JP2011240438A - Surface coated cutting tool excellent in heat resistance and fusion resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool in which a hard coating layer exhibits excellent heat resistance and fusion resistance at the high-speed high-feed cutting of a hardly machinable material having high hardness such as Ti alloy, high hardness stainless steel, and an Ni base heat resistant alloy.SOLUTION: The surface coated cutting tool has, on the surface of a tool base body, a hard coating layer composed of the alternate lamination of (a) and (b): (a) an AlCr(M)N thin layer composed of a composite nitride layer of Al and Cr (and M) that satisfies a composition formula: (AlCr)N or a composition formula: (AlCrM)N (where, M denotes one or two kinds or more of added components selected from elements Si, B, Y of 4a, 5a, 6a groups in periodic tables except for Al and Cr, and α and β are in a range of 0.45≤α≤0.75 and 0.01≤β≤0.25, respectively, in an atomic ratio); and (b) an NbYN thin layer of a composite nitride layer of Nb and Y that satisfies a composition formula: (NbY)N (where, γ is in a range of 0.01≤γ≤0.15 in an atomic ratio).

Description

  The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool). More specifically, for example, a high-hardness hard-to-cut material such as a Ti alloy, high-hardness stainless steel, or Ni-base heat-resistant alloy is cut with high heat generation. The present invention relates to a coated tool that exhibits excellent heat resistance and welding resistance with a hard coating layer when it is machined under high-speed and high-feed conditions in which a large mechanical load is applied to the blade portion.

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

In addition, as a coated tool, on the surface of a tool base composed of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet,
Composition formula: (Al _1-P Cr _P ) N or composition formula: (Al _1-P-Q Cr _P M _Q ) N (where M is the periodic table 4a, 5a, 6a group excluding Al and Cr) Al, which satisfies one or two or more additional components selected from Si, B, and Y, and P and Q indicate the content ratios of Cr component and M component by atomic ratio) A hard coating layer comprising a composite nitride layer of Al and Cr or a composite nitride layer of Al, Cr and M (hereinafter collectively referred to as (Al, Cr, M) N) is coated by physical vapor deposition. (Al, Cr, M) N layer, which is a hard coating layer of the above-mentioned coated tool, has a high temperature hardness due to the constituent component Al, a high temperature strength due to the same Cr, and a combination of Al and Cr. The heat resistance is improved by the coexistence inclusion, and further, Al, Cr are used as the M component. Excluding one or two or more elements selected from the elements of groups 4a, 5a, and 6a of the periodic table, Si, B, and Y, wear resistance and high-temperature oxidation resistance of the hard coating layer It is also known that excellent cutting performance is exhibited when it is used for continuous cutting and intermittent cutting of various general steels and ordinary cast iron.

  Further, for example, the above-mentioned coated tool is loaded with the tool base in an arc ion plating apparatus which is one type of physical vapor deposition apparatus shown schematically in FIG. An Al—Cr alloy or an Al—Cr—M alloy (hereinafter collectively referred to as an Al—Cr—M alloy) having a predetermined composition corresponding to the target composition of the hard coating layer in a state heated to a temperature of 500 ° C. Between the cathode electrode (evaporation source) set and the anode electrode, for example, an arc discharge is generated under the condition of current: 100 A, and nitrogen gas is introduced as a reaction gas into the apparatus at the same time. On the other hand, the tool base is composed of an (Al, Cr, M) N layer having a target composition on the surface of the tool base, for example, under the condition that a bias voltage of −150 V is applied. It is also known to be produced by depositing the quality coating layers respectively.

JP 9-41127 A Japanese Patent Laid-Open No. 10-25566 JP 2004-106183 A JP 2004-269985 A Japanese Patent Laying-Open No. 2005-330539 JP 2006-82209 A

  However, in recent years, the FA of cutting machines has been remarkable. On the other hand, there has been a strong demand for labor saving and energy saving and further cost reduction for cutting, and as a result, cutting tools have as much influence on the type of work material as possible. However, in the above-mentioned conventional coated tools, this is a Ti alloy, high-hardness stainless steel, Ni-base heat-resistant. There is no problem when it is used for cutting hard hard-to-cut materials (work materials) such as alloys at the normal cutting speed, but these hard-cut materials have high heat generation and are locally applied to the cutting edge. When cutting under high-speed and high-feed conditions where a heavy load is applied, the work material and chips are heated to a high temperature due to the heat generated during cutting, and the viscosity increases accordingly. Increase further Becomes way, this result chipping in the cutting edge (small chipping) it increases rapidly, which is at present, leading to a relatively short time service life due.

  Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to produce a high-hardness difficult-to-cut material such as Ti alloy, high-hardness stainless steel, Ni-base heat-resistant alloy with high heat generation and high It is an object of the present invention to provide a coated tool that exhibits excellent heat resistance and welding resistance even when cutting under high-speed high-feed conditions under load.

  In view of the above, the inventors of the present invention particularly cut high-hardness difficult-to-cut materials such as Ti alloy, high-hardness stainless steel, and Ni-base heat-resistant alloy under high-load and high-feed cutting conditions under high load. In order to develop a coated tool that exhibits excellent heat resistance and excellent welding resistance when the hard coating layer is machined, as a result of conducting research while focusing on the conventional coated tool, WC-based cemented carbide or An (Al, Cr) N thin layer or (Al, Cr, M) N thin layer having an average layer thickness of 0.01 to 0.1 μm is vapor-deposited on the surface of a tool substrate made of TiCN-based cermet, and then formed thereon. From the Nb and Y composite nitride layer (hereinafter referred to as (Nb, Y) N layer) containing the Y component so that the Y content in the total amount with Nb is 1 to 15 atomic%. (Nb, Y) N thin layer having an average layer thickness of 0.01 to 0.1 μm. The hard coating is formed by alternately forming the (Al, Cr) N thin layer or the (Al, Cr, M) N thin layer and the (Nb, Y) N thin layer alternately. When the layers are formed, the (Al, Cr) N thin layer or the (Al, Cr, M) N thin layer exhibits excellent high-temperature hardness, high-temperature strength, and heat resistance, and is alternately laminated. The (Nb, Y) N thin layer exhibits excellent welding resistance. In particular, the high temperature hardness of the (Nb, Y) N thin layer is improved by the Y component contained in the (Nb, Y) N thin layer. Thus, it has been found that the excellent welding resistance of the (Nb, Y) N thin layer is maintained even in the cutting process with high heat generation.

  Therefore, even in a high-speed, high-feed cutting of a hard material difficult to cut that easily adheres to the tool surface, even if the cutting edge becomes hot, (Al, Cr) N thin layer or (Al, Cr, M) N thin The (Nb, Y) N thin layers alternately laminated with this layer have the welding resistance that is insufficient for the layer, which improves the welding resistance with the work material as the entire hard coating layer. The present inventors have found that chipping (slight chipping) in the blade portion is prevented, and that excellent wear resistance is exhibited over a long period of time.

The present invention has been made based on the research results,
“(1) In a surface-coated cutting tool in which a hard coating layer is formed on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
A composite nitride of Al and Cr that satisfies the composition formula: (Al _1-α Cr _α ) N (where α is the Cr content ratio, and the atomic ratio is 0.45 ≦ α ≦ 0.75). (Al, Cr) N thin layer consisting of layers,
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Nb and Y composite nitride satisfying the composition formula: (Nb _1-γ Y _γ ) N (where γ represents the content ratio of Y and the atomic ratio is 0.01 ≦ γ ≦ 0.15) (Nb, Y) N thin layer consisting of layers,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm.
(2) In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of a tungsten carbide-based cemented carbide or a titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Al _1-α-β Cr _α M _β ) N (where M is selected from elements of groups 4a, 5a and 6a of the periodic table excluding Al and Cr, Si, B and Y) 1 or 2 or more kinds of additive components, α represents the Cr content ratio, β represents the M content ratio, and the atomic ratio is 0.45 ≦ α ≦ 0.75, 0.01 ≦ (Al, Cr, M) N thin layer composed of a composite nitride layer of Al, Cr, and M satisfying β ≦ 0.25.
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Nb and Y composite nitride satisfying the composition formula: (Nb _1-γ Y _γ ) N (where γ represents the content ratio of Y and the atomic ratio is 0.01 ≦ γ ≦ 0.15) (Nb, Y) N thin layer consisting of layers,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm. "
Excellent heat resistance even when cutting high-hardness difficult-to-cut materials such as Ti alloy, high-hardness stainless steel, and Ni-base heat-resistant alloy with high heat generation and high-speed high-feed cutting conditions with high load. And it has the characteristic of exhibiting welding resistance.

