JP2007105841A - Surface coated cutting tool having hard coated layer exhibiting excellent wear resistance in high speed cutting for highly reactive material to be cut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having a hard coated layer exhibiting excellent wear resistance in high speed cutting for highly reactive material to be cut. <P>SOLUTION: In this surface coated cutting tool, a hard coated layer including the followings is formed on the surface of cemented carbide base or on the surface of high speed tool steel base by vapor deposition: (a) an upper layer and a lower layer, which are both formed of (Ti, Al, Ta)N, the upper layer has an average layer thickness of 0.5 to 1.5 μm and the lower layer has an average layer thickness of 2 to 6 μm; (b) the upper layer has an alternately stacked layer structure of a thin layer A and a thin layer B, both of which have an average layer thickness per layer ranging from 5 to 20 nm, the thin layers A, B are respectively formed of (Ti, Al, Ta) N layer satisfying a specific composition formula; and (c) the lower layer is formed of (Ti, Al, Ta) N layer having a single phase structure and satisfying the formula [Ti<SB>1-(X+Y)</SB>Al<SB>X</SB>Ta<SB>Y</SB>]N (wherein by atomic ratio, X is 0.50 to 0.65 and Y is 0.01 to 0.10). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This invention is particularly suitable for high-speed cutting with high heat generation of highly reactive work materials such as Ti alloys, high Si-containing Al alloys, and free-cutting steels, and the hard coating layer is highly reactive. Carbide made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet that exhibits extremely low reactivity to the workable material and results in excellent wear resistance over a long period of time. The present invention relates to a surface-coated cutting tool in which a hard coating layer is formed on the surface of a base or the surface of a high-speed tool steel base.

  In general, surface-coated cutting tools include a throw-away tip that is detachably attached to the tip of a cutting tool for turning and planing of various steels and cast irons, and drilling of the work material. There are drills and miniature drills used for processing, etc., and solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material. A slow-away end mill tool that performs cutting work in the same manner as a type end mill is known.

Also, as one of the surface-coated cutting tools, for example, on the surface of a cemented carbide substrate composed of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet, Having a single phase structure, and
_{Formula: [Ti 1- (X + Y} ) Al X Ta Y] N ( provided that an atomic ratio, X is from .50 to 0.65, Y represents a 0.01-0.10)
Surface-coated carbide formed by vapor-depositing a hard coating layer composed of a composite nitride of Ti, Al, and Ta [hereinafter referred to as (Ti, Al, Ta) N] satisfying the following conditions with an average layer thickness of 2 to 8 μm A tool is known, and in such a conventional surface-coated carbide tool, the (Ti, Al, Ta) N layer constituting the hard coating layer has high temperature hardness and heat resistance due to Al as a constituent component. It is also known that Ti exerts a high temperature strength, and further Ta exerts a reaction suppressing effect with the work material.

Furthermore, the above-mentioned surface-coated carbide tool is loaded with the above-mentioned carbide substrate in an arc ion plating apparatus which is one of physical vapor deposition apparatuses schematically shown in FIG. For example, a cathode electrode (evaporation source) in which a Ti—Al—Ta alloy having a composition corresponding to the composition of the (Ti, Al, Ta) N layer, which is a hard coating layer, is heated to a temperature of 500 ° C. For example, an arc discharge is generated between the anode electrode and the anode electrode under the condition of current: 90A, and simultaneously nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 2 Pa, for example. For example, it is also known to manufacture by depositing a hard coating layer made of the (Ti, Al, Ta) N layer on the surface of the cemented carbide substrate under the condition that a bias voltage of −100 V is applied.
Japanese Patent No. 3351054

In recent years, the performance of cutting devices has been dramatically improved. On the other hand, there is a strong demand for labor saving and energy saving and further cost reduction for cutting, and with this, cutting tends to be faster. In surface-coated carbide tools, when used for cutting carbon steel, low alloy steel, and ordinary cast iron under high-speed cutting conditions, there is no problem, showing normal cutting performance. Particularly hard when cutting highly reactive work materials such as Ti alloys, high Si-containing Al alloys, and free-cutting steel under high-speed cutting conditions with high heat generation. The reaction between the coating layer and the highly reactive work material, coupled with the acceleration of high heat generation, proceeds rapidly, resulting in a wear life in a relatively short time. Is the current situation.

