the above-mentioned conventional coated tool in order to develop a coated tool that exhibits excellent chipping resistance with a hard coating layer, particularly in high-speed heavy cutting of difficult-to-cut materials. As a result of conducting research with a focus on
(A) A composition change (Ti, Al, Si) N layer, which is a hard coating layer of the above-mentioned conventional coated tool, is formed as a lower layer with an average layer thickness of 1 to 5 μm, and an upper layer is made of vanadium oxide (oxidation) Vanadium can take various compound forms such as VO, V ₂ O ₃ and VO ₂ depending on the degree of oxidation, but when these are collectively referred to as VO), the VO layer is surface slippery. As a result, even when the work material (difficult-to-cut material) and its swarf are heated at high temperature due to heat generated during cutting, the cutting edge (the rake face and flank face and the cutting edge ridge line where these two surfaces intersect) Excellent slipperiness is ensured between the workpiece and the cutting material, and the adhesiveness and reactivity of the cutting material and the cutting surface to the cutting edge surface are remarkably reduced, and the composition change of the lower layer (Ti, Al, Si) N layer is sufficiently preserved. Since the composition changes (Ti, Al, Si) having excellent characteristics N layer may become to be sufficiently exhibited for a long time.

(B) However, when a VO layer is provided directly on the lower layer composed of the composition change (Ti, Al, Si) N layer, the composition change (Ti, Al, Si) as the lower layer is provided. The adhesion between the N layer and the VO layer as the upper layer is not sufficient, and the high temperature strength of the VO layer itself as the upper layer is not sufficient, so that the adhesion between the lower layer and the upper layer of the hard coating layer is insufficient. Chipping cannot be sufficiently prevented due to insufficient high-temperature strength of the layer.

(C) When the upper layer is configured as an alternate layered structure of VO layers and VN layers, and an upper layer of an alternate layered structure in which a VNO layer is interposed between the VO layer and VN layer, the VN layer is Wear resistance of the VO and VN layers to compensate for the high temperature strength that the VO layer lacks, and the VNO layer enhances film formation reactivity during film formation of the VO layer or VN layer and at the same time promotes grain refinement. In addition, since the VNO layer has excellent adhesion to both the VN layer and the VO layer, the intervening VNO layer also improves the bonding strength between the VO layer and the VN layer. Therefore, the upper layer composed of such an alternately laminated structure has excellent surface slipperiness provided by the VO layer and excellent high temperature strength possessed by the VN layer, and the intervening VNO layer provides the bonding strength and resistance to each layer. wear There will those further improved, as a result, the hard coating layer comprises more more excellent high-temperature strength and excellent surface slipperiness, excellent chipping resistance, it is shown the wear resistance.

(D) The hard coating layer of (c) is an arc ion plating apparatus having a structure shown in, for example, a schematic plan view in FIG. 1 (a) and a schematic front view in FIG. A substrate mounting turntable is provided, a cathode electrode (evaporation source) is provided across the turntable, and a metal V is disposed on one of them as a cathode electrode (evaporation source), along the turntable, and Ti-Al-Si alloy having a relatively high Al content (low Ti content) as a cathode electrode (evaporation source) on one side at a position 90 degrees away from each of the metals V, and relatively on the other side A vapor deposition apparatus in which a Ti-Al-Si alloy having a high Ti content (low Al content) is disposed as a cathode electrode (evaporation source) is used as a cathode electrode (evaporation source), and a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. Separation At this position, a plurality of tool bases are mounted in a ring shape along the outer periphery, and in this state, the rotary table is rotated with the atmosphere inside the apparatus as a nitrogen atmosphere, and the thickness of the hard coating layer formed by vapor deposition is made uniform. Basically, while rotating the tool base itself for the purpose, first, arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of both the Ti-Al-Si alloys arranged opposite to each other. A composition change (Ti, Al, Si) N layer is deposited on the surface of the tool base as an underlayer with an average layer thickness of 1 to 5 μm.
Next, the arc discharge between the cathode electrode (evaporation source) and the anode electrode of both the Ti—Al—Si alloys is stopped, and the cathode atmosphere (evaporation source) is maintained while maintaining the atmosphere in the apparatus in a nitrogen atmosphere. An arc discharge is generated between a certain metal V and an anode electrode, and a VN layer is deposited with an average thickness of 0.4 to 2 μm, and then the arc discharge between the metal V and the anode electrode is stopped. At the same time, the supply of nitrogen gas into the apparatus is stopped, the inside of the apparatus is evacuated for about 10 seconds,
Thereafter, the supply of a mixed gas of oxygen gas and nitrogen gas into the apparatus (however, the volume composition ratio of O ₂ : N ₂ = 1: 2) is started, and the atmosphere in the vapor deposition apparatus is changed to an oxygen-nitrogen mixed gas of 1.5 Pa. While maintaining the atmosphere, a current of 120 A was passed between the metal V, which is the cathode electrode (evaporation source), and the anode electrode to generate arc discharge to form a 0.02-0.2 μm VNO layer. Thereafter, the arc discharge between the metal V and the anode electrode is stopped, and at the same time, the supply of the oxygen-nitrogen mixed gas into the apparatus is stopped, and the inside of the apparatus is evacuated for about 10 seconds,
Thereafter, supply of oxygen gas into the apparatus is started to switch the atmosphere in the apparatus to an oxygen atmosphere, and then arc discharge is again generated between the metal V as the cathode electrode (evaporation source) and the anode electrode, After depositing a VO layer with an average thickness of 0.4-2 μm on the VNO layer, the arc discharge between the metal V and the anode electrode is stopped, and the supply of oxygen gas into the apparatus is stopped. After evacuating the device for about 10 seconds,
Supply of oxygen-nitrogen mixed gas (capacitance composition ratio of O ₂ : N ₂ = 1: 2) into the apparatus was started and the atmosphere in the vapor deposition apparatus was maintained in an oxygen-nitrogen mixed gas atmosphere of 1.5 Pa. Then, a current of 120 A is passed between the metal V as the cathode electrode (evaporation source) and the anode electrode to generate arc discharge to form a 0.02-0.2 μm VNO layer, and then the metal V The arc discharge between the anode electrode and the anode electrode is stopped, at the same time, the supply of the oxygen-nitrogen mixed gas into the apparatus is stopped, the inside of the apparatus is evacuated for about 10 seconds,
Thereafter, supply of nitrogen gas into the apparatus is started to switch the atmosphere to a nitrogen atmosphere, and arc discharge is generated again between the metal V, which is the cathode electrode (evaporation source), and the anode electrode, and is superimposed on the VNO layer. VN layer is vapor-deposited with an average layer thickness of 0.4-2 μm,
Thereafter, the VNO layer, the VO layer, and the VN layer are vapor-deposited by repeating the same procedure as described above, so that the VN layer and the VO layer are alternately stacked. An upper layer having a target total layer thickness (1 to 5 μm) having a laminated structure with a VNO layer interposed can be formed by vapor deposition.

(E) A coated tool formed by vapor-depositing a hard coating layer composed of the lower layer and the upper layer of a laminated structure is particularly difficult to cut stainless steel, high manganese steel, and mild steel with high viscosity and adhesion. Even if the material is machined under high speed with high heat generation, and under high speed heavy cutting conditions such as high cutting and high feed with high load, the composition change (Ti, Al, Si) N as the lower layer The layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and the upper layer composed of the laminated structure has excellent surface slipperiness possessed by the VO layer and high-temperature strength possessed by the VN layer, By interposing the VNO layer, the wear resistance of the VO layer and the VN layer is improved, and the bonding strength between the layers is also improved. As a result, not only the entire upper layer has excellent surface slipperiness, but also excellent high temperature strength and Combines wear resistance The hard coating layer having such a structure as a whole has excellent surface slipperiness, excellent high-temperature strength, wear resistance, and the hard-to-cut materials and chips. In the meantime, excellent surface slipperiness is ensured, and high-speed heavy cutting processing is performed with the stickiness and reactivity of difficult-to-cut materials and chips to the cutting edge surface being significantly reduced. There is no chipping at the blade, and it has excellent wear resistance over a long period of time.
The research results shown in (a) to (e) above were obtained.

This invention was made based on the above research results, and on the surface of the tool base,
(A) It has an average layer thickness of 1 to 5 μm, and along the layer thickness direction, Al maximum content points and Al minimum content points are alternately present at predetermined intervals, and the Al maximum content A component concentration distribution structure in which the Al and Ti contents continuously change from the point to the Al minimum content point, from the Al minimum content point to the Al maximum content point,
Furthermore, the Al highest content point is the composition formula: (Ti _1-XY Al _X Si _Y ) N (wherein the atomic ratio, X is 0.60 to 0.85, and Y is 0.01 to 0.00. 10),
The Al minimum content point, composition _{formula: (Ti 1-A-B} Al A Si B) N ( provided that an atomic ratio, A is from .40 to 0.55, B is a 0.01 to 0.10 Show),
A lower layer composed of a composition change (Ti, Al, Si) N layer in which the interval between the Al highest content point and the Al lowest content point adjacent to each other is 0.03 to 0.1 μm,
(B) a vanadium nitride layer having a single layer average layer thickness of 0.4 to 2 μm and a vanadium oxide layer having a single layer average layer thickness of 0.4 to 2 μm, and a vanadium nitride layer and a vanadium oxide layer; An upper layer having an overall average layer thickness of 1 to 5 μm, with a vanadium oxynitride layer having an average layer thickness of 0.02 to 0.2 μm interposed between each of the layers,
It is characterized by a coated tool that exhibits excellent chipping resistance in high-speed heavy cutting of difficult-to-cut materials, which is formed by forming a hard coating layer composed of (a) and (b) above. is there.

Next, regarding the constituent layers of the hard coating layer of the coated tool of the present invention, the reason why the numerical values are limited as described above will be described.
(A) Lower layer (a) Composition of Al highest content point Al in composition change (Ti, Al, Si) N layer improves high temperature hardness and heat resistance, Ti improves high temperature strength, and further The Si component has the effect of further improving the heat resistance. Therefore, the Al highest content point, which has a relatively high Al component content, has excellent high temperature hardness and heat resistance, and high wear resistance with high speed heavy cutting. However, if the Al ratio (X value) at the highest Al content point exceeds 0.85 in terms of the total amount of Ti and Si (atomic ratio), the Ti ratio decreases. After that, the high temperature strength rapidly decreases, and chipping (small chipping) is likely to occur on the cutting edge. On the other hand, if the ratio (X value) is also less than 0.60, the Al ratio becomes too low. Excellent high temperature hardness and heat resistance desired If the Y value indicating the proportion of the Si component is less than 0.01 in terms of the total amount of Al and Ti (atomic ratio), the desired heat resistance improvement effect cannot be obtained. When the Y value exceeds 0.10, the high-temperature strength suddenly decreases, so the X value was set to 0.60 to 0.85, and the Y value was set to 0.01 to 0.10.

(B) Composition of Al minimum content point As described above, the Al maximum content point is excellent in high-temperature hardness and heat resistance, but on the other hand, it is inferior in high-temperature strength. In order to compensate for this, the content of Ti is relatively high, and thereby the Al minimum content point that has a high high-temperature strength is alternately interposed in the thickness direction. Therefore, the proportion of Al (A value) is If the ratio (atomic ratio) in the total amount of Ti and Si exceeds 0.55, the desired excellent high-temperature strength cannot be ensured, while the ratio (A value) is also less than 0.40. The ratio of Ti is set to 0.40 to 0.55 because the ratio of Ti becomes relatively large and the Al minimum content point cannot be provided with desired high-temperature hardness and heat resistance. And the Si component The B value indicating the ratio was determined to be 0.01 to 0.10 for the same reason as in the above Al highest content point.

(C) Interval between the highest Al content point and the lowest Al content point If the distance is less than 0.03 μm, it is difficult to clearly form each point with the above composition. As a result, each layer has a desired high temperature. When it becomes impossible to secure the characteristics and high temperature strength and the interval exceeds 0.1 μm, the disadvantages of each point, that is, when the Al highest content point is insufficient high temperature strength, when the Al minimum content point is high temperature characteristics The shortage appears locally in the layer, which makes it easier for chipping to occur on the cutting edge and promotes the progress of wear. Therefore, the interval was set to 0.03 to 0.1 μm.

(D) Average layer thickness If the average layer thickness is less than 1 μm, the desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 5 μm, chipping tends to occur on the cutting edge. The average layer thickness was determined to be 1 to 5 μm.

(B) Upper layer (a) Single layer average layer thickness of vanadium nitride layer (VN layer) constituting alternate layered structure of upper layer VN layer constituting alternate layered structure of upper layer of hard coating layer itself was excellent It has high-temperature strength and compensates for the lack of high-temperature strength of the VO layer. However, if the average layer thickness of the VN layer is less than 0.4 μm, the improvement of the high-temperature strength of the upper layer is not sufficient, while the average layer thickness is 2 μm. If exceeded, the lubricating properties (surface slipperiness) required for the upper layer of the hard coating layer in heavy cutting of difficult-to-cut materials cannot be fully exhibited, and the high temperature hardness of the hard coating layer also decreases. Since this causes a decrease in wear resistance, the average layer thickness was determined to be 0.4 to 2 μm.

(B) Single layer average layer thickness of the vanadium oxide layer (VO layer) constituting the alternate layer structure of the upper layer The VO layer constituting the alternate layer structure of the upper layer of the hard coating layer has excellent surface slipperiness, The adhesion and reactivity to the work material (difficult-to-cut material) and swarf are extremely low, and this is the lower layer because the work material is maintained without change even when the work material is heated at the time of cutting. Protects the Ti, Al, Si) N layer from the work material and chips heated at high temperature and suppresses the occurrence of chipping. However, when the average layer thickness is less than 0.4 μm, On the other hand, if the average layer thickness exceeds 2 μm, the chipping is likely to occur even if the high temperature strength is reinforced by the alternately laminated structure with the VN layer. Layer thickness is 0.4-2μ m.

(C) Single layer average layer thickness of vanadium oxynitride layer (VNO layer) constituting the laminated structure of the upper layer The VNO layer is formed by forming a VO layer or a VN layer on the VNO layer. It enhances film formation reactivity and promotes crystal grain refinement during film formation, thus improving the wear resistance of the VO layer or VN layer. In addition, both the VN layer and the VO layer are effective. Since it has excellent adhesion, by interposing the VNO layer between the VN layer and the VO layer, the adhesion / bonding strength between the layers of the upper layer of the laminated structure is improved. As a result, the upper layer as a whole is improved. Although it contributes to the improvement of high temperature strength and wear resistance, if the average layer thickness of the VNO layer is less than 0.02 μm, the effect of improving the bonding strength and wear resistance is not sufficient, while the average layer thickness is 0 Hard coating when exceeding 2μm Since the can not be sufficiently exhibited surface slip properties required for the upper layer, it was determined and the average layer thickness and 0.02～0.2Myuemu.

(D) Overall average layer thickness of the upper layer If the overall average layer thickness of the upper layer is less than 1 μm, the high-speed heavy cutting of difficult-to-cut materials cannot sufficiently exhibit the excellent surface slipperiness, It cannot be expected to reduce the adhesion and reactivity of the work material (difficult-to-cut material) and cutting chips to the surface of the cutting edge. On the other hand, if the overall average layer thickness exceeds 5 μm, the hard coating layer is hard Therefore, the overall average layer thickness was determined to be 1 to 5 μm.

  In the coated tool of the present invention, the composition change (Ti, Al, Si) N layer of the lower layer constituting the hard coating layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and a VNO layer The upper layer consisting of an alternating layer structure with intervening layers has excellent surface slipperiness, high temperature strength, and wear resistance as the entire upper layer, so the hard coating layer as a whole has excellent high temperature hardness and heat resistance. , High-temperature strength, wear resistance and surface slipperiness, which results in large heat generation of difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel, which are particularly viscous and sticky. Even such high-speed heavy cutting shows excellent chipping resistance and exhibits excellent wear resistance over a long period of time.

  Next, the coated tool of the present invention will be specifically described with reference to examples.

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 tool bases A-1 to A-10 were formed.

In addition, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC, all having an average particle diameter of 0.5 to 2 μm. Prepare powder, Co powder, and Ni powder, mix these raw material powders into the composition shown in Table 2, wet mix for 24 hours with a ball mill, dry, and press-mold into green compact at 100 MPa pressure The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to meet ISO standards / Tool bases B-1 to B-6 made of TiCN base cermet having a chip shape of CNMG120408 were formed.