  Next, the hard coating layer of the coated tool of the present invention will be described in detail.

(A) Composition of (Al, Cr) N thin layer or (Al, Cr, M) N thin layer and average layer thickness Composition of (Al, Cr) N thin layer or (Al, Cr, M) N thin layer The Al component, which is a component, improves the high temperature hardness of the hard coating layer, the Cr component has the effect of improving the high temperature strength, and improves the heat resistance by coexistence of Al and Cr. Among the components, elements of the periodic tables 4a, 5a and 6a excluding Al and Cr, Si and B, have an effect of improving the wear resistance of the hard coating layer, and Y has a hard coating layer. The α value indicating the ratio of Cr is less than 0.45 in terms of the total amount of Al or the total amount of Al and M (atomic ratio, the same shall apply hereinafter). The specified high-temperature hardness cannot be ensured, and this is the cause of reduced wear resistance. On the other hand, when the α value indicating the Cr ratio exceeds 0.75, the Al content ratio is relatively decreased, and the high-temperature strength required for high-speed high-feed cutting cannot be ensured. In addition, it becomes difficult to prevent the occurrence of chipping, and when the β value indicating the content ratio of the M component is less than 0.01 in terms of the total amount with Al (atomic ratio, the same shall apply hereinafter), The improvement in properties such as wear resistance and high-temperature oxidation resistance due to inclusion cannot be expected. On the other hand, if the β value exceeds 0.25, the high-temperature strength tends to decrease. 0.45 to 0.75 and β value were set to 0.01 to 0.25.

  Further, if the average layer thickness is less than 0.01 μm, it is insufficient to exhibit its excellent wear resistance over a long period of time, whereas if the average layer thickness exceeds 0.1 μm, In the high-speed and high-feed cutting, since the lack of lubricity becomes obvious and chipping is likely to occur at the cutting edge portion, the average layer thickness is determined to be 0.01 to 0.1 μm.

(B) Composition of (Nb, Y) N thin layer and average single layer thickness The composite of Nb and Y constituting an alternate stacked structure with the (Al, Cr) N thin layer or (Al, Cr, M) N thin layer The nitride layer ((Nb, Y) N layer) has a predetermined high-temperature hardness, high-temperature strength, and welding resistance, and also has excellent heat resistance due to its component Y component. , (Al, Cr) N thin layer or (Al, Cr, M) N thin layer is supplemented with insufficient lubricity, and the low friction coefficient of the hard coating layer is maintained even under high temperature cutting conditions. To come out. However, if the γ value indicating the content ratio of Y is less than 0.01 in the ratio to the total amount with Nb (atomic ratio, the same shall apply hereinafter), heat resistance cannot be ensured and a lubricating effect is expected. On the other hand, when the γ value indicating the Y content exceeds 0.15, the Nb content decreases relatively, and high-speed high-feed cutting of a high-hardness work material with high weldability is possible. Not only can the required high-temperature strength not be ensured, but also the welding resistance is lowered and it becomes difficult to prevent chipping, so the γ value is 0.01 to 0.15 (atomic ratio, below) The same).

  In addition, when the average layer thickness of the (Nb, Y) N layers constituting the alternate lamination is less than 0.01 μm, it is not possible to improve the characteristics of the hard coating layer due to its excellent heat resistance and welding resistance. On the other hand, if the average layer thickness exceeds 0.1 μm, the entire hard coating layer is reduced due to the decrease in the ratio of the relative (Al, Cr) N thin layer or (Al, Cr, M) N thin layer. As a result, high-temperature hardness and high-temperature strength as a result are reduced. As a result, high-hardness hard-cutting materials such as Ti alloys, high-hardness stainless steels, Ni-base heat-resistant alloys, etc., with high heat generation and high load are high In the feed cutting process, chipping is likely to occur at the cutting edge portion and wear is promoted, so that the average layer thickness is set to 0.01 to 0.1 μm.

