阅读说明：本技术 表面被覆切削工具及其制造方法 (Surface-coated cutting tool and method for manufacturing same ) 是由 小野聪 今村晋也 奥野晋 阿侬萨克·帕索斯 于 2018-12-14 设计创作，主要内容包括：该表面被覆切削工具包括基材和被覆基材的覆膜。基材包括前刀面和后刀面。覆膜包括TiCN层。TiCN层在前刀面的区域d1中具有(311)取向,并且在后刀面的区域d2中具有(422)取向。当前刀面和后刀面通过切削刃面而彼此连续时,区域d1是介于前刀面和切削刃面的边界线与假想线D1之间的区域,其中假想线D1在前刀面上并且与假想棱线相隔500μm,并且区域d2是介于后刀面和切削刃面的边界线与假想线D2之间的区域,其中假想线D2位于后刀面上并且与假想棱线相隔500μm。在前刀面和后刀面通过棱线而彼此连续时,区域d1为介于棱线和假想线D1之间的区域,其中假想线D1位于前刀面上并且与棱线相隔500μm,并且区域d2是介于棱线和假想线D2之间的区域,其中假想线D2位于后刀面上并且与棱线相隔500μm。(The surface-coated cutting tool includes a base material and a coating film coating the base material. The substrate includes a rake face and a relief face. The coating includes a TiCN layer. The TiCN layer has (311) orientation in the region d1 of the rake face and (422) orientation in the region d2 of the flank face. When the rake face and the flank face are continuous with each other by the cutting edge face, a region D1 is a region between a boundary line of the rake face and the cutting edge face and an imaginary line D1, wherein the imaginary line D1 is on the rake face and is spaced from the imaginary ridge by 500 μm, and a region D2 is a region between a boundary line of the flank face and the cutting edge face and an imaginary line D2, wherein the imaginary line D2 is located on the flank face and is spaced from the imaginary ridge by 500 μm. When the rake face and the flank face are continuous with each other by the ridge line, the region D1 is a region between the ridge line and an imaginary line D1, in which the imaginary line D1 is located on the rake face and is spaced 500 μm from the ridge line, and the region D2 is a region between the ridge line and an imaginary line D2, in which the imaginary line D2 is located on the flank face and is spaced 500 μm from the ridge line.)

1. A surface-coated cutting tool comprising:

a substrate; and

a coating film for coating the substrate, wherein

The base material comprises a front cutter face and a rear cutter face,

the coating film comprises a TiCN layer,

the TiCN layer has (311) orientation in the region d1 of the rake face,

the TiCN layer has a (422) orientation in the region d2 of the flank face,

when the rake face and the flank face are continuous with each other with the cutting edge face therebetween,

the region D1 is a region between an imaginary line D1 and a boundary between the rake face and the cutting edge face, the imaginary line D1 is located on the rake face and is 500 μm apart from an imaginary ridge line where a face obtained by extending the rake face and a face obtained by extending the flank face intersect, and

the region D2 is a region between an imaginary line D2 and a boundary between the flank face and the cutting edge face, the imaginary line D2 is located on the flank face and is 500 μm apart from the imaginary ridge, and

when the rake face and the flank face are continuous with each other with a ridge line therebetween,

the region D1 is a region between the ridge and an imaginary line D1, wherein the imaginary line D1 is located on the rake face and is 500 μm apart from the ridge, and

the region D2 is a region between the ridge and an imaginary line D2, where the imaginary line D2 is located on the flank face and is 500 μm apart from the ridge.

2. The surface-coated cutting tool according to claim 1, wherein

The TiCN layer having (311) orientation means that, in a texture coefficient TC (hkl) defined by the following equation (1), the texture coefficient TC (311) of the (311) plane in the TiCN layer is larger than that of any other crystal orientation plane, and

the TiCN layer having an orientation of (422) means that, in a texture coefficient TC (hkl) defined by the following equation (1), the texture coefficient TC (422) of a (422) plane in the TiCN layer is larger than that of any other crystal orientation plane,

wherein

I (hkl) and I (h)_xk_yl_z) Respectively, the measured diffraction intensities of the (hkl) plane and (h)_xk_yl_z) The measured diffraction intensity of the surface,

I_o(hkl) and I_o(h_xk_yl_z) Respectively represent the average values of powder diffraction intensities of TiC and TiN according to the (hkl) plane of the JCPDS database and (h) according to the JCPDS database_xk_yl_z) Average value of powder diffraction intensities of TiC and TiN of the face, and

(hkl) and (h)_xk_yl_z) Each represents any one of eight faces including a (111) face, a (200) face, a (220) face, a (311) face, a (331) face, a (420) face, a (422) face, and a (511) face.

3. The surface-coated cutting tool according to claim 2, wherein a ratio TC of (311) texture coefficient to (422) texture coefficient in the region d1 of the rake face_rake(311)/TC_rake(422) Greater than 1.

4. The surface-coated cutting tool according to claim 2 or 3, wherein a ratio TC of a (422) texture coefficient in the region d1 of the rake face to a (422) texture coefficient in the region d2 of the flank face_rake(422)/TC_flank(422) Is 1 or less.

5. The surface-coated cutting tool according to any one of claims 1 to 4, wherein the TiCN layer has a thickness of 6 μm or more and 10 μm or less.

6. The surface-coated cutting tool according to any one of claims 1 to 5, wherein the base material comprises one selected from the group consisting of cemented carbide, cermet, high-speed steel, ceramic, cBN sintered body, and diamond sintered body.

7. The surface-coated cutting tool according to claim 6, wherein when the base material is a cemented carbide, the base material contains cobalt in an amount of 7 mass% or more and 12 mass% or less with respect to the total mass of the base material.

8. The surface-coated cutting tool according to any one of claims 1 to 7, wherein the coating film further comprises Al formed on the TiCN layer₂O₃And (3) a layer.

9. The surface-coated cutting tool according to claim 8, wherein the Al₂O₃The thickness of the layer is 0.5 to 4 μm.

10. A method of manufacturing the surface-coated cutting tool according to any one of claims 1 to 7, the method comprising:

a substrate preparation step of preparing the substrate;

a TiCN layer coating step of coating at least a portion of the rake face and at least a portion of the flank face with the TiCN layer; and

a shot blasting step of shot blasting the TiCN layer in the rake face,

wherein the TiCN layer coating step is performed by chemical vapor deposition and includes discontinuously supplying a raw material gas of the TiCN layer.

11. The method of claim 10, wherein

The coating film further includes Al formed on the TiCN layer₂O₃A layer of

The method further comprises Al₂O₃A layer stacking step in which the Al is applied after the TiCN layer coating step or the shot blasting step₂O₃A layer is stacked on the TiCN layer.

Technical Field

The present disclosure relates to a surface-coated cutting tool and a method of manufacturing the same. This application claims priority from japanese patent application No.2018-049284, filed 3, 16, 2018, the entire contents of which are incorporated herein by reference.

Background

Conventionally, various studies have been made to extend the life of a cutting tool. For example, japanese patent unexamined publication No.06-158325 (patent document 1) and japanese patent unexamined publication No.11-124672 (patent document 2) each disclose a cutting tool including a base material and a coating film formed on a surface of the base material.

Reference list

Patent document

Patent document 1: japanese patent unexamined publication No.06-158325

Patent document 2: japanese patent unexamined publication No.11-124672

Disclosure of Invention

A surface-coated cutting tool according to the present disclosure is a surface-coated cutting tool including: a base material and a coating film for coating the base material, wherein

The base material comprises a front cutter face and a rear cutter face,

the coating film comprises a TiCN layer,

the TiCN layer has (311) orientation in the region d1 of the rake face,

the TiCN layer has a (422) orientation in the region d2 of the flank face,

when the rake face and the flank face are continuous with each other with the cutting edge face therebetween,

the region D1 is a region between an imaginary line D1 and a boundary between the rake face and the cutting edge face, an imaginary line D1 is located on the rake face and is 500 μm apart from an imaginary ridge line where a face obtained by extending the rake face and a face obtained by extending the flank face intersect, and

the region D2 is a region between an imaginary line D2 and a boundary between the flank face and the cutting edge face, the imaginary line D2 is located on the flank face and is spaced 500 μm from the imaginary ridge line, and

when the rake face and the flank face are continuous with each other with a ridge therebetween,

the region D1 is a region between the ridge line and an imaginary line D1, wherein the imaginary line D1 is located on the rake face and is spaced 500 μm from the ridge line, and

region D2 is the region between the ridge and the imaginary line D2, where the imaginary line D2 lies on the flank face and is 500 μm apart from the ridge.

A method of manufacturing a surface-coated cutting tool according to the present disclosure is a method of manufacturing the above-described surface-coated cutting tool, the method including:

a substrate preparation step of preparing a substrate;

a TiCN layer coating step of coating at least a part of the rake face and at least a part of the flank face with a TiCN layer; and

a shot blasting step of shot blasting the TiCN layer in the rake face,

wherein the TiCN layer coating step is performed by chemical vapor deposition and includes discontinuously supplying a raw material gas of the TiCN layer.

Drawings

FIG. 1 is a perspective view illustrating one aspect of a cutting tool.

Fig. 2 is a sectional view taken along line X-X in fig. 1.

Fig. 3 is a partially enlarged view of fig. 2.

Fig. 4 shows another shape of the cutting edge portion.

Fig. 5 shows yet another shape of the cutting edge portion.

Fig. 6 shows yet another shape of the cutting edge portion.

Fig. 7 is a schematic diagram showing the measurement positions of the rake face or the flank face in the X-ray diffraction measurement.

Fig. 8 is a graph showing the texture coefficient of each orientation plane in the region d1 of the rake face.

Fig. 9 is a graph showing the texture coefficient of each orientation plane in the region d2 of the flank face.

Detailed Description

[ technical problems to be solved by the present disclosure ]

According to patent documents 1 and 2, the performance (e.g., chipping resistance or wear resistance) of the cutting tool is improved by providing a hard coating on the surface of the base material. Although it is desirable that the rake face and the flank face of the cutting tool have different properties, in the cutting tools described in patent documents 1 and 2, the rake face and the flank face are provided with the coating film of the same property. As a result, even if the performance of the rake face, for example, is improved by providing the coating, the performance of the flank face may be insufficient. Under such circumstances, it is desired to further improve a cutting tool provided with a coating film on its surface.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a surface-coated cutting tool having excellent chipping resistance and also excellent wear resistance, and a method for manufacturing the same.

[ advantageous effects of the present disclosure ]

As described above, it is possible to provide a surface-coated cutting tool having excellent chipping resistance and excellent wear resistance, and a method for manufacturing the same.

[ description of the embodiments ]

First, the present disclosure is described based on the following listed aspects.

[1] A surface-coated cutting tool according to an aspect of the present disclosure is a surface-coated cutting tool including: a base material and a coating film for coating the base material, wherein

The base material comprises a front cutter face and a rear cutter face,

the coating film comprises a TiCN layer,

the TiCN layer has (311) orientation in the region d1 of the rake face,

the TiCN layer has a (422) orientation in the region d2 of the flank face,

when the rake face and the flank face are continuous with each other with the cutting edge face therebetween,

the region D1 is a region between an imaginary line D1 and a boundary between the rake face and the cutting edge face, an imaginary line D1 is located on the rake face and is 500 μm apart from an imaginary ridge line where a face obtained by extending the rake face and a face obtained by extending the flank face intersect, and

the region D2 is a region between an imaginary line D2 and a boundary between the flank face and the cutting edge face, the imaginary line D2 is located on the flank face and is spaced 500 μm from the imaginary ridge line, and

when the rake face and the flank face are continuous with each other with a ridge therebetween,

the region D1 is a region between the ridge line and an imaginary line D1, wherein the imaginary line D1 is located on the rake face and is spaced 500 μm from the ridge line, and

region D2 is the region between the ridge and the imaginary line D2, where the imaginary line D2 lies on the flank face and is 500 μm apart from the ridge.

The surface-coated cutting tool having the above features can have both a rake face excellent in toughness and a flank face excellent in hardness. Therefore, the surface-coated cutting tool has excellent chipping resistance and also has excellent wear resistance.

[2] The TiCN layer having (311) orientation means that, among the texture coefficient TC (hkl) defined by the following equation (1), the texture coefficient TC (311) of the (311) plane in the TiCN layer is larger than that of any other crystal orientation plane, and

the TiCN layer having an orientation of (422) means that, in the texture coefficient TC (hkl) defined by the following equation (1), the texture coefficient TC (422) of the (422) plane in the TiCN layer is larger than that of any other crystal orientation plane,

[ mathematical formula 1]

Wherein

I (hkl) and I (h)_xk_yl_z) Respectively, the measured diffraction intensities of the (hkl) plane and (h)_xk_yl_z) The measured diffraction intensity of the surface,

I_o(hkl) and I_o(h_xk_yl_z) Respectively represent the average values of powder diffraction intensities of TiC and TiN according to the (hkl) plane of the JCPDS database and (h) according to the JCPDS database_xk_yl_z) Average value of powder diffraction intensities of TiC and TiN of the face, and

(hkl) and (h)_xk_yl_z) Each represents any one of eight faces including a (111) face, a (200) face, a (220) face, a (311) face, a (331) face, a (420) face, a (422) face, and a (511) face.

[3]In the region d1 of the rake face, the ratio TC of the (311) to the (422) texture factor_rake(311)/TC_rake(422) Greater than 1. The ratio thus defined yields a surface-coated cutting tool having more excellent chipping resistance.

[4]The (422) texture index in the region d1 of the rake face and the (422) texture index in the region d2 of the flank faceRatio TC_rake(422)/TC_flank(422) Is 1 or less. The ratio thus defined yields a surface-coated cutting tool having more excellent wear resistance.

[5] The TiCN layer has a thickness of 6 to 10 [ mu ] m. The thus-defined TiCN layer results in a surface-coated cutting tool having excellent wear resistance and excellent chipping resistance.

[6] The base material includes one selected from the group consisting of cemented carbide, cermet, high speed steel, ceramic, cBN sintered body, and diamond sintered body. The base material thus defined allows the surface-coated cutting tool to have excellent hardness and excellent strength at high temperatures.

[7] When the base material is a cemented carbide, the amount of cobalt contained in the base material is 7 mass% or more and 12 mass% or less with respect to the total mass of the base material. The substrate thus defined gives a surface-coated cutting tool having excellent wear resistance and excellent chipping resistance.

[8]The coating film further includes Al formed on the TiCN layer₂O₃And (3) a layer. The coating film thus defined achieves a surface-coated cutting tool having excellent heat resistance and excellent chemical stability.

[9]Al₂O₃The thickness of the layer is 0.5 to 4 μm. Al thus defined₂O₃The layer provides a surface-coated cutting tool having more excellent heat resistance and more excellent chemical stability.

[10] A method of manufacturing a surface-coated cutting tool according to the present disclosure is a method of manufacturing the surface-coated cutting tool according to any one of the above [1] to [7], the method including:

a substrate preparation step of preparing a substrate;

a TiCN layer coating step of coating at least a part of the rake face and at least a part of the flank face with a TiCN layer; and

a shot blasting step of shot blasting the TiCN layer in the rake face,

wherein the TiCN layer coating step is performed by chemical vapor deposition and includes discontinuously supplying a raw material gas of the TiCN layer.

The method includes the steps as described above, and thus a surface-coated cutting tool having excellent chipping resistance and also having excellent wear resistance can be manufactured.

[11]The coating film further includes Al formed on the TiCN layer₂O₃A layer, and the method further comprises Al₂O₃A layer stacking step in which Al is added after the TiCN layer coating step or the shot blasting step₂O₃The layers are stacked on top of a TiCN layer. The method thus defined enables the production of a surface-coated cutting tool having excellent heat resistance and excellent chemical stability.

[ detailed description of embodiments of the present disclosure ]

Hereinafter, embodiments of the present disclosure (hereinafter also referred to as "the present embodiments") will be described. However, the present embodiment is not limited thereto. In the drawings used in the following description of the embodiments, the same reference numerals denote the same parts or corresponding parts. In the present specification, the expression of the form "a to B" means the upper and lower limits of the range (i.e., a above and below B), and when a has no unit but only B has a unit, a has the same unit as B. Further, in the present specification, when a compound is represented by a composition formula (chemical formula) such as "TiC" whose constituent element ratio is unspecified, the composition formula (or chemical formula) shall include any conventionally known composition (or element ratio). The compositional formula (chemical formula) shall include not only stoichiometric compositions but also non-stoichiometric compositions. For example, the compositional formula (chemical formula) "TiC" includes not only the stoichiometric composition "Ti₁C_l", also includes non-stoichiometric compositions (e.g.," Ti ")₁C_0.8". The same applies to compounds other than "TiC".

Surface-coated cutting tool

The surface-coated cutting tool according to the present embodiment is a surface-coated cutting tool including: a base material and a coating film for coating the base material, wherein

The base material comprises a front cutter face and a rear cutter face,

the coating film comprises a TiCN layer,

the TiCN layer has (311) orientation in the region d1 of the rake face,

the TiCN layer has a (422) orientation in the region d2 of the flank face,

when the rake face and the flank face are continuous with each other with the cutting edge face therebetween,

the region D1 is a region between an imaginary line D1 and a boundary between the rake face and the cutting edge face, an imaginary line D1 is located on the rake face and is 500 μm apart from an imaginary ridge line where a face obtained by extending the rake face and a face obtained by extending the flank face intersect, and

the region D2 is a region between an imaginary line D2 and a boundary between the flank face and the cutting edge face, the imaginary line D2 is located on the flank face and is spaced 500 μm from the imaginary ridge line, and

when the rake face and the flank face are continuous with each other with a ridge therebetween,

the region D1 is a region between the ridge line and an imaginary line D1, wherein the imaginary line D1 is located on the rake face and is spaced 500 μm from the ridge line, and

region D2 is the region between the ridge and the imaginary line D2, where the imaginary line D2 lies on the flank face and is 500 μm apart from the ridge.

The surface-coated cutting tool of the present embodiment (hereinafter, also simply referred to as "cutting tool") includes a base material and a coating film covering the base material. The cutting tool may for example be a drill, an end mill, replaceable cutting inserts for drills, replaceable cutting inserts for end mills, replaceable cutting inserts for milling, replaceable cutting inserts for turning, a metal saw, a gear cutting tool, a reamer or a tap.

< substrate >

The substrate of the present embodiment may be any conventionally known such substrate. For example, the substrate preferably includes one selected from the group consisting of: cemented carbides (e.g., