JP4697390B2 - Cutting tool made of surface-coated cemented carbide that exhibits excellent wear resistance in high-speed cutting of heat-resistant alloys. - Google Patents

Description

  The present invention provides a surface coating that exhibits excellent wear resistance, especially when cutting heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys under high-speed cutting conditions with high heat generation. The present invention relates to a cemented carbide cutting tool (hereinafter referred to as a coated carbide tool).

  Generally, for coated carbide tools, a throw-away tip that is attached to the tip of a cutting tool for turning or flattening of various steel and cast iron work materials, 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.

Further, as a coated carbide tool, on the surface of a carbide substrate composed of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet,
Composition formula: (Ti _{1-(X + Z)} Al _X Si _Z ) N (wherein X is 0.25 to 0.65 and Z: 0.01 to 0.10 in atomic ratio) is satisfied. There is known a coated carbide tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride of Ti, Al and Si [hereinafter referred to as (Ti, Al, Si) N] layer with an average layer thickness of 1 to 10 μm. And the (Ti, Al, Si) N layer, which is a hard coating layer of the coated carbide tool, has high-temperature hardness and heat resistance due to Al as a component, high-temperature strength due to the Ti, and further the same Si Combined with the effect of improving the heat resistance by one step, it is also known that when this is used for continuous cutting and intermittent cutting of various steels and cast irons, excellent cutting performance is exhibited.

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—Si 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, Si) N layer.
Japanese Patent No. 2793773

  In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and with this, cutting tends to be faster. In coated carbide tools, there is no problem when this is used to cut steel or cast iron under normal cutting conditions, but especially Ti-based alloys, Ni-based alloys, Co-based alloys, etc. When cutting a heat-resistant alloy or the like under high-speed cutting conditions, the coated carbide tool and the work material are heated to a high temperature because of particularly high heat generation. As a result, the heat-resistant alloy Because the reaction between the work material and the (Ti, Al, Si) N layer, which is a hard coating layer, becomes extremely active and the wear progress of the hard coating layer is further accelerated, it can be used in a relatively short time. It is the current situation that reaches the end of life

In view of the above, the present inventors have developed the above-mentioned conventional coated carbide tool in order to develop a coated carbide tool exhibiting excellent wear resistance with a hard coating layer particularly in high-speed cutting of a heat-resistant alloy. As a result of conducting research with a focus on tools,
(A) A (Ti, Al, Si) N layer, which is a hard coating layer of the above conventional coated carbide tool, is used as a lower layer, and a chromium boride (hereinafter referred to as CrB ₂ ) layer is formed thereon as an upper layer. Then, the CrB ₂ layer is excellent in thermal stability, and particularly has a high affinity with the heat-resistant alloy as the work material even in a state where the heat-resistant alloy as the work material is heated at a high temperature and at a high temperature. The lower (Ti, Al, Si) N layer is protected because of its low and low reactivity, and as a result, the excellent characteristics of the (Ti, Al, Si) N layer can be maintained over a long period of time. To be fully demonstrated.