(C) Total average layer thickness of hard coating layer (Al, Cr) N thin layer or (Al, Cr, M) N thin layer and (Nb, Y) N thin layer, If the total average layer thickness is less than 1 μm, sufficient wear resistance cannot be exhibited over a long period of use. On the other hand, if the total average layer thickness exceeds 10 μm, particularly Ti alloy, high hardness stainless steel, Ni base High-hardness difficult-to-cut materials such as heat-resistant alloys have high heat generation, and high-speed high-feed cutting with high load tends to cause chipping at the cutting edge, so the total average layer thickness is 1 to 10 μm Determined.

(D) The (Al, Cr) N thin layer or the alternating lamination of the (Al, Cr, M) N thin layer and the (Nb, Y) N thin layer is shown schematically in FIG. A base is placed in an arc ion plating apparatus, which is one type of physical vapor deposition apparatus, and the apparatus is heated to a temperature of, for example, 500 ° C. with a heater. -A cathode electrode (evaporation source) made of a Cr-M alloy and a cathode electrode (evaporation source) made of an Nb-Y alloy having a predetermined composition are arranged. First, an anode electrode and a cathode electrode made of an Al-Cr-M alloy (Evaporation source), for example, an arc discharge is generated under the condition of current: 100 A, and simultaneously, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 3 Pa, for example. Is, for example, -1. Under the condition that a bias voltage of 0 V is applied, a thin (Al, Cr) N layer or a thin (Al, Cr, M) N layer is deposited on the surface of the substrate, and after the arc discharge is stopped, By performing arc discharge in the same manner as described above between the cathode electrode (evaporation source) made of an Nb-Y alloy, forming a thin (Nb, Y) N layer on the substrate surface, and repeating the above operation, Hard coating with a predetermined total average layer thickness comprising an (Al, Cr) N thin layer having a predetermined average layer thickness or an alternately laminated structure of (Al, Cr, M) N thin layers and (Nb, Y) N thin layers Layers can be deposited.

  In the coated tool of the present invention, the (Al, Cr) N thin layer or the (Al, Cr, M) N thin layer has a high temperature hardness, heat resistance, and high temperature strength. In addition, since the (Nb, Y) N thin layer has excellent heat resistance and welding resistance, the hard coating layer has excellent wear resistance and high temperature oxidation resistance. As a whole, in addition to excellent high-temperature hardness, heat resistance, high-temperature strength, etc., it also has excellent welding resistance. As a result, it is particularly difficult to achieve high hardness such as Ti gold, high-hardness stainless steel, Ni-base heat-resistant alloy, etc. Excellent chipping resistance and excellent wear resistance over a long period of time, even with high-speed, high-feed cutting, which involves large heat generation of the cutting material and a heavy load on the cutting edge. Is.

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

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

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders are blended in the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. Medium, sintered at 1400 ° C. for 1 hour, and after sintering, tool bases A-1 to A-10 made of WC-based cemented carbide with ISO standard / CNMG120408 chip shape were formed. .

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

(A) Next, each of the tool bases A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then the arc ion plating apparatus shown in FIG. It is mounted along the outer periphery at a position that is a predetermined distance in the radial direction from the central axis on the inner rotary table, and cathode electrodes (evaporation sources) are arranged on both sides facing each other across the rotary table. Has an Al—Cr alloy or Al—Cr—M alloy with a predetermined composition as a cathode electrode (evaporation source), and an Nb—Y alloy with a predetermined composition as a cathode electrode (evaporation source) on the other side,
(B) First, the inside of the apparatus is heated to 500 ° C. with a heater while the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and then the tool base that rotates while rotating on the rotary table is −1000 V. A DC bias voltage is applied, and an arc discharge is generated by flowing a current of 100 A between the Al—Cr alloy or Al—Cr—M alloy of the cathode electrode and the anode electrode, so that the surface of the tool base is made of Al. -Bombard cleaning with Cr alloy or Al-Cr-M alloy,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 3 Pa, a DC bias voltage of −150 V is applied to the tool base that rotates while rotating on the rotary table, and A current of 150 A is passed between the Al—Cr alloy or Al—Cr—M alloy of the cathode electrode and the anode electrode to generate arc discharge, and the targets shown in Tables 3 and 4 are formed on the surface of the tool base. After depositing (Al, Cr) N thin layer or (Al, Cr, M) N thin layer having a composition and a target layer thickness, the cathode electrode (evaporation source) of the Al-Cr alloy or Al-Cr-M alloy is formed. ) And the anode discharge between the anode electrode and
(D) Subsequently, an arc discharge is generated by flowing a current of 150 A between the Nb—Y alloy electrode, which is the cathode electrode (evaporation source), and the anode electrode while keeping the atmosphere in the apparatus in a nitrogen atmosphere of 3 Pa. The (Nb, Y) N thin layer having the target composition shown in Tables 3 and 4 and the target layer thickness is formed by vapor deposition.
The operations of (c) and (d) are repeated until a predetermined total average layer thickness is obtained, and a hard coating layer is formed by vapor deposition, and the present surface-coated throwaway tip (hereinafter referred to as the present invention) as the coated tool of the present invention. 1 to 39 were manufactured.