(A) Next, each of the tool bases A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then the arc ion plating shown in FIG. Attached along the outer periphery at a position that is a predetermined distance in the radial direction from the central axis on the rotary table in the apparatus, a cathode electrode (evaporation source) is provided across the rotary table, and one of the cathode electrodes (evaporation source) The metal V is arranged as a source), and the Al content is relatively high as a cathode electrode (evaporation source) on one side of the position along the rotary table and 90 degrees away from each of the metals V ( Ti-Al-Si alloy with low Ti content), Ti-Al-Si alloy with relatively high Ti content (low Al content) on the other side as a cathode electrode (evaporation source), facing each other,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the carbide substrate that rotates while rotating on the rotary table is set to −1000 V. And a 100 A current is passed between one of the two Ti-Al-Si alloys for forming the lower layer of the cathode electrode and the anode electrode to generate an arc discharge. The surface of the tool substrate is bombarded with the Ti-Al-Si alloy,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, and a DC bias voltage of −100 V is applied to the tool base that rotates while rotating on the rotary table. A current of 100 A was passed between the cathode electrode (Ti-Al-Si alloy for forming the highest Al content point and Ti-Al-Si alloy for forming the lowest Al content point) and the anode electrode to generate an arc discharge, Accordingly, the highest Al content point and the lowest Al content point of the target composition shown in Tables 3 and 4 are alternately repeated at the target intervals shown in Tables 3 and 4 along the layer thickness direction on the surface of the tool base. And a component concentration distribution structure in which the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, One also change in composition with a target layer thickness shown in Table 3,4 (Ti, Al, Si) N layer were vapor deposited as the lower layer of the hard coating layer,
(D) The arc discharge between the cathode electrode and the anode electrode of the both Ti-Al-Si alloys for forming the lower layer is stopped, and the atmosphere in the apparatus is similarly maintained in a 4 Pa nitrogen atmosphere, and to the tool substrate. Similarly, under the condition that the DC bias voltage is -100 V, a current of 120 A is passed between the metal V of the cathode electrode and the anode electrode to generate arc discharge, and the target layer thicknesses shown in Tables 3 and 4 are also shown. After the VN layer was deposited, the arc discharge between the metal V and the anode electrode was stopped, and at the same time, the supply of nitrogen gas into the apparatus was stopped, and the inside of the apparatus was evacuated for about 10 seconds,
(E) Thereafter, supply of a mixed gas of oxygen gas and nitrogen gas (however, a volume composition ratio of O ₂ : N ₂ = 1: 2) into the apparatus was started, and the atmosphere in the vapor deposition apparatus was changed to 1.5 Pa of oxygen − While maintaining the nitrogen mixed gas atmosphere, a current of 120 A is passed between the cathode V (evaporation source) metal V and the anode electrode to generate arc discharge, and thus the single layer shown in Tables 3 and 4 After the VNO layer having the target layer thickness is formed by vapor deposition, the arc discharge between the metal V and the anode electrode is stopped. At the same time, the supply of the oxygen-nitrogen mixed gas is stopped into the apparatus, and the apparatus is evacuated for about 10 seconds. Pull,
(F) Thereafter, supply of oxygen gas into the apparatus is started to switch the atmosphere in the vapor deposition apparatus to an oxygen atmosphere of 0.2 Pa, and again 120 A between the metal V as the cathode electrode (evaporation source) and the anode electrode. Then, an arc discharge is generated by depositing a VO layer having a target layer thickness shown in Tables 3 and 4 on the VNO layer, and then an arc between the metal V and the anode electrode is formed. The discharge is stopped, the supply of oxygen gas into the apparatus is stopped, the inside of the apparatus is evacuated for about 10 seconds (g), and then the oxygen-nitrogen mixed gas (O ₂ : N ₂ = 1: 2 capacity) is entered into the apparatus. (Composition ratio) was started, and the atmosphere in the vapor deposition apparatus was maintained in a 1.5 Pa oxygen-nitrogen mixed gas atmosphere, while 120 A of the cathode V (evaporation source) was placed between the metal V and the anode electrode. An electric current is passed to generate an arc discharge, Thus, after the VNO layer having the target layer thickness shown in Tables 3 and 4 is formed by vapor deposition, the arc discharge between the metal V and the anode electrode is stopped, and at the same time, the oxygen-nitrogen mixed gas is supplied into the apparatus. Stop and evacuate the device for about 10 seconds,
(H) Thereafter, supply of nitrogen gas into the apparatus is started, and the atmosphere in the vapor deposition apparatus is kept at a nitrogen atmosphere of 2 Pa, and 120 A is provided between the metal V as the cathode electrode (evaporation source) and the anode electrode. Then, arc discharge is caused to flow, and after VN layer having a target layer thickness shown in Tables 3 and 4 is formed by vapor deposition, arc discharge between the metal V and the anode electrode is stopped, At the same time, the supply of nitrogen gas into the apparatus is stopped, the inside of the apparatus is evacuated for about 10 seconds,
(J) The above steps (e) to (h) are repeated, and an upper layer having a target total layer thickness consisting of an alternately laminated structure of VN layers and VO layers through VNO layers as shown in Tables 3 and 4 is formed by vapor deposition. To do.
Hard coating layers were formed by vapor deposition according to the above (a) to (j), and surface coating throwaway tips (hereinafter referred to as the present invention coated tips) 1 to 16 as the present invention coated tools were produced, respectively.