(B-1) The hard coating layer of the above (a) is, for example, an arc ion plating apparatus (hereinafter referred to as an AIP apparatus) having a structure shown in a schematic plan view in FIG. 1A and a schematic front view in FIG. And a sputtering apparatus (hereinafter abbreviated as SP apparatus) coexisting, that is, a rotating table for mounting a carbide substrate is provided at the center of the apparatus, and the AIP apparatus is provided on one side with the rotating table in between. Ti-Al-Si alloy having a predetermined composition as a cathode electrode (evaporation source), and CrB ₂ sintered body (for example, CrB ₂ powder as a raw material powder) as a cathode electrode (evaporation source) of the SP device on the other side , A sintered body formed by hot pressing) is disposed opposite to each other, and a plurality of along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. The carbide substrate is mounted in a ring shape, and in this state, the atmosphere inside the apparatus is changed to a nitrogen atmosphere, the rotary table is rotated, and the carbide substrate itself is rotated for the purpose of uniforming the thickness of the hard coating layer formed by vapor deposition. Basically, first, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of the Ti—Al—Si alloy to form a lower layer (Ti, Al) on the surface of the cemented carbide substrate. , Si) N layer is deposited with an average layer thickness of 0.8 to 5 μm, and then arc discharge between the cathode electrode (evaporation source) and anode electrode of the Ti—Al—Si alloy is stopped, and the deposition is performed. the atmosphere in the apparatus, with the Ar atmosphere in place of nitrogen atmosphere, the sputtering of CrB ₂ sintered body was placed as a cathode electrode of the SP device (evaporation source) starts, the CrB ₂ sintered for a predetermined time Performing sputtering, it may be an average layer thickness of 0.8~5μm as an upper layer is formed by depositing a CrB ₂ layers.
(B-2) After the formation of the lower layer, Ar is substituted for nitrogen gas in the apparatus while continuing the arc discharge between the cathode electrode and the anode electrode of the Ti—Al—Si alloy for forming the lower layer. A mixed gas of nitrogen was introduced, and at the same time , spatter was generated in the CrB ₂ sintered body arranged as a cathode electrode (evaporation source) of the SP device, and kept in this state for a predetermined time, and Ti and Al were used as an adhesive bonding layer. When a Cr composite boronitride [hereinafter referred to as (Ti, Al, Cr) BN] layer is formed with an average layer thickness of 0.1 to 0.5 μm, it is the above-mentioned already deposited lower layer ( Excellent adhesion and bonding properties are ensured between the ( Ti, Al, Si) N layer and the CrB ₂ layer, which is the upper layer formed later .

(C) The coated carbide tool formed by vapor-depositing the hard coating layer composed of the lower layer, the adhesive bonding layer , and the upper layer is a Ti-based alloy or Ni-based alloy with particularly high heat generation, Furthermore, even in high-speed cutting of heat-resistant alloys such as Co-based alloys, the (Ti, Al, Si) N layer, which is the lower layer, has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and is the upper layer. The CrB ₂ layer ensures excellent thermal stability (very low reactivity) with the heat-resistant alloy that is the work material, so that it exhibits excellent wear resistance over a long period of time. thing.
The research results shown in (a) to (c) above were obtained.

The present invention has been made based on the above research results, and in a coated carbide tool formed by physically vapor-depositing a hard coating layer on the surface of a cemented carbide substrate , the hard coating layer is provided with an AIP device and an SP device. Using vapor deposition equipment
(A) The lower layer is formed by vapor deposition using the AIP apparatus ,
_{Formula: (Ti 1- (X + Z} ) Al X Si Z) N ( provided that an atomic ratio, X is 0.25 to 0.65, Z represents a 0.01-0.10)
(Ti, Al, Si) N layer having an average layer thickness of 0.8-5 μm,
(B) (Ti, Al, Cr) BN layer having an average layer thickness of 0.1 to 0.5 μm formed by vapor deposition using the AIP device and the SP device at the same time as the adhesive bonding layer ;
(C) As an upper layer, a CrB ₂ layer having an average layer thickness of 0.8 to 5 μm, formed by vapor deposition using the SP apparatus ,
The present invention is characterized by a coated carbide tool composed of a hard coating layer composed of the above (a) to (c) and exhibiting excellent wear resistance in high-speed cutting of a heat-resistant alloy.

Next, the reason why the numerical values of the constituent layers of the hard coating layer of the coated carbide tool of the present invention are limited as described above will be described.
(A) X value and Z value of the composition formula of the lower layer, and average layer thickness The Al component in the (Ti, Al, Si) N layer constituting the lower layer improves high temperature hardness and heat resistance, while the same Ti The component has the effect of improving the high-temperature strength, and the Si component has the effect of further improving the heat resistance in the coexistence with Al, but the ratio of the X value indicating the proportion of Al to the total amount of Ti and Si (atom If the ratio is less than 0.25, the proportion of Ti is relatively increased, and the high temperature hardness and heat resistance required for high-speed cutting cannot be ensured, resulting in rapid progress of wear. On the other hand, when the X value indicating the proportion of Al exceeds 0.65, the proportion of Ti becomes relatively small, and the high-temperature strength rapidly decreases. Chipping (slight chipping) is likely to occur. Therefore, the X value was determined to be 0.25 to 0.65. Moreover, if the Z value indicating the proportion of Si is a proportion of the total amount of Ti and Al, and less than 0.01, the desired heat resistance improvement effect cannot be obtained, while if the Z value exceeds 0.10, Since the high-temperature strength is lowered, the Z value is set to 0.01 to 0.10.
Further, if the average layer thickness is less than 0.8 μm, it is insufficient to exhibit its excellent wear resistance over a long period of time, while if the average layer thickness exceeds 5 μm, the above heat-resistant alloy In this high-speed cutting, chipping is likely to occur at the cutting edge, so the average layer thickness was set to 0.8 to 5 μm.

