JP2006026882A - Surface-coated cemented carbide cutting tool having hard coating layer exhibiting excellent wear resistance in high-speed cutting of heat resistant alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool having a hard coating layer exhibiting excellent wear resistance in high-speed cutting of a heat resistant alloy. <P>SOLUTION: The surface coated cemented carbide cutting tool has a cemented carbide body formed of a tungsten-carbide-based cemented carbide or a titanium-carbonitride-based cermet, and the hard coating layer consisting of (a) a lower layer, (b) a tight bonding layer, and (c) an upper layer, on the surface of the body. (a) The lower layer is formed of a (Ti, Al, B)N layer which has a mean layer thickness of 0.8 to 5 μm and satisfies the following composition formula: (Ti<SB>1-(X+Z)</SB>Al<SB>X</SB>B<SB>Z</SB>)N (where X is in the range of 0.25 to 0.65, and Z in the range of 0.01 to 0.10 by atomic ratio, respectively). (b) The tight bonding layer is formed of a CrN layer having a mean layer thickness of 0.1 to 0.5 μm. (c) The upper layer is formed of a CrB<SB>2</SB>layer having a mean layer thickness of 0.8 to 5 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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).

  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.

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 B _Z ) N (wherein, X is 0.25 to 0.65, Z: 0.01 to 0.10 in atomic ratio) is satisfied. Coated carbide tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride of Ti, Al and B (boron) [hereinafter referred to as (Ti, Al, B) N] layer with an average layer thickness of 1 to 10 μm And (Ti, Al, B) N layer, which is a hard coating layer of the above-mentioned coated carbide tool, has high temperature hardness and heat resistance due to Al as a component, and high temperature strength due to the Ti, Furthermore, combined with the effect of improving the high-temperature hardness by B, it is also known to exhibit excellent cutting performance when used for continuous cutting and intermittent cutting of various steels and cast irons. .

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—B 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, B) N layer.
Japanese Patent No. 2793696

  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 Since the reaction between the work material and the (Ti, Al, B) N layer, which is a hard coating layer, becomes extremely active and the progress of wear of the hard coating layer is further promoted, it can be used in a relatively short time. The current situation is that it reaches the end of its 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, B) 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, B) N layer is protected because it is low and retains low reactivity. As a result, the excellent characteristics of the (Ti, Al, B) N layer can be maintained over a long period of time. To be fully demonstrated.

(B) However, the adhesion between the CrB ₂ layer as the upper layer and the (Ti, Al, B) N layer as the lower layer is not sufficient, and peeling phenomenon occurs especially when intermittent cutting is performed at high speed. However, when a chromium nitride (hereinafter, referred to as CrN) layer is interposed between the CrB ₂ layer and the (Ti, Al, B) N layer, the CrN layer becomes the CrB ₂ layer and (Ti, Al). , B) Since the N layer is firmly adhered to the N layer, the CrB ₂ layer is coupled with the fact that the (Ti, Al, B) N layer has excellent adhesion to the surface of the carbide substrate. The hard coating layer with a CrN layer interposed between the (Ti, Al, B) N layer and excellent wear resistance without delamination even during high-speed cutting of heat-resistant alloys with high heat generation To come out.

(C) The hard coating layer of (b) is, for example, an arc ion plating apparatus (hereinafter, abbreviated as AIP apparatus) having a structure shown in a schematic plan view in FIG. 1 (a) and a schematic front view in (b). And a sputtering apparatus (hereinafter abbreviated as SP apparatus), that is, a carbide substrate mounting rotary table is provided at the center of the apparatus, and the cathode of the AIP apparatus is placed on one side of the rotary table. Metal Cr as electrode (evaporation source), CrB ₂ sintered body as cathode electrode (evaporation source) of SP device on the other side (for example, sintered body formed by hot pressing using CrB ₂ powder as raw material powder) was opposed, further cathode electrode along said rotary table, and the AIP device in a position 90 degrees apart from each of the metal Cr and CrB ₂ sintered body (evaporation source) Then, using a vapor deposition apparatus in which a Ti—Al—B alloy having a predetermined composition is disposed, a plurality of carbides are disposed along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. In this state, the substrate is mounted in a ring shape, 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—B alloy to form a lower layer (Ti, Al, B) on the surface of the cemented carbide substrate. ) N layer is deposited with an average layer thickness of 0.8 to 5 μm, and then the arc discharge between the cathode electrode (evaporation source) and anode electrode of the Ti—Al—B alloy is stopped, and the AIP device Cathode electrode (evaporation source Arc discharge is generated between the metal Cr and the anode electrode, and a CrN layer is deposited as an adhesion bonding layer with an average layer thickness of 0.1 to 0.5 μm, and then the atmosphere in the deposition apparatus is Instead of the nitrogen atmosphere, a mixed gas atmosphere of Ar and nitrogen is used, but the Ar introduction rate is gradually increased over time, while the nitrogen introduction rate is gradually reduced, and finally the Ar atmosphere is obtained. At the same time, sputtering of the CrB ₂ sintered body arranged as the cathode electrode (evaporation source) of the SP apparatus is started, and arc discharge between the metal Cr and the anode electrode is stopped after a predetermined time has elapsed after the start of the sputtering. Then, the CrB ₂ sintered body is sputtered for a predetermined time, and is formed by depositing a CrB ₂ layer as an upper layer on the CrN layer with an average layer thickness of 0.8 to 5 μm. What you can do.