For comparison purposes,
(A) Each of the above-mentioned tool bases A1 to A10 and B1 to B6 is ultrasonically cleaned in acetone and dried, and on the rotating table in the arc ion plating apparatus shown in FIG. Therefore, as the cathode electrode (evaporation source) on one side, various components are used as the Ti-Al-Si alloy for forming the lowest Al content point with various component compositions and the cathode electrode (evaporation source) on the other side. A Ti-Al-Si alloy for forming the highest Al content point having a composition is disposed oppositely across the rotary table,
(B) First, the inside of the apparatus was heated to 500 ° C. with a heater while the inside of the apparatus was evacuated and maintained at a vacuum of 0.1 Pa or less, and then a −1000 V DC bias voltage was applied to the tool base, and the cathode An arc discharge is generated by passing a current of 100 A between one of the two Ti—Al—Si alloys of the electrode and the anode electrode, and the tool substrate surface is bombarded with the Ti—Al—Si alloy. And
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, and a DC bias voltage of −100 V is applied to the tool base that rotates while rotating on the rotary table. A current of 100 A was passed between the cathode electrode (the Ti-Al-Si alloy for forming the lowest Al content point and the Ti-Al-Si alloy for forming the highest Al content point) and the anode electrode to generate an arc discharge, Therefore, the lowest Al content point and the highest Al content point of the target composition shown in Tables 5 and 6 are alternately repeated at the target intervals shown in Tables 5 and 6 along the layer thickness direction on the surface of the tool base. And a component concentration distribution structure in which the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, Similarly, the composition change (Ti, Al, Si) N layer corresponding to the lower layer of the coated chip of the present invention having the target layer thickness shown in Tables 5 and 6 is vapor-deposited as a hard coating layer. Conventional surface-coated throwaway chips (hereinafter referred to as conventional coated chips) 1 to 16 were produced.

Next, in the state where each of the above various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1 to 16 and the conventional coated chips 1 to 16 are as follows.
Work material: JIS / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 320 m / min. ,
Cutting depth: 4 mm,
Feed: 0.25 mm / rev. ,
Cutting time: 5 minutes,
In the above condition (cutting condition A), a stainless steel dry interrupted high cutting test (normal cutting speed and cutting amount are 230 m / min. And 1.5 mm, respectively),
Work material: JIS / S15C round bar,
Cutting speed: 300 m / min. ,
Cutting depth: 4 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-cut cutting test of mild steel under the above conditions (cutting condition B) (normal cutting speed and cutting amount are 210 m / min. And 1.5 mm, respectively),
Work material: JIS / SCMnH1 round bar,
Cutting speed: 350 m / min. ,
Cutting depth: 1.5 mm,
Feed: 0.50 mm / rev. ,
Cutting time: 5 minutes,
The dry continuous high-feed cutting test (normal cutting speed and feed are 260 m / min. And 0.25 mm / rev., Respectively) of high manganese steel under the above conditions (cutting condition C). In the test, the flank wear width of the cutting edge was also measured. The measurement results are shown in Table 7.

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 Powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [by mass ratio, TiC / WC = 50/50] powder, and 1 Prepare 8 μm Co powder, mix these raw material powders with the composition shown in Table 8, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and press at a pressure of 100 MPa. The green compacts were press-molded, and these green compacts were 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. After holding at temperature for 1 hour, sintering under furnace cooling conditions Then, three types of round rod sintered bodies for forming a tool base having diameters of 8 mm, 13 mm, and 26 mm are formed, and further, the three types of round bar sintered bodies are ground and are shown in Table 7. Made of WC-base cemented carbide with a combination of 4 blade square shape with diameter and length of 6mm × 13mm, 10mm × 22mm, and 20mm × 45mm respectively, and a twist angle of 30 degrees. Tool bases (end mills) C-1 to C-8 were produced.

  Subsequently, the surfaces of these tool bases (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1, the Al lowest content point and the Al highest content point of the target composition shown in Table 9 along the layer thickness direction are alternately repeated at the target interval shown in Table 9, and It has a component concentration distribution structure in which the Al (Ti) content continuously changes from the highest Al content point to the lowest Al content point, from the lowest Al content point to the highest Al content point, and is also shown in Table 9 Composition of target layer thickness (Ti, Al, Si) It is composed of a lower layer composed of an N layer, and an alternately laminated structure of a VN layer, a VNO layer and a VO layer having a target layer thickness shown in Table 9 (target) Consists of upper layer (total thickness) By depositing form a hard coating layer, the present invention surface-coated cemented carbide end mills of the present invention coated tool (hereinafter, the present invention refers to the coating end mill) 1-8 were prepared, respectively.

  For the purpose of comparison, the surfaces of the tool bases (end mills) C-1 to C-8 are ultrasonically cleaned in acetone and dried, and then mounted on the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the lowest Al content point and the highest Al content point of the target composition shown in Table 10 along the layer thickness direction are alternately repeated at the target interval shown in Table 10 as well. And having a component concentration distribution structure in which the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, and The composition change (Ti, Al, Si) N layer corresponding to the lower layer of the above-described coated end mill of the present invention having the target layer thickness shown in Table 10 is deposited as a hard coating layer, thereby allowing a conventional surface coating tool as a conventional coating tool. Hard made Mills (hereinafter, conventional coating end mill called) was 1-8 were prepared, respectively.

Next, of the present invention coated end mills 1-8 and the conventional coated end mills 1-8,
About this invention coated end mills 1-3 and conventional coated end mills 1-3,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 120 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 200 mm / min,
Stainless steel dry-type high-groove grooving test (normal cutting speed and groove depth are 60 m / min. And 3 mm, respectively),
About this invention coated end mills 4-6 and conventional coated end mills 4-6,
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 120 m / min. ,
Groove depth (cut): 4 mm,
Table feed: 240 mm / min,
Dry high-grooving groove cutting test of mild steel under the conditions (normal cutting speed and table feed are 70 m / min. And 120 mm / min, respectively)
For the coated end mills 7 and 8 of the present invention and the conventional coated end mills 7 and 8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 120 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 200 mm / min,
A high-manganese steel dry high-groove grooving test (normal cutting speed and groove depth is 60 m / min., 10 mm, respectively) under the conditions described above. The cutting groove length was measured until the flank wear width of the blade reached 0.1 mm, which is a guide for the service life. The measurement results are shown in Tables 9 and 10, respectively.

  The diameters produced in Example 2 above were 8 mm (for forming the tool bases C-1 to C-3), 13 mm (for forming the tool bases C-4 to C-6), and 26 mm (tool bases C-7 and C). -8 for forming), and from these three types of round bar sintered bodies, the diameter x length of the groove forming part is 4 mm x 13 mm (tool base D) by grinding. −1 to D-3), 8 mm × 22 mm (tool base D-4 to D-6), and 16 mm × 45 mm (tool bases D-7 and D-8), and all having a twist angle of 30 degrees 2 WC-base cemented carbide tool bases (drills) D-1 to D-8 having a single-blade shape were produced, respectively.

  Next, the cutting edges of these carbide substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus shown in FIG. 1 is also used. In the same conditions as in Example 1 above, the target minimum distance between the Al minimum content point and the Al maximum content point of the target composition shown in Table 11 along the layer thickness direction is also shown in Table 11 alternately. And having a component concentration distribution structure in which the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, And the composition change (Ti, Al, Si) N layer of the target layer thickness also shown in Table 11 and the VN layer and VO through the VNO layer of the single target layer thickness also shown in Table 11 From the alternating layered structure of layers The surface-coated carbide drill of the present invention (hereinafter referred to as the present invention-coated drill) 1 to 1 as the present invention-coated tool is formed by vapor-depositing a hard coating layer composed of an upper layer (with a target total layer thickness). 8 were produced respectively.

  For the purpose of comparison, the surface of the tool base (drill) D-1 to D-8 is subjected to honing, ultrasonically cleaned in acetone and dried, and the arc ions shown in FIG. In the plating apparatus, under the same conditions as in Example 1 above, the Al minimum content point and the Al maximum content point of the target composition shown in Table 12 along the layer thickness direction are also shown in Table 12 alternately. And a component concentration distribution structure in which the Al (Ti) content continuously changes from the highest Al content point to the lowest Al content point and from the lowest Al content point to the highest Al content point. And a conventional coated tool by depositing a composition change (Ti, Al, Si) N layer corresponding to the lower layer of the above-described coated drill of the present invention having the target layer thickness shown in Table 12 as a hard coating layer. As conventional Surface coated cemented carbide drills (hereinafter, conventional coating drill called) was 1-8 were prepared, respectively.

Next, among the above-mentioned present invention coated drills 1-8 and conventional coated drills 1-8,
About this invention coated drill 1-3 and conventional coated drill 1-3,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 100 m / min. ,
Feed: 0.40 mm / rev,
Hole depth: 8 mm,
Wet high-speed drilling test of stainless steel under the following conditions (normal cutting speed and feed are 60 m / min. And 0.25 mm / rev, respectively)
About this invention coated drill 4-6 and conventional coated drills 4-6,
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 160 m / min. ,
Feed: 0.40 mm / rev,
Hole depth: 20 mm,
Wet high-speed drilling test of mild steel under the following conditions (normal cutting speed and feed are 90 m / min. And 0.25 mm / rev, respectively)
About this invention covering drills 7 and 8 and conventional covering drills 7 and 8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 200 m / min. ,
Feed: 0.40 mm / rev,
Hole depth: 28 mm,
Wet high-speed drilling test of manganese steel under the conditions (normal cutting speed and feed are 110 m / min. And 0.20 mm / rev, respectively)
In each wet high-speed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.3 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