(B) Average layer thickness of the upper layer The CrB ₂ layer constituting the upper layer has a thermally very stable property as described above, and has extremely low reactivity with the work material and chips heated at high temperature. Since it has characteristics, even in high-speed cutting of heat-resistant alloys that generate significant heat, the (Ti, Al, Si) N layer, which is the lower layer, is protected from the high-temperature heated work material and chips, Demonstrates the effect of suppressing the progress of wear. If the average layer thickness is less than 0.8 μm, the desired effect cannot be obtained. On the other hand, if the average layer thickness exceeds 5 μm, chipping occurs. The average layer thickness was determined to be 0.8 to 5 μm.

In the coated carbide tool of the present invention, the lower layer (Ti, Al, Si) N layer constituting the hard coating layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and as an upper layer. The CrB ₂ layer ensures excellent thermal stability (very low reactivity) with the work material. Therefore, Ti-base alloys and Ni-base alloys with particularly high heat generation, and further Co base Even in high-speed cutting of heat-resistant alloys such as alloys, it exhibits excellent 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. TiCN-based cemented carbide substrates B-1 to B-6 having the following chip shape were formed.
Furthermore, as a cathode electrode (evaporation source) for forming the upper layer of the hard coating layer, CrB ₂ powder having an average particle diameter of 0.8 μm was hot pressed under the conditions of temperature: 1500 ° C., pressure: 20 MPa, holding time: 3 hours. Then, a CrB ₂ sintered body formed by molding was prepared.

(A) Next, each of the above-mentioned carbide substrates A-1 to A-10 and B-1 to B-6 was ultrasonically cleaned in acetone and dried, and then in the vapor deposition apparatus shown in FIG. Ti-Al for forming a lower layer having a predetermined composition as a cathode electrode (evaporation source) of an AIP device on one side, mounted along a peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table -A CrB ₂ sintered body for forming an upper layer as a cathode electrode (evaporation source) of the Si alloy and the SP device on the other side,
(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 current of 100 A is passed between the Ti—Al—Si alloy of the cathode electrode and the anode electrode to generate an arc discharge, whereby the surface of the carbide substrate is made to the Ti—Al—Si. Bombard washed by alloy and
(C) Nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 3 Pa, a DC bias voltage of −100 V is applied to a carbide substrate rotating while rotating on the rotary table, and a cathode electrode A current of 100 A was passed between the Ti-Al-Si alloy and the anode electrode to generate an arc discharge, so that the surface of the cemented carbide substrate had a target composition and target layer thickness (Ti) shown in Table 3. , Al, Si) N layer is deposited as a lower layer of the hard coating layer,
(D) Next, for the purpose of improving the adhesion bonding between the (Ti, Al, Si) N layer, which is the lower layer already formed by vapor deposition, and the CrB ₂ layer, which is the upper layer formed by vapor deposition, While continuing the arc discharge between the cathode electrode and the anode electrode of the Ti—Al—Si alloy for forming the lower layer, a mixed gas of Ar and nitrogen (N ₂ : Ar = volume ratio) is used instead of nitrogen gas in the apparatus. 3: 1), and the atmosphere in the apparatus is set to 3 Pa. At the same time, the CrB ₂ sintered body arranged as the cathode electrode (evaporation source) of the SP apparatus is sputtered at an output of 3 kW. Is held for 20 minutes, and the (Ti, Al, Cr) BN layer as an adhesion bonding layer has an average layer thickness of 0.3 μm (the coated end mills 1 to 8 of the present invention in Examples 2 and 3 described later and the present invention). Hardness of covered drills 1-8 Also in Kutsugaeso formation, the average layer thickness of the adhesion bonding layer is formed of both was 0.3 [mu] m),
(E) Subsequently, while continuing the sputtering of the CrB ₂ sintered body arranged as the cathode electrode (evaporation source) of the SP apparatus under the same conditions (sputtering output: 3 kW), the gas introduced into the apparatus is Ar and While changing from nitrogen mixed gas to Ar gas, the atmosphere in the apparatus is set to 0.5 Pa, and at the same time, the arc discharge between the cathode electrode and the anode electrode of the Ti-Al-Si alloy for forming the lower layer is stopped. The surface of the present invention as a coated carbide tool of the present invention is formed by performing sputtering for a time corresponding to the layer thickness and depositing a CrB ₂ layer having the target layer thickness shown in Table 3 as the upper layer of the hard coating layer. Coated carbide throwaway tips (hereinafter referred to as the present invention coated tips) 1 to 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, in the vapor deposition apparatus shown in FIG. Insert the Ti-Al-Si alloy with various component compositions as the cathode electrode (evaporation source), and first evacuate the inside of the device and keep it at a vacuum of 0.1 Pa or less, while using a heater. After heating the interior to 500 ° C., a DC bias voltage of −1000 V is applied to the cemented carbide substrate, and a current of 100 A is passed between the Ti—Al—Si alloy of the cathode electrode and the anode electrode to cause arc discharge. Thus, the surface of the carbide substrate is bombarded with the Ti—Al—Si alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 3 Pa, and is applied to the carbide substrate. Bahia The voltage is lowered to −100 V, and arc discharge is generated between the cathode electrode and the anode electrode of the Ti—Al—Si alloy, so that the carbide substrates A-1 to A-10 and B-1 to B— 6 by depositing a (Ti, Al, Si) N layer having a target composition and a target layer thickness shown in Table 4 on each surface as a hard coating layer. Hard throwaway tips (hereinafter referred to as conventional coated tips) 1 to 16 were produced.