(D) 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 lower layer (Ti, Al, B) N layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and as an adhesive bonding layer The CrB ₂ layer firmly adhered by the CrN layer ensures excellent thermal stability (very low reactivity) with the heat-resistant alloy that is the work material, so there is no delamination and excellent The wear resistance should be demonstrated over a long period of time.
The research results shown in (a) to (d) above were obtained.

This invention was made based on the above research results, and on the surface of the carbide substrate,
(A) having an average layer thickness of 0.8 to 5 μm and a composition formula: (Ti _{1- (X + Z)} Al _X B _Z ) N (wherein, X is 0.25 to 0 in atomic ratio) .65, Z represents 0.01 to 0.10) (Ti, Al, B) lower layer composed of N layer,
(B) an adhesive bonding layer comprising a CrN layer having an average layer thickness of 0.1 to 0.5 μm;
(C) an upper layer composed of _two CrB layers having an average layer thickness of 0.8 to 5 μm,
It is characterized by a coated carbide tool that forms a hard coating layer composed of the above (a) to (c) and exhibits excellent wear resistance by 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 lower layer composition formula, and average layer thickness The (Ti, Al, B) N layer constituting the lower layer improves the high temperature hardness and heat resistance, while the Ti layer The component has the effect of improving the high temperature strength, and the component B has the effect of further improving the high temperature hardness in the coexistence with Al, but the ratio of the X value indicating the proportion of Al to the total amount of Ti and B ( If the atomic ratio (hereinafter the same) is less than 0.25, the proportion of Ti becomes relatively large, and the high-temperature hardness and heat resistance required for high-speed cutting cannot be secured, and wear progresses. 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. As a result, the cutting edge portion Is it easy for chipping (slight chipping) to occur? Therefore, the X value was determined to be 0.25 to 0.65.
Further, if the Z value indicating the ratio of B is less than 0.01 in the ratio of the total amount of Ti and Al, the desired high temperature hardness improvement effect cannot be obtained, and if the Z value exceeds 0.10, Since the high temperature strength suddenly decreases, the Z value is determined to be 0.01 to 0.10.
Furthermore, 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 Since high-speed cutting tends to cause chipping at the cutting edge, the average layer thickness is set to 0.8 to 5 μm.

(B) Average layer thickness of the adhesive bonding layer If the average layer thickness is less than 0.1 μm, a strong bonding strength cannot be ensured between the upper layer and the lower layer, while the average layer thickness is 0.5 μm. If it exceeds 1, the strength of the hard coating layer suddenly decreases in the tight bonding layer portion, which causes chipping, so the average layer thickness was determined to be 0.1 to 0.5 μm.

(C) Average layer thickness of the upper layer The CrB ₂ layer constituting the upper layer has a thermally stable property as described above, and has extremely low reactivity with the work material and chips heated at high temperature. Because it has characteristics, even in high-speed cutting of heat-resistant alloys that generate significant heat, the (Ti, Al, B) 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.

The coated carbide tool of the present invention has a high-temperature hardness and heat resistance in which the lower layer (Ti, Al, B) N layer constituting the hard coating layer has excellent high-temperature strength, and the same adhesive bonding layer Since the CrB ₂ layer as the upper layer firmly adhered and bonded by the CrN layer as the material ensures excellent thermal stability (very low reactivity) with the work material, particularly high heat generation is achieved. Even with high-speed cutting of heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys, excellent wear resistance is exhibited over a long period of time without delamination.

