JP2006224198A - Cutting tool made of surface coated cemented carbide alloy with hard coating layer displaying excellent abrasion resistance in high speed cutting work of highly reactive work material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide alloy a hard coating layer of which displays excellent abrasion resistance in high speed cutting work of a highly reactive work material. <P>SOLUTION: This cutting tool is made by forming the hard coating layer, on the surface of a carbide substrate by vapor deposition, which is constituted of: (a) an upper layer and a lower layer both of which are made of (Ti, Al, Ta)N, the upper layer has layer thickness of 0.5 to 1.5μm and the lower layer has layer thickness of 2 to 6μm respectively; (b) the upper layer has an alternately laminated structure of a thin layer A and a thin layer B both of which have layer thickness of 5 to 20 nm (nanometer), the thin layer A is made of a (Ti, Al, Ta)N layer to satisfy a specific composition formula, [Ti<SB>1-(A+B)</SB>Al<SB>A</SB>Ta<SB>B</SB>]N, the thin layer B is made of a (Ti, Al, Ta)N layer to satisfy a specific composition formula, [Ti<SB>1-(C+D)</SB>Al<SB>C</SB>Ta<SB>D</SB>]; and (c) the lower layer having a single phase structure and made of a (Ti, Al, Ta)N layer to satisfy a specific composition formula, [Ti<SB>1-(E+F)</SB>Al<SB>E</SB>Ta<SB>F</SB>]N. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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. For surface-coated cemented carbide cutting tools (hereinafter referred to as coated cemented carbide tools) that exhibit extremely low reactivity to porous work materials and as a result, exhibit excellent wear resistance over a long period of time It is.

  In general, coated carbide tools include a throw-away tip that is 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.

In addition, as a coated carbide tool, a single-phase structure is formed on the surface of a cemented carbide substrate made of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet. Have and
_{Formula: [Ti 1- (X + Y} ) Al X Ta Y] N ( provided that an atomic ratio, X is from 0.50 to .65, Y represents a 0.01 to 0.09),
Coated carbide tool 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 above conditions with an average layer thickness of 2 to 8 μm The (Ti, Al, Ta) N layer has a high temperature hardness and heat resistance by Al as a constituent component, and a high temperature strength is improved by the Ti, and further between the work material by the Ta. It is also known to exert a reaction deterrent effect.

Furthermore, the above-mentioned coated carbide tool is, for example, the above-mentioned carbide substrate is inserted into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. For example, an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which a Ti—Al—Ta alloy having a predetermined composition is set, for example, at a current of 90 A, while being heated to a temperature of 500 ° C. At the same time, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa. On the other hand, the carbide substrate is applied to the surface of the carbide substrate under a condition that a bias voltage of, for example, −100 V is applied. It is also known that it is produced by vapor-depositing a hard coating layer composed of the (Ti, Al, Ta) N layer.
Japanese Patent No. 3351054

  In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting, and with this, cutting tends to be faster. In coated carbide tools, when used to cut carbon steel, low alloy steel, and ordinary cast iron under high-speed cutting conditions, there is no problem with normal cutting performance. Especially when used to cut extremely reactive work materials such as alloys, high Si content Al alloys and free-cutting steel under high-speed cutting conditions with high heat generation. The reaction between the layer and the highly reactive work material is accelerated in conjunction with the generation of high heat, resulting in rapid progress, resulting in a wear time in a relatively short time. Currently.

In view of the above, the present inventors have developed the above-mentioned coated carbide tool exhibiting excellent wear resistance with a hard coating layer particularly 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 9 atomic% can satisfactorily suppress the reaction with the highly reactive work material by high-speed cutting with high heat generation. In order to satisfactorily suppress the reaction with the highly reactive work material by high-speed cutting, it is necessary to contain 50 to 70 atomic% of Ta far exceeding the above 1 to 9 atomic%, while 50 to 70%. In order to use a (Ti, Al, Ta) N layer containing 70 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 unavoidably low. Results hot hardness and shall become that heat resistance of very low.

(B) Composition formula: (Ti _{1− (A + B)} Al _A Ta _B ) N (provided that atomic ratio is 0.01 to 0.10 and B is 0.50 to 0.70) A (Ti, Al, Ta) N layer having a Ta content ratio of 50 to 70 atomic%;
Composition formula: (Ti _{1− (C + D)} Al _C Ta _D ) N (wherein, C is 0.30 to 0.45 and D is 0.20 to 0.35 in atomic ratio), relative In particular, the content ratio of the Al component is increased, while the content ratio of the Ta component is relatively lowered in order to ensure a high temperature strength by containing a predetermined amount of the Ti component (Ti, Al, Ta) N layer,
Are alternately laminated in a state where each layer has an average layer thickness of 5 to 20 nm (nanometers), and the resulting (Ti, Al, Ta) N layer has a thin layer of alternately laminated structure, The above-mentioned high Ta content (Ti, Al, Ta) N layer (hereinafter referred to as the thin layer A) has an excellent work material reaction suppressing effect, and the Ta content ratio is relatively higher than that of the thin layer A. The hard coating layer has a relatively high high temperature hardness and heat resistance of the (Ti, Al, Ta) N layer (hereinafter referred to as the thin layer B) having a low and high Al content. To be able to be put to practical use.

(C) The (Ti, Al, Ta) N layer having the alternately laminated structure of the thin layer A and the thin layer B of (b) is a work material required for high-speed cutting of a highly reactive work material. Although it has a reaction suppressing effect, it does not have a sufficiently satisfactory high-temperature hardness and heat resistance, so it is provided as an 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-mentioned conventional hard coating layer having a relatively high Al component content and excellent high-temperature hardness and heat resistance,
Compositional formula: [Ti _{1− (E + F)} Al _E Ta _F ] N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in terms of atomic ratio) (Ti, Al, Ta) N layer of single phase structure,
With this structure, the hard coating layer has high temperature hardness and heat resistance, as well as high temperature strength, in addition to the excellent work material reaction suppression effect. In the coated carbide tool formed by vapor deposition, the reactive wear between the highly reactive work material and the hard coating layer is remarkably suppressed even in the high-speed cutting with high heat generation of the highly reactive work material. Since cutting is performed in a state, it has excellent wear resistance for a long 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, and on the surface of the carbide substrate,
(A) Both are composed of an upper layer and a lower layer made of (Ti, Al, Ta) N, the upper layer has a layer thickness of 0.5 to 1.5 μm, and the lower layer has a layer thickness of 2 to 6 μm. ,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
_{Formula: [Ti 1- (A + B} ) Al A Ta B] N ( provided that an atomic ratio, A is 0.01 to 0.10, B represents a 0.50 to 0.70) satisfies (Ti , Al, Ta) N layer,
The thin layer B is
_{Formula: [Ti 1- (C + D} ) Al C Ta D] N ( provided that an atomic ratio, C is 0.30 to 0.45, D represents a 0.20 to 0.35) satisfies (Ti , Al, Ta) N layer,
(C) the lower layer has a single phase structure;
Composition formula: [Ti _{1− (E + F)} Al _E Ta _F ] N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in atomic ratio) (Ti , Al, Ta) N layer,
It is characterized by a coated carbide 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