Next, in the state where each of the above-mentioned various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1-16 and the conventional coated chips 1-16,
Work material: Ni having a composition of Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9% Ti-0.5% Al in mass%. Base alloy round bar,
Cutting speed: 65 m / min. ,
Cutting depth: 1mm,
Feed: 0.1 mm / rev. ,
Cutting time: 5 minutes
A dry continuous high-speed cutting test of a Ni-based alloy under the following conditions (referred to as cutting condition A) (normal cutting speed is 40 m / min.),
Work material: Co-base alloy round bar having a composition of Co-23% Cr-6% Mo-2% Ni-1% Fe-0.6% Si-0.4% C,
Cutting speed: 60 m / min. ,
Cutting depth: 0.8mm,
Feed: 0.15 mm / rev. ,
Cutting time: 4 minutes
A dry continuous high-speed cutting test of a Co-based alloy under the conditions (cutting condition B) (normal cutting speed is 40 m / min.),
Work material: Round bar with four longitudinal grooves at equal intervals in the longitudinal direction of a Ti-based alloy having a composition of Ti-6% Al-4% V in mass%,
Cutting speed: 60 m / min. ,
Cutting depth: 1.2mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
A dry intermittent high-speed cutting test (normal cutting speed is 30 m / min.) Of a Ti-based alloy 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 5.

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 .8 μm Co powders were prepared, each of these raw material powders was blended in the composition shown in Table 6, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then shaped into a predetermined shape 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. In combination, the diameter x length of the cutting edge is 6 mm x 13 mm, 10 mm x 22 mm, and 20 mm x 45 mm, respectively, and each is made of a WC-based cemented carbide with a 4-flute square shape with a twist angle of 30 degrees Carbide substrates (end mills) C-1 to C-8 were produced.

