WO2016084939A1 - Surface-coated cutting tool with excellent chipping resistance and wear resistance - Google Patents

Surface-coated cutting tool with excellent chipping resistance and wear resistance Download PDF

Info

Publication number
WO2016084939A1
WO2016084939A1 PCT/JP2015/083407 JP2015083407W WO2016084939A1 WO 2016084939 A1 WO2016084939 A1 WO 2016084939A1 JP 2015083407 W JP2015083407 W JP 2015083407W WO 2016084939 A1 WO2016084939 A1 WO 2016084939A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
hard coating
coating layer
tool
average
Prior art date
Application number
PCT/JP2015/083407
Other languages
French (fr)
Japanese (ja)
Inventor
峻 佐藤
正訓 高橋
Original Assignee
三菱マテリアル株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2015229736A external-priority patent/JP6634647B2/en
Application filed by 三菱マテリアル株式会社 filed Critical 三菱マテリアル株式会社
Priority to EP15862876.8A priority Critical patent/EP3225337B1/en
Priority to CN201580063713.5A priority patent/CN107000068B/en
Priority to US15/529,008 priority patent/US10556273B2/en
Priority to KR1020177013816A priority patent/KR102326622B1/en
Publication of WO2016084939A1 publication Critical patent/WO2016084939A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • B23B27/18—Cutting tools of which the bits or tips or cutting inserts are of special material with cutting bits or tips or cutting inserts rigidly mounted, e.g. by brazing
    • B23B27/20—Cutting tools of which the bits or tips or cutting inserts are of special material with cutting bits or tips or cutting inserts rigidly mounted, e.g. by brazing with diamond bits or cutting inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B51/00—Tools for drilling machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/16—Milling-cutters characterised by physical features other than shape
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/583—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on boron nitride
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material