Next, the reason why the numerical values of the hard coating layer of the coated carbide tool of the present invention are limited as described above will be described.
(A) Composition formula and layer thickness of the lower layer As described above, the Al component in the (Ti, Al, Ta) N layer constituting the hard coating layer improves high-temperature hardness and heat resistance, while the Ti component Has the effect of significantly reducing the reactivity with the work material, especially the Ta component, and in the lower layer, the overall content of the Al component is increased in the lower layer to achieve high high temperature hardness and heat resistance. However, if the E value indicating the content ratio of Al is less than 0.50 in terms of the total amount of Ti and Ta (atomic ratio, the same shall apply hereinafter), the proportion of Ti is relatively high and high-speed cutting is performed. The excellent high-temperature hardness and heat resistance required for processing cannot be secured, and the progress of wear is rapidly promoted. On the other hand, if the E value indicating the Al ratio exceeds 0.65, In particular, the ratio of Ti is too low and the high temperature strength is sudden As a result, chipping (slight chipping) or the like is likely to occur, so the E value was set to 0.50 to 0.65.
Further, if the F 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 F value is 0. If it exceeds 0.09, the high-temperature strength suddenly decreases, so the F value was determined to be 0.01 to 0.09.
Furthermore, if the 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 if the layer thickness exceeds 6 μm Since the chipping is likely to occur, the layer thickness is set to 2 to 6 μm.

(B) Composition formula of upper layer thin layer A The Ta component in (Ti, Al, Ta) N of the upper layer thin layer A is made as high as possible to reduce the reaction of the work material as described above. Is included for the purpose of reducing reactive wear in high-speed cutting of high-reactive work materials with high heat generation, and therefore, if the B value is less than 0.50, desired excellent work can be obtained. The material reaction suppression effect cannot be ensured. On the other hand, when the B value exceeds 0.70, the content ratio of the Ti component is relatively decreased, and the high temperature strength that the layer itself should have can be ensured. The B value was determined to be 0.50 to 0.70 because it was not possible.
In addition, the A value indicating the proportion of Al is the proportion of the total amount of Ti and Ta, and if it is less than 0.01, the minimum high-temperature hardness and heat resistance cannot be ensured, leading to accelerated wear. On the other hand, if the A value exceeds 0.10, the high-temperature strength decreases, causing chipping. Therefore, the A value was set to 0.01 to 0.10.

(C) Composition formula of thin layer B of the upper layer 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, and the content ratio of the Al component is relatively By keeping the thin layer A high, the thin layer A has insufficient high-temperature hardness and heat resistance, reinforces the high-temperature hardness and heat resistance shortage of the adjacent thin layer A, and thus has the excellent thin layer A. The upper layer having a relatively high high-temperature hardness and heat resistance of the thin layer B is formed, and the C value indicating the Al content in the composition formula is If it is less than 0.30, the predetermined high temperature hardness and heat resistance cannot be ensured, and the progress of wear is promoted. On the other hand, if the C value exceeds 0.45, the high temperature strength of the entire upper layer is increased. Decrease is unavoidable and causes chipping. .30 to 0.45.
Further, the D value indicating the ratio of Ta is the ratio of the total amount of Ti and Al. If the D value is less than 0.20, the reduction in the work material reaction suppression effect of the entire upper layer is unavoidable, while the D value is If it exceeds 0.35, the high-temperature strength of the entire upper layer suddenly decreases, so the D value was set to 0.20 to 0.35.

(D) Layer thicknesses of upper layer thin layer A and layer B If each layer thickness is less than 5 nm, it is difficult to form each thin layer clearly with the above composition. Excellent work material reaction suppressing effect, and it becomes impossible to ensure a predetermined high temperature hardness and heat resistance, and if each layer thickness exceeds 20 nm, each thin layer has a defect, that is, if it is a thin layer A Insufficient high-temperature hardness and heat resistance, and thin layer B, the lack of work material reaction suppression effect appears locally in the layer, which makes it easier for chipping to occur and promotes the progress of wear. Each layer thickness was determined to be 5 to 20 nm.

(E) Layer thickness of the upper layer If the layer thickness is less than 0.5 μm, it is impossible to provide the hard coating layer with long-lasting work material reaction suppressing effect and predetermined high-temperature hardness and heat resistance, The tool life is short-lived. On the other hand, if the layer thickness exceeds 1.5 μm, chipping tends to occur. Therefore, the layer thickness is set to 0.5 to 1.5 μm.