In view of the above, the present inventors have developed a surface-coated cutting tool that exhibits excellent wear resistance in which a hard coating layer is excellent in high-speed cutting of the highly reactive work material. As a result of conducting research by paying attention to the (Ti, Al, Ta) N layer that constitutes the hard coating layer of conventional coated carbide tools,

(a) In the (Ti, Al, Ta) N layer constituting the hard coating layer, the reactivity with the highly reactive work material decreases as the content ratio of the Ta component increases. In the conventional (Ti, Al, Ta) N layer, the Ta content ratio of about 1 to 10 atomic% can satisfactorily suppress the reaction with the highly reactive work material by high-speed cutting with high heat generation. In order to sufficiently suppress the reaction with the highly reactive work material in high-speed cutting, it is necessary to contain 20 to 35 atomic% of Ta, far exceeding the above 1 to 10 atomic%, In order to practically use a (Ti, Al, Ta) N layer containing 20 to 35 atomic% Ta component as a hard coating layer, it is necessary to contain a predetermined amount of Ti to ensure a predetermined high temperature strength. In this case, the content ratio of the Al component is avoided to be extremely low. Are not those become very low for this result high-temperature hardness.

(B) a (Ti, Al, Ta) N layer (hereinafter referred to as a thin layer A) in which the Ta content ratio in (a) is increased to 20 to 35 atomic% to improve the reaction suppression effect with the work material; The Ta content ratio is lower than that of the thin layer A, but the Al content ratio is relatively high, and a (Ti, Al, Ta) N layer (hereinafter, referred to as “high temperature hardness”) is provided. When the thin layers B are alternately laminated in a state where each layer has an average layer thickness of 5 to 20 nm (nanometers), the (Ti, Al, Ta) N layer having this alternately laminated structure has a high Ta layer. Combining the excellent work material reaction suppressing effect of the contained thin layer A and the predetermined high-temperature hardness of the thin layer B having a relatively high Al content.

Here, the composition formulas of the thin layer A and the thin layer B are as follows.
Composition formula of the thin layer _{A: [Ti 1- (E +} F) Al E Ta F] N ( where, in terms of atomic ratio, E is 0.15 to 0.30, F represents a 0.20 to 0.35)

Composition formula of the thin layer _{B: [Ti 1- (M +} N) Al M Ta N] N ( where, in terms of atomic ratio, M is .50 to 0.65, N denotes the 0.01-0.10)

(C) The (Ti, Al, Ta) N layer having the alternately laminated structure of the thin layer A and the thin layer B in (b) is a work material reaction required for high-speed cutting of a highly reactive work material. Although it has a suppressing effect, it does not have a sufficiently satisfactory high-temperature hardness and heat resistance, so this is provided as the upper layer of the hard coating layer, while the lower layer is insufficient in the work material reaction suppressing effect (Ti, Al, Ta) N layer having a composition corresponding to the above conventional hard coating layer having a relatively high content of Al component and having excellent high temperature hardness and heat resistance,

_{Formula: [Ti 1- (X + Y} ) Al X Ta Y] N ( provided that an atomic ratio, X is from .50 to 0.65, Y represents a 0.01-0.10) satisfies the single (Ti, Al, Ta) N layer of single phase structure,
With this structure, the hard coating layer composed of the upper layer and the lower layer has excellent high-temperature hardness and heat resistance, as well as high-temperature strength, in addition to excellent work material reaction suppression effect. Therefore, the coated carbide tool formed by vapor-depositing this hard coating layer can be used for the high-reactive work material and the hard coating layer even in high-speed cutting with high heat generation of the high-reactivity work material. Since cutting is performed in a state in which reactive wear is remarkably suppressed, excellent wear resistance can be exhibited over a long period of time without occurrence of chipping.

The research results shown in (a) to (c) above were obtained.

This invention was made based on the above research results,

On the surface of a cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet, or on the surface of a high-speed tool steel substrate,
(A) Both are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al, and Ta, the upper layer has an average layer thickness of 0.5 to 1.5 μm, and the lower layer has an average layer thickness of 2 to 6 μm. Have
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: [Ti _{1− (E + F)} Al _E Ta _F ] N (wherein E represents 0.15 to 0.30 and F represents 0.20 to 0.35 in atomic ratio) A composite nitride layer of Al and Ta,
The thin layer B is
Ti satisfying the composition formula: [Ti _{1− (M + N)} Al _M Ta _N ] N (wherein M is 0.50 to 0.65 and N is 0.01 to 0.10 in atomic ratio) A composite nitride layer of Al and Ta,
(C) the lower layer has a single phase structure;
_{Formula: [Ti 1- (X + Y} ) Al X Ta Y] N ( provided that an atomic ratio, X is from .50 to 0.65, Y denotes the 0.01-0.10) and Ti which satisfies A composite nitride layer of Al and Ta,
It is characterized by a surface-coated cutting tool that exhibits excellent wear resistance in high-speed cutting of a highly reactive work material formed by vapor-depositing a hard coating layer comprising:

Next, the reason why the numerical values of the hard coating layer of the surface-coated cutting tool of the present invention are limited as described above will be described.
(A) Composition formula and average layer thickness of the hard coating layer constituting the lower layer The Al component in the hard coating layer (Ti, Al, Ta) N layer improves the high temperature hardness and heat resistance, while the Ti component Has the effect of significantly reducing the reactivity with the work material, particularly the Ta component, and the lower layer increases the Al component content to provide high high temperature hardness and heat resistance. When the X value indicating the Al content ratio is less than 0.50 in the total amount of Ti and Ta (atomic ratio, the same shall apply hereinafter), the Ti ratio is relatively high, and highly reactive cutting. The excellent high-temperature hardness and heat resistance required for high-speed cutting of the material cannot be ensured, and wear progresses rapidly, while the X value indicating the Al ratio is 0.65. If it exceeds, the proportion of Ti becomes relatively small and high. The X value was determined to be 0.50 to 0.65 because the temperature strength dropped sharply and as a result chipping (slight chipping) was likely to occur.
Further, if the Y value indicating the proportion of Ta is a proportion of the total amount of Ti and Al, and less than 0.01, a predetermined work material reaction suppression effect cannot be ensured, while the Y value is 0. When it exceeds 10, since a clear decreasing tendency appears in the high-temperature strength, the Y value was set to 0.01 to 0.10.
Furthermore, if the average layer thickness is less than 2 μm, the excellent high-temperature hardness and heat resistance cannot be imparted to the hard coating layer over a long period of time, resulting in a short tool life, while the average layer thickness is 6 μm. If it exceeds, chipping is likely to occur, so the average layer thickness was set to 2 to 6 μm.

(B) Composition formula of the hard coating layer constituting the thin layer A of the upper layer The Ta component in (Ti, Al, Ta) N of the thin layer A of the upper layer is made as high as possible, as described above, It is included for the purpose of further improving the work material reaction suppressing effect and reducing reactive wear in high-speed cutting of high-reactive work material accompanied by high heat generation. Is a proportion of the total amount of Ti and Al, and if it is less than 0.20, the desired excellent work material reaction suppressing effect cannot be ensured during high-speed cutting, while the F value exceeds 0.35. And the content ratio of the Ti component becomes relatively small, the high temperature strength that the layer itself should have cannot be ensured, and the high temperature strength rapidly decreases, which causes a decrease in the high temperature strength of the entire upper layer. , Chipping is likely to occur Therefore, the F value was determined to be 0.20 to 0.35.
Further, the E value indicating the proportion of Al is the proportion of the total amount of Ti and Ta, and if it is less than 0.15, the minimum high-temperature hardness and heat resistance cannot be ensured, causing wear promotion, On the other hand, if the E value exceeds 0.30, the high-temperature strength decreases and causes chipping, so the E value was set to 0.15 to 0.30.

(C) Composition formula of the hard coating layer constituting the thin layer B of the upper layer The thin layer B is an upper layer composed of an alternating laminated structure of the thin layer A and the thin layer B. The main purpose is to supplement (high temperature hardness, heat resistance).

As described above, the thin layer A of the upper layer is intended to increase the content ratio of the Ta component and improve the work material reaction suppression effect, but the upper layer is also required to have a predetermined high temperature strength. In order to ensure this, the thin layer A needs to contain a predetermined amount of Ti. If it does so, the content rate of Al in the thin layer A must be reduced, As a result, the thin layer A becomes inadequate in high temperature hardness and heat resistance, and it leads to the fall of abrasion resistance by extension.
Therefore, in the thin layer B of the upper layer, the content ratio of the Ta component is relatively lower than that of the thin layer A, while the content ratio of the Al component is kept relatively high, High temperature hardness and heat resistance are provided to compensate for the lack of heat resistance and heat resistance of the adjacent thin layer A, so that the thin layer A has excellent work material reaction suppression effect and the thin layer B has An upper layer having a predetermined high temperature hardness and heat resistance is formed.

When the M value indicating the Al content ratio in the composition formula of the thin layer B is less than 0.50, the Al content ratio is too small, and the predetermined high-temperature hardness and heat resistance cannot be ensured. As a result, the progress of wear is promoted. On the other hand, if the M value exceeds 0.65, the content ratio of the Ti component is relatively reduced, and the high-temperature strength of the upper layer is inevitably lowered, causing chipping. Therefore, the M value was set to 0.50 to 0.65.

Further, if the N value indicating the ratio of Ta is the ratio of the total amount of Ti and Al, and less than 0.01, a reduction in the work material reaction suppression effect of the entire upper layer is inevitable, while the N value is 0. If it exceeds .10, the high temperature strength decreases and chipping is likely to occur, so the N value was determined to be 0.01 to 0.10.

(D) Single layer average layer thickness of thin layer A and thin layer B of the upper layer Thin layer A and thin layer B of the upper layer, and if each single layer average layer thickness is less than 5 nm, each thin layer is of the above composition It is difficult to form clearly, and as a result, it is not possible to ensure a desired excellent work material reaction suppressing effect on the upper layer, furthermore, a predetermined high-temperature hardness and heat resistance, and each layer thickness is 20 nm. If it exceeds, the defects of each thin layer, that is, if it is thin layer A, high temperature hardness and insufficient heat resistance, and if it is thin layer B, insufficient effect of suppressing the reaction of the work material will appear locally in the layer, which causes chipping Therefore, the thickness of each layer was set to 5 to 20 nm.

That is, the thin layer B is provided to reinforce the characteristics of the thin layer A, but if the average layer thickness of each of the thin layer A and the thin layer B is within the range of 5 to 20 nm, the thin layer B is thin. The upper layer composed of the alternately laminated structure of the layer A and the thin layer B is a single layer having excellent work material reaction suppressing action and having a predetermined high temperature hardness, high temperature strength, and heat resistance. However, when the average layer thickness of each of the thin layer A and the thin layer B exceeds 20 nm, the disadvantage of each thin layer, that is, if the thin layer A is high temperature hardness and insufficient heat resistance, thin In layer B, the lack of work material reaction suppression effect appears locally in the layer, and the upper layer cannot exhibit good characteristics as a single layer as a whole. The average layer thickness of each layer B was determined to be 5 to 20 nm.

By forming an upper layer having an alternate laminated structure with a single layer average layer thickness of the thin layer A and the thin layer B in the range of 5 to 20 nm on the lower layer surface, it has an excellent work material reaction suppression effect, And the hard coating layer which has high temperature hardness, high temperature strength, and heat resistance is obtained.

(E) Average layer thickness of the upper layer If the average layer thickness of the entire upper layer is less than 0.5 μm, the hard coating layer has a long-lasting effect of suppressing its own work material reaction and predetermined high-temperature hardness and heat resistance. However, when the layer thickness exceeds 1.5 μm, chipping is likely to occur. Therefore, the layer thickness is determined to be 0.5 to 1.5 μm.

  In the surface-coated cutting tool of the present invention, the hard coating layer is composed of a (Ti, Al, Ta) N layer, and the upper layer of the hard coating layer has an alternate laminated structure of thin layers A and thin layers B. In particular, since the lower layer of the single-phase structure has relatively high high temperature hardness and heat resistance while maintaining the high temperature hardness and heat resistance of Even in high-speed cutting with high heat generation of extremely reactive work materials such as alloys, high-Si content Al alloys, and free-cutting steel, the reactive wear of the hard coating layer is remarkably suppressed, which is excellent. It exhibits wear resistance over a long period of time.

  Next, the surface-coated cutting 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 into the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. Medium, sintered at 1400 ° C for 1 hour, after sintering, WC-based carbide with honing of R: 0.03 on the cutting edge and chip shape of ISO standard CNMG120408 Alloy carbide substrates A-1 to A-10 were formed.

In addition, as raw material powders, all are TiCN (weight ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then pressed into a compact at a pressure of 100 MPa. The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to obtain ISO standard / CNMG120408. The carbide substrates B-1 to B-6 made of TiCN base cermet having the following chip shape were formed.

(A) Next, each of the above carbide substrates A-1 to A-10 and B-1 to B-6 was ultrasonically cleaned in acetone and dried, and then the arc ion plate shown in FIG. Attached along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table in the coating apparatus, and used as a cathode electrode (evaporation source) on one side with the target compositions shown in Tables 3 and 4, respectively. As the upper layer Ti-Al-Ta alloy for forming the thin layer A having the corresponding component composition and the cathode electrode (evaporation source) on the other side, the component compositions corresponding to the target compositions shown in Tables 3 and 4 are also used. The upper layer thin layer B and the lower layer forming Ti-Al-Ta alloy are disposed opposite to each other with the rotary table interposed therebetween,
(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 400 ° C. with a heater, and then the carbide substrate that rotates while rotating on the rotary table is set to −1000 V. And applying a current of 100 A between the thin layer B and Ti-Al-Ta alloy for forming the lower layer and the lower layer and the anode electrode to generate arc discharge. Bombard cleaning with Ti-Al-Ta alloy,
(C) Introducing nitrogen gas as a reaction gas into the apparatus to make a reaction atmosphere of 3 Pa, applying a DC bias voltage of −100 V to a carbide substrate rotating while rotating on the rotary table, and An arc discharge is generated by passing a current of 100 A between the layer B and the Ti—Al—Ta alloy for forming the lower layer and the anode electrode, and the target composition shown in Tables 3 and 4 is formed on the surface of the carbide substrate. And a (Ti, Al, Ta) N layer having a single phase structure with a target layer thickness is deposited as a lower layer of the hard coating layer,

(D) Next, the flow rate of nitrogen gas as a reaction gas introduced into the apparatus is adjusted to a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V is applied to the carbide substrate rotating while rotating on the rotary table. In the applied state, a predetermined current in the range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Ti-Al-Ta alloy for forming the thin layer A to generate arc discharge, and the carbide A thin layer A having a predetermined layer thickness is formed on the surface of the substrate. After the thin layer A is formed, the arc discharge is stopped. Instead, the cathode electrode of the Ti-Al-Ta alloy for forming the thin layer B and the lower layer Similarly, a predetermined current in the range of 50 to 200 A is passed between the anode electrodes to generate arc discharge to form a thin layer B having a predetermined layer thickness. Then, the arc discharge is stopped and the thin layer A is formed again. Ti-Al-Ta alloy The formation of thin layer A by arc discharge between the cathode electrode and the anode electrode and the formation of thin layer B by arc discharge between the cathode electrode and the anode electrode of the Ti-Al-Ta alloy for forming the thin layer B and the lower layer are alternately performed. Thus, an upper layer composed of alternately laminated thin layers A and B having a target composition and a target layer thickness of one layer along the layer thickness direction is similarly formed on the surface of the cemented carbide substrate. By carrying out vapor deposition with the overall target layer thicknesses shown in Tables 3 and 4, the present invention surface-coated carbide throwaway tip (hereinafter referred to as the present invention coated carbide tip) 1 to 1 as the present invention coated carbide tool. 16 were produced respectively.

  For the purpose of comparison, these carbide substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating apparatus shown in FIG. A Ti—Al—Ta alloy having a component composition corresponding to the target composition shown in Table 5 was attached as a cathode electrode (evaporation source), and the inside of the apparatus was first evacuated to 0.1 Pa. While maintaining the following vacuum, the inside of the apparatus was heated to 400 ° C. with a heater, a DC bias voltage of −1000 V was applied to the carbide substrate, and the Ti—Al—Ta alloy and anode electrode of the cathode electrode were applied. A current of 100 A is passed between them to generate an arc discharge, so that the surface of the carbide substrate is bombarded with the Ti—Al—Ta alloy, and then nitrogen gas is introduced into the apparatus as a reactive gas to obtain 3 Pa of And a bias voltage applied to the cemented carbide substrate is lowered to -100 V to generate an arc discharge between the cathode electrode and the anode electrode of the Ti-Al-Ta alloy. Each of A-1 to A-10 and B-1 to B-6 has a (Ti, Al, Ta) N layer having a single-phase structure having a target composition and a target layer thickness shown in Table 5. By forming the hard coating layer by vapor deposition, conventional surface-coated carbide throw-away tips (hereinafter referred to as conventional coated carbide tips) 1 to 16 as conventional coated carbide tools were produced, respectively.

Next, the coated carbide chips 1 to 16 of the present invention and the conventional coated carbide chip 1 in the state in which each of the various coated carbide chips is screwed to the tip of the tool steel tool with a fixing jig. About ~ 16
Work material: Round bar of JIS 60 types (composition, mass%, Ti-6% Al-4% V),
Cutting speed: 90 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed cutting test of Ti alloy under the conditions (cutting condition A) (normal cutting speed is 40 m / min.),
Work material: JIS-AC9B (composition, mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) in the longitudinal direction at equal intervals, 4 longitudinally round bars.
Cutting speed: 300 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.12 mm / rev. ,
Cutting time: 10 minutes,
Dry interrupted high-speed cutting test (normal cutting speed is 150 m / min.) Of a high Si content Al alloy under the conditions (cutting condition B)
Work material: JIS / SUM22 (composition, mass%, Fe-1% Mn-0.3% S-0.1% P) round bar,
Cutting speed: 400 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
The dry continuous high-speed cutting test (normal cutting speed is 200 m / min.) Of free-cutting steel under the above conditions (referred to as cutting condition C), and the flank wear width of the cutting edge was measured in any cutting test. . The measurement results are shown in Table 6.

(A) As raw material powder, medium coarse WC powder having an average particle size of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, 2 μm ZrC 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, Co powder of 1.8 μm was prepared, and these raw material powders were blended in the blending composition shown in Table 7, respectively, and added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then pressure of 100 MPa Are pressed into various green compacts of a predetermined shape, and these green compacts are heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a heating rate of 7 ° C./min in a vacuum atmosphere of 6 Pa. And after holding at this temperature for 1 hour, As a result, three types of cemented carbide substrate-forming round bar sintered bodies having diameters of 8 mm, 13 mm, and 26 mm were formed. In the combination shown in the above, the diameter × length of the cutting edge is 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and each has a four-blade square shape with a twist angle of 30 degrees. Cemented carbide substrates (end mills) C-1 to C-8 were produced, respectively.
(B) Also, the diameter of the cutting edge part x in the combinations shown in Table 7 by machining from three types of high-speed tool steel (JIS / SKH55) materials with a diameter of 8 mm, 13 mm, and 26 mm. High-speed tool steel (hereinafter referred to as HSS) base (end mill) E having a four-blade square shape with dimensions of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and a twist angle of 30 degrees. -1 to E-6 were produced. The dimensions and shapes of the HSS substrates (end mills) E-1 to E-2, E-3 to E-4, and E-5 to E-6 are the same as the carbide substrates (end mills) C-1 to C-3. , C-4 to C-6, and C-7 to C-8.

  Next, the surfaces of these carbide substrates (end mills) C-1 to C-8 and HSS substrates (end mills) E-1 to E-6 were ultrasonically cleaned in acetone and dried, as shown in FIG. From the (Ti, Al, Ta) N layer having a single phase structure with the target composition and target layer thickness shown in Table 8 under the same conditions as in Example 1 above. The total target layer thickness shown in Table 8 is also the lower layer, and the upper layer consisting of the alternating layers of the thin layer A and the thin layer B having the target composition and the single target layer thickness are also shown in Table 8 along the layer thickness direction. As a surface-coated cutting tool of the present invention, the surface-coated carbide end mill (hereinafter referred to as the present invention coated carbide end mill) 1 to 8 and the surface-coated high-speed tool steel end mill (hereinafter referred to as the present invention) Hereinafter, the present invention coated HSS engine Mill and refers) 9-14 were prepared, respectively.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 and HSS substrates (end mills) E-1 to E-6 were ultrasonically cleaned in acetone and dried. 2 is charged in the arc ion plating apparatus shown in FIG. 2 and has a single-phase structure with the target composition and target layer thickness shown in Table 9 under the same conditions as in Example 1 (Ti, Al). , Ta) By depositing a hard coating layer comprising an N layer, conventional surface-coated carbide end mills (hereinafter referred to as conventional coated carbide end mills) 1 to 8 as conventional surface-coated cutting tools and conventional surface-coated high speeds Tool steel end mills (hereinafter referred to as conventional coated HSS end mills) 9 to 14 were produced.

(A) Next, of the present invention coated carbide end mills 1-8 and conventional coated carbide end mills 1-8,

(A-1) About this invention coated carbide end mills 1-3 and conventional coated carbide end mills 1-3,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS · SUM22 (mass%, Fe-1% Mn-0.3% S-0.1% P) plate material,
Cutting speed: 220 m / min. ,
Groove depth (cut): 2.0 mm,
Table feed: 750 mm / min,
A dry high-speed grooving test of free-cutting steel under the conditions (normal cutting speed is 100 m / min.)
(A-2) About this invention coated carbide end mills 4-6 and conventional coated carbide end mills 4-6,

Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS.60 type (mass%, Ti-6% Al-4% V) plate material Cutting speed: 90 m / min. ,
Groove depth (cut): 3.5 mm,
Table feed: 400 mm / min,
A dry high-speed grooving test of the Ti alloy under the conditions (normal cutting speed is 40 m / min.),
(A-3) About the coated carbide end mills 7 and 8 of the present invention and the conventional coated carbide end mills 7 and 8,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / AC9B (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) plate material,
Cutting speed: 200 m / min. ,
Groove depth (cut): 7.0 mm,
Table feed: 500 mm / min,

A dry high-speed grooving test of a high Si content Al alloy under the conditions (normal cutting speed is 100 m / min.),
In any of the above groove cutting tests (a-1) to (a-3), the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life. Was measured.

(B) Next, among the present coated HSS end mills 9 to 14 and the conventional coated HSS end mills 9 to 14,

(B-1) About the present coated HSS end mills 9 and 10 and the conventional coated HSS end mills 9 and 10,

Work material-Plane: 100 mm x 250 mm, thickness: 50 mm JIS 60 type (mass%, Ti-6% Al-4% V) plate material,

Cutting speed: 30 m / min. ,
Groove depth (cut): 2.0 mm,
Table feed: 80 mm / min,
A dry high-speed grooving test of the Ti alloy under the conditions (normal cutting speed is 15 m / min.),
(B-2) About this invention coated HSS end mills 11 and 12 and conventional coated HSS end mills 11 and 12,

Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / AC9B (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) plate material,

Cutting speed: 120 m / min. ,
Groove depth (cut): 4.0 mm,
Table feed: 320 mm / min,
A dry high-speed grooving test of a high Si content Al alloy under the conditions (normal cutting speed is 60 m / min.),
(B-3) About this invention coated HSS end mills 13 and 14 and conventional coated HSS end mills 13 and 14,

Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS · SUM22 (mass%, Fe-1% Mn-0.3% S-0.1% P) plate material,

Cutting speed: 80 m / min. ,
Groove depth (cut): 8.0 mm,
Table feed: 250 mm / min,
A dry high-speed grooving test of free-cutting steel under the conditions (normal cutting speed is 40 m / min.)
In any of the groove cutting tests of (b-1) to (b-3) above, the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life. Was measured.
The measurement results of the above (a-1) to (a-3) and (b-1) to (b-3) are shown in Tables 8 and 9, respectively.

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

In addition, using the high-speed tool steel (JIS / SKH55) material used in Example 2 above, the diameter and length of the groove forming portion were 4 mm × 25 mm (HSS substrates F-1, F- 2), 8 mm x 45 mm (HSS bases F-3, F-4), and 16 mm x 90 mm (HSS bases F-5, F-6), and each has a two-blade shape with a twist angle of 30 degrees. HSS substrates (drills) F-1 to F-6 made of high-speed tool steel were produced.

  Next, the cutting edges of these carbide substrates (drills) D-1 to D-8 and HSS substrates (drills) F-1 to F-6 are honed, ultrasonically cleaned in acetone, and dried. In the same manner, the arc ion plating apparatus shown in FIG. 1 was charged, and under the same conditions as in Example 1, it had a single phase structure with the target composition and target layer thickness shown in Table 10 (Ti, Al , Ta) The lower layer composed of N layer and the upper layer composed of the alternating layers of the thin layer A and the thin layer B having the target composition and the single target layer thickness which are also shown in Table 10 along the layer thickness direction. By carrying out vapor deposition with the overall target layer thickness shown, the present invention surface coated carbide drills (hereinafter referred to as the present invention coated carbide drill) 1 to 8 as the present invention surface coated cutting tool and the present invention surface coated HSS. Drill (hereinafter referred to as the present invention HSS drill) Say) 9-14 was prepared, respectively.

  For comparison purposes, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 and HSS substrates (drills) F-1 to F-6 are subjected to honing and ultrasonically cleaned in acetone. In a dry state, the same was put into the arc ion plating apparatus shown in FIG. 2, and under the same conditions as in Example 1, a single phase structure with the target composition and target layer thickness also shown in Table 11 was obtained. By vapor-depositing a hard coating layer comprising a (Ti, Al, Ta) N layer, conventional surface-coated carbide drills (hereinafter referred to as conventional coated carbide drills) 1 to 8 as conventional surface-coated cutting tools and Conventional surface-coated HSS drills (hereinafter referred to as conventional coated HSS drills) 9 to 14 were produced.

(C) Next, of the present invention coated carbide drills 1-8 and conventional coated carbide drills 1-8,
(C-1) About this invention coated carbide drills 1-3 and conventional coated carbide drills 1-3,

Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS · SUM22 (mass%, Fe-1% Mn-0.3% S-0.1% P) plate material,
Cutting speed: 90 m / min. ,
Feed: 0.18 mm / rev,
Hole depth: 6 mm,
A wet high speed drilling test of free cutting steel under the conditions (normal cutting speed is 45 m / min.)
(C-2) About the present coated carbide drills 4-6 and the conventional coated carbide drills 4-6,

Work material-Plane: 100 mm x 250 mm, thickness: 50 mm JIS 60 type (mass%, Ti-6% Al-4% V) plate material,
Cutting speed: 50 m / min. ,
Feed: 0.1 mm / rev,
Hole depth: 10 mm,
A wet high-speed drilling test of the Ti alloy under the conditions (normal cutting speed is 25 m / min.),
(C-3) About the coated carbide drills 7 and 8 of the present invention and the conventional coated carbide drills 7 and 8,

Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / AC9B (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) plate material,
Cutting speed: 140 m / min. ,
Feed: 0.25 mm / rev,
Hole depth: 20 mm,
Wet high speed drilling test of high Si content Al alloy under the conditions (normal cutting speed is 70 m / min.)

In any of the wet high-speed drilling tests (using water-soluble cutting oil) of any of the above (c-1) to (c-3), the number of drilling processes until the flank wear width of the tip cutting edge surface reaches 0.3 mm Was measured. The measurement results are shown in Tables 10 and 11, respectively.
(D) Next, among the above-mentioned present invention coated HSS drills 9-14 and conventional coated HSS drills 9-14,
(D-1) For the coated HSS drills 9 and 10 of the present invention and the conventional coated HSS drills 9 and 10,

Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS · SUM22 (mass%, Fe-1% Mn-0.3% S-0.1% P) plate material,

Cutting speed: 70 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 12 mm,
A wet high speed drilling test of free cutting steel under normal conditions (normal cutting speed is 35 m / min.)
(D-2) About this invention coated HSS drills 11 and 12 and conventional coated HSS drills 11 and 12,

Work material-Plane: 100 mm x 250 mm, thickness: 50 mm JIS 60 type (mass%, Ti-6% Al-4% V) plate material,

Cutting speed: 30 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 24 mm,
A wet high-speed drilling test of the Ti alloy under the conditions (normal cutting speed is 15 m / min.),
(D-3) About this invention coated HSS drills 13 and 14 and conventional coated HSS drills 13 and 14,

Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / AC9B (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) plate material,

Cutting speed: 70 m / min. ,
Feed: 0.25 mm / rev,
Hole depth: 48 mm,
Wet high speed drilling test of high Si content Al alloy under the conditions (normal cutting speed is 35 m / min.)
In any of the wet high-speed drilling tests (using water-soluble cutting oil) in any of the above (d-1) to (d-3), the number of drilling processes until the flank wear width of the tip cutting edge surface reaches 0.3 mm Was measured.
The measurement results of the above (c-1) to (c-3) and (d-1) to (d-3) are shown in Tables 10 and 11, respectively.

  As a result, the present coated carbide tips 1 to 16 as the present surface coated cutting tool, the present coated carbide end mill 1 to 8, the present coated HSS end mill 9 to 14, the present coated carbide drill 1 to 8 and the present invention coated HSS drills 9 to 14 (Ti, Al, Ta) N hard coating layer composed of (Ti, Al, Ta) N, upper layer thin layer A and thin layer B, the composition of the same lower layer, as a conventional coated tool Conventional coated carbide tips 1 to 16, conventional coated carbide end mills 1 to 8, conventional coated HSS end mills 9 to 14, conventional coated carbide drills 1 to 8 and conventional coated HSS drills 9 to 14 (Ti, Al, Ta ) When the composition of the hard coating layer made of N was measured by an energy dispersive X-ray analysis method using a transmission electron microscope, each showed substantially the same composition as the target composition.

Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a transmission electron microscope, all showed the same average value (average value of five locations) as the target layer thickness.

  From the results shown in Tables 3 to 11, the surface-coated cutting tool of the present invention has an upper layer in which the hard coating layer has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm. Workpiece reaction with an excellent upper layer (consisting of an average layer thickness of 0.5 to 1.5 μm) and a lower layer of single phase structure (having an average layer thickness of 2 to 6 μm) Since the lower layer has excellent high-temperature hardness and heat resistance, it has a highly effective work material such as Ti alloy, high Si content Al alloy, and free-cutting steel. Even when used for high-speed cutting with high heat generation, cutting is performed in a state where the reactive wear is remarkably suppressed between the hard coating layer and the highly reactive work material. The hard coating layer is a single-phase (Ti, Al, Ta) N layer? The comparative coated cutting tool is used in a relatively short time, especially in the high-speed cutting of the high-reactive work material, especially the reactive wear between the hard coating layer and the high-reactive work material. It is clear that it reaches the end of its life.

As described above, the surface-coated cutting tool of the present invention is capable of cutting at normal cutting conditions such as various steels and cast irons, particularly high-speed cutting with high heat generation of highly reactive work materials. Because it exhibits excellent wear resistance even during machining and exhibits excellent cutting performance over a long period of time, it is sufficient for improving the performance of cutting equipment, saving labor and energy, and reducing costs It can respond to satisfaction.

The arc ion plating apparatus used for forming the hard coating layer which comprises the surface coating cutting tool of this invention is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of a normal arc ion plating apparatus.

Claims (1)

On the surface of a cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet, or on the surface of a high-speed tool steel substrate,
(A) Both are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al, and Ta, the upper layer has an average layer thickness of 0.5 to 1.5 μm, and the lower layer has an average layer thickness of 2 to 6 μm. Have
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: [Ti _{1− (E + F)} Al _E Ta _F ] N (wherein E represents 0.15 to 0.30 and F represents 0.20 to 0.35 in atomic ratio) A composite nitride layer of Al and Ta,
The thin layer B is
Ti satisfying the composition formula: [Ti _{1− (M + N)} Al _M Ta _N ] N (wherein M is 0.50 to 0.65 and N is 0.01 to 0.10 in atomic ratio) A composite nitride layer of Al and Ta,
(C) the lower layer has a single phase structure;
_{Formula: [Ti 1- (X + Y} ) Al X Ta Y] N ( provided that an atomic ratio, X is from .50 to 0.65, Y denotes the 0.01-0.10) and Ti which satisfies A composite nitride layer of Al and Ta,
A surface-coated cutting tool that exhibits excellent wear resistance in high-speed cutting of a highly reactive work material formed by vapor-depositing a hard coating layer made of

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