Definitions

  • the present invention relates to a surface-coated cutting tool (hereinafter referred to as “coated tool”) having a hard coating layer with excellent chipping resistance and wear resistance.
  • the coated tool of the present invention is a coated tool in which a hard coating layer is coated on a substrate whose cutting edge used for cutting is cubic boron nitride (hereinafter referred to as “cBN”).
  • cBN cubic boron nitride
  • the coated tool of the invention exhibits excellent wear resistance over a long period of time without causing chipping even when subjected to high-speed cutting such as alloy steel.
  • 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.
  • 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.
  • drills miniature drills
  • solid-type end mills that are used for chamfering, grooving, and shouldering of work materials.
  • an insert type end mill is known in which an insert is detachably attached and cutting is performed in the same manner as a solid type end mill.
  • a coated tool for example, a coated tool in which a WC-based cemented carbide, a TiCN-based cermet, and a cBN sintered body are used as a tool base and a hard coating layer is formed on the tool base is known.
  • Various proposals have been made for the purpose.
  • Patent Document 1 discloses that an Al—Ti—Si composite nitride layer is formed on the surface of a WC-based cemented carbide substrate or a TiCN cermet substrate via a crystal orientation history layer made of a Ti—Al composite nitride layer. It is disclosed to physically vapor-deposit a hard coating layer.
  • the crystal orientation history layer composed of the Ti—Al composite nitride layer has (a) an average layer thickness of 0.05 to 0.5 ⁇ m and a composition formula: (Ti 1-X Al X ) N (wherein the atomic ratio And X represents 0.01 to 0.15), and the maximum peak appears on the (200) plane as measured by an X-ray diffractometer using Cu-K ⁇ rays, and the maximum peak An X-ray diffraction pattern having a half width of 2 ⁇ of 0.5 degrees or less is shown.
  • the hard coating layer made of an Al—Ti—Si composite nitride layer has (b) an average layer thickness of 2 to 10 ⁇ m, and a composition formula: (Al 1 ⁇ (A + B) Ti A Si B ) N (provided that atoms (A is 0.35 to 0.55 and B is 0.05 to 0.20), and the (200) plane was measured by an X-ray diffractometer using Cu-K ⁇ rays. An X-ray diffraction pattern in which the highest peak appears and the half width of the highest peak is 2 ⁇ and 0.5 degrees or less is shown.
  • Patent Document 1 the wear resistance of the hard coating layer in high-speed cutting is improved by forming the crystal orientation history layer and the hard coating layer on the WC-based cemented carbide substrate or the TiCN cermet substrate. It has been proposed to obtain a surface-coated cemented carbide cutting tool.
  • the nitride layer of Ti and Al (hereinafter referred to as “(Al, Ti) N”) proposed in Patent Document 1 and the nitride layer of Al, Ti, and Si (hereinafter referred to as “(Al, Ti)”. , Si) N ”), a coated tool in which a hard coating layer with a controlled crystal orientation is coated on the surface of a WC-based cemented carbide substrate or a TiCN-based cermet substrate is high in hardness and has excellent wear resistance. Demonstrate sex.
  • the (Al, Ti, Si) N layer is fragile because it contains Si and the distortion of the crystal lattice is increased, and the substrate- (Al, Ti) N layer- (Al, The bonding strength between the Ti, Si) N layers was not sufficient. Therefore, when a cBN sintered body is used as a tool base and a coated tool on which the above nitride is formed is used, chipping resistance is not sufficient under high-speed cutting conditions in which a high load acts on the cutting edge. There was a problem of reaching the end of life early. Accordingly, there is a need for a coated tool that has excellent chipping resistance and wear resistance even when subjected to high-speed cutting, and exhibits excellent cutting performance over a long period of time.
  • the present inventors diligently studied about the structure of the hard coating layer in order to solve the above problems, and obtained the following knowledge.
  • a hard coating layer made of an (Al, Ti, Si) N layer is vapor-deposited on the surface using, for example, an arc ion plating apparatus.
  • a (Al, Ti) N layer is formed between the cBN substrate and the (Al, Ti, Si) N layer.
  • the present inventors set the (Al, Ti) N layer as a buffer layer for buffering strain due to lattice mismatch between the cBN substrate and the (Al, Ti, Si) N layer. It has been found that chipping resistance can be improved.
  • the (Al, Ti, Si) N layer when the (Al, Ti, Si) N layer is formed directly on the cBN substrate, the (Al, Ti, Si) N layer itself has a large lattice distortion due to the inclusion of the Si component, Since strain due to lattice mismatch of the (Al, Ti, Si) N layer is also added, it is difficult to control the orientation of the (Al, Ti, Si) N layer to a desired value. However, the inventors can also control the orientation of the (Al, Ti, Si) N layer formed thereon by controlling the orientation of the (Al, Ti) N layer. It has been found that both chipping resistance and wear resistance can be achieved.
  • the present invention has been made based on the above findings.
  • the surface-coated cutting tool of the present invention is At least the cutting edge is formed by vapor-depositing a hard coating layer on a tool base made of a cubic boron nitride sintered body,
  • the cubic boron nitride sintered body is at least one selected from the group consisting of cubic boron nitride particles, Ti nitride, carbide, carbonitride, boride, Al nitride, and oxide.
  • the average particle diameter of the cubic boron nitride particles is 0.5 to 4.0 ⁇ m, and the content ratio of the cubic boron nitride particles in the entire cubic boron nitride sintered body is 40 to 70% by volume.
  • the hard coating layer is composed of an A layer coated on the tool base surface and a B layer coated on the A layer surface
  • the A layer is When represented by the composition formula: (Al 1-x Ti x ) N, the atomic ratio satisfies 0.35 ⁇ x ⁇ 0.6
  • the B layer is When represented by the composition formula: (Al 1-yz Ti y Si z ) N, the atomic ratio satisfies 0.35 ⁇ y ⁇ 0.6, 0.01 ⁇ z ⁇ 0.1),
  • the hard coating layer has
  • x indicating the Ti content ratio of the A layer and y indicating the Ti content ratio of the B layer have a relationship of
  • the surface-coated cutting tool (hereinafter referred to as “coated cBN tool”) formed with a nitride film of the present invention has a (Al 1-x Ti x ) having a predetermined composition on the surface of a tool substrate having at least a cutting edge made of a cBN sintered body.
  • a hard coating layer is formed by coating an A layer composed of an N layer and a B layer composed of an (Al 1-yz Ti y Si z ) N layer having a predetermined composition as a laminated structure in the order of the A layer and the B layer. is doing.
  • the layer thickness ratio t B / t A between the A layer and the B layer is further set to 2 or more and 5 or less, and the X-ray diffraction intensity ratio I (200) / I (111) as the whole hard coating layer is 3
  • the A layer functions as a buffer layer between the cBN substrate and the B layer by setting the half width of the peak of I (200) to 0.3 or more and 1.0 or less.
  • the coated cBN tool having a hard coating layer according to the present invention exhibits excellent chipping resistance and high wear resistance in high-speed cutting processing such as alloy steel in which a high load acts on the cutting edge, and is used for a long time. It exhibits excellent cutting performance.
  • the cross-sectional schematic diagram of the hard coating layer of this invention coated tool is shown. It is the schematic of the arc ion plating apparatus for vapor-depositing and forming a hard coating layer, and shows a top view. It is the schematic of the arc ion plating apparatus for vapor-depositing and forming a hard coating layer, and shows a side view.
  • the coated cBN tool of the present invention is described in more detail below.
  • the coated cBN tool of this embodiment is obtained by vapor-depositing a hard coating layer composed of an A layer 12 and a B layer 13 on a tool substrate (cBN substrate) 11 composed of a cBN sintered body. It is.
  • cBN particles Fine and hard cubic boron nitride particles (hereinafter referred to as “cBN particles”) are dispersed in the cBN sintered body, thereby suppressing chipping due to falling off of cBN particles at the cutting edge during tool use. can do.
  • the fine cBN particles in the cBN sintered body are dispersed in the propagation of cracks that develop from the interface between the cBN particles and the binder phase caused by the stress applied to the cutting edge during use of the tool, or the cracks that propagate when the cBN particles break -Since it plays the role of slowing down, it can exhibit excellent chipping resistance.
  • the average particle size of the cBN particles is set to 0.5 to 4.0 ⁇ m.
  • the average particle size of the cBN particles is determined by using a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) of a cross-sectional structure of the prepared cBN sintered body.
  • the shape of the cBN particle is approximated to a circular shape with an equivalent area,
  • the diameter of the approximate circle was taken as the diameter of each cBN particle, the average value of the diameters of cBN particles in one image was determined, and the average of the average values determined for at least three images was defined as the average particle size ( ⁇ m) of cBN.
  • the observation area used for the image processing is determined by performing preliminary observation. However, considering that the average particle size of the cBN particles is 0.5 to 4.0 ⁇ m, it is desirable that the viewing area is about 15 ⁇ m ⁇ 15 ⁇ m.
  • volume ratio of cBN particles in the cBN sintered body When the content ratio of the cBN particles in the cBN sintered body is less than 40% by volume, the hard body is less in the sintered body and the hardness of the cBN sintered body is lowered, so that the wear resistance is lowered. On the other hand, if it exceeds 70% by volume, since the binder phase is insufficient, voids serving as starting points of cracks are generated in the sintered body, and the fracture resistance is lowered. Therefore, the content ratio of cBN particles in the cBN sintered body is determined to be in the range of 40 to 70% by volume.
  • the measurement method of the content ratio (volume%) of the cBN particles in the cBN sintered body is that the cBN particle portion in the secondary electron image obtained by observing the cross-sectional structure of the cBN sintered body with the SEM is used.
  • the area occupied by the cBN particles with respect to the entire area of the cBN sintered body in the observation region is calculated by image processing, and the average value of the values obtained by processing at least three images is calculated as the content ratio (volume%) of the cBN particles. ).
  • the observation region used for image processing is desirably a visual field region of about 15 ⁇ m ⁇ 15 ⁇ m.
  • the main hard component in the cBN sintered body in the present embodiment is the above-mentioned average particle size and volume proportion of cBN particles, but as a component for forming a binder phase, a well-known Ti nitride, At least one kind of particles selected from the group consisting of carbide, carbonitride, boride, Al nitride, and oxide can be used.
  • a well-known Ti nitride At least one kind of particles selected from the group consisting of carbide, carbonitride, boride, Al nitride, and oxide can be used.
  • the average particle size of the binder phase was 1 ⁇ m or less.
  • the lower limit value of the average particle size of the binder phase is not particularly limited, but is preferably 0.1 ⁇ m or more.
  • the average particle size of the binder phase is determined by the same method as the average particle size of cBN particles.
  • the layer A having the composition represented by the composition formula: (Al 1-x Ti x ) N has a content ratio x (where x is an atomic ratio) in the total amount of Ti and Al in Ti: 0.35 ⁇ x ⁇ 0.6 is satisfied.
  • x is an atomic ratio
  • the content x of the Ti component is set to 0.35 or more and 0.6 or less. .
  • the B layer constituting the hard coating layer The B layer having a composition represented by the composition formula: (Al 1-yz Ti y Si z ) N is a content ratio y, z (provided that y, z is an atomic ratio) satisfying 0.35 ⁇ y ⁇ 0.6 and 0.01 ⁇ z ⁇ 0.1, respectively.
  • the (Al 1-yz Ti y Si z ) N layer constituting the B layer exhibits desired oxidation resistance and high wear resistance during high-speed cutting such that the temperature becomes high during cutting. .
  • the Ti component content ratio y is less than 0.35, the crystal structure distortion becomes large and the rock salt crystal structure cannot be maintained, and the orientation control becomes difficult.
  • the Ti component content y When the value exceeds 0.6, not only the hardness is lowered but also the oxidation resistance is not sufficient. Further, when the content ratio z of the Si component is less than 0.01, the desired wear resistance is not exhibited, and when it exceeds 0.1, the distortion of the crystal lattice increases and the fracture resistance decreases. Therefore, the content y of the Ti component is set to 0.35 or more and 0.6 or less, and the content ratio z of the Si component is set to 0.01 or more and 0.1 or less. In addition, when the A layer serves as a buffer layer for the B layer and the substrate, it is more preferable that the content ratio of the A layer and the B layer in the metal component of Ti is close.
  • the absolute value of the difference in y is 0.15 or less (
  • the range of the absolute value of the difference between x and y is more preferably
  • the hard coating layer according to the present embodiment is formed on an (Al 1-x Ti x ) N layer (provided that the atomic ratio is 0.35 ⁇ x ⁇ 0.6), which is an A layer directly above the tool base.
  • Layered structure with (Al 1-yz Ti y Si z ) N layer (wherein the atomic ratio is 0.35 ⁇ y ⁇ 0.6, 0.01 ⁇ z ⁇ 0.1) Configured as
  • the Ti component contained in the A layer ensures excellent strength and toughness
  • the Al component improves high-temperature hardness and heat resistance, and at the same time provides high-temperature oxidation resistance in the state where Al and Ti coexist. The action to improve is shown.
  • the (Al 1-x Ti x ) N layer has a rock salt type crystal structure (rock salt type cubic crystal), it has high hardness, and by forming the A layer on the tool substrate, the wear resistance can be improved. it can.
  • the B layer is a layer containing the Si component in the A layer and has a rock salt type crystal structure (rock salt type cubic crystal). Further, the B layer is a layer having further improved heat resistance by containing the Si component in the A layer. Since the B layer has a high oxidation start temperature and high high-temperature oxidation resistance, the formation of the B layer improves the wear resistance during high-speed cutting, which is particularly high during cutting.
  • the hard coating layer composed of the laminated structure of the A layer and the B layer cannot exhibit sufficient wear resistance over a long period of use, while the average total layer When the thickness exceeds 4.0 ⁇ m, the hard coating layer is liable to self-destruct, so the average total layer thickness of the hard coating layer was determined to be 1.5 to 4.0 ⁇ m. Furthermore, when the average layer thickness of the A layer constituting the laminated structure is t A and the average layer thickness of the B layer is t B , the B layer is relatively thin when the value of t B / t A is less than 2. Therefore, sufficient wear resistance cannot be obtained.
  • the thickness of the A layer becomes relatively thin, and the lattice loss between the A layer of the B layer and the substrate is not good.
  • the value of t B / t A was determined to be 2 or more and 5 or less because not only the function as a buffer layer for buffering the strain due to the alignment could not be sufficiently exhibited, but also the orientation control of the B layer could not be sufficiently performed.
  • the value of t B / t A is more preferably 3 or more and 5 or less.
  • the layer thickness of the hard coating layer is the thickness of the layer in the direction perpendicular to the surface of the tool substrate. A reference line for interface roughness between the substrate and the hard coating layer is used.
  • composition of the A layer represented by the composition formula: (Al 1-x Ti x ) N and the composition of the B layer represented by the composition formula: (Al 1-yz Ti y Si z ) N are respectively the A layer and B
  • the average composition of the A layer and the B layer, the average layer thickness t A , the average layer thickness t B , and the average total layer thickness of the hard coating layer are the scanning electron in the vertical section of the hard coating layer perpendicular to the tool base surface.
  • the average value of the measurement at each of the five locations measured by the cross-sectional measurement is the average composition of the A layer and the B layer, the average layer thickness t A , the average layer thickness t B , and the average total layer thickness of the hard coating layer. It was.
  • the desired orientation of the B layer is maintained by controlling the orientation of the A layer. That is, in this embodiment, the hard coating layer composed of the A layer and the B layer is formed using, for example, the arc ion plating apparatus 20 shown in FIGS. 2A and 2B.
  • the orientation can be controlled by controlling the value, the partial pressure of nitrogen gas as a reaction gas, the bias voltage, and the film formation temperature, and adjusting the crystal growth rate and the atomic diffusion rate.
  • the (200) plane having a lower surface energy than the (111) plane in the rock salt cubic structure is oriented parallel to the tool base surface.
  • the B layer is formed on the upper layer of the A layer whose orientation is controlled as described above while similarly controlling the film formation parameters.
  • the orientation of the A layer and the B layer can be made uniform.
  • the diffraction peak intensity on the (200) plane is I (200)
  • the diffraction peak intensity on the (111) plane is I (111), I (200) / I
  • the chipping resistance is lowered, while the value of I (200) / I (111) exceeds 12.
  • the value of I (200) / I (111) needs to be more than 3 and 12 or less.
  • the value of I (200) / I (111) is preferably 4 or more and 10 or less.
  • the half-value width of the peak intensity I (200) of the (200) plane is less than 0.3, the crystal grains are likely to be coarsened, so that the chipping resistance is lowered.
  • the half-value width exceeds 1.0, it is desirable.
  • the orientation cannot be controlled, or the crystal structure has a large strain, so that stable performance cannot be exhibited. Therefore, the half width of I (200) must be 0.3 or more and 1.0 or less.
  • the full width at half maximum of I (200) is preferably 0.4 or more and 0.8 or less.
  • X-ray diffraction for layer A For the entire hard coating layer, the value of I (200) / I (111) should be more than 3 and 12 or less, and the half width of the peak of I (200) should be 0.3 to 1.0. As described above, in forming such a hard coating layer, when X-ray diffraction is performed on the A layer, 2 ⁇ I A (200) / I A (111) ⁇ 10 is satisfied, and It is desirable that the half width of the peak of I A (200) is 0.3 to 1.0.
  • I A (200) and I A (111) refer to the diffraction peak intensity of the (200) plane in the A layer and the diffraction peak intensity of the (111) plane in the A layer, respectively.
  • the value of I A (200) / I A (111) is more preferably 3 or more and 8 or less, and the half width of the peak of I A (200) is more preferably 0.4 or more and 0.8 or less. .
  • the orientation of the B layer formed thereon is controlled, and as a result, 3 ⁇ I (200) / I (111) ⁇ 12 as the entire hard coating layer.
  • a hard coating layer satisfying and having a half-value width of a peak of I (200) of 0.3 to 1.0 is easily formed.
  • the peak intensity ratio I (200) / I (111) for the entire hard coating layer is that the diffraction peak where the A layer and the B layer overlap is regarded as one diffraction peak, and the diffraction peak where the (200) plane overlaps. This is the value of I (200) / I (111) calculated with the intensity as I (200) and the diffraction peak intensity where the (111) planes overlap as I (111).
  • the diffraction peak intensities I A (200) and I A (111) of the A layer are, for example, described after the B layer is processed and removed by a method such as a focused ion beam (FIB) method. It can be measured by using an X-ray diffraction method.
  • FIB focused ion beam
  • Tool substrate production As raw material powder, cBN particles having an average particle size of 1 to 4 ⁇ m are used as raw material powder for forming a hard phase, and TiN powder, TiC powder, TiCN powder, Al powder, AlN powder, and Al 2 O 3 powder are used for forming a binder phase. Prepared as raw powder. Among these, the blending ratio shown in Table 1 was blended so that the content ratio of cBN particles was 40 to 70% by volume when the total amount of some raw material powder and cBN powder was 100% by volume. Next, the raw material powder was wet-mixed for 72 hours in a ball mill, dried, and then press-molded at a molding pressure of 100 MPa to a size of diameter: 50 mm ⁇ thickness: 1.5 mm.
  • a cBN sintered body was prepared by sintering at a predetermined temperature.
  • This sintered body is cut into a predetermined size with a wire electric discharge machine, Co: 5% by mass, TaC: 5% by mass, WC: remaining composition and insert made of WC-based cemented carbide with ISO standard CNGA120408 insert shape Brazing to the brazing part (corner part) of the main body using an Ag-based brazing material having a composition consisting of Cu: 26%, Ti: 5%, and Ag: the rest, and polishing the upper and lower surfaces and outer periphery, By performing the honing process, cBN tool bases 1 to 3 having an insert shape of ISO standard CNGA120408 were manufactured.
  • a hard coating layer was formed on the tool bases 1 to 3 using the arc ion plating apparatus 20 shown in FIGS. 2A and 2B.
  • the Al—Ti alloy target 22 in FIGS. 2A and 2B a plurality of Al—Ti alloy targets 22 having different compositions were arranged in the apparatus according to the target (Al, Ti) N layer.
  • the tool bases 1 to 3 are ultrasonically cleaned in acetone and dried, and the outer peripheral portion is located at a predetermined radial distance from the central axis on the rotary table 23 in the arc ion plating apparatus 20.
  • Tool base 11 in FIGS. 2A and 2B Tool base 11 in FIGS. 2A and 2B).
  • an Al—Ti alloy target 22 having a predetermined composition was disposed as a cathode electrode (evaporation source).
  • C Next, the A layer was formed as follows.
  • Nitrogen gas is introduced into the apparatus as a reaction gas to obtain a predetermined reaction atmosphere of 2 to 10 Pa shown in Table 2, and the apparatus is also maintained at the apparatus temperature shown in Table 2 and rotates while rotating on the rotary table 23.
  • a predetermined DC bias voltage of ⁇ 25 to ⁇ 75 V shown in Table 2 is applied to the tool base 11 and the cathode electrode (evaporation source) composed of the Al—Ti alloy target 22 having the predetermined composition and the anode electrode 21
  • a predetermined current of 80 to 120 A shown in Table 2 is simultaneously supplied for a predetermined time to generate arc discharge, and the target composition and target average layer thickness (Al, Ti) shown in Table 4 are formed on the surface of the tool base 11.
  • a layer composed of N layer was formed by vapor deposition (A layer 12 in FIG. 1).
  • the B layer was formed as follows. First, nitrogen gas is introduced into the apparatus as a reaction gas so as to obtain a predetermined reaction atmosphere within the range of 2 to 10 Pa shown in Table 2, while maintaining the temperature in the apparatus shown in Table 2 as well. A predetermined DC bias voltage within the range of ⁇ 25 to ⁇ 75 V shown in Table 2 is applied to the tool base 11 rotating while rotating at the same time, and a cathode electrode (evaporation source) made of the Al—Ti alloy target 22 is applied. A predetermined current in the range of 80 to 120 A shown in Table 2 is passed between the anode electrode 21 and an arc discharge to generate an arc discharge.
  • nitrogen gas is introduced into the apparatus as a reaction gas so as to obtain a predetermined reaction atmosphere within the range of 2 to 10 Pa shown in Table 2, while maintaining the temperature in the apparatus shown in Table 2 as well.
  • a predetermined DC bias voltage within the range of ⁇ 25 to ⁇ 75 V shown
  • the target composition and the target average layer thickness shown in Table 4 ( A B layer composed of a Ti, Al) N layer was formed by vapor deposition (B layer 13 in FIG. 1).
  • a coated cBN tool of the present invention (hereinafter referred to as “the present invention tool”) 1 to 10 shown in Table 4 in which a hard coating layer formed by laminating the A layer and the B layer is formed by vapor deposition according to the above (a) to (d). was made.
  • a lower layer and an upper layer are deposited on the tool bases 1 to 3 under the conditions shown in Table 3 to obtain a coated tool of a comparative example shown in Table 5 (hereinafter referred to as “comparative tool”). 1 to 12 were produced.
  • the lower layer and the upper layer of the comparative example tool are layers corresponding to the A layer and the B layer of the present invention, respectively, in the following, the lower layer and the upper layer of the comparative example tool are respectively referred to for convenience. In particular, they are referred to as A layer and B layer.
  • the width in the direction parallel to the tool base surface is 10 ⁇ m
  • the hard coating layer For the field of view set to include all the thickness regions, cross-sectional measurement using a scanning electron microscope (SEM), a transmission electron microscope (TEM), and energy dispersive X-ray spectroscopy (EDS) was performed. The layer composition and the layer thickness were measured at five locations for each layer and averaged to calculate the average composition of layer A and layer B, average layer thickness t A , and average layer thickness t B. In addition, the value of t B / t A was obtained.
  • SEM scanning electron microscope
  • TEM transmission electron microscope
  • EDS energy dispersive X-ray spectroscopy
  • the diffraction peak intensity ratio I (200) / I (111) of the entire hard coating layer is the diffraction peak intensity of the (200) plane where the A layer and the B layer overlap by X-ray diffraction using a Cr tube.
  • I (200) is measured, and the diffraction peak intensity of the (111) plane where the A layer and the B layer overlap is measured as I (111) to obtain the half width of the peak of I (200).
  • 200) / I (111) Further, the diffraction peak intensity of the A layer is measured by using the X-ray diffraction method described above after processing and removing the B layer by a method such as a focused ion beam (FIB) method after film formation.
  • FIB focused ion beam
  • Cutting condition A Work material: Round bar with hole of quenching material of JIS / SCr420, Cutting speed: 220 m / min, Cutting depth: 0.15 mm, Feed: 0.15 mm
  • Cutting condition B Work material: JIS / SCM415 quenching material round bar, Cutting speed: 315 m / min. , Cutting depth: 0.1 mm, Feed: 0.1 mm
  • the condition A was cut to a cutting length of 880 m
  • the condition B was cut to a cutting length of 945 m
  • the flank wear amount was measured. Table 6 shows the results.
  • the “presence / absence of chipping” shown in Table 6 indicates that the wear surfaces of the inventive tools 1 to 10 and comparative tools 1 to 12 after the dry continuous cutting test under the cutting conditions A and B were observed by SEM. The presence or absence is confirmed.
  • the “flank wear amount” shown in Table 6 is obtained by observing the flank surfaces of the inventive tools 1 to 10 and comparative tools 1 to 12 after the dry continuous cutting test under the cutting conditions A and B by SEM. The width is measured from the length on the SEM photograph. When the flank wear amount exceeded 0.2 mm, the cutting performance such as machining accuracy deteriorated, and the case where the flank wear amount exceeded 0.25 mm was judged as the service life.
  • the inventive tools 1 and 2 and 4 to 10 can perform cutting without causing chipping, and the average flank wear amount is the cutting condition A. It is about 0.11 mm and cutting condition B is about 0.13 mm, and it can be seen that the wear resistance is also excellent.
  • the inventive tool 3 chipping was observed, but the flank wear amount was 0.2 mm or less, and the wear resistance was confirmed.
  • the comparative tools 1 to 12 reach the end of their lives in a short time due to the occurrence of chipping or the progress of flank wear. From this result, it can be seen that the tool of the present invention is superior in both chipping resistance and wear resistance as compared with the comparative example tool.
  • the surface-coated cutting tool of the present invention is capable of cutting at normal cutting conditions such as various types of steel, particularly high-speed cutting such as alloy steel that is accompanied by high heat generation and a heavy load on the cutting edge. Also in machining, it exhibits excellent chipping resistance and wear resistance, and exhibits excellent cutting performance over a long period of time. Furthermore, it can cope with cost reduction sufficiently satisfactorily.