Subsequently, 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 vapor deposition apparatus shown in FIG. And a lower layer composed of a (Ti, Al, Si) N layer having a target composition and a target layer thickness shown in Table 7, and an upper layer consisting of a CrB ₂ layer having the target layer thickness also shown in Table 7 The surface-coated carbide end mills (hereinafter referred to as the present invention-coated end mills) 1 to 8 as the present invention coated carbide tools were produced by vapor-depositing the hard coating layer composed of

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then loaded into the vapor deposition apparatus shown in FIG. By depositing a hard coating layer composed of a (Ti, Al, Si) N layer having the target composition and target layer thickness shown in Table 7 under the same conditions as in Example 1 above, as a conventional coated carbide tool Conventional surface-coated carbide end mills (hereinafter referred to as conventional coated end mills) 1 to 8 were produced.

Next, of the present invention coated end mills 1 to 8 and the conventional coated end mills 1 to 8, the present coated end mills 1 to 3 and the conventional coated end mills 1 to 3 are as follows:
Work Material-Plane: 100mm x 250mm, Thickness: 50mm, and mass%, Co-20% Cr-15% W-10% Ni-1.5% Mn-1% Si-1% Fe- A Co-base alloy plate having a composition of 0.12% C;
Cutting speed: 50 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 200 mm / min,
The dry high-speed grooving test of the Co-based alloy under the conditions (normal cutting speed is 25 m / min.), The present invention coated end mills 4-6 and the conventional coated end mills 4-6,
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm, and Mass%, Ni-19% Cr-14% Co-4.5% Mo-2.5% Ti-2% Fe-1. A Ni-based alloy plate having a composition of 2% Al-0.7% Mn-0.4% Si,
Cutting speed: 55 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 250 mm / min,
With respect to the dry high-speed grooving test of a Ni-based alloy under the conditions (normal cutting speed is 30 m / min.), The present coated end mills 7 and 8 and the conventional coated end mills 7 and 8,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm, and Ti-based alloy plate material having a composition of Ti-3% Al-2.5% V in mass%,
Cutting speed: 45 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 120 mm / min,
A dry high-speed grooving test (normal cutting speed is 20 m / min.) Of a Ti-based alloy under the above conditions is performed, and the flank wear width of the outer peripheral edge of the cutting edge is the service life in any grooving test. The cutting groove length up to 0.1 mm, which is a guideline, was measured. The measurement results are shown in Table 7, 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 then loaded into the vapor deposition apparatus shown in FIG. Then, under the same conditions as in Example 1, the lower layer composed of the (Ti, Al, Si) N layer having the target composition and target layer thickness shown in Table 8, and the CrB having the target layer thickness also shown in Table 8 By forming a hard coating layer composed of _two upper layers by vapor deposition, the surface-coated carbide drills (hereinafter referred to as the present invention-coated drills) 1 to 8 as the present invention coated carbide tools are provided. Each was manufactured.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried, as shown in FIG. By charging the apparatus and vapor-depositing a hard coating layer comprising a (Ti, Al, Si) N layer having the target composition and target layer thickness shown in Table 8 under the same conditions as in Example 1 above. Conventional surface coated carbide drills (hereinafter referred to as conventional coated drills) 1 to 8 as conventional coated carbide tools were manufactured, respectively.

Next, of the present invention coated drills 1 to 8 and the conventional coated drills 1 to 8, the present invention coated drills 1 to 3 and the conventional coated drills 1 to 3 are:
Work material-plane: 100 mm × 250 mm, thickness: 50 mm, and Ti-based alloy plate material having a composition of Ti-3% Al-2.5% V in mass%,
Cutting speed: 40 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 8mm,
For the high-speed wet drilling test of a Ti-based alloy under the conditions (normal cutting speed is 20 m / min.), The present invention coated drills 4-6 and the conventional coated drills 4-6,
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm in Dimensions and Mass%, Co-20% Cr-20% Ni-4% Mo-4% W-4% Cd-3% Fe-1. A plate material of a Co-based alloy having a composition of 5% Mn-0.7% Si-0.38% C;
Cutting speed: 45 m / min. ,
Feed: 0.15mm / rev,
Hole depth: 14mm,
With respect to the Co-based alloy wet high speed drilling cutting test (normal cutting speed is 25 m / min.), The present invention coated drills 7 and 8 and the conventional coated drills 7 and 8,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm, and mass%, Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0. A Ni-based alloy plate having a composition of 9% Ti-0.5% Al-0.3% Si-0.2% Mn-0.05% Cu-0.04% C;
Cutting speed: 55 m / min. ,
Feed: 0.25mm / rev,
Hole depth: 25mm,
The high-speed drilling test of Ni-based alloy under normal conditions (normal cutting speed is 30 m / min.), And the cutting edge surface of any wet high-speed drilling test (using water-soluble cutting oil) The number of drilling processes until the flank wear width was 0.3 mm was measured. The measurement results are shown in Table 8, respectively.

