JP6331003B2 - Surface coated cutting tool - Google Patents

Description

  The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool), and more specifically, for example, a work material that is accompanied by high heat generation such as a heat-resistant alloy, stainless steel, titanium alloy, etc. and has a remarkable weldability to a cutting blade. The present invention relates to a coated tool that exhibits high-temperature stability, heat resistance, wear resistance, and welding resistance with excellent hard coating layers when high-speed cutting is performed.

  In general, coated tools are used for turning and planing of work materials such as various types of steel and cast iron, inserts that can be used detachably attached to the tip of a cutting tool, drilling processing of work materials, etc. There are drills, miniature drills, solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material, etc. Also, inserts are detachably attached and cutting is performed in the same way as solid type end mills Insert type end mill tools are known.

  In recent years, there is a high demand for higher efficiency in cutting metal materials, and it is required to increase the cutting speed. For this reason, it is required to improve the wear resistance and fracture resistance of the hard coating layer covering the tool base surface of the cutting tool.

Patent Document 1, a hard coating layer containing aluminum oxide as the _{base, Al 1-X M X (} O 1-Y N Y) Z (0 ≦ X ≦ 0.5,0 <Y ≦ 0. 4, Z> 0), and M in this composition is at least one element selected from Ti, Zr, V, Nb, Mo, W, Y, Mg, Si, and B It is disclosed that a certain AlM (ON) hard coating layer is excellent in wear resistance and heat resistance, and can be formed at a tool substrate temperature of 1000 ° C. or lower, specifically 400 to 600 ° C.

  Patent Document 2 forms a hard coating layer on a tool base of a coated tool, and the hard coating layer is formed by alternately laminating at least one first super multi-layer film and two second super multi-layer films. The first super multi-layer film is formed by alternately laminating one or more layers of A1 layers and B layers, and the second super multi-layer film is composed of A2 layers and C layers. Each of the A1 and A2 layers is composed of any one of TiN, TiCN, TiAlN, or TiAlCN, and the B layer is composed of TiSiN or TiSiCN. The C layer is composed of AlCrN or AlCrCN to provide a coated tool having a laminated hard coating layer that reduces brittleness problems while maintaining wear resistance and heat resistance. That.

Further, Patent Document 3 has (a) an average layer thickness of 0.05 to 0.5 μm on the surface of a tungsten carbide base cemented carbide substrate or a titanium carbonitride cermet substrate, and a composition formula: (Ti _{1− X} Al _X ) N (wherein X is 0.05 to 0.25 in atomic ratio), the highest peak appears on the (111) plane as measured by an X-ray diffractometer, and half of the highest peak (B) having an average layer thickness of 2 to 10 μm through a crystal orientation history layer composed of a Ti-based composite nitride layer showing an X-ray diffraction pattern with a valence width of 2θ of 0.8 degrees or less, and a composition formula : (Ti _1-Y Al _Y ) N (wherein Y is 0.4 to 0.7 in atomic ratio), and the highest peak appears on the (111) plane as measured by an X-ray diffractometer. Ti and Al showing an X-ray diffraction pattern in which the half width of the highest peak is 2θ and 0.8 degrees or less It is disclosed that a surface-coated cemented carbide cutting tool exhibiting excellent wear resistance in high-speed cutting is provided by physically vapor-depositing a hard coating layer composed of a composite nitride layer.

  As another conventional coated tool, for example, a tool base is loaded into an arc ion plating apparatus which is one of physical vapor deposition apparatuses schematically shown in FIG. 2, and the tool base is heated to a predetermined temperature with a heater. In this state, an arc discharge is generated under a predetermined condition between the anode electrode and a cathode electrode (evaporation source) on which an Al—Ti alloy having a predetermined composition is set, and at the same time, nitrogen gas is supplied as a reaction gas in the apparatus. Introduced into a nitrogen atmosphere, on the other hand, the tool base is hardened with an (Al, Ti) N layer by evaporating evaporated particles on the surface of the tool base, for example, under the condition that a predetermined bias voltage is applied. It is also known that a coating layer is formed (see, for example, Patent Document 4).