Abstract

This surface-coated cutting tool is one in which at least the tip comprises a tool base constituted of a sintered cBN object and, formed on the surface thereof, a multilayered coating comprising layer A consisting of an (Al1-xTix)N layer (where 0.35≤x≤0.6 in terms of atomic ratio) and layer B consisting of an (Al1-y-zTiySiz)N layer (where 0.35≤y≤0.6 and 0.01≤z≤0.1 in terms of atomic ratio), wherein the ratio of the thickness of the layer B to the thickness of the layer A, tB/tA, is 2-5 and the hard coating layers as a whole have an X-ray diffraction intensity ratio, I(200)/I(111), more than 3 but not more than 12, the half-value width of the I(200) peak being 0.3-1.0. Desirably, the layer A has an IA(200)/IA(111) intensity ratio more than 2 but not more than 10, and the half-value width of the IA(200) peak is 0.3-1.0.

Description

耐チッピング性、耐摩耗性にすぐれた表面被覆切削工具Surface coated cutting tool with excellent chipping resistance and wear resistance
　本発明は、硬質被覆層がすぐれた耐チッピング性、耐摩耗性を備えた表面被覆切削工具（以下、「被覆工具」という。）に関する。詳しくは、本発明の被覆工具は、切削に使用する刃先が立方晶窒化ほう素（以下、「ｃＢＮ」で示す。）からなる基体上に硬質被覆層が被覆形成された被覆工具であり、本発明の被覆工具は、合金鋼などの高速切削加工に供した場合であっても、チッピングを発生することなく、長期に亘ってすぐれた耐摩耗性を発揮する。
　本願は、２０１４年１１月２７日に日本に出願された特願２０１４－２３９９５６号、及び２０１５年１１月２５日に日本に出願された特願２０１５－２２９７３６号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a surface-coated cutting tool (hereinafter referred to as “coated tool”) having a hard coating layer with excellent chipping resistance and wear resistance. Specifically, the coated tool of the present invention is a coated tool in which a hard coating layer is coated on a substrate whose cutting edge used for cutting is cubic boron nitride (hereinafter referred to as “cBN”). The coated tool of the invention exhibits excellent wear resistance over a long period of time without causing chipping even when subjected to high-speed cutting such as alloy steel.
This application claims priority based on Japanese Patent Application No. 2014-23956 filed in Japan on November 27, 2014 and Japanese Patent Application No. 2015-229736 filed in Japan on November 25, 2015. The contents are incorporated herein.
　一般に、被覆工具には、各種の鋼や鋳鉄などの被削材の旋削加工や平削り加工にバイトの先端部に着脱自在に取り付けて用いられるインサート、被削材の穴あけ切削加工などに用いられるドリルやミニチュアドリル、さらに被削材の面削加工や溝加工、肩加工などに用いられるソリッドタイプのエンドミルなどがある。また被覆工具として、インサートを着脱自在に取り付けてソリッドタイプのエンドミルと同様に切削加工を行うインサート式エンドミルなどが知られている。
　従来から、被覆工具としては、例えば、ＷＣ基超硬合金、ＴｉＣＮ基サーメット、ｃＢＮ焼結体を工具基体とし、これに硬質被覆層を形成した被覆工具が知られており、切削性能の改善を目的として種々の提案がなされている。 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, and solid-type end mills that are used for chamfering, grooving, and shouldering of work materials. Further, as a coated tool, an insert type end mill is known in which an insert is detachably attached and cutting is performed in the same manner as a solid type end mill.
Conventionally, as a coated tool, for example, a coated tool in which a WC-based cemented carbide, a TiCN-based cermet, and a cBN sintered body are used as a tool base and a hard coating layer is formed on the tool base is known. Various proposals have been made for the purpose.
　例えば、特許文献１には、ＷＣ基超硬合金基体またはＴｉＣＮ系サーメット基体の表面に、Ｔｉ－Ａｌ複合窒化物層からなる結晶配向履歴層を介して、Ａｌ－Ｔｉ－Ｓｉ複合窒化物層からなる硬質被覆層を物理蒸着することが開示されている。Ｔｉ－Ａｌ複合窒化物層からなる結晶配向履歴層は、（ａ）０．０５～０．５μｍの平均層厚を有し、組成式：（Ｔｉ１－ＸＡｌＸ）Ｎ（ただし、原子比で、Ｘは０．０１～０．１５を示す）を満足し、さらに、Ｃｕ－Ｋα線を用いたＸ線回折装置による測定で、（２００）面に最高ピークが現われ、かつ前記最高ピークの半価幅が２θで０．５度以下であるＸ線回折パターンを示す。Ａｌ－Ｔｉ－Ｓｉ複合窒化物層からなる硬質被覆層は、（ｂ）２～１０μｍの平均層厚を有し、組成式：（Ａｌ１－（Ａ＋Ｂ）ＴｉＡＳｉＢ）Ｎ（ただし、原子比で、Ａは０．３５～０．５５、Ｂは０．０５～０．２０を示す）を満足し、同じくＣｕ－Ｋα線を用いたＸ線回折装置による測定で、（２００）面に最高ピークが現われ、かつ前記最高ピークの半価幅が２θで０．５度以下であるＸ線回折パターンを示す。特許文献１では、前記ＷＣ基超硬合金基体または前記ＴｉＣＮ系サーメット基体に、前記結晶配向履歴層と前記硬質被覆層とを形成することで、高速切削加工における硬質被覆層の耐摩耗性を改善した表面被覆超硬合金製切削工具を得ることが提案されている。 For example, Patent Document 1 discloses that an Al—Ti—Si composite nitride layer is formed on the surface of a WC-based cemented carbide substrate or a TiCN cermet substrate via a crystal orientation history layer made of a Ti—Al composite nitride layer. It is disclosed to physically vapor-deposit a hard coating layer. The crystal orientation history layer composed of the Ti—Al composite nitride layer has (a) an average layer thickness of 0.05 to 0.5 μm and a composition formula: (Ti 1-X Al X ) N (wherein the atomic ratio And X represents 0.01 to 0.15), and the maximum peak appears on the (200) plane as measured by an X-ray diffractometer using Cu-Kα rays, and the maximum peak An X-ray diffraction pattern having a half width of 2θ of 0.5 degrees or less is shown. The hard coating layer made of an Al—Ti—Si composite nitride layer has (b) an average layer thickness of 2 to 10 μm, and a composition formula: (Al 1− (A + B) Ti A Si B ) N (provided that atoms (A is 0.35 to 0.55 and B is 0.05 to 0.20), and the (200) plane was measured by an X-ray diffractometer using Cu-Kα rays. An X-ray diffraction pattern in which the highest peak appears and the half width of the highest peak is 2θ and 0.5 degrees or less is shown. In Patent Document 1, the wear resistance of the hard coating layer in high-speed cutting is improved by forming the crystal orientation history layer and the hard coating layer on the WC-based cemented carbide substrate or the TiCN cermet substrate. It has been proposed to obtain a surface-coated cemented carbide cutting tool.
特開２００３－１４５３１３号公報JP 2003-145313 A
　前記特許文献１で提案されているＴｉとＡｌの窒化物（以下、「（Ａｌ，Ｔｉ）Ｎ」で示す）層および、ＡｌとＴｉとＳｉの窒化物（以下、以下、「（Ａｌ，Ｔｉ，Ｓｉ）Ｎ」で示す）層からなる結晶配向を制御した硬質被覆層を、ＷＣ基超硬合金基体またはＴｉＣＮ系サーメット基体の表面に被覆した被覆工具は、高硬度であるためすぐれた耐摩耗性を発揮する。しかしながらその一方で、（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層はＳｉを含有することで結晶格子の歪が大きくなるため脆く、また、被覆工具における、基体－（Ａｌ，Ｔｉ）Ｎ層－（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層間での接合強度が十分でなかった。
　したがって、ｃＢＮ焼結体を工具基体として、この上に上記窒化物を成膜した被覆工具を使用した場合に、切れ刃に高負荷が作用する高速切削条件においては、耐チッピング性が十分でないため、早期に寿命を迎えるという問題があった。
　そこで、高速切削加工に供した場合であっても、耐チッピング性、耐摩耗性にすぐれ、長期にわたってすぐれた切削性能を発揮する被覆工具が求められている。 The nitride layer of Ti and Al (hereinafter referred to as “(Al, Ti) N”) proposed in Patent Document 1 and the nitride layer of Al, Ti, and Si (hereinafter referred to as “(Al, Ti)”. , Si) N ”), a coated tool in which a hard coating layer with a controlled crystal orientation is coated on the surface of a WC-based cemented carbide substrate or a TiCN-based cermet substrate is high in hardness and has excellent wear resistance. Demonstrate sex. However, on the other hand, the (Al, Ti, Si) N layer is fragile because it contains Si and the distortion of the crystal lattice is increased, and the substrate- (Al, Ti) N layer- (Al, The bonding strength between the Ti, Si) N layers was not sufficient.
Therefore, when a cBN sintered body is used as a tool base and a coated tool on which the above nitride is formed is used, chipping resistance is not sufficient under high-speed cutting conditions in which a high load acts on the cutting edge. There was a problem of reaching the end of life early.
Accordingly, there is a need for a coated tool that has excellent chipping resistance and wear resistance even when subjected to high-speed cutting, and exhibits excellent cutting performance over a long period of time.
　本発明者らは、前記課題を解決すべく硬質被覆層の構造について鋭意検討したところ、次のような知見を得た。 The present inventors diligently studied about the structure of the hard coating layer in order to solve the above problems, and obtained the following knowledge.
　ｃＢＮ焼結体を工具基体（以下、「ｃＢＮ基体」という）とし、この表面に、例えばアークイオンプレーティング装置を用いて（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層からなる硬質被覆層を蒸着形成するにあたり、ｃＢＮ基体と（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層との間に、（Ａｌ，Ｔｉ）Ｎ層を被覆形成する。本発明者らは、このとき、該（Ａｌ，Ｔｉ）Ｎ層をｃＢＮ基体と（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層の格子不整合による歪を緩衝する緩衝層とすることにより、高速切削加工における耐チッピング性を向上させ得ることを見出した。
　さらに、ｃＢＮ基体に直接（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層を形成した場合には、（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層自身がＳｉ成分の含有により格子の歪が大きいことに加え、ｃＢＮ基体と（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層の格子不整合による歪も加わるため、（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層の配向性を所望の値に制御することは困難であった。しかしながら本発明者らは、該（Ａｌ，Ｔｉ）Ｎ層の配向性制御によって、この上に形成される（Ａｌ，Ｔｉ，Ｓｉ）Ｎ層の配向性をも制御することができ、これによって、耐チッピング性と耐摩耗性の両特性を兼備させ得ることができることを見出したのである。 When a cBN sintered body is used as a tool base (hereinafter referred to as “cBN base”), a hard coating layer made of an (Al, Ti, Si) N layer is vapor-deposited on the surface using, for example, an arc ion plating apparatus. A (Al, Ti) N layer is formed between the cBN substrate and the (Al, Ti, Si) N layer. At this time, the present inventors set the (Al, Ti) N layer as a buffer layer for buffering strain due to lattice mismatch between the cBN substrate and the (Al, Ti, Si) N layer. It has been found that chipping resistance can be improved.
Further, when the (Al, Ti, Si) N layer is formed directly on the cBN substrate, the (Al, Ti, Si) N layer itself has a large lattice distortion due to the inclusion of the Si component, Since strain due to lattice mismatch of the (Al, Ti, Si) N layer is also added, it is difficult to control the orientation of the (Al, Ti, Si) N layer to a desired value. However, the inventors can also control the orientation of the (Al, Ti, Si) N layer formed thereon by controlling the orientation of the (Al, Ti) N layer. It has been found that both chipping resistance and wear resistance can be achieved.
　本発明は、前記の知見に基づいてなされたものである。
（１）本発明の表面被覆切削工具は、
　少なくとも刃先が立方晶窒化ほう素焼結体からなる工具基体上に硬質被覆層を蒸着形成したものであり、
（ａ）前記立方晶窒化ほう素焼結体は、立方晶窒化硼素粒子と、Ｔｉの窒化物、炭化物、炭窒化物、硼化物およびＡｌの窒化物、酸化物からなる群から選ばれた少なくとも１種以上、並びに不可避不純物を含む結合相と、からなり、
（ｂ）前記立方晶窒化ほう素粒子の平均粒径は０．５～４．０μｍ、また、立方晶窒化ほう素焼結体全体に占める立方晶窒化ほう素粒子の含有割合は４０～７０体積％であり、さらに、前記結合相の平均粒径は１μｍ以下であり、
（ｃ）前記硬質被覆層は、工具基体表面に被覆されたＡ層と、Ａ層表面に被覆されたＢ層とからなり、
（ｄ）前記Ａ層は、
　組成式：（Ａｌ１－ｘＴｉｘ）Ｎで表した場合、原子比で、０．３５≦ｘ≦０．６を満足し、
　前記Ｂ層は、
　組成式：（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎで表した場合、原子比で、０．３５≦ｙ≦０．６、０．０１≦ｚ≦０．１）を満足し、
（ｅ）前記Ａ層とＢ層の平均合計層厚は１．５～４．０μｍであって、かつ、Ａ層の平均層厚をｔＡ、Ｂ層の平均層厚をｔＢとした場合、２≦ｔＢ／ｔＡ≦５を満足し、
（ｆ）前記Ａ層とＢ層からなる硬質被覆層全体についてＸ線回折を行った場合、硬質被覆層は全体として岩塩型立方晶の結晶構造を有し、また、硬質被覆層を構成する結晶粒の（２００）面の回折ピーク強度をＩ（２００）、（１１１）面の回折ピーク強度をＩ（１１１）としたとき、３＜Ｉ（２００）／Ｉ（１１１）≦１２を満足し、かつ、Ｉ（２００）のピークの半値幅が０．３～１．０であることを特徴とする表面被覆切削工具。
（２）（１）に記載の表面被覆切削工具では、前記Ａ層のＴｉ含有割合を示すｘと、前記Ｂ層のＴｉ含有割合を示すｙが、｜ｘ－ｙ｜≦０．１５の関係を満足することが好ましい。
（３）（１）または（２）に記載の表面被覆切削工具では、前記Ａ層についてＸ線回折を行った場合、（２００）面の回折ピーク強度をＩＡ（２００）、（１１１）面の回折ピーク強度をＩＡ（１１１）としたとき、２＜ＩＡ（２００）／ＩＡ（１１１）≦１０を満足し、かつ、ＩＡ（２００）のピークの半値幅が０．３～１．０であることが好ましい。 The present invention has been made based on the above findings.
(1) The surface-coated cutting tool of the present invention is
At least the cutting edge is formed by vapor-depositing a hard coating layer on a tool base made of a cubic boron nitride sintered body,
(A) The cubic boron nitride sintered body is at least one selected from the group consisting of cubic boron nitride particles, Ti nitride, carbide, carbonitride, boride, Al nitride, and oxide. Comprising a seed phase or more, and a binder phase containing inevitable impurities,
(B) The average particle diameter of the cubic boron nitride particles is 0.5 to 4.0 μm, and the content ratio of the cubic boron nitride particles in the entire cubic boron nitride sintered body is 40 to 70% by volume. And the average particle size of the binder phase is 1 μm or less,
(C) The hard coating layer is composed of an A layer coated on the tool base surface and a B layer coated on the A layer surface,
(D) The A layer is
When represented by the composition formula: (Al 1-x Ti x ) N, the atomic ratio satisfies 0.35 ≦ x ≦ 0.6,
The B layer is
When represented by the composition formula: (Al 1-yz Ti y Si z ) N, the atomic ratio satisfies 0.35 ≦ y ≦ 0.6, 0.01 ≦ z ≦ 0.1),
(E) When the average total thickness of the A layer and the B layer is 1.5 to 4.0 μm, the average layer thickness of the A layer is t A , and the average layer thickness of the B layer is t B 2 ≦ t B / t A ≦ 5,
(F) When X-ray diffraction is performed on the entire hard coating layer composed of the A layer and the B layer, the hard coating layer has a rock salt cubic crystal structure as a whole, and crystals constituting the hard coating layer When the diffraction peak intensity of the (200) plane of the grain is I (200) and the diffraction peak intensity of the (111) plane is I (111), 3 <I (200) / I (111) ≦ 12 is satisfied, A surface-coated cutting tool, wherein the half width of the peak of I (200) is 0.3 to 1.0.
(2) In the surface-coated cutting tool according to (1), x indicating the Ti content ratio of the A layer and y indicating the Ti content ratio of the B layer have a relationship of | xy− ≦ 0.15 Is preferably satisfied.
(3) In the surface-coated cutting tool according to (1) or (2), when X-ray diffraction is performed on the A layer, the diffraction peak intensity of the (200) plane is set to I A (200), (111) plane When the diffraction peak intensity of I A (111) is I A (111), 2 <I A (200) / I A (111) ≦ 10 is satisfied, and the half width of the peak of I A (200) is 0.3 to 1.0 is preferable.