  For comparison purposes, these tool bases A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating shown in FIG. The apparatus was charged and an Al—Cr alloy or Al—Cr—M alloy having a predetermined composition was mounted as a cathode electrode (evaporation source). First, while evacuating the apparatus and maintaining a vacuum of 0.1 Pa or less, After heating the inside of the apparatus to 500 ° C. with a heater, a DC bias voltage of −1000 V was applied to the tool base, and 150 A was applied between the cathode electrode Al—Cr alloy or Al—Cr—M alloy and the anode electrode. The tool substrate surface is bombarded with an Al—Cr alloy or an Al—Cr—M alloy by flowing an electric current to generate arc discharge, and then nitrogen as a reaction gas in the apparatus. And a bias voltage applied to the tool base is lowered to −150 V to generate an arc discharge between each cathode electrode and anode electrode of the predetermined composition. On the surface of each of the substrates A-1 to A-10 and B-1 to B-6, the (Al, Cr) N layer having the target composition and the target layer thickness shown in Tables 5 and 6 or (Al, Cr, M) Surface-coated throwaway tips (hereinafter referred to as comparative coated tips) 1 to 16 as comparative coated tools were manufactured by vapor-depositing a hard coating layer composed of N layers.

Next, in the state where each of the various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1 to 39 and the comparative coated chips 1 to 16 are as follows:
Work material: Ti-6Al-4V (HB400) round bar,
Cutting speed: 55 m / min. ,
Incision: 2 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes,
Wet continuous high-speed high-feed cutting test of Ti alloy under the following conditions (cutting condition A) (normal cutting speed and feed are 30 m / min. And 0.15 mm / rev., Respectively),
Work material: JIS / SUS630 (HB370) round bar,
Cutting speed: 120 m / min. ,
Cutting depth: 3 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes,
(Continuous cutting speed and feed are 90 m / min. And 0.2 mm / rev., Respectively)
Work material: A round bar of Ni-18Cr-3Mo-18.5Fe-0.9Ti-1.0 (Nb + Ta) -0.5Al (HB450),
Cutting speed: 50 m / min. ,
Cutting depth: 3 mm,
Feed: 0.25 mm / rev. ,
Cutting time: 5 minutes,
Wet continuous high-speed high-feed cutting test of Ni-base heat-resistant alloy under the following conditions (cutting condition C) (normal cutting speed and feed are 30 m / min. And 0.15 mm / rev., Respectively),
The flank wear width of the cutting edge was measured in any high-speed, high-feed cutting test. The measurement results are shown in Tables 7 and 8.

As in Example 1, all of WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder having an average particle diameter of 1 to 3 μm. The raw material powder is blended into the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. , Temperature: Sintered at 1400 ° C. for 1 hour to form a round tool sintered body for forming a tool base having a diameter of 13 mm. WC-base cemented carbide tool bases (end mills) A-1 to A-10 having a four-blade square shape with a diameter x length of 10 mm x 22 mm and a twist angle of 30 degrees were manufactured, respectively. .

  Then, the surfaces of these tool bases (end mills) A-1 to A-10 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. (Al, Cr) N thin layer or (Al, Cr, M) N thin layer having the target composition and single layer thickness shown in Table 10 under the same conditions as in Example 1, and the target also shown in Table 9 A hard coating layer composed of an alternately laminated structure of (Nb, Y) N thin layers having a composition and a target layer thickness of one layer is formed by vapor deposition to form a surface-coated carbide end mill (hereinafter referred to as the present invention) as the coated tool of the present invention. 1 to 27 were manufactured.