  In the coated carbide tool of the present invention, the hard coating layer is composed of a (Ti, Al, Ta) N layer. 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 coated carbide 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 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. A Ti-Al-Ta alloy for forming a thin layer B as an upper layer is disposed opposite to the rotary table, and a cathode is formed along the rotary table at a position shifted by 90 degrees from both the Ti-Al-Ta alloys. Electrode (evaporation source) The Ti-Al-Ta alloy for the lower layer formed attached to,
(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 applying a current of 100 A between the Ti-Al-Ta alloy for forming the lower layer and the anode electrode to generate an arc discharge, so that the surface of the cemented carbide substrate is Ti-Al- Bombard cleaning with 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-forming Ti—Al—Ta alloy and the anode electrode, and the target composition and target layer thickness shown in Tables 3 and 4 are formed on the surface of the cemented carbide substrate. (Ti, Al, Ta) N layer having a single phase structure is deposited as a lower layer of the hard coating layer,
(D) Next, nitrogen gas was introduced into the apparatus as a reaction gas to make a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V was applied to a carbide substrate rotating while rotating on the rotary table, 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 surface of the carbide substrate is predetermined. After the formation of the thin layer A, the arc discharge is stopped, and instead, between the cathode electrode and the anode electrode of the Ti-Al-Ta alloy for forming the thin layer B, 50 to 200 A The arc discharge is generated by flowing a predetermined current within the range of forming a thin layer B having a predetermined layer thickness, and then the arc discharge is stopped (in this case, the formation of the thin layer B may be started) Again, the thin layer A forming Ti- Formation of thin layer A by arc discharge between the cathode electrode and anode electrode of l-Ta alloy, and formation of thin layer B by arc discharge between the cathode electrode and anode electrode of the Ti-Al-Ta alloy for forming thin layer B The upper layer is formed by alternately laminating the thin layer A and the thin layer B having the target composition and the target layer thickness shown in Tables 3 and 4 along the layer thickness direction on the surface of the cemented carbide substrate. Are formed by vapor deposition with the overall target layer thicknesses shown in Tables 3 and 4, so that the surface coated carbide throwaway tip of the present invention as the coated carbide tool of the present invention (hereinafter referred to as the coated carbide chip of the present invention) is used. 1 to 16 were produced.

  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 plate shown in FIG. A Ti—Al—Ta alloy having a component composition corresponding to the target composition shown in Table 5 was mounted as a cathode electrode (evaporation source) as a cathode electrode (evaporation source). The apparatus was heated to 500 ° C. with a heater while maintaining a vacuum of 1 Pa or less, and then a −1000 V DC bias voltage was applied to the carbide substrate, and the Ti—Al—Ta alloy and anode of the cathode electrode were applied. An arc discharge is generated by passing a current of 100 A between the electrodes, and the carbide substrate surface is bombarded with the Ti—Al—Ta alloy, and then nitrogen gas is introduced into the apparatus as a reactive gas. 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, thereby (Ti, Al, Ta) N layer having a single phase structure with a target composition and target layer thickness shown in Table 5 on each surface of hard substrates A-1 to A-10 and B-1 to B-6 A comparative surface-coated carbide throw-away tip (hereinafter referred to as a comparative coated carbide tip) 1-16 as a comparative coated carbide tool corresponding to a conventional coated carbide tool is formed by vapor-depositing a hard coating layer made of Were manufactured respectively.

Next, the coated carbide tips 1 to 16 of the present invention and the comparative coated carbide tips 1 to 16 of the present invention are screwed to the tip of the tool steel tool with a fixing jig. about,
Work material: JIS / 60 type (composition, mass%, Ti-6% Al-4% V) round bar,
Cutting speed: 100 m / min. ,
Incision: 1.5mm,
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: 1mm,
Feed: 0.1 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. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
The dry continuous high-speed cutting test (normal cutting speed was 200 m / min.) Of free-cutting steel under the above conditions (cutting condition C) was performed, and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 6.

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 .mu.m Co powder, mix these raw material powders with the composition shown in Table 7, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and then 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 Three types of sintered carbide rod forming bodies for forming a carbide substrate having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three types of round rod sintered bodies described above were subjected to grinding and 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. Carbide substrates (end mills) C-1 to C-8 were produced.