この結果得られた本発明被覆超硬工具としての本発明被覆チップ１〜１６、本発明被覆エンドミル１〜８、および本発明被覆ドリル１〜８の硬質被覆層を構成する（Ｔｉ，Ａｌ，Ｓｉ）Ｎ層（下部層）の組成、並びに従来被覆超硬工具としての従来被覆チップ１〜１６、従来被覆エンドミル１〜８、および従来被覆ドリル１〜８の（Ｔｉ，Ａｌ，Ｓｉ）Ｎ層からなる硬質被覆層の組成を、透過型電子顕微鏡を用いてのエネルギー分散Ｘ線分析法により測定したところ、それぞれ目標組成と実質的に同じ組成を示した。

The hard coating layers of the present coated chips 1-16, the present coated end mills 1-8, and the present coated drills 1-8 as the present coated carbide tools obtained as a result (Ti, Al, Si) ) From the composition of the N layer (lower layer) and the conventional coated chips 1-16 as a conventional coated carbide tool, the conventional coated end mills 1-8, and the (Ti, Al, Si) N layer of the conventional coated drills 1-8 When the composition of the resulting hard coating layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, it showed substantially the same composition as the target composition.

  Moreover, when the average layer thickness of the constituent layers of the hard coating layer was measured by a cross-section 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 8, the coated carbide tool of the present invention is hard-coated even in high-speed cutting of heat-resistant alloys composed of Ti-based alloys, Ni-based alloys, and Co-based alloys, all of which generate significant heat. The (Ti, Al, Si) N layer, which is the lower layer of the layer, has excellent high temperature hardness and heat resistance, and excellent high temperature strength, and the upper layer CrB ₂ layer is a heat resistant alloy that is a work material Excellent thermal stability (very low reactivity) is ensured between the two and the hard coating layer (Ti, Al, Si) while exhibiting excellent wear resistance over a long period of time. ) It is clear that all of the conventional coated carbide tools composed of N layers have a fast wear progress in the high-speed cutting of the heat-resistant alloy and reach the service life in a relatively short time.

  As described above, the coated cemented carbide tool of the present invention can be used not only for cutting under normal cutting conditions such as various steels and cast iron, but also for high-speed cutting of the above hard alloy with particularly high heat generation. However, because it exhibits excellent wear resistance and excellent cutting performance over a long period of time, it is possible to improve the performance and automation of cutting equipment, reduce labor and energy of cutting, and reduce costs. It can respond satisfactorily.

The vapor deposition apparatus used in forming the hard coating layer which comprises a 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)

In a surface-coated cemented carbide cutting tool in which a hard coating layer is physically vapor-deposited on the surface of a cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride cermet, the hard coating layer is arc-ion plated. Using a vapor deposition device where the device and sputtering device coexist,
(A) The lower layer is formed by vapor deposition using the arc ion plating apparatus ,
_{Formula: (Ti 1- (X + Z} ) Al X Si Z) N ( provided that an atomic ratio, X is 0.25 to 0.65, Z represents a 0.01-0.10)
And a composite nitride layer of Ti, Al and Si having an average layer thickness of 0.8 to 5 μm,
(B) A Ti, Al, and Cr composite boronitride layer having an average layer thickness of 0.1 to 0.5 μm, which is formed by vapor deposition using the arc ion plating apparatus and the sputtering apparatus at the same time as the adhesive bonding layer. ,
(C) As an upper layer, a chromium boride layer having an average layer thickness of 0.8 to 5 μm, formed by vapor deposition using the sputtering apparatus ,
A surface-coated cemented carbide cutting tool that exhibits excellent wear resistance in high-speed cutting of heat-resistant alloys, characterized by comprising a hard coating layer comprising the above (a) to (c) .

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