JP 2010-236092 A International Publication No. 2008/146727 JP 2003-117705 A Japanese Patent No. 2644710

  However, the automation of cutting machines in recent years has been remarkable. On the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and as a result, cutting tools have as much influence on the type of work material as possible. However, in conventional coated tools using a coating layer composed of (Al, Ti) N layers, there is a tendency to be versatile, that is, cutting tools capable of cutting as many grades as possible. Is used for cutting at normal cutting speeds of work materials such as steel and cast iron, but heat-resistant alloys, stainless steel, titanium alloys, etc. are accompanied by high heat generation and are applied to the cutting edge. When cutting under high-speed cutting conditions with remarkable impact and weldability, the (Al, Ti) N layer is a hard film, but the film itself collapses or peels off due to its hardness and high residual stress. Questions There are, as a result, occurs rapidly increased in defects in the cutting edge (small chipping), which is at present, leading to a relatively short time service life due.

For example, according to Patent Document 1, although it is possible to improve the wear resistance and heat resistance to some extent, since the problem of such an AlM (ON) hard coating layer shows brittleness, impact during cutting, etc. This causes a problem that the coating itself is broken or peeled off.
Further, even with the hard coating layer of Patent Document 2, even under severe cutting conditions, the individual coatings constituting the laminated structure cannot be sufficiently prevented from being broken or peeled, resulting in a sufficient hard coating. In some cases, the wear resistance of the entire layer could not be obtained.
Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to provide excellent heat resistance even when heat-resistant alloy, stainless steel, titanium alloy, etc. are cut under high-speed cutting conditions with high heat generation, An object of the present invention is to provide a coated tool that exhibits wear resistance and welding resistance and exhibits excellent cutting performance over a long period of time.

  In view of the above, the inventors of the present invention cut high-temperature alloys, stainless steels, titanium alloys, etc., with high-temperature heat generation, and work materials with remarkable weldability to cutting edges under high-speed cutting conditions. In this case, intensive research was conducted to develop a coated tool having a hard coating layer with excellent heat resistance, wear resistance and welding resistance.

As a result, the following new findings were obtained.
(1) By increasing the Al content ratio of the (Al, Ti) N layer, when Al ₂ O ₃ is formed during cutting, the amount of Al supplied is increased, and dense Al ₂ O ₃ is formed. Therefore, it exhibits excellent heat resistance, wear resistance, and welding resistance to difficult-to-cut materials that easily generate heat during cutting.
(2) The (Al, Ti) N layer is a material in which the Ti oxide itself is very stable, and when introduced into the Al oxide, the high temperature stability of the Ti oxide is improved. Play. By further developing this, the Al content ratio a relative to the total amount of Al and Ti is controlled to form an Al-rich composite nitride of Al and Ti, thereby improving wear resistance compared to each nitride. To do.
(3) The (Al, Ti) N layer consisting only of the cubic crystal structure has high hardness and can improve the wear resistance by being formed on the tool substrate, but the hardness causes defects and chipping. Cheap.
(4) When the half-width of the highest peak of the cubic (111) plane is 2θ and 0.6 ≦ 2θ ≦ 1.1, the crystal structure becomes a granular structure and cracks generated during cutting propagate through the grain boundary. Therefore, it is possible to suppress defects and chipping, which are defects of the (Al, Ti) N layer composed only of the cubic crystal structure as described above.
(5) Since the closest packed surface in the cubic crystal structure is the (111) plane, when the hard coating layer is oriented in the (111) plane, the density is increased and the hardness is increased. Therefore, when the orientation index and hardness on the (111) plane were evaluated by the orientation index Tc (111), when the value of Tc (111) is 1.0 to 2.0, it is particularly excellent in cutting performance. I found it.
The half width of the present invention is a site where the relative intensity of the (111) plane is half of the peak height from the background in the X-ray diffraction line measured by the θ-2θ method using Cu-Kα ray. The width of the diffraction line.

  The present invention is obtained as a result of detailed analysis of the relationship between the composition, crystal structure, orientation index Tc (111) and cutting performance of the (Al, Ti) N layer constituting the hard coating layer based on such knowledge. Specifically, it has the following configuration.

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 a tungsten carbide-based cemented carbide,
(A) The hard coating layer has an average layer thickness of 0.5 to 5.0 μm formed on the surface of the tool base, and a composition formula: (Al _X Ti _1-X ) N (X is Al and occupying the total amount of Ti indicates the content of Al, atomic ratio, made of a composite nitride layer of Al and Ti having a cubic crystal structure which satisfies a 0.75 ≦ X ≦ 0.90),
(B) The half-width of the highest peak of diffraction intensity of the (111) plane of the Al and Ti composite nitride layer having the cubic structure is 2θ, 0.6 ≦ 2θ ≦ 1.1, and the orientation index Tc ( 111) is 1.0 <= Tc (111) <= 2.0. The surface coating cutting tool characterized by the above-mentioned. "
It is characterized by.

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

(A) Composition of hard coating layer:
The (Al _X Ti _1-X ) N layer constituting the hard coating layer exhibits uniform wear resistance, heat resistance and toughness throughout the entire layer, but has excellent high-temperature strength due to its constituent Ti component. In addition, the Al component supplements high-temperature hardness and heat resistance. For this reason, a low friction coefficient is maintained even under high temperature cutting conditions, and excellent heat resistance is exhibited. However, an X value (atomic ratio, the same applies hereinafter) indicating the Al content in the total amount of Al and Ti. If it is less than 0.65, high temperature strength cannot be ensured, and abnormal damage is caused at the boundary portion of the cutting edge and defects are likely to occur, so a long life cannot be expected. On the other hand, the total amount of Al When the X value indicating the Al content ratio exceeds 0.90, the Ti content ratio is relatively decreased, and not only the high-temperature strength required for high-speed cutting can be secured, but also wear resistance. It also becomes difficult to prevent the occurrence of chipping . In the present invention, the X value is determined to be 0.75 to 0.90 based on the example .

(B) Average layer thickness of the hard coating layer:
When the average thickness of the hard coating layer is less than 0.5 μm, it is difficult to clearly form the hard coating layer as having a predetermined composition, and the above-mentioned excellent characteristics of the hard coating layer are exhibited. I can't. On the other hand, when the average layer thickness of the hard coating layer exceeds 5.0 μm, the chipping resistance and chipping resistance are reduced due to the decrease in film strength due to the coarsening of particles. Therefore, the average thickness of the hard coating layer is set to 0.5 to 5.0 μm.

(D) Crystal structure and crystal orientation of composite nitride of Al and Ti:
The (Al, Ti) N layer composite nitride consisting only of the cubic crystal structure has high hardness and can improve the wear resistance by being formed on the tool substrate. It is easy to happen.
However, when the half-value width 2θ of the diffraction intensity peak on the (111) plane of the X-ray diffraction pattern is 0.6 degrees or more and 1.1 or less, the crystal structure becomes a fine grain structure and cracks generated during cutting propagate. It becomes difficult. That is, when the half width 2θ of the diffraction intensity peak at the (111) plane of the X-ray diffraction pattern is less than 0.6, the crystal structure forms columnar crystals, and cracks generated during cutting propagate through the grain boundaries. This is not preferable because the hard coating layer easily breaks. On the other hand, if the half width 2θ exceeds 1.1, the crystal structure becomes nearly amorphous and the hardness of the hard coating layer is lowered, which is not preferable.
Therefore, the half-value width 2θ of the diffraction intensity peak on the (111) plane of the X-ray diffraction pattern is set to 0.6 to 1.1.
(E) Orientation index TC (111) value of composite nitride of Al and Ti having a cubic crystal structure:
The orientation index TC (hkl) is defined by the following formula (I).
Formula (I)
In formula (I), I (hkl) represents the peak intensity (diffraction intensity) of the measured (hkl) plane, and I ₀ (hkl) represents a JCPDS file (Joint Committee on Powder Diffraction Standards (powder X-ray diffraction standard)). File; 37-1140 (Ti3AlN), 38-1420 (TiN)) is the average value of the powder diffraction intensities of AlN and TiN constituting the (hkl) plane, and (hkl) is (111), (200), ( 220, (311), (331), (420), (422), and (511).
When the value of the orientation index TC (111) in the texture coefficient TC (hkl) is 1.0 to 2.0, the density is increased and the level is increased. As a result, it is possible to improve the wear resistance of the hard coating layer, in high-speed cutting of work materials such as heat-resistant alloys, stainless steel, titanium alloys, etc., accompanied by high temperature generation and severe welding to the cutting edge, Good wear resistance.

In addition, the (Al, Ti) N layer which comprises the hard coating layer of this invention can be formed by the following methods, for example.
(A) Bombard process:
A tool base is loaded into an arc ion plating apparatus which is one of physical vapor deposition apparatuses shown in the schematic explanatory diagram of FIG. 1, and the inside of the apparatus is heated to, for example, a temperature of 500 ° C. with a heater. In this state, a bias voltage of -1000 V is applied to the tool base to clean the surface of the tool base with Cr bombardment. In the conventional method for manufacturing a coated carbide tool, the surface of the above-mentioned carbide substrate was cleaned with Ar 2 gas bombardment and Ti bombardment, but metal Cr was used as the cathode electrode and generated by arc discharge between this and the anode electrode. When the surface of the cemented carbide substrate is subjected to a Cr bombardment cleaning process with the Cr ions, the adhesion of the (Al, Ti) N layer as a hard coating layer to the surface of the cemented carbide substrate is determined by the Ar gas bombardment and the Ti bombardment cleaning process. Compared with the case, it will improve further.
(B) Film formation process:
Between the anode electrode and the Al—Ti alloy as the cathode electrode (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. The reaction atmosphere is set to 3.0 Pa, and the bias voltage applied to the tool base is reduced to, for example, -70 V and vapor deposition is performed for a predetermined time, whereby the tool base surface has a predetermined target composition and target layer thickness. An (Al, Ti) N layer having an orientation index TC (111) is formed.

According to the coated tool of the present invention, the hard coating layer formed on the surface of the tool substrate has an average layer thickness of 0.5 to 5.0 μm, and the composition formula: (Al _X Ti _1-X ) N Al / Ti composite nitride having a cubic crystal structure satisfying (X represents the Al content in the total amount of Al and Ti, and the atomic ratio is 0.75 ≦ X ≦ 0.90) The half-width of the highest peak of diffraction intensity on the (111) plane of the composite nitride layer is 2θ, 0.6 ≦ 2θ ≦ 1.1, and the orientation index Tc (111) is 1.0 ≦ Tc. By being (111) ≦ 2.0, the hard coating layer is obtained by the synergistic effect of the excellent wear resistance and heat resistance exhibited by the composite nitride layer of Al and Ti and the excellent high temperature hardness, heat resistance and toughness. Excellent high temperature hardness, heat resistance, high temperature strength, wear resistance, lubricity, impact resistance, fracture resistance, As a result, it has excellent chipping resistance, especially with high heat resistance such as heat-resistant alloys, stainless steel, titanium alloys, etc. It exhibits heat resistance.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated tool and a comparative 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 explaining a prior art.

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

As raw material powders, WC powder, VC powder, Cr ₃ C ₂ powder, and Co powder each having an average particle diameter of 1 to ₃ μm are prepared, and these raw material powders are blended in the blending composition shown in Table 1. , 72 hours wet mixing with a ball mill, drying, press molding into a green compact at a pressure of 100 MPa, and sintering the green compact in a 6 Pa vacuum at a temperature of 1400 ° C. for 1 hour, After sintering, tool bases A-1 to A-3 made of a WC-based cemented carbide having an ISO standard / CNMG120408 insert shape were formed.

(A) Next, each of the tool bases A-1 to A-3 is ultrasonically cleaned in acetone and dried, and the center axis on the rotary table in the arc ion plating apparatus shown in FIG. The two cathode electrodes (evaporation source) made of Cr, Al-Ti alloy, which are mounted along the outer peripheral portion at a predetermined distance in the radial direction from the outer periphery and have a predetermined composition facing each other across the rotary table,
(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 rotated to a tool base that rotates while rotating on a rotary table. A DC bias voltage is applied and a current of 100 A is passed between Cr (cathode electrode) and the anode electrode to generate an arc discharge, thereby cleaning the tool base surface with Cr bombardment,
(C) Next, the atmosphere in the apparatus is maintained in a nitrogen atmosphere of 0.5 to 9.0 Pa, and a DC bias voltage of -20 to -150 V is applied to the rotating tool base while rotating on the rotary table, and the cathode A current of 100 A is passed between an Al-Ti alloy electrode, which is an electrode (evaporation source), and an anode electrode to generate an arc discharge, and a predetermined orientation index TC with a target composition and target layer thickness shown in Table 2 (Al, Ti) N layers having (111) were formed by vapor deposition, and surface coated inserts (hereinafter referred to as the present invention coated inserts) 1 to 5 as the present coated tools were produced.

For comparison purposes,
(A) Each of the tool bases A-1 to A-3 is ultrasonically cleaned in acetone and dried, and is radiused from the central axis on the turntable in the arc ion plating apparatus shown in FIG. Attached along the outer periphery at a position separated by a predetermined distance in the direction, Al-Ti alloy having a predetermined composition and Cr (cathode electrode) facing each other across the rotary table,
(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 rotated to a tool base that rotates while rotating on a rotary table. A DC bias voltage is applied, and an electric current of 100 A is passed between the Al—Ti alloy or Cr (cathode electrode) and the anode electrode to generate an arc discharge, thereby bombarding the tool base surface.
(C) Next, the atmosphere in the apparatus is maintained in a nitrogen atmosphere of 0.5 to 9.0 Pa, and a DC bias voltage of -20 to -150 V is applied to the rotating tool base while rotating on the rotary table, and the cathode An arc discharge is generated by flowing a current of 120 A between the Al—Ti alloy electrode, which is an electrode (evaporation source), and the anode electrode, and the target composition and target layer thickness (Al, Ti) N shown in Table 3 are generated. Layers were vapor-deposited to produce surface-coated inserts (hereinafter referred to as comparative coated inserts) 1 to 5 as comparative coated tools. The formation conditions (bias voltage, oxygen partial pressure, nitrogen partial pressure) of each layer are also shown in Table 3.

The present invention coated inserts 1-5 and Comparative coated inserts 1-5 were cutting test under the following cutting conditions.
Work Material: Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9% Ti-0.5% Al-0.3% by mass% Ni-based alloy round bar having a composition of Si-0.2% Mn-0.05% Cu-0.04% C;
Cutting speed: 60 m / min. ,
Cutting depth: 2.0 mm,
Feed: 0.25 mm / rev. ,
Cutting time: 5 minutes,
Wet continuous high-speed high-feed cutting test of Ni-based alloy under the following conditions (cutting condition A) (normal cutting speed and feed are 35 m / min. And 0.15 mm / rev., Respectively),
Work material: JIS / SUS304 (HB180) round bar,
Cutting speed: 150 m / min. ,
Cutting depth: 2.0mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
Wet continuous high-speed cutting test of stainless steel under the following conditions (cutting condition B) (normal cutting speed and feed are 120 m / min. And 0.3 mm / rev., Respectively),
Work material: Round bar of Ti base alloy having a composition of Ti-6% Al-4% V in mass%,
Cutting speed: 70 m / min. ,
Cutting depth: 2.0mm,
Feed: 0.25 mm / rev. ,
Cutting time: 10 minutes,
Wet continuous high speed and high feed cutting test of Ti-based alloy under the conditions (cutting conditions C) of (normal cutting speed, feed rehabilitation, respectively, 40m / min., 0.15 mm / rev.),
The flank wear width of the cutting edge was measured in any high-speed cutting test. The measurement results are shown in Table 4.

As in Example 1, all of the raw material powders consisting of WC powder, VC powder, Cr ₃ C ₂ powder, and Co powder having an average particle diameter of 1 to 3 μm were blended in the blending composition shown in Table 1, and ball mill The mixture is wet-mixed for 72 hours and dried, and then pressed into a green compact at a pressure of 100 MPa. The green compact is sintered in a 6 Pa vacuum at a temperature of 1400 ° C. for 1 hour, and the diameter is A 13 mm round sintered body for forming a tool base is formed, and from the above round bar sintered body, the diameter x length of the cutting edge portion is 10 mm x 22 mm and the helix angle is 30 degrees by grinding. WC-base cemented carbide tool bases (end mills) A-1 to A-3 having a four-blade square shape were manufactured.

Next, the surfaces of these tool bases (end mills) A-1 to A-3 were ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. 1 by depositing a hard coating layer made of an (Al, Ti) N layer having a predetermined orientation index TC (111) with the target composition and target layer thickness shown in Table 5 under the same conditions as in Table 1. The surface-coated carbide end mills (hereinafter referred to as the present invention-coated end mills) 1 to 6 as the invention-coated tools were produced, respectively.

For comparison purposes, the surfaces of the tool bases (end mills) A-1 to A-3 are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, in the same process as in Example 1, using the formation conditions (bias voltage, nitrogen partial pressure) shown in Table 6, the hard coating layer having the target composition and target thickness shown in Table 6 is formed by vapor deposition. Surface coated carbide end mills (hereinafter referred to as comparative coated end mills) 1 to 5 as comparative coated tools were manufactured, respectively.
Next, for the coated end mills 1 to 6 and the comparative coated end mills 1 to 5 of the present invention,
Work Material-Plane Dimensions: 100mm x 250mm, Thickness: 50mm, Mass%, Ni-19% Cr-14% Co-4.5% Mo-2.5% Ti-2% Fe-1.2 Ni-base alloy plate material having a composition of% Al-0.7% Mn-0.4% Si,
Cutting speed: 60 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 140 mm / min,
Wet high-speed grooving test of Ni-based alloy under the conditions (normal cutting speed and groove depth are 50 m / min. And 1.0 mm, respectively),
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 Tables 5 and 6, respectively.

  The round bar sintered body with a diameter of 13 mm manufactured in Example 2 was used, and from this round bar sintered body, the dimensions of the groove forming part diameter × length were 8 mm × 22 mm and the twist angle by grinding. WC-base cemented carbide tool bases (drills) A-1 to A-3 having a 30-degree two-blade shape were produced, respectively.

Next, the cutting blades of these tool bases (drills) A-1 to A-3 are subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. The hard coating layer having a predetermined orientation index (111) consisting of the (Al, Ti) N layer having the target composition and target layer thickness shown in Table 7 was deposited under the same conditions as in Example 1. By forming, the surface-coated carbide drills (hereinafter referred to as the present invention-coated drills) 1 to 5 as the present invention-coated tools were produced, respectively.

  For the purpose of comparison, the surface of the tool base (drill) A- to 3 is subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. In the same process as in Example 1, using the formation conditions (bias voltage, nitrogen partial pressure) shown in Table 8, the (Al, Ti) N layer having the target composition and target layer thickness shown in Table 8 Surface-coated carbide drills (hereinafter referred to as comparative coated drills) 1 to 5 as comparative coated tools were manufactured by vapor deposition of hard coating layers made of

Next, the present invention cover the drill 1-5 and Comparative coating Drill 1-5,
Work Material—Plane Size: 100 mm × 250 mm, Thickness: 50 mm, Mass%, Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9 Ni-based alloy plate having a composition of% Ti-0.5% Al-0.3% Si-0.2% Mn-0.05% Cu-0.04% C,
Cutting speed: 40 m / min. ,
Feed: 0.25 mm / rev,
Hole depth: 30 mm,
Wet high-speed drilling machining test of Ni-based alloy under the conditions (normal cutting speed and feed are 20 m / min. And 0.12 mm / rev, respectively),
(Using water-soluble cutting oil), and the number of drilling operations was measured until the flank wear width of the cutting edge surface reached 0.3 mm. The measurement results are shown in Tables 7 and 8, respectively.

(Al, Ti) N layer constituting the hard coating layer of the present invention coated inserts 1 to 5 , the present invention coated end mills 1 to 6 , and the present invention coated drills 1 to 5 as the present coated tool obtained as a result. Composition, comparative coating inserts 1 to 5 as comparative coating tools, comparative coating end mills 1 to 5 and the composition of the (Al, Ti) N layer constituting the hard coating layer of comparative coating drills 1 to 5 When measured by an energy dispersive X-ray analysis method using a microscope, each showed substantially the same composition as the target composition.

  Further, when the average layer thickness of the hard coating layer was subjected to cross-sectional measurement using a scanning electron microscope, all showed an average layer thickness (average value of five locations) substantially equal to the target layer thickness.

From the results shown in Tables 2-8, the coated tool of the present invention is formed by (Al, Ti) N layer having a predetermined composition, target crystal thickness and orientation on the Cr bombardment and the tool substrate. With improved tightness, fracture resistance, high temperature hardness, high temperature strength, and excellent heat resistance and wear resistance in a tightly bonded state to the tool base surface, impact resistance, chipping resistance, crack resistance As a result of improving the progress, excellent fracture resistance is ensured even in high-speed cutting of heat-resistant alloys, stainless steel, titanium alloys, etc., and no chipping occurs, and excellent wear resistance is exhibited over a long period of time.
On the other hand, in the comparative coated tool in which any of the layers constituting the hard coating layer deviates from the composition, crystal structure, and orientation defined in the present invention, all are high-speed cutting of heat-resistant alloy, stainless steel, and titanium alloy. In the processing, since the wear resistance is not sufficient and the toughness of the film is lowered, it is apparent that chipping occurs in the cutting edge portion and the service life is reached in a relatively short time.

  As described above, the coated tool of the present invention is excellent in wear resistance and fracture resistance not only in cutting of general work materials, but also in high-speed cutting of heat-resistant alloys, stainless steel, titanium alloys, etc. Since it exhibits excellent cutting performance and exhibits excellent cutting performance over a long period of time, it can satisfactorily respond to automation of the cutting apparatus, labor saving and energy saving of cutting, and cost reduction.

Claims (1)

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,
(A) the hard coating layer, pre-SL has an average layer thickness of 0.5~5.0μm formed in the tool substrate surface, and the composition _{formula: (Al X Ti 1-X} ) N (X is It indicates the content ratio of Al to total the total amount of Al and Ti, atomic ratio, made of a composite nitride layer of Al and Ti having a cubic crystal structure which satisfies a 0.75 ≦ X ≦ 0.90) ,
(B) The half-value width of the highest peak of the diffraction intensity of the cubic (111) plane of the composite nitride layer of Al and Ti having the cubic structure is 2θ, 0.6 ≦ 2θ ≦ 1.1, and orientation The surface-coated cutting tool, wherein the property index Tc (111) is 1.0 ≦ Tc (111) ≦ 2.0.