  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. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 and 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 Pa, 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. Attached along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table, a close contact bonding layer forming metal Cr as the cathode electrode (evaporation source) of the AIP device on one side, and the SP on the other side As a cathode electrode (evaporation source) of the apparatus, a CrB ₂ sintered body for forming an upper layer is disposed oppositely, and further along the rotary table and at a position 90 degrees away from each of the metal Cr and CrB ₂ sintered bodies. A lower layer forming Ti—Al—B alloy having a predetermined composition is disposed as a cathode electrode (evaporation source) of the AIP device,
(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 applied between the Ti—Al—B alloy of the cathode electrode and the anode electrode to generate an arc discharge, and thus the surface of the carbide substrate is made to the Ti—Al—B. 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—B 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, B) N layer is deposited as a lower layer of the hard coating layer,
(D) The arc discharge between the cathode electrode and the anode electrode of the Ti-Al-B alloy for forming the lower layer is stopped, and the atmosphere in the apparatus is maintained in the same nitrogen atmosphere of 3 Pa. While maintaining the same DC bias voltage (−100 V), an arc discharge is generated by flowing a current of 100 A between the metal Cr and the anode electrode of the cathode electrode. A CrN layer is vapor-deposited as an adhesive bonding layer of a hard coating layer,
(E) While continuing the arc discharge between the metal Cr and the anode electrode, the atmosphere in the vapor deposition apparatus is changed to a mixed gas atmosphere of Ar and nitrogen instead of a nitrogen atmosphere. The ratio is gradually increased, while the nitrogen introduction ratio is gradually decreased, and finally the Ar atmosphere is obtained, and the reaction atmosphere is gradually decreased from 3 Pa to 0.3 Pa with time, and the vapor deposition apparatus. Simultaneously with the introduction of a mixed gas of Ar and nitrogen into the inside, sputtering was started on a CrB ₂ sintered body arranged as a cathode electrode (evaporation source) of the SP apparatus under the condition of sputtering output: 3 kW, and the metal Cr and anode electrode Arc discharge with the reaction atmosphere was stopped when the ratio of nitrogen in the mixed gas of Ar and nitrogen reached 10% by volume,
(F) After that, while maintaining the Ar atmosphere of 0.3 Pa, the sputtering was continued under the same conditions as the sputtering output of 3 kW between the CrB ₂ sintered body and the anode electrode. By depositing a CrB ₂ layer having a target layer thickness as an upper layer of the hard coating layer, the surface-coated carbide throw-away tip of the present invention as the coated carbide tool of the present invention (hereinafter referred to as the present coated chip). 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, in the vapor deposition apparatus shown in FIG. A Ti-Al-B alloy having various composition is mounted as a cathode electrode (evaporation source), and the apparatus is first heated with a heater while evacuating the apparatus and maintaining a vacuum of 0.1 Pa or less. After heating the inside 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—B 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—B alloy, and then nitrogen gas is introduced into the apparatus to form a reaction atmosphere of 3 Pa and applied to the carbide substrate. Bias voltage The voltage is lowered to −100 V, and an arc discharge is generated between the cathode electrode and the anode electrode of the Ti—Al—B alloy, so that the carbide substrates A-1 to A-10 and B-1 to B-6 The conventional surface-coated carbide as a conventional coated carbide tool is formed by vapor-depositing a (Ti, Al, B) N layer having the target composition and target layer thickness shown in Table 4 on each surface as a hard coating layer. Slow away chips (hereinafter referred to as conventional coated chips) 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: Round bar of Ti base alloy having a composition of Ti-6% Al-4% V in mass% Cutting speed: 120 m / min. ,
Cutting depth: 1.2mm,
Feed: 0.15 mm / rev. ,
Cutting time: 3 minutes
Dry continuous high-speed cutting test of Ti-based alloy under the conditions (cutting condition A) (normal cutting speed is 50 m / min.),
Work Material: Ni-19% Cr-14% Co-4.5% Mo-2.5% Ti-2% Fe-1.2% Al-0.7% Mn-0.4% by mass% Ni-based alloy round bar with Si composition Cutting speed: 80 m / min. ,
Cutting depth: 0.3 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 8 minutes
Dry continuous high-speed cutting test of Ni-based alloy under the following conditions (cutting condition B) (normal cutting speed is 45 m / min.),
Work material: Equal intervals in the length direction of Co-based alloy having a composition of Co-23% Cr-6% Mo-2% Ni-1% Fe-0.6% Si-0.4% C in mass% Four vertical grooved round bars Cutting speed: 60 m / min. ,
Cutting depth: 0.5mm,
Feed: 0.1 mm / rev. ,
Cutting time: 4 minutes
A dry interrupted high-speed cutting test (normal cutting speed was 30 m / min.) Of the Co-based alloy under the above conditions (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. 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.

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. A lower layer composed of a (Ti, Al, B) N layer having the target composition and target layer thickness shown in Table 7 and an adhesive bonding layer consisting of a CrN layer having the target layer thickness also shown in Table 7 And a hard coating layer composed of an upper layer composed of _two layers of CrB, by vapor deposition, the present surface coated carbide end mill (hereinafter referred to as the present coated end mill) 1 to 1 as the coated carbide tool of the present invention. 8 were produced respectively.

  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, B) N layer having the target composition and target layer thickness shown in Table 7 under the same conditions as in Example 1, the 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: 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% Mn-0.05% Cu-0.04% C;
Cutting speed: 50 m / min. ,
Groove depth (cut): 1mm,
Table feed: 350 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 coated end mills 4 to 6 and the conventional coated end mills 4 to 6
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: 120 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 540 mm / min,
With respect to the dry high-speed grooving test of the Ti-based alloy under the conditions (normal cutting speed is 50 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 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. ,
Groove depth (cut): 5 mm,
Table feed: 145 mm / min,
A dry high-speed grooving test (normal cutting speed is 25 m / min.) Of a Co-based alloy under the above conditions was performed, and the flank wear width of the outer peripheral edge of the cutting edge was 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, B) N layer having the target composition and target layer thickness shown in Table 8, and CrN having the target layer thickness also shown in Table 8 A hard coating layer composed of an adhesive bonding layer composed of layers and an upper layer composed of _two CrB layers is formed by vapor deposition to form the surface coated carbide drill of the present invention as the coated carbide tool of the present invention (hereinafter, coated with the present invention). (Referred to as drills) 1 to 8 were produced.

  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, B) 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: 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 with a composition of 0.12% C;
Cutting speed: 45 m / min. ,
Feed: 0.1 mm / rev,
Hole depth: 6mm,
About the wet high speed drilling cutting test (normal cutting speed is 25 m / min.) Of the Co-based alloy under the conditions of the present invention, the coated drills 4 to 6 and the conventional coated drills 4 to 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: 50 m / min. ,
Feed: 0.12 mm / rev,
Hole depth: 14mm,
The wet-type high-speed drilling test of the Ni-based alloy under the conditions (normal cutting speed is 30 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 Ti-based alloy plate material having a composition of Ti-3% Al-2.5% V in mass%,
Cutting speed: 70 m / min. ,
Groove depth (cut): 0.2 mm,
Table feed: 28mm / min,
The high-speed drilling machining test (normal cutting speed is 40 m / min.) Of the Ti-based alloy under the above conditions, and the cutting edge surface of the tip in any wet high-speed drilling machining 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，Ｂ）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，Ｂ）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 tool obtained as a result of this (Ti, Al, B) ) Composition of N layer (lower layer), and from conventional coated chips 1-16 as a conventional coated carbide tool, conventional coated end mills 1-8, and (Ti, Al, B) N layer of 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, B) N layer, which is the lower layer of the layer, has excellent high-temperature hardness and heat resistance, excellent high-temperature strength, and a CrB ₂ layer firmly adhered by a CrN layer as an adhesive bonding layer. Since excellent thermal stability (very low reactivity) is ensured with the heat-resistant alloy that is the work material, it exhibits excellent wear resistance over a long period of time without delamination On the other hand, in the conventional coated carbide tools in which the hard coating layer is composed of (Ti, Al, B) N layer, the wear progress is fast in the high-speed cutting of the heat-resistant alloy, and it is used in a relatively short time. It is clear that it reaches the end of its life.

  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)

On the surface of the cemented carbide substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(A) having an average layer thickness of 0.8 to 5 μm and a composition formula: (Ti _{1- (X + Z)} Al _X B _Z ) N (wherein, X is 0.25 to 0 in atomic ratio) .65, Z represents 0.01 to 0.10), and a lower layer composed of a composite nitride layer of Ti, Al, and B (boron),
(B) an adhesive bonding layer comprising a chromium nitride layer having an average layer thickness of 0.1 to 0.5 μm;
(C) an upper layer comprising a chromium boride layer having an average layer thickness of 0.8 to 5 μm;
A surface-coated cemented carbide cutting tool that exhibits the wear resistance of a hard coating layer excellent in high-speed cutting of a heat-resistant alloy, formed by forming a hard coating layer composed of (a) to (c) above.

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