  For comparison purposes, the surfaces of the tool bases (end mills) A-1 to A-10 are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, a hard coating layer composed of an (Al, Cr) N thin layer or (Al, Cr, M) N layer having the target composition and target layer thickness shown in Table 10 is deposited. Thus, surface coated carbide end mills (hereinafter referred to as comparative coated end mills) 1 to 10 as comparative coated tools were produced, respectively.

Next, the present invention coated end mills 1-27 and comparative coated end mills 1-10,
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm Ti-6Al-4V (HB400) plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 120 mm / min,
Wet high-speed, high-feed groove cutting test of Ti alloy under the following conditions (cutting condition D) (normal cutting speed and table feed are 30 m / min. And 80 mm / min, respectively)
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS630 (HB370) plate material,
Cutting speed: 130 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 250 mm / min,
Wet high-speed high-feed groove cutting test of stainless steel under the above conditions (cutting condition E) (normal cutting speed and table feed are 90 m / min. And 200 mm / min, respectively),
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm Ni-18Cr-3Mo-18.5Fe-0.9Ti-1.0 (Nb + Ta) -0.5Al (HB450) plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 250 mm / min,
Wet high-speed high-feed groove cutting test of Ni-base heat-resistant alloy under the following conditions (cutting condition F) (normal cutting speed and table feed are 30 m / min. And 80 mm / min, respectively)
In each of the high-speed and high-feed groove cutting test, the cutting groove length was measured until the flank wear width of the outer peripheral edge of the cutting edge reached 0.1 mm, which is a guide for the service life. The measurement results are shown in Table 9 and Table 10, respectively.

  Using the round bar sintered body having a diameter of 13 mm manufactured in Example 2 described above, from this round bar sintered body, the diameter x length of the groove forming portion is 8 mm x 22 mm, respectively, by grinding, and WC-base cemented carbide tool bases (drills) A-1 to A-10 having a two-blade shape with a twist angle of 30 degrees were manufactured.

  Next, the cutting edges of these tool bases (drills) A-1 to A-10 are subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1, the target composition and the target layer thickness (Al, Cr) N thin layer or (Al, Cr, M) N thin layer shown in Table 11 and The surface coating cemented carbide of the present invention as the coated tool of the present invention is formed by vapor-depositing a hard coating layer composed of an alternately laminated structure of (Nb, Y) N thin layers having a target composition and a target layer thickness shown in Table 11. Drills (hereinafter referred to as the present invention-coated drills) 1 to 27 were produced.

  For the purpose of comparison, honing is performed on the surfaces of the tool bases (drills) A-1 to A-10, ultrasonic cleaning is performed in acetone, and the arc ion plate shown in FIG. From the (Al, Cr) N thin layer or the (Al, Cr, M) N thin layer having the target composition and the target layer thickness shown in Table 12 under the same conditions as in Example 1. Surface-coated cemented carbide drills (hereinafter referred to as comparative coated drills) 1 to 10 as comparative coated tools were manufactured by vapor-depositing the hard coating layers to be formed.

Next, for the present invention coated drill 1-27 and comparative coated drill 1-10,
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm Ti-6Al-4V (HB400) plate material,
Cutting speed: 50 m / min. ,
Feed: 0.3 mm / rev,
Hole depth: 5 mm,
Wet high-speed high-feed drilling test of Ti alloy under the following conditions (cutting condition G) (normal cutting speed and feed are 30 m / min. And 0.1 mm / rev., Respectively),
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS630 (HB370) plate material,
Cutting speed: 100 m / min. ,
Feed: 0.35 mm / rev,
Hole depth: 5 mm,
Wet high-speed high-feed drilling test of stainless steel under the following conditions (cutting condition H) ((normal cutting speed and feed are 60 m / min. And 0.15 mm / rev., Respectively),
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm Ni-18Cr-3Mo-18.5Fe-0.9Ti-1.0 (Nb + Ta) -0.5Al (HB450) plate material,
Cutting speed: 50 m / min. ,
Feed: 0.3 mm / rev,
Hole depth: 5 mm,
Wet high-speed high-feed drilling test of Ni-base heat-resistant alloy under the following conditions (cutting condition I) (normal cutting speed and feed are 30 m / min. And 0.1 mm / rev., Respectively),
In each wet high-speed high-feed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.3 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

  (Al, Cr) N thin layers constituting the hard coating layers of the present coated chips 1 to 39, the present coated end mills 1 to 27, and the present coated drills 1 to 27 as the present coated tools obtained as a result. Alternatively, the composition of the (Al, Cr, M) N thin layer and the (Nb, Y) N thin layer, and the comparative coated tips 1 to 16, the comparative coated end mills 1 to 10, and the comparative coated drill 1 to 1 as a comparative coated tool The composition of the hard coating layer consisting of 10 (Al, Cr) N thin layers or (Al, Cr, M) N thin layers was measured by energy dispersive X-ray analysis using a transmission electron microscope. The composition was substantially the same as the target composition.

  Moreover, when the average layer thickness of each layer which comprises the said hard coating layer was cross-sectional measured using the scanning electron microscope, all showed the average value (average value of five places) substantially the same as target layer thickness.

  From the results shown in Tables 7 to 12, all of the coated tools of the present invention have large heat generation and high load, especially of hard hard-to-cut materials such as Ti alloy, high-hardness stainless steel, and Ni-base heat-resistant alloy. Even in such high-speed high-feed cutting, (Al, Cr) N thin layers or (Al, Cr, M) N thin layers that constitute an alternating laminated structure of hard coating layers have excellent high-temperature hardness, heat resistance, and high-temperature strength. In addition to this, the (Nb, Y) N thin layer which has the further excellent wear resistance and high-temperature oxidation resistance and also constitutes the alternately laminated structure has excellent lubricity, and the above-mentioned cutting even under high-temperature conditions. The excellent welding resistance between the material and the chips is maintained, and as a result, the welding resistance that is insufficient for the (Al, Cr) N thin layer or the (Al, Cr, M) N thin layer is alternated with this. By being supplemented by (Nb, Y) N thin layers stacked on The hard coating layer as a whole exhibits excellent wear resistance over a long period of time without occurrence of chipping, whereas the hard coating layer is an (Al, Cr) N thin layer or an (Al, Cr, M) N thin layer. In the comparative coated tool which is composed of layers and does not include the (Nb, Y) N layer, all of the work material (hard-to-cut material) and the chips and the hard coating layer in the high-speed and high-feed cutting of the work material It is clear that chipping occurs at the cutting edge part and the service life is reached in a relatively short time.

  As described above, the coated tool of the present invention is capable of cutting not only general work materials, but also high-speed and high-feed of high-hardness difficult-to-cut materials such as Ti alloy, high-hardness stainless steel, and Ni-base heat-resistant alloy. Since it exhibits excellent wear resistance and welding resistance even in cutting processing and exhibits excellent cutting performance over a long period of time, it is possible to use FA for cutting equipment, labor saving and energy saving of cutting processing, and even lower It can cope with cost reduction sufficiently.

Claims (2)

In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
A composite nitride of Al and Cr that satisfies the composition formula: (Al _1-α Cr _α ) N (where α is the Cr content ratio, and the atomic ratio is 0.45 ≦ α ≦ 0.75). (Al, Cr) N thin layer consisting of layers,
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Nb and Y composite nitride satisfying the composition formula: (Nb _1-γ Y _γ ) N (where γ represents the content ratio of Y and the atomic ratio is 0.01 ≦ γ ≦ 0.15) (Nb, Y) N thin layer consisting of layers,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm. In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Al _1-α-β Cr _α M _β ) N (where M is selected from elements of groups 4a, 5a and 6a of the periodic table excluding Al and Cr, Si, B and Y) In addition, one or two or more kinds of additive components are shown, α is a content ratio of Cr, β is a content ratio of M, and the atomic ratio is 0.45 ≦ α ≦ 0.75, 0.01 ≦ (Al, Cr, M) N thin layer composed of a composite nitride layer of Al, Cr, and M satisfying β ≦ 0.25.
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Nb and Y composite nitride satisfying the composition formula: (Nb _1-γ Y _γ ) N (where γ represents the content ratio of Y and the atomic ratio is 0.01 ≦ γ ≦ 0.15) (Nb, Y) N thin layer consisting of layers,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm.

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