As a result, the composition change (Ti, Al, Si) constituting the hard coating layers of the present coated chips 1 to 16, the present coated end mills 1 to 8, and the present coated drills 1 to 8 as the present coated tool obtained as a result. ) N layer (lower layer), as well as composition changes (Ti, Al, conventional coating tip 1 to 16 as conventional coated carbide tool, conventional coated end mills 1 to 8 and conventional coated drills 1 to 8 as hard coated layers) The composition of the Al minimum content point and the Al maximum content point of the Si) N layer was measured by energy dispersive X-ray analysis using a transmission electron microscope. And substantially the same composition.
Furthermore, when the composition of the vanadium nitride layer, vanadium oxynitride layer, and vanadium oxide layer constituting the upper layer of the hard coating layer of the coated tool of the present invention was measured by energy dispersive X-ray analysis using a transmission electron microscope, The vanadium nitride layer is composed mainly of VN, the vanadium oxynitride layer is composed mainly of VNO, and the vanadium oxide layer is composed mainly of VO, which contains V ₂ O ₃ and VO _2. Showed the organization.

  In addition, the average layer thickness of the lower layer of the hard coating layer, the average layer thickness of the vanadium nitride layer, vanadium oxynitride layer and vanadium oxide layer constituting the upper layer of the alternately laminated structure, and the total thickness of the upper layer are scanned. When a cross-section was measured using a scanning electron microscope, all showed an average value (average value of five locations) substantially the same as the target layer thickness.

  From the results shown in Tables 3 to 7 and 8 to 12, the coated tools of the present invention are all high speed conditions accompanied by high heat generation of difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel, which are particularly highly viscous and sticky. The composition change (Ti, Al, Si) N layer, which is the lower layer of the hard coating layer, has excellent high-temperature hardness and heat resistance even in high-speed heavy cutting under heavy cutting conditions such as high cutting and high feed. In addition, it has excellent high-temperature strength, and is superior between the work material and the chips by the upper layer composed of an alternately laminated structure of vanadium nitride layers and vanadium oxide layers with vanadium oxynitride layers interposed therebetween. Since the surface slipperiness is ensured and at the same time the high temperature strength and wear resistance of the entire upper layer are maintained, excellent wear resistance is exhibited over a long period of time without occurrence of chipping. On the other hand, in the conventional coated tool in which the hard coating layer is composed of a composition change (Ti, Al, Si) N layer, both are accompanied by high heat generation in the high-speed heavy cutting of the difficult-to-cut material. The adhesiveness and reactivity between the work material (difficult-to-cut material) and chips and the hard coating layer are further increased, and this causes chipping at the cutting edge, which can be used in a relatively short time. It is clear that it will reach the end of its life.

  As described above, the coated tool of the present invention is not only for cutting of general steel and ordinary cast iron, but also has high heat generation, and the high-speed heavy load of difficult-to-cut materials in which a high load is locally applied to the cutting edge. Even when used for cutting, it exhibits excellent chipping resistance and exhibits excellent cutting performance over a long period of time. It can cope with cost reductions with sufficient satisfaction.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated tool is shown, (a) is a schematic plan view, (b) is a schematic front view. The arc ion plating apparatus used for forming the hard coating layer which comprises a conventional coating tool is shown, (a) is a schematic plan view, (b) is a schematic front view.

Claims (1)

On the surface of the tool base composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(A) It has an average layer thickness of 1 to 5 μm, and along the layer thickness direction, Al maximum content points and Al minimum content points are alternately present at predetermined intervals, and the Al maximum content A component concentration distribution structure in which the Al and Ti contents continuously change from the point to the Al minimum content point, from the Al minimum content point to the Al maximum content point,
Furthermore, the Al highest content point is the composition formula: (Ti _1-XY Al _X Si _Y ) N (wherein the atomic ratio, X is 0.60 to 0.85, and Y is 0.01 to 0.00. 1),
The Al minimum content point is a composition formula: (Ti _{1-A B} Al _A Si _B ) N (where A is 0.40 to 0.55 and B is 0.01 to 0.1 in terms of atomic ratio). Show),
A lower layer composed of a composite nitride layer of Ti, Al, and Si, in which the interval between the Al highest content point and the Al lowest content point adjacent to each other is 0.03 to 0.1 μm,
(B) a vanadium nitride layer having a single layer average layer thickness of 0.4 to 2 μm and a vanadium oxide layer having a single layer average layer thickness of 0.4 to 2 μm, and a vanadium nitride layer and a vanadium oxide layer; An upper layer having an overall average layer thickness of 1 to 5 μm, with a vanadium oxynitride layer having an average layer thickness of 0.02 to 0.2 μm interposed between each of the layers,
A surface-coated cutting tool that exhibits a chipping resistance with excellent hard coating layer in high-speed heavy cutting of difficult-to-cut materials, formed by forming the hard coating layer composed of (a) and (b) above.

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