　本発明の窒化物を成膜した表面被覆切削工具（以下、「被覆ｃＢＮ工具」という）は、少なくとも刃先がｃＢＮ焼結体からなる工具基体表面に、所定組成の（Ａｌ１－ｘＴｉｘ）Ｎ層からなるＡ層と所定組成の（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎ層からなるＢ層を、Ａ層とＢ層の順番の積層構造として被覆することにより硬質被覆層を形成している。本発明では、さらに、Ａ層とＢ層の層厚比ｔＢ／ｔＡを２以上５以下と定め、硬質被覆層全体としてのＸ線回折強度比Ｉ（２００）／Ｉ（１１１）を３を超え１２以下と定め、また、Ｉ（２００）のピークの半値幅を０．３以上１．０以下と定めることによって、Ａ層がｃＢＮ基体とＢ層の間の緩衝層として機能するとともに、Ａ層の配向性制御によって、Ｂ層の配向性も制御され、硬質被覆層全体として所定の配向性を備える硬質被覆層が得られる。本発明の硬質被覆層を有する被覆ｃＢＮ工具は、刃先に高負荷が作用する合金鋼等の高速切削加工において、すぐれた耐チッピング性を示すと同時にすぐれた耐摩耗性を発揮し、長期の使用にわたってすぐれた切削性能を発揮するのである。 The surface-coated cutting tool (hereinafter referred to as “coated cBN tool”) formed with a nitride film of the present invention has a (Al 1-x Ti x ) having a predetermined composition on the surface of a tool substrate having at least a cutting edge made of a cBN sintered body. A hard coating layer is formed by coating an A layer composed of an N layer and a B layer composed of an (Al 1-yz Ti y Si z ) N layer having a predetermined composition as a laminated structure in the order of the A layer and the B layer. is doing. In the present invention, the layer thickness ratio t B / t A between the A layer and the B layer is further set to 2 or more and 5 or less, and the X-ray diffraction intensity ratio I (200) / I (111) as the whole hard coating layer is 3 And the A layer functions as a buffer layer between the cBN substrate and the B layer by setting the half width of the peak of I (200) to 0.3 or more and 1.0 or less. By controlling the orientation of the A layer, the orientation of the B layer is also controlled, and a hard coating layer having a predetermined orientation is obtained as the entire hard coating layer. The coated cBN tool having a hard coating layer according to the present invention exhibits excellent chipping resistance and high wear resistance in high-speed cutting processing such as alloy steel in which a high load acts on the cutting edge, and is used for a long time. It exhibits excellent cutting performance.
本発明被覆工具の硬質被覆層の断面概略模式図を示す。The cross-sectional schematic diagram of the hard coating layer of this invention coated tool is shown. 硬質被覆層を蒸着形成するためのアークイオンプレーティング装置の概略図であり、平面図を示す。It is the schematic of the arc ion plating apparatus for vapor-depositing and forming a hard coating layer, and shows a top view. 硬質被覆層を蒸着形成するためのアークイオンプレーティング装置の概略図であり、側面図を示す。It is the schematic of the arc ion plating apparatus for vapor-depositing and forming a hard coating layer, and shows a side view.
　本発明の被覆ｃＢＮ工具の一実施形態について、以下により詳細に説明する。
　本実施形態の被覆ｃＢＮ工具は、図１で示すように、ｃＢＮ焼結体からなる工具基体（ｃＢＮ基体）１１上に、Ａ層１２とＢ層１３とからなる硬質被覆層を蒸着形成したものである。 One embodiment of the coated cBN tool of the present invention is described in more detail below.
As shown in FIG. 1, the coated cBN tool of this embodiment is obtained by vapor-depositing a hard coating layer composed of an A layer 12 and a B layer 13 on a tool substrate (cBN substrate) 11 composed of a cBN sintered body. It is.
ｃＢＮ焼結体中のｃＢＮ粒子の平均粒径：
　ｃＢＮ焼結体中に、微細で硬質な立方晶窒化硼素粒子（以下「ｃＢＮ粒子」という）が分散していることにより、工具使用中に刃先のｃＢＮ粒子が脱落することによるチッピングの発生を抑制することができる。
　また、ｃＢＮ焼結体中の微細ｃＢＮ粒子が、工具使用中に刃先に加わる応力により生じるｃＢＮ粒子と結合相との界面から進展するクラック、あるいは、ｃＢＮ粒子が割れて進展するクラックの伝搬を分散・緩消する役割を担うため、すぐれた耐欠損性を発揮することが出来る。
　しかしながら、ｃＢＮ粒子の平均粒径が０．５μｍ未満になると、微細すぎて硬質粒子としてのｃＢＮ粒子の機能が十分に発揮できない。一方、４．０μｍを超えると、ｃＢＮ粒子の脱落によりチッピングが誘発する恐れがある。
　したがって、ｃＢＮ粒子の平均粒径は、０．５～４．０μｍと定めた。
　ここで、ｃＢＮ粒子の平均粒径は、作製したｃＢＮ焼結体の断面組織を走査型電子顕微鏡（Ｓｃａｎｎｉｎｇ　Ｅｌｅｃｔｒｏｎ　Ｍｉｃｒｏｓｃｏｐｙ：ＳＥＭ）およびエネルギー分散型Ｘ線分光法（Ｅｎｅｒｇｙ　Ｄｉｓｐｅｒｓｉｖｅ Ｘ－ｒａｙ　Ｓｐｅｃｔｒｏｓｃｏｐｙ：ＥＤＳ）にて観察し、観察領域内のｃＢＮ粒子の部分を特定し、観察した画像内のｃＢＮ粒子の部分を画像処理にて抜き出したのち、ｃＢＮ粒子の形状を等価な面積の円形状に近似し、近似した円の直径を各ｃＢＮ粒子の直径とし、１画像におけるｃＢＮ粒子の直径の平均値を求め、少なくとも３画像について求めた平均値の平均をｃＢＮの平均粒径（μｍ）とした。画像処理に用いる観察領域は予備観察を行うことによって定めたが、ｃＢＮ粒子の平均粒径が０．５～４．０μｍであることをかんがみ、１５μｍ×１５μｍ程度の視野領域とすることが望ましい。 Average particle size of cBN particles in the cBN sintered body:
Fine and hard cubic boron nitride particles (hereinafter referred to as “cBN particles”) are dispersed in the cBN sintered body, thereby suppressing chipping due to falling off of cBN particles at the cutting edge during tool use. can do.
In addition, the fine cBN particles in the cBN sintered body are dispersed in the propagation of cracks that develop from the interface between the cBN particles and the binder phase caused by the stress applied to the cutting edge during use of the tool, or the cracks that propagate when the cBN particles break -Since it plays the role of slowing down, it can exhibit excellent chipping resistance.
However, when the average particle size of the cBN particles is less than 0.5 μm, the function of the cBN particles as the hard particles cannot be sufficiently exhibited because the particles are too fine. On the other hand, when the thickness exceeds 4.0 μm, chipping may be induced due to dropping of cBN particles.
Therefore, the average particle size of the cBN particles is set to 0.5 to 4.0 μm.
Here, the average particle size of the cBN particles is determined by using a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) of a cross-sectional structure of the prepared cBN sintered body. After identifying the cBN particle part in the observation region, extracting the cBN particle part in the observed image by image processing, the shape of the cBN particle is approximated to a circular shape with an equivalent area, The diameter of the approximate circle was taken as the diameter of each cBN particle, the average value of the diameters of cBN particles in one image was determined, and the average of the average values determined for at least three images was defined as the average particle size (μm) of cBN. The observation area used for the image processing is determined by performing preliminary observation. However, considering that the average particle size of the cBN particles is 0.5 to 4.0 μm, it is desirable that the viewing area is about 15 μm × 15 μm.
ｃＢＮ焼結体中のｃＢＮ粒子の体積割合：
　ｃＢＮ焼結体に占めるｃＢＮ粒子の含有割合が４０体積％未満では、焼結体中に硬質物質が少なく、ｃＢＮ焼結体の硬度が低下するため、耐摩耗性が低下する。一方、７０体積％を超えると、結合相が不足するため、焼結体中にクラックの起点となる空隙が生成し、耐欠損性が低下する。そのため、ｃＢＮ焼結体に占めるｃＢＮ粒子の含有割合は、４０～７０体積％の範囲と定めた。
　ここで、ｃＢＮ焼結体に占めるｃＢＮ粒子の含有割合（体積％）の測定方法は、ｃＢＮ焼結体の断面組織をＳＥＭによって観察して得られた二次電子画像内のｃＢＮ粒子の部分を画像処理によって抜き出し、画像解析によって観察領域におけるｃＢＮ焼結体の全体の面積に対するｃＢＮ粒子が占める面積を算出し、少なくとも３画像を処理し求めた値の平均値をｃＢＮ粒子の含有割合（体積％）とした。画像処理に用いる観察領域は、ｃＢＮ粒子の平均粒径が０．５～４．０μｍであることをかんがみ、１５μｍ×１５μｍ程度の視野領域とすることが望ましい。 Volume ratio of cBN particles in the cBN sintered body:
When the content ratio of the cBN particles in the cBN sintered body is less than 40% by volume, the hard body is less in the sintered body and the hardness of the cBN sintered body is lowered, so that the wear resistance is lowered. On the other hand, if it exceeds 70% by volume, since the binder phase is insufficient, voids serving as starting points of cracks are generated in the sintered body, and the fracture resistance is lowered. Therefore, the content ratio of cBN particles in the cBN sintered body is determined to be in the range of 40 to 70% by volume.
Here, the measurement method of the content ratio (volume%) of the cBN particles in the cBN sintered body is that the cBN particle portion in the secondary electron image obtained by observing the cross-sectional structure of the cBN sintered body with the SEM is used. The area occupied by the cBN particles with respect to the entire area of the cBN sintered body in the observation region is calculated by image processing, and the average value of the values obtained by processing at least three images is calculated as the content ratio (volume%) of the cBN particles. ). Considering that the average particle size of cBN particles is 0.5 to 4.0 μm, the observation region used for image processing is desirably a visual field region of about 15 μm × 15 μm.
結合相：
　本実施形態におけるｃＢＮ焼結体中における主たる硬質成分は、前記平均粒径、体積割合のｃＢＮ粒子であるが、結合相を形成する成分としては、既によく知られている、Ｔｉの窒化物、炭化物、炭窒化物、硼化物およびＡｌの窒化物、酸化物からなる群から選ばれた少なくとも１種以上の粒子を用いることができる。
　ただ、上記結合相の平均粒径が１μｍを超えると、原料粉末を配合した際に隙間が多くなるため、焼結時に焼結体内にポアが残りやすくなり、耐欠損性が低下することから、結合相の平均粒径は１μｍ以下とした。結合相の平均粒径の下限値は特に限定されないが、０．１μｍ以上であることが好ましい。
　結合相の平均粒径はｃＢＮ粒子の平均粒径と同じ方法で求められる。 Bond phase:
The main hard component in the cBN sintered body in the present embodiment is the above-mentioned average particle size and volume proportion of cBN particles, but as a component for forming a binder phase, a well-known Ti nitride, At least one kind of particles selected from the group consisting of carbide, carbonitride, boride, Al nitride, and oxide can be used.
However, when the average particle size of the binder phase exceeds 1 μm, the gap increases when the raw material powder is blended, and pores are likely to remain in the sintered body at the time of sintering. The average particle size of the binder phase was 1 μm or less. The lower limit value of the average particle size of the binder phase is not particularly limited, but is preferably 0.1 μm or more.
The average particle size of the binder phase is determined by the same method as the average particle size of cBN particles.
硬質被覆層を構成するＡ層：
　組成式：（Ａｌ１－ｘＴｉｘ）Ｎで示される組成を有するＡ層は、ＴｉのＴｉとＡｌの合量に占める含有割合ｘ（但し、ｘは原子比）が、０．３５≦ｘ≦０．６を満足する。
　Ｔｉ成分の含有量ｘが０．３５未満では、結晶組織の歪が大きくなり、岩塩型結晶構造を維持できなくなるばかりか、配向性制御が困難になる。一方、Ｔｉ成分の含有量ｘが０．６を超えると硬さが低下するばかりか耐酸化性が十分でなくなることから、Ｔｉ成分の含有量ｘは０．３５以上０．６以下と定めた。 A layer constituting the hard coating layer:
The layer A having the composition represented by the composition formula: (Al 1-x Ti x ) N has a content ratio x (where x is an atomic ratio) in the total amount of Ti and Al in Ti: 0.35 ≦ x ≦ 0.6 is satisfied.
When the content x of the Ti component is less than 0.35, the distortion of the crystal structure becomes large and the rock salt type crystal structure cannot be maintained, and the orientation control becomes difficult. On the other hand, when the content x of the Ti component exceeds 0.6, not only the hardness decreases but also the oxidation resistance becomes insufficient. Therefore, the content x of the Ti component is set to 0.35 or more and 0.6 or less. .
硬質被覆層を構成するＢ層：
　組成式：（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎで示される組成を有するＢ層は、ＴｉおよびＳｉのＴｉとＡｌとＳｉの合量に占める含有割合ｙ、ｚ（但し、ｙ、ｚはいずれも原子比）が、それぞれ、０．３５≦ｙ≦０．６、０．０１≦ｚ≦０．１を満足する。
　この条件を満たすとき、Ｂ層を構成する（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎ層は所望の耐酸化性および切削時に高温となるような高速切削時における高い耐摩耗性を発揮する。
　一方、Ｔｉ成分の含有割合ｙが０．３５未満では、結晶組織の歪が大きくなり、岩塩型結晶構造を維持できなくなるばかりか、配向性制御が困難になり、一方、Ｔｉ成分の含有量ｙが０．６を超えると硬さが低下するばかりか耐酸化性が十分でなくなる。
　また、Ｓｉ成分の含有割合ｚが０．０１未満では所望の耐摩耗性が発揮されず、０．１を超えると結晶格子の歪みが大きくなり、耐欠損性が低下する。
　したがって、Ｔｉ成分の含有量ｙは０．３５以上０．６以下、また、Ｓｉ成分の含有割合ｚは０．０１以上０．１以下と定めた。
　また、Ａ層がＢ層と基体の緩衝層として働く上では、Ａ層とＢ層の、Ｔｉの金属成分に占める含有割合が近しいことがより好ましく、好ましい値の範囲としては、含有割合ｘとｙの差の絶対値が０．１５以下（｜ｘ－ｙ｜≦０．１５）である。ｘとｙの差の絶対値の範囲は、より好ましくは｜ｘ－ｙ｜≦０．１０である。ｘとｙの差の絶対値が０．１０を超えると耐欠損性が低下する傾向がある。 B layer constituting the hard coating layer:
The B layer having a composition represented by the composition formula: (Al 1-yz Ti y Si z ) N is a content ratio y, z (provided that y, z is an atomic ratio) satisfying 0.35 ≦ y ≦ 0.6 and 0.01 ≦ z ≦ 0.1, respectively.
When this condition is satisfied, the (Al 1-yz Ti y Si z ) N layer constituting the B layer exhibits desired oxidation resistance and high wear resistance during high-speed cutting such that the temperature becomes high during cutting. .
On the other hand, if the Ti component content ratio y is less than 0.35, the crystal structure distortion becomes large and the rock salt crystal structure cannot be maintained, and the orientation control becomes difficult. On the other hand, the Ti component content y When the value exceeds 0.6, not only the hardness is lowered but also the oxidation resistance is not sufficient.
Further, when the content ratio z of the Si component is less than 0.01, the desired wear resistance is not exhibited, and when it exceeds 0.1, the distortion of the crystal lattice increases and the fracture resistance decreases.
Therefore, the content y of the Ti component is set to 0.35 or more and 0.6 or less, and the content ratio z of the Si component is set to 0.01 or more and 0.1 or less.
In addition, when the A layer serves as a buffer layer for the B layer and the substrate, it is more preferable that the content ratio of the A layer and the B layer in the metal component of Ti is close. The absolute value of the difference in y is 0.15 or less (| xy− ≦ 0.15). The range of the absolute value of the difference between x and y is more preferably | x−y | ≦ 0.10. When the absolute value of the difference between x and y exceeds 0.10, the chipping resistance tends to decrease.
硬質被覆層の合計平均層厚：
　本実施形態の硬質被覆層は、工具基体直上のＡ層である（Ａｌ１－ｘＴｉｘ）Ｎ層（但し、原子比で、０．３５≦ｘ≦０．６）とその上に形成されたＢ層である（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎ層（但し、原子比で、０．３５≦ｙ≦０．６、０．０１≦ｚ≦０．１）との積層構造として構成される。
　この硬質被覆層では、Ａ層に含まれるＴｉ成分によってすぐれた強度と靭性を確保し、Ａｌ成分が高温硬さと耐熱性を向上させ、同時にＡｌとＴｉが共存含有した状態で高温耐酸化性を向上させる作用を示す。更に、（Ａｌ１－ｘＴｉｘ）Ｎ層が岩塩型結晶構造（岩塩型立方晶）を有するため高硬度であり、Ａ層を工具基体上に形成することで耐摩耗性を向上させることができる。
　Ｂ層は、前記Ａ層にＳｉ成分を含有させた層であり、岩塩型結晶構造（岩塩型立方晶）を有する。また、Ｂ層は、前記Ａ層にＳｉ成分を含有させることで、さらに耐熱性が向上している層である。Ｂ層は、酸化開始温度が高くて高温耐酸化性が高いため、Ｂ層を形成することで、特に切削時に高温となるような高速切削時の耐摩耗性が向上する。