  Then, the surfaces of these carbide substrates (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, a lower layer composed of a (Ti, Al, Ta) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 8 is also shown along the layer thickness direction. A coated carbide tool of the present invention is formed by vapor-depositing an upper layer composed of alternating layers of thin layers A and B having a target composition shown in FIG. The present invention surface-coated carbide end mills (hereinafter referred to as the present invention coated carbide end mills) 1 to 8 were produced.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 are ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus shown in FIG. Then, a hard coating layer composed of a (Ti, Al, Ta) N layer having a single-phase structure having the target composition and target layer thickness shown in Table 9 is deposited under the same conditions as in Example 1 above. Thus, comparative surface-coated carbide end mills (hereinafter referred to as comparative coated carbide end mills) 1 to 8 as comparative coated carbide tools corresponding to conventional coated carbide tools were produced, respectively.

Next, of the present invention coated carbide end mills 1-8 and comparative coated carbide end mills 1-8, the present invention coated carbide end mills 1-3 and comparative coated carbide end mills 1-3 are as follows:
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / SUM22 plate material with the above composition (mass%, Fe-1% Mn-0.3% S-0.1% P) ,
Cutting speed: 200 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 800mm / min,
With respect to the dry high-speed grooving test of free-cutting steel under the following conditions (normal cutting speed is 100 m / min.), The coated carbide end mills 4 to 6 and the comparative coated carbide end mills 4 to 6 of the present invention,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS 60 type plate material of the above composition (mass%, Ti-6% Al-4% V),
Cutting speed: 100 m / min. ,
Groove depth (cut): 3.5 mm,
Table feed: 500 mm / min,
With respect to the dry high-speed grooving test of Ti alloy under the following conditions (the normal cutting speed is 40 m / min.), The coated carbide end mills 7 and 8 and the comparative coated carbide end mills 7 and 8 of the present invention,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / AC9B plate material of the above composition (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) ,
Cutting speed: 200 m / min. ,
Groove depth (cut): 8 mm,
Table feed: 480 mm / min,
A dry high-speed grooving test (normal cutting speed is 100 m / min.) Of a high Si-containing Al alloy under the above conditions was performed. The cutting groove length up to 0.1 mm, which is a guide for the service life, was measured. The measurement results 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), 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), respectively. 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.

  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. A lower layer composed of a (Ti, Al, Ta) N layer having a single phase structure with the target composition and target layer thickness shown in Table 10 under the same conditions as in Example 1 and the same layer By vapor-depositing an upper layer composed of alternating layers of the thin layer A and the thin layer B having the target composition shown in Table 10 and a single target layer thickness along the thickness direction, with the overall target layer thickness also shown in Table 10, The surface coated carbide drills (hereinafter referred to as the present invention coated carbide drills) 1 to 8 as the present invention coated carbide tools were produced, respectively.

  For comparison purposes, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried, and the arc shown in FIG. A hard material comprising a (Ti, Al, Ta) N layer having a single-phase structure with the target composition and target layer thickness similarly shown in Table 11 under the same conditions as in Example 1 above, charged in the ion plating apparatus By vapor-depositing the coating layer, comparative surface-coated carbide drills (hereinafter referred to as comparative coated carbide drills) 1 to 8 as comparative coated carbide tools corresponding to conventional coated carbide tools were produced, respectively.