　Ａ層とＢ層の積層構造からなる硬質被覆層は、その平均合計層厚が１．５μｍ未満であると長期の使用にわたって十分な耐摩耗性を発揮することができず、一方、平均合計層厚が４．０μｍを超えると硬質被覆層が自壊しやすくなるので、硬質被覆層の平均合計層厚は１．５～４．０μｍと定めた。
　さらに、積層構造を構成するＡ層の平均層厚をｔＡ、Ｂ層の平均層厚をｔＢとした場合、ｔＢ／ｔＡの値が２未満では、相対的にＢ層が薄くなるため、十分な耐摩耗性を得ることができず、一方、ｔＢ／ｔＡの値が５を超えるとＡ層の厚さが相対的に薄くなり、Ｂ層のＡ層と基体の格子不整合による歪を緩衝する緩衝層としての機能を十分発揮できなくなるばかりか、Ｂ層の配向性制御も十分できなくなることから、ｔＢ／ｔＡの値は２以上５以下と定めた。ｔＢ／ｔＡの値は、より好ましくは３以上５以下である。
　なお、硬質被覆層の層厚とは、工具基体表面に垂直な方向の層の厚みとし、工具基体表面とは、基体の硬質被覆層と接する面の面方向に垂直な断面の観察像における、基体と硬質被覆層の界面粗さの基準線とする。 Total average layer thickness of the hard coating layer:
The hard coating layer according to the present embodiment is formed on an (Al 1-x Ti x ) N layer (provided that the atomic ratio is 0.35 ≦ x ≦ 0.6), which is an A layer directly above the tool base. Layered structure with (Al 1-yz Ti y Si z ) N layer (wherein the atomic ratio is 0.35 ≦ y ≦ 0.6, 0.01 ≦ z ≦ 0.1) Configured as
In this hard coating layer, the Ti component contained in the A layer ensures excellent strength and toughness, the Al component improves high-temperature hardness and heat resistance, and at the same time provides high-temperature oxidation resistance in the state where Al and Ti coexist. The action to improve is shown. Furthermore, since the (Al 1-x Ti x ) N layer has a rock salt type crystal structure (rock salt type cubic crystal), it has high hardness, and by forming the A layer on the tool substrate, the wear resistance can be improved. it can.
The B layer is a layer containing the Si component in the A layer and has a rock salt type crystal structure (rock salt type cubic crystal). Further, the B layer is a layer having further improved heat resistance by containing the Si component in the A layer. Since the B layer has a high oxidation start temperature and high high-temperature oxidation resistance, the formation of the B layer improves the wear resistance during high-speed cutting, which is particularly high during cutting.
When the average total layer thickness is less than 1.5 μm, the hard coating layer composed of the laminated structure of the A layer and the B layer cannot exhibit sufficient wear resistance over a long period of use, while the average total layer When the thickness exceeds 4.0 μm, the hard coating layer is liable to self-destruct, so the average total layer thickness of the hard coating layer was determined to be 1.5 to 4.0 μm.
Furthermore, when the average layer thickness of the A layer constituting the laminated structure is t A and the average layer thickness of the B layer is t B , the B layer is relatively thin when the value of t B / t A is less than 2. Therefore, sufficient wear resistance cannot be obtained. On the other hand, if the value of t B / t A exceeds 5, the thickness of the A layer becomes relatively thin, and the lattice loss between the A layer of the B layer and the substrate is not good. The value of t B / t A was determined to be 2 or more and 5 or less because not only the function as a buffer layer for buffering the strain due to the alignment could not be sufficiently exhibited, but also the orientation control of the B layer could not be sufficiently performed. The value of t B / t A is more preferably 3 or more and 5 or less.
The layer thickness of the hard coating layer is the thickness of the layer in the direction perpendicular to the surface of the tool substrate. A reference line for interface roughness between the substrate and the hard coating layer is used.
　組成式：（Ａｌ１－ｘＴｉｘ）Ｎで示されるＡ層の組成、組成式：（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎで示されるＢ層の組成は、それぞれＡ層、Ｂ層の平均組成である。
　また、Ａ層、Ｂ層の平均組成、平均層厚ｔＡ、平均層厚ｔＢ、、硬質被覆層の平均合計層厚は、工具基体表面に垂直な硬質被覆層縦断面について、走査型電子顕微鏡（Ｓｃａｎｎｉｎｇ　Ｅｌｅｃｔｒｏｎ　Ｍｉｃｒｏｓｃｏｐｙ：ＳＥＭ）、透過型電子顕微鏡（Ｔｒａｎｓｍｉｓｓｉｏｎ　Ｅｌｅｃｔｒｏｎ　Ｍｉｃｒｏｓｃｏｐｅ：ＴＥＭ）、エネルギー分散型Ｘ線分光法（Ｅｎｅｒｇｙ　Ｄｉｓｐｅｒｓｉｖｅ Ｘ－ｒａｙ　Ｓｐｅｃｔｒｏｓｃｏｐｙ：ＥＤＳ）を用いた断面測定により、測定することができる。
　具体的には、断面測定で測定した、それぞれ５箇所の測定の平均値を、Ａ層、Ｂ層の平均組成、平均層厚ｔＡ、平均層厚ｔＢ、硬質被覆層の平均合計層厚とした。 The composition of the A layer represented by the composition formula: (Al 1-x Ti x ) N and the composition of the B layer represented by the composition formula: (Al 1-yz Ti y Si z ) N are respectively the A layer and B The average composition of the layers.
The average composition of the A layer and the B layer, the average layer thickness t A , the average layer thickness t B , and the average total layer thickness of the hard coating layer are the scanning electron in the vertical section of the hard coating layer perpendicular to the tool base surface. Microscope (Scanning Electron Microscopy: SEM), transmission electron microscope (Transmission Electron Microscope: TEM), energy dispersive X-ray spectroscopy (Energy Dispersive X-ray Spectroscopy can be measured by X-ray Spectroscopy: EDS) .
Specifically, the average value of the measurement at each of the five locations measured by the cross-sectional measurement is the average composition of the A layer and the B layer, the average layer thickness t A , the average layer thickness t B , and the average total layer thickness of the hard coating layer. It was.
硬質被覆層全体についてＸ線回折：
　本実施形態では、Ａ層の配向性を制御することにより、Ｂ層について所望の配向性を維持させる。
　すなわち、本実施形態では、Ａ層とＢ層からなる硬質被覆層を、例えば、図２Ａ及び図２Ｂに示すアークイオンプレーティング装置２０を用いて成膜するが、アークイオンプレーティングに際してのアーク電流値、反応ガスとしての窒素ガス分圧、バイアス電圧および成膜温度を制御し、結晶成長の速度と原子の拡散速度を調整することで、配向性を制御することができる。相対的にゆっくりと結晶を成長させることで、岩塩型立方晶構造における（１１１）面より表面エネルギーが小さい（２００）面が工具基体表面と平行に配向する。Ａ層とＢ層は同じ岩塩型立方晶構造であることから、前述のようにして配向性を制御したＡ層の上層に、同様に成膜パラメータを制御しながらＢ層を形成させることで、Ａ層とＢ層の配向性を揃えることができる。
　そして、硬質被覆層全体についてＸ線回折を行い、（２００）面の回折ピーク強度をＩ（２００）、（１１１）面の回折ピーク強度をＩ（１１１）とした場合、Ｉ（２００）／Ｉ（１１１）の値が３以下であると、最密面である（１１１）面配向が強いことから耐チッピング性が低下し、一方、Ｉ（２００）／Ｉ（１１１）の値が１２を超えると、（２００）配向が極端に強くなるため耐摩耗性が低下する。
　したがって、すぐれた耐チッピング性と耐摩耗性を兼備するためには、Ｉ（２００）／Ｉ（１１１）の値は３を超え１２以下であることが必要である。Ｉ（２００）／Ｉ（１１１）の値は、４以上１０以下であることが好ましい。
　また、（２００）面のピーク強度Ｉ（２００）の半値幅が０．３未満であると結晶粒が粗大化しやすいため耐チッピング性が低下し、一方、半値幅が１．０を超えると所望の配向性に制御できていない、あるいは、結晶組織の歪が大きいために、安定した性能を発揮できない。
　したがって、Ｉ（２００）の半値幅は０．３以上１．０以下としなければならない。Ｉ（２００）の半値幅は、０．４以上０．８以下であることが好ましい。 X-ray diffraction of the entire hard coating layer:
In the present embodiment, the desired orientation of the B layer is maintained by controlling the orientation of the A layer.
That is, in this embodiment, the hard coating layer composed of the A layer and the B layer is formed using, for example, the arc ion plating apparatus 20 shown in FIGS. 2A and 2B. The orientation can be controlled by controlling the value, the partial pressure of nitrogen gas as a reaction gas, the bias voltage, and the film formation temperature, and adjusting the crystal growth rate and the atomic diffusion rate. By growing the crystal relatively slowly, the (200) plane having a lower surface energy than the (111) plane in the rock salt cubic structure is oriented parallel to the tool base surface. Since the A layer and the B layer have the same rock salt type cubic crystal structure, the B layer is formed on the upper layer of the A layer whose orientation is controlled as described above while similarly controlling the film formation parameters. The orientation of the A layer and the B layer can be made uniform.
Then, when X-ray diffraction is performed on the entire hard coating layer, the diffraction peak intensity on the (200) plane is I (200), and the diffraction peak intensity on the (111) plane is I (111), I (200) / I When the value of (111) is 3 or less, since the (111) plane orientation which is the close-packed surface is strong, the chipping resistance is lowered, while the value of I (200) / I (111) exceeds 12. And, since the (200) orientation becomes extremely strong, the wear resistance decreases.
Therefore, in order to combine excellent chipping resistance and wear resistance, the value of I (200) / I (111) needs to be more than 3 and 12 or less. The value of I (200) / I (111) is preferably 4 or more and 10 or less.
Further, if the half-value width of the peak intensity I (200) of the (200) plane is less than 0.3, the crystal grains are likely to be coarsened, so that the chipping resistance is lowered. On the other hand, if the half-value width exceeds 1.0, it is desirable. The orientation cannot be controlled, or the crystal structure has a large strain, so that stable performance cannot be exhibited.
Therefore, the half width of I (200) must be 0.3 or more and 1.0 or less. The full width at half maximum of I (200) is preferably 0.4 or more and 0.8 or less.
Ａ層についてＸ線回折：
　硬質被覆層全体について、Ｉ（２００）／Ｉ（１１１）の値は３を超え１２以下とすること、さらに、Ｉ（２００）のピークの半値幅を０．３～１．０とすることは前述のとおりであるが、このような硬質被覆層を形成するうえでは、Ａ層についてＸ線回折を行った場合、２＜ＩＡ（２００）／ＩＡ（１１１）≦１０を満足させ、かつ、ＩＡ（２００）のピークの半値幅を０．３～１．０とすることが望ましい。
　ここで、ＩＡ（２００）およびＩＡ（１１１）は、それぞれ、Ａ層における（２００）面の回折ピーク強度、Ａ層における（１１１）面の回折ピーク強度をいう。ＩＡ（２００）／ＩＡ（１１１）の値はより好ましくは、３以上８以下であり、ＩＡ（２００）のピークの半値幅はより好ましくは、０．４以上０．８以下である。
　上記のようなＡ層を形成することによって、この上に形成されるＢ層の配向性が制御され、その結果、硬質被覆層全体として、３＜Ｉ（２００）／Ｉ（１１１）≦１２を満足し、かつ、Ｉ（２００）のピークの半値幅が０．３～１．０である硬質被覆層が形成され易くなる傾向がある。 X-ray diffraction for layer A:
For the entire hard coating layer, the value of I (200) / I (111) should be more than 3 and 12 or less, and the half width of the peak of I (200) should be 0.3 to 1.0. As described above, in forming such a hard coating layer, when X-ray diffraction is performed on the A layer, 2 <I A (200) / I A (111) ≦ 10 is satisfied, and It is desirable that the half width of the peak of I A (200) is 0.3 to 1.0.
Here, I A (200) and I A (111) refer to the diffraction peak intensity of the (200) plane in the A layer and the diffraction peak intensity of the (111) plane in the A layer, respectively. The value of I A (200) / I A (111) is more preferably 3 or more and 8 or less, and the half width of the peak of I A (200) is more preferably 0.4 or more and 0.8 or less. .
By forming the A layer as described above, the orientation of the B layer formed thereon is controlled, and as a result, 3 <I (200) / I (111) ≦ 12 as the entire hard coating layer. There is a tendency that a hard coating layer satisfying and having a half-value width of a peak of I (200) of 0.3 to 1.0 is easily formed.
　なお、硬質被覆層全体についてのピーク強度比Ｉ（２００）／Ｉ（１１１）とは、Ａ層とＢ層の重なった回折ピークを一つの回折ピークとみなし、（２００）面の重なった回折ピーク強度をＩ（２００）、（１１１）面の重なった回折ピーク強度をＩ（１１１）として計算したＩ（２００）／Ｉ（１１１）の値をいう。また、Ａ層の回折ピーク強度ＩＡ（２００）、ＩＡ（１１１）については、例えば、Ｂ層を集束イオンビーム（Ｆｏｃｕｓｅｄ　Ｉｏｎ　Ｂｅａｍ：ＦＩＢ）法などの手法で加工・除去したのち、前述したＸ線回折法を用いることで測定することができる。 Note that the peak intensity ratio I (200) / I (111) for the entire hard coating layer is that the diffraction peak where the A layer and the B layer overlap is regarded as one diffraction peak, and the diffraction peak where the (200) plane overlaps. This is the value of I (200) / I (111) calculated with the intensity as I (200) and the diffraction peak intensity where the (111) planes overlap as I (111). The diffraction peak intensities I A (200) and I A (111) of the A layer are, for example, described after the B layer is processed and removed by a method such as a focused ion beam (FIB) method. It can be measured by using an X-ray diffraction method.
　つぎに、本発明の被覆工具を実施例により具体的に説明する。 Next, the coated tool of the present invention will be specifically described with reference to examples.
工具基体の作製：
　原料粉末として、平均粒径が１～４μｍのｃＢＮ粒子を硬質相形成用原料粉末として、また、ＴｉＮ粉末、ＴｉＣ粉末、ＴｉＣＮ粉末、Ａｌ粉末、ＡｌＮ粉末、Ａｌ２Ｏ３粉末を結合相形成用原料粉末として用意した。
　これらの中からいくつかの原料粉末とｃＢＮ粉末の合量を１００体積％としたときのｃＢＮ粒子の含有割合が４０～７０容量％となるように表１に示される配合比で配合した。
　次いで、この原料粉末をボールミルで７２時間湿式混合し、乾燥した後、成形圧１００ＭＰａで直径：５０ｍｍ×厚さ：１．５ｍｍの寸法にプレス成形し、ついでこの成形体を、圧力：１Ｐａ以下の真空雰囲気中、９００～１３００℃の範囲内の所定温度に保持して仮焼結し、その後、超高圧焼結装置に装入して、圧力：５ＧＰa、温度：１２００～１４００℃の範囲内の所定の温度で焼結することにより、ｃＢＮ焼結体を作製した。
　この焼結体をワイヤー放電加工機で所定寸法に切断し、Ｃｏ：５質量％、ＴａＣ：５質量％、ＷＣ：残りの組成およびＩＳＯ規格ＣＮＧＡ１２０４０８のインサート形状をもったＷＣ基超硬合金製インサート本体のろう付け部（コーナー部）に、質量％で、Ｃｕ：２６％、Ｔｉ：５％、Ａｇ：残りからなる組成を有するＡｇ系ろう材を用いてろう付けし、上下面および外周研磨、ホーニング処理を施すことによりＩＳＯ規格ＣＮＧＡ１２０４０８のインサート形状をもったｃＢＮ工具基体１～３を製造した。 Tool substrate production:
As raw material powder, cBN particles having an average particle size of 1 to 4 μm are used as raw material powder for forming a hard phase, and TiN powder, TiC powder, TiCN powder, Al powder, AlN powder, and Al 2 O 3 powder are used for forming a binder phase. Prepared as raw powder.
Among these, the blending ratio shown in Table 1 was blended so that the content ratio of cBN particles was 40 to 70% by volume when the total amount of some raw material powder and cBN powder was 100% by volume.
Next, the raw material powder was wet-mixed for 72 hours in a ball mill, dried, and then press-molded at a molding pressure of 100 MPa to a size of diameter: 50 mm × thickness: 1.5 mm. Preliminarily sintered in a vacuum atmosphere at a predetermined temperature within a range of 900 to 1300 ° C., and then charged into an ultra-high pressure sintering apparatus, pressure: 5 GPa, temperature: within a range of 1200 to 1400 ° C. A cBN sintered body was prepared by sintering at a predetermined temperature.
This sintered body is cut into a predetermined size with a wire electric discharge machine, Co: 5% by mass, TaC: 5% by mass, WC: remaining composition and insert made of WC-based cemented carbide with ISO standard CNGA120408 insert shape Brazing to the brazing part (corner part) of the main body using an Ag-based brazing material having a composition consisting of Cu: 26%, Ti: 5%, and Ag: the rest, and polishing the upper and lower surfaces and outer periphery, By performing the honing process, cBN tool bases 1 to 3 having an insert shape of ISO standard CNGA120408 were manufactured.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
硬質被覆層の成膜：
　前記工具基体１～３に対して、図２Ａ及び図２Ｂに示すアークイオンプレーティング装置２０を用いて、硬質被覆層を形成した。
　なお、図２Ａ及び図２ＢのＡｌ－Ｔｉ合金ターゲット２２としては、目標とする（Ａｌ，Ｔｉ）Ｎ層に応じて、組成の異なる複数のＡｌ－Ｔｉ合金ターゲット２２を装置内に配備した。
（ａ）工具基体１～３を、アセトン中で超音波洗浄し、乾燥した状態で、アークイオンプレーティング装置内２０の回転テーブル２３上の中心軸から半径方向に所定距離離れた位置に外周部にそって装着する（図２Ａ及び図２Ｂの工具基体１１）。また、カソード電極（蒸発源）として、所定組成のＡｌ－Ｔｉ合金ターゲット２２を配置した。
（ｂ）まず、装置内を排気して１０－２Ｐａ以下の真空に保持しながら、ヒーター２４で装置内を５００℃に加熱した後、０．５～２．０ＰａのＡｒガス雰囲気に設定し、前記回転テーブル２３上で自転しながら回転する工具基体１１に－２００～－１０００Ｖの直流バイアス電圧を印加し、もって工具基体表面をアルゴンイオンによって５～３０分間ボンバード処理した。
（ｃ）次に、Ａ層の成膜を、次のとおり行った。
　装置内に反応ガスとして窒素ガスを導入して表２に示す２～１０Ｐａの所定の反応雰囲気とすると共に、同じく表２に示す装置内温度に維持し、前記回転テーブル２３上で自転しながら回転する工具基体１１に表２に示す－２５～－７５Ｖの所定の直流バイアス電圧を印加し、かつ、前記所定組成のＡｌ－Ｔｉ合金ターゲット２２からなるカソード電極（蒸発源）とアノード電極２１との間に表２に示す８０～１２０Ａの所定の電流を同時に所定時間流してアーク放電を発生させ、前記工具基体１１の表面に、表４に示される目標組成、目標平均層厚の（Ａｌ，Ｔｉ）Ｎ層からなるＡ層を蒸着形成した（図１のＡ層１２）。
（ｄ）次いで、Ｂ層の成膜を、次のとおり行った。
　まず、装置内に反応ガスとして窒素ガスを導入して表２に示す２～１０Ｐａの範囲内の所定の反応雰囲気とすると共に、同じく表２に示す装置内温度に維持し、前記回転テーブル２３上で自転しながら回転する工具基体１１に表２に示す－２５～－７５Ｖの範囲内の所定の直流バイアス電圧を印加し、かつ、前記Ａｌ－Ｔｉ合金ターゲット２２からなるカソード電極（蒸発源）とアノード電極２１との間に表２に示す８０～１２０Ａの範囲内の所定の電流を流してアーク放電を発生させ、前記Ａ層表面に、表４に示される目標組成、目標平均層厚の（Ｔｉ，Ａｌ）Ｎ層からなるＢ層を蒸着形成した（図１のＢ層１３）。
　上記の（ａ）～（ｄ）によって、Ａ層およびＢ層の積層からなる硬質被覆層を蒸着形成した表４に示す本発明の被覆ｃＢＮ工具（以下、「本発明工具」という）１～１０を作製した。 Formation of hard coating layer:
A hard coating layer was formed on the tool bases 1 to 3 using the arc ion plating apparatus 20 shown in FIGS. 2A and 2B.
As the Al—Ti alloy target 22 in FIGS. 2A and 2B, a plurality of Al—Ti alloy targets 22 having different compositions were arranged in the apparatus according to the target (Al, Ti) N layer.
(A) The tool bases 1 to 3 are ultrasonically cleaned in acetone and dried, and the outer peripheral portion is located at a predetermined radial distance from the central axis on the rotary table 23 in the arc ion plating apparatus 20. (Tool base 11 in FIGS. 2A and 2B). Further, an Al—Ti alloy target 22 having a predetermined composition was disposed as a cathode electrode (evaporation source).
(B) First, the inside of the apparatus is heated to 500 ° C. with the heater 24 while the inside of the apparatus is evacuated and kept at a vacuum of 10 −2 Pa or less, and then an Ar gas atmosphere of 0.5 to 2.0 Pa is set. A DC bias voltage of −200 to −1000 V was applied to the tool base 11 rotating while rotating on the rotary table 23, and the tool base surface was bombarded with argon ions for 5 to 30 minutes.
(C) Next, the A layer was formed as follows.
Nitrogen gas is introduced into the apparatus as a reaction gas to obtain a predetermined reaction atmosphere of 2 to 10 Pa shown in Table 2, and the apparatus is also maintained at the apparatus temperature shown in Table 2 and rotates while rotating on the rotary table 23. A predetermined DC bias voltage of −25 to −75 V shown in Table 2 is applied to the tool base 11 and the cathode electrode (evaporation source) composed of the Al—Ti alloy target 22 having the predetermined composition and the anode electrode 21 In the meantime, a predetermined current of 80 to 120 A shown in Table 2 is simultaneously supplied for a predetermined time to generate arc discharge, and the target composition and target average layer thickness (Al, Ti) shown in Table 4 are formed on the surface of the tool base 11. ) A layer composed of N layer was formed by vapor deposition (A layer 12 in FIG. 1).
(D) Next, the B layer was formed as follows.
First, nitrogen gas is introduced into the apparatus as a reaction gas so as to obtain a predetermined reaction atmosphere within the range of 2 to 10 Pa shown in Table 2, while maintaining the temperature in the apparatus shown in Table 2 as well. A predetermined DC bias voltage within the range of −25 to −75 V shown in Table 2 is applied to the tool base 11 rotating while rotating at the same time, and a cathode electrode (evaporation source) made of the Al—Ti alloy target 22 is applied. A predetermined current in the range of 80 to 120 A shown in Table 2 is passed between the anode electrode 21 and an arc discharge to generate an arc discharge. On the surface of the A layer, the target composition and the target average layer thickness shown in Table 4 ( A B layer composed of a Ti, Al) N layer was formed by vapor deposition (B layer 13 in FIG. 1).
A coated cBN tool of the present invention (hereinafter referred to as “the present invention tool”) 1 to 10 shown in Table 4 in which a hard coating layer formed by laminating the A layer and the B layer is formed by vapor deposition according to the above (a) to (d). Was made.
　比較のため、前記工具基体１～３に対して、表３に示す条件で下部層および上部層を蒸着することにより、表５に示す比較例の被覆工具（以下、「比較例工具」という）１～１２を作製した。
　なお、比較例工具の下部層および上部層は、それぞれ、本発明のＡ層、Ｂ層に対応させる層であることから、以下においては、比較例工具の下部層および上部層を、それぞれを便宜的にＡ層、Ｂ層ということとした。 For comparison, a lower layer and an upper layer are deposited on the tool bases 1 to 3 under the conditions shown in Table 3 to obtain a coated tool of a comparative example shown in Table 5 (hereinafter referred to as “comparative tool”). 1 to 12 were produced.
In addition, since the lower layer and the upper layer of the comparative example tool are layers corresponding to the A layer and the B layer of the present invention, respectively, in the following, the lower layer and the upper layer of the comparative example tool are respectively referred to for convenience. In particular, they are referred to as A layer and B layer.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　上記で作製した本発明工具１～１０および比較例工具１～１２の工具基体表面に垂直な硬質被覆層の縦断面について、工具基体表面に平行な方向の幅が１０μｍであり、硬質被覆層の厚み領域が全て含まれるよう設定された視野について、走査型電子顕微鏡（ＳＥＭ）、透過型電子顕微鏡（ＴＥＭ）、エネルギー分散型Ｘ線分光法（ＥＤＳ）を用いた断面測定により、Ａ層、Ｂ層の組成、層厚をそれぞれの層に対して５箇所で測定し、これを平均することにより、Ａ層、Ｂ層の平均組成、平均層厚ｔＡ、平均層厚ｔＢ、を算出し、また、ｔＢ／ｔＡの値を求めた。 Regarding the longitudinal sections of the hard coating layer perpendicular to the tool base surface of the inventive tools 1 to 10 and comparative tools 1 to 12 produced as described above, the width in the direction parallel to the tool base surface is 10 μm, and the hard coating layer For the field of view set to include all the thickness regions, cross-sectional measurement using a scanning electron microscope (SEM), a transmission electron microscope (TEM), and energy dispersive X-ray spectroscopy (EDS) was performed. The layer composition and the layer thickness were measured at five locations for each layer and averaged to calculate the average composition of layer A and layer B, average layer thickness t A , and average layer thickness t B. In addition, the value of t B / t A was obtained.
　次に、硬質被覆層全体の回折ピーク強度比Ｉ（２００）／Ｉ（１１１）は、Ｃｒ管球を用いたＸ線回折によってＡ層とＢ層の重なった（２００）面の回折ピーク強度をＩ（２００）として測定し、また、Ａ層とＢ層の重なった（１１１）面の回折ピーク強度をＩ（１１１）として測定し、Ｉ（２００）のピークの半値幅を求めるとともに、Ｉ（２００）／Ｉ（１１１）の値を求めた。
　また、Ａ層の回折ピーク強度については、成膜後にＢ層を集束イオンビーム（Ｆｏｃｕｓｅｄ　Ｉｏｎ　Ｂｅａｍ：ＦＩＢ）法などの手法で加工・除去したのち、前述したＸ線回折法を用いることで測定し、Ａ層の（２００）面の回折ピーク強度ＩＡ（２００）と、（１１１）面の回折ピーク強度ＩＡ（１１１）を測定し、ＩＡ（２００）のピークの半値幅を求めるとともに、ＩＡ（２００）／ＩＡ（１１１）の値を求めた。 Next, the diffraction peak intensity ratio I (200) / I (111) of the entire hard coating layer is the diffraction peak intensity of the (200) plane where the A layer and the B layer overlap by X-ray diffraction using a Cr tube. I (200) is measured, and the diffraction peak intensity of the (111) plane where the A layer and the B layer overlap is measured as I (111) to obtain the half width of the peak of I (200). 200) / I (111).
Further, the diffraction peak intensity of the A layer is measured by using the X-ray diffraction method described above after processing and removing the B layer by a method such as a focused ion beam (FIB) method after film formation. , an a layer of (200) plane of the diffraction peak intensity I a (200), (111) measuring the diffraction peak intensity I a (111) of the surface portions to determine the half-value width of the peak of I a (200), The value of I A (200) / I A (111) was determined.
　表４、表５に、上記で求めた各種の値を示す。 Tables 4 and 5 show the various values obtained above.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　次いで、本発明工具１～１０および比較例工具１～１２について、次の切削条件Ａ、Ｂで切削試験を行った。
切削条件Ａ：
　被削材：ＪＩＳ・ＳＣｒ４２０の焼入れ材の穴付き丸棒、
　切削速度：２２０　ｍ／ｍｉｎ、
　切り込み：０．１５　ｍｍ、
　送り：０．１５　ｍｍ、
切削条件Ｂ：
　被削材：ＪＩＳ・ＳＣＭ４１５の焼入れ材の丸棒、
　切削速度：３１５　ｍ／ｍｉｎ．、
　切り込み：０．１　ｍｍ、
　送り：０．１　ｍｍ、
　上記切削条件Ａ、Ｂの乾式連続切削試験において、条件Ａは切削長８８０ｍ、条件Ｂは切削長９４５ｍまで切削し、逃げ面摩耗量を測定した。
　表６にその結果を示す。 Next, cutting tests were performed on the inventive tools 1 to 10 and the comparative example tools 1 to 12 under the following cutting conditions A and B.
Cutting condition A:
Work material: Round bar with hole of quenching material of JIS / SCr420,
Cutting speed: 220 m / min,
Cutting depth: 0.15 mm,
Feed: 0.15 mm,
Cutting condition B:
Work material: JIS / SCM415 quenching material round bar,
Cutting speed: 315 m / min. ,
Cutting depth: 0.1 mm,
Feed: 0.1 mm,
In the dry continuous cutting test under the above cutting conditions A and B, the condition A was cut to a cutting length of 880 m, the condition B was cut to a cutting length of 945 m, and the flank wear amount was measured.
Table 6 shows the results.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　表６で示す「チッピングの有無」は、切削条件Ａ、Ｂの乾式連続切削試験を行った後の本発明工具１～１０及び比較例工具１～１２の摩耗面をＳＥＭで観察し、チッピングの有無を確認したものである。
　表６で示す「逃げ面摩耗量」は、切削条件Ａ、Ｂの乾式連続切削試験を行った後の本発明工具１～１０及び比較例工具１～１２の逃げ面をＳＥＭで観察し、摩耗幅をＳＥＭ写真上における長さから測定したものである。逃げ面摩耗量が０．２ｍｍを超えると加工精度などの切削性能が低下し、逃げ面摩耗量が０．２５ｍｍを超えた場合を使用寿命と判断した。
　表６の結果によれば、本発明工具１～２、及び４～１０は、チッピングが発生することもなく切削を行うことが可能であり、しかも、逃げ面摩耗量の平均は切削条件Ａで約０．１１ｍｍ、切削条件Ｂで約０．１３ｍｍであって、耐摩耗性にもすぐれていることが分かる。本発明工具３については、チッピングの発生は観察されたが、逃げ面摩耗量が０．２ｍｍ以下であり、耐摩耗性が確認された。
　一方、比較例工具１～１２は、チッピングの発生あるいは逃げ面摩耗の進行により、短時間で寿命に至ることは明らかである。
　この結果から、本発明工具は、比較例工具に比して、耐チッピング性、耐摩耗性のいずれにおいてもすぐれていることが分かる。 The “presence / absence of chipping” shown in Table 6 indicates that the wear surfaces of the inventive tools 1 to 10 and comparative tools 1 to 12 after the dry continuous cutting test under the cutting conditions A and B were observed by SEM. The presence or absence is confirmed.
The “flank wear amount” shown in Table 6 is obtained by observing the flank surfaces of the inventive tools 1 to 10 and comparative tools 1 to 12 after the dry continuous cutting test under the cutting conditions A and B by SEM. The width is measured from the length on the SEM photograph. When the flank wear amount exceeded 0.2 mm, the cutting performance such as machining accuracy deteriorated, and the case where the flank wear amount exceeded 0.25 mm was judged as the service life.
According to the results in Table 6, the inventive tools 1 and 2 and 4 to 10 can perform cutting without causing chipping, and the average flank wear amount is the cutting condition A. It is about 0.11 mm and cutting condition B is about 0.13 mm, and it can be seen that the wear resistance is also excellent. As for the inventive tool 3, chipping was observed, but the flank wear amount was 0.2 mm or less, and the wear resistance was confirmed.
On the other hand, it is obvious that the comparative tools 1 to 12 reach the end of their lives in a short time due to the occurrence of chipping or the progress of flank wear.
From this result, it can be seen that the tool of the present invention is superior in both chipping resistance and wear resistance as compared with the comparative example tool.
　本発明の表面被覆切削工具は、各種の鋼などの通常の切削条件での切削加工は勿論のこと、特に高熱発生を伴うとともに、切刃部に対して大きな負荷がかかる合金鋼などの高速切削加工においても、すぐれた耐チッピング性、耐摩耗性を発揮し、長期に亘ってすぐれた切削性能を示すものであるから、切削加工装置の高性能化、並びに切削加工の省力化および省エネ化、さらに低コスト化に十分満足に対応できるものである。 The surface-coated cutting tool of the present invention is capable of cutting at normal cutting conditions such as various types of steel, particularly high-speed cutting such as alloy steel that is accompanied by high heat generation and a heavy load on the cutting edge. Also in machining, it exhibits excellent chipping resistance and wear resistance, and exhibits excellent cutting performance over a long period of time. Furthermore, it can cope with cost reduction sufficiently satisfactorily.
　１１　　ｃＢＮ基体、工具基体
　１２　　Ａ層：（Ａｌ，Ｔｉ）Ｎ
　１３　　Ｂ層：（Ａｌ，Ｔｉ，Ｓｉ）Ｎ
　２０　　アークイオンプレーティング装置
　２１　　アノード電極
　２２　　Ａｌ－Ｔｉ合金ターゲット（蒸発源）、カソード電極
　２３　　回転テーブル
　２４　　ヒーター
　２５　　アーク電極
　２６　　バイアス電極
　３１　　反応ガス導入口
　３２　　排ガス口 11 cBN substrate, tool substrate 12 A layer: (Al, Ti) N
13 B layer: (Al, Ti, Si) N
20 Arc ion plating apparatus 21 Anode electrode 22 Al-Ti alloy target (evaporation source), cathode electrode 23 Rotary table 24 Heater 25 Arc electrode 26 Bias electrode 31 Reactive gas inlet 32 Exhaust gas outlet