Next, of the present invention coated carbide drills 1-8 and comparative coated carbide drills 1-8, for the present invention coated carbide drills 1-3 and comparative coated carbide drills 1-3,
Work material-Plane: 100 mm × 250, thickness: 50 mm JIS / SUM22 plate with the above composition (mass%, Fe-1% Mn-0.3% S-0.1% P) ,
Cutting speed: 100 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 6mm,
The wet high speed drilling test of free cutting steel under the conditions (normal cutting speed is 45 m / min.), The present invention coated carbide drills 4-6 and comparative coated carbide drills 4-6,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS 60 type plate material of the above composition (mass%, Ti-6% Al-4% V),
Cutting speed: 55 m / min. ,
Feed: 0.1 mm / rev,
Hole depth: 10mm,
With regard to the Ti alloy wet high-speed drilling machining test under the conditions (normal cutting speed is 25 m / min.), The present invention coated carbide drills 7 and 8 and the comparative coated carbide drills 7 and 8,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / AC9B plate material of the above composition (mass%, Al-19% Si-1% Cu-1% Mg-1% Ni) ,
Cutting speed: 150 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 20mm,
Wet high speed drilling test of high Si content Al alloy under normal conditions (normal cutting speed is 70m / min.), And any wet high speed drilling test (using water soluble cutting oil) The number of drilling processes until the flank wear width of the blade surface reached 0.3 mm was measured. The measurement results are shown in Table 8, respectively.

  The resulting coated carbide tips 1-16 of the present invention, the coated carbide end mills 1-8 of the present invention, and the coated carbide drills 1-8 of the present invention (Ti, Al, Ta). ) Comparison of coated carbide tip 1 as a comparative coated carbide tool equivalent to the conventional coated carbide tool, and the composition of the lower layer A and thin layer B constituting the hard coating layer made of N and the lower layer. ˜16, comparative coated carbide end mills 1-8, and comparative coated carbide drills 1-8, the composition of the hard coating layer made of (Ti, Al, Ta) N is an energy dispersion type using a transmission electron microscope When measured by X-ray analysis, 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 coated carbide tool of the present invention has a single-phase structure lower layer composed of (Ti, Al, Ta) N, each of which has a hard coating layer having a different composition, and a layer thickness. Is composed of an upper layer having an alternating laminated structure of thin layers A and B each having a thickness of 5 to 20 nm, the lower layer has excellent high-temperature hardness and heat resistance, and the upper layer has excellent work material reaction suppression. Since the hard coating layer has these excellent characteristics, the heat generation of highly reactive work materials such as Ti alloy, high Si content Al alloy, and free-cutting steel is particularly high. Even when used in high-speed cutting, the cutting is performed in a state where the reactive wear is remarkably suppressed between the hard coating layer and the highly reactive work material, so that it exhibits excellent wear resistance. On the other hand, the hard coating layer has a single phase structure (Ti, A , Ta) N comparative coated carbide tools, particularly in high-speed cutting of the highly reactive work material, the reactive wear between the hard coated layer and the highly reactive work material is particularly significant. It is clear that the service life is reached in a relatively short time.

  As described above, the coated cemented carbide tool of the present invention is not only for cutting under high-speed cutting conditions such as various types of carbon steel, low alloy steel, and ordinary cast iron, and particularly for the above highly reactive work material. It exhibits excellent wear resistance even in high-speed cutting with high heat generation, exhibits excellent cutting performance over a long period of time, and is versatile for work materials. It can cope with labor saving, energy saving and cost reduction of processing sufficiently satisfactorily.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated carbide tool 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 the cemented carbide substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(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 a thickness of 0.5 to 1.5 μm, and the lower layer has a thickness of 2 to 6 μm. And
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
_{Formula: [Ti 1- (A + B} ) Al A Ta B] N ( provided that an atomic ratio, A is 0.01 to 0.10, B represents a 0.50 to 0.70) and Ti which satisfies A composite nitride layer of Al and Ta,
The thin layer B is
Ti satisfying the composition formula: [Ti _{1− (C + D)} Al _C Ta _D ] N (wherein C is 0.30 to 0.45 and D is 0.20 to 0.35 in atomic ratio) A composite nitride layer of Al and Ta,
(C) the lower layer has a single phase structure;
Ti satisfying the composition formula: [Ti _{1− (E + F)} Al _E Ta _F ] N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in atomic ratio) A composite nitride layer of Al and Ta,
A surface-coated cemented carbide 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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