Claims (3)

  1. 　表面被覆切削工具であって、
    　少なくとも刃先が立方晶窒化ほう素焼結体からなる工具基体上に硬質被覆層が形成されており、
    （ａ）前記立方晶窒化ほう素焼結体は、
    　立方晶窒化硼素粒子と、
    　Ｔｉの窒化物、炭化物、炭窒化物、硼化物およびＡｌの窒化物、酸化物からなる群から選ばれた少なくとも１種以上、並びに不可避不純物を含む結合相と、からなり、
    （ｂ）前記立方晶窒化ほう素粒子の平均粒径は０．５～４．０μｍ、また、立方晶窒化ほう素焼結体全体に占める立方晶窒化ほう素粒子の含有割合は４０～７０体積％であり、さらに、前記結合相の平均粒径は１μｍ以下であり、
    （ｃ）前記硬質被覆層は、工具基体表面に被覆されたＡ層と、Ａ層表面に被覆されたＢ層とからなり、
    （ｄ）前記Ａ層は、
    　組成式：（Ａｌ１－ｘＴｉｘ）Ｎで表した場合、原子比で、０．３５≦ｘ≦０．６を満足し、
    　前記Ｂ層は、
    　組成式：（Ａｌ１－ｙ－ｚＴｉｙＳｉｚ）Ｎで表した場合、原子比で、０．３５≦ｙ≦０．６、０．０１≦ｚ≦０．１）を満足し、
    （ｅ）前記Ａ層とＢ層の平均合計層厚は１．５～４．０μｍであって、かつ、Ａ層の平均層厚をｔＡ、Ｂ層の平均層厚をｔＢとした場合、２≦ｔＢ／ｔＡ≦５を満足し、
    （ｆ）前記Ａ層とＢ層からなる硬質被覆層全体についてＸ線回折を行った場合、硬質被覆層は全体として岩塩型立方晶の結晶構造を有し、また、硬質被覆層を構成する結晶粒の（２００）面の回折ピーク強度をＩ（２００）、（１１１）面の回折ピーク強度をＩ（１１１）としたとき、３＜Ｉ（２００）／Ｉ（１１１）≦１２を満足し、かつ、Ｉ（２００）のピークの半値幅が０．３～１．０であることを特徴とする。     A surface-coated cutting tool,
    A hard coating layer is formed on a tool substrate having at least a cutting edge made of a cubic boron nitride sintered body,
    (A) The cubic boron nitride sintered body is:
    Cubic boron nitride particles;
    Ti nitride, carbide, carbonitride, boride and Al nitride, at least one selected from the group consisting of oxides, and a binder phase containing inevitable impurities,
    (B) The average particle diameter of the cubic boron nitride particles is 0.5 to 4.0 μm, and the content ratio of the cubic boron nitride particles in the entire cubic boron nitride sintered body is 40 to 70% by volume. And the average particle size of the binder phase is 1 μm or less,
    (C) The hard coating layer is composed of an A layer coated on the tool base surface and a B layer coated on the A layer surface,
    (D) The A layer is
    When represented by the composition formula: (Al 1-x Ti x ) N, the atomic ratio satisfies 0.35 ≦ x ≦ 0.6,
    The B layer is
    When represented by the composition formula: (Al 1-yz Ti y Si z ) N, the atomic ratio satisfies 0.35 ≦ y ≦ 0.6, 0.01 ≦ z ≦ 0.1),
    (E) When the average total thickness of the A layer and the B layer is 1.5 to 4.0 μm, the average layer thickness of the A layer is t A , and the average layer thickness of the B layer is t B 2 ≦ t B / t A ≦ 5,
    (F) When X-ray diffraction is performed on the entire hard coating layer composed of the A layer and the B layer, the hard coating layer has a rock salt cubic crystal structure as a whole, and crystals constituting the hard coating layer When the diffraction peak intensity of the (200) plane of the grain is I (200) and the diffraction peak intensity of the (111) plane is I (111), 3 <I (200) / I (111) ≦ 12 is satisfied, In addition, the half width of the peak of I (200) is 0.3 to 1.0.
  2. 　前記Ａ層のＴｉ含有割合を示すｘと、前記Ｂ層のＴｉ含有割合を示すｙが、｜ｘ－ｙ｜≦０．１５の関係を満足する請求項１に記載の表面被覆切削工具。 2. The surface-coated cutting tool according to claim 1, wherein x indicating the Ti content ratio of the A layer and y indicating the Ti content ratio of the B layer satisfy a relationship of | xy− ≦ 0.15.
  3. 　前記Ａ層についてＸ線回折を行った場合、（２００）面の回折ピーク強度をＩＡ（２００）、（１１１）面の回折ピーク強度をＩＡ（１１１）としたとき、２＜ＩＡ（２００）／ＩＡ（１１１）≦１０を満足し、かつ、ＩＡ（２００）のピークの半値幅が０．３～１．０である請求項１または２に記載の表面被覆切削工具。 When X-ray diffraction is performed on the A layer, when the diffraction peak intensity on the (200) plane is I A (200) and the diffraction peak intensity on the (111) plane is I A (111), 2 <I A ( The surface-coated cutting tool according to claim 1 or 2, wherein 200) / I A (111) ≤ 10 is satisfied, and the half width of the peak of I A (200) is 0.3 to 1.0.
PCT/JP2015/083407 2014-11-27 2015-11-27 Surface-coated cutting tool with excellent chipping resistance and wear resistance WO2016084939A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP15862876.8A EP3225337B1 (en) 2014-11-27 2015-11-27 Surface-coated cutting tool with excellent chipping resistance and wear resistance
CN201580063713.5A CN107000068B (en) 2014-11-27 2015-11-27 The excellent surface-coated cutting tool of chipping resistance, wearability
US15/529,008 US10556273B2 (en) 2014-11-27 2015-11-27 Surface-coated cutting tool having excellent chipping resistance and wear resistance
KR1020177013816A KR102326622B1 (en) 2014-11-27 2015-11-27 Surface-coated cutting tool with excellent chipping resistance and wear resistance

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2014-239956 2014-11-27
JP2014239956 2014-11-27
JP2015229736A JP6634647B2 (en) 2014-11-27 2015-11-25 Surface coated cutting tool with excellent chipping and wear resistance
JP2015-229736 2015-11-25

Publications (1)

Publication Number Publication Date
WO2016084939A1 true WO2016084939A1 (en) 2016-06-02

Family

ID=56074485

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/083407 WO2016084939A1 (en) 2014-11-27 2015-11-27 Surface-coated cutting tool with excellent chipping resistance and wear resistance

Country Status (1)

Country Link
WO (1) WO2016084939A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110461615A (en) * 2017-03-29 2019-11-15 京瓷株式会社 Thermal head and thermal printer
CN113166919A (en) * 2018-11-30 2021-07-23 韩国冶金株式会社 Hard coating for cutting tool
CN113874144A (en) * 2019-08-06 2021-12-31 住友电工硬质合金株式会社 Cutting tool
CN114829676A (en) * 2019-12-20 2022-07-29 瓦尔特公开股份有限公司 Coated cutting tool

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63145726A (en) * 1987-11-06 1988-06-17 Mitsubishi Metal Corp Production of cubic boron nitride-base ultra-high pressure sintereo material for cutting tool
JP2010284788A (en) * 2009-06-15 2010-12-24 Hitachi Tool Engineering Ltd Hard film coated tool
JP2011110653A (en) * 2009-11-27 2011-06-09 Kyocera Corp Cutting tool
WO2014136755A1 (en) * 2013-03-04 2014-09-12 株式会社タンガロイ Coated cutting tool
JP2015160259A (en) * 2014-02-26 2015-09-07 三菱マテリアル株式会社 Surface-coated cutting tool excellent in abrasion resistance

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63145726A (en) * 1987-11-06 1988-06-17 Mitsubishi Metal Corp Production of cubic boron nitride-base ultra-high pressure sintereo material for cutting tool
JP2010284788A (en) * 2009-06-15 2010-12-24 Hitachi Tool Engineering Ltd Hard film coated tool
JP2011110653A (en) * 2009-11-27 2011-06-09 Kyocera Corp Cutting tool
WO2014136755A1 (en) * 2013-03-04 2014-09-12 株式会社タンガロイ Coated cutting tool
JP2015160259A (en) * 2014-02-26 2015-09-07 三菱マテリアル株式会社 Surface-coated cutting tool excellent in abrasion resistance

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110461615A (en) * 2017-03-29 2019-11-15 京瓷株式会社 Thermal head and thermal printer
US10882329B2 (en) 2017-03-29 2021-01-05 Kyocera Corporation Thermal head and thermal printer
CN113166919A (en) * 2018-11-30 2021-07-23 韩国冶金株式会社 Hard coating for cutting tool
CN113166919B (en) * 2018-11-30 2023-08-01 韩国冶金株式会社 Hard coating for cutting tool
CN113874144A (en) * 2019-08-06 2021-12-31 住友电工硬质合金株式会社 Cutting tool
CN114829676A (en) * 2019-12-20 2022-07-29 瓦尔特公开股份有限公司 Coated cutting tool
CN114829676B (en) * 2019-12-20 2023-11-14 瓦尔特公开股份有限公司 Coated cutting tool

Similar Documents

Publication Publication Date Title
JP6634647B2 (en) Surface coated cutting tool with excellent chipping and wear resistance
JP6384341B2 (en) Surface coated cutting tool with excellent abnormal damage resistance and wear resistance
US20190040519A1 (en) Surface-coated cutting tool providing excellent chipping resistance and wear resistance in heavy intermittent cutting
JP5838769B2 (en) Surface coated cutting tool
JP6850980B2 (en) Surface-coated cubic boron nitride sintered body tool
WO2010150335A1 (en) Tool having coated cubic boron nitride sintered body
JP6421934B2 (en) Surface coated cutting tool with excellent abnormal damage resistance and wear resistance
JP2015160259A (en) Surface-coated cutting tool excellent in abrasion resistance
JP2018094670A (en) Surface-coated cubic boron nitride sintered tool
WO2016084939A1 (en) Surface-coated cutting tool with excellent chipping resistance and wear resistance
US10883166B2 (en) Surface-coated cubic boron nitride sintered material tool
JP6296295B2 (en) Surface coated cutting tool with excellent wear resistance
JP2015110256A (en) Surface-coated cutting tool
JP2008254159A (en) Surface-coated cutting tool made of cubic boron nitride group ultrahigh-pressure sintered material
JP6493800B2 (en) Surface coated cutting tool with excellent wear resistance in high speed cutting
JP2021126738A (en) Surface-coated cutting tool exhibiting excellent chipping resistance and wear resistance in strong intermittent cutting
JP2016221672A (en) Surface-coated cutting tool having hard coating layer exerting excellent chipping resistance
WO2017154730A1 (en) Surface-coated cubic boron nitride sintered tool
JP2007253271A (en) Cutting tool made from surface coated cubic boron nitride group ultra high pressure sintering material with excellent finished surface accuracy
JP2012139795A (en) Surface coated cutting tool with hard coating layer exhibiting superior resistance against peeling and chipping in high speed cutting of soft hard-to-cut material
JP6759536B2 (en) Cover cutting tool
JP6213066B2 (en) A surface-coated cutting tool that exhibits excellent chipping resistance with a hard coating layer in high-speed intermittent cutting
JP2016064470A (en) Surface coat cutting tool excellent in chipping resistance and wear resistance
JP2007136653A (en) Surface coated cutting tool made of cubic boron nitride-base ultra-high pressure sintered material having hard coated layer exhibiting chipping resistance in high-speed heavy cutting of high-hardness steel
JP6172519B2 (en) Surface-coated cutting tool that exhibits excellent chipping resistance over a long period of time when cutting hardened steel

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15862876

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20177013816

Country of ref document: KR

Kind code of ref document: A

REEP Request for entry into the european phase

Ref document number: 2015862876

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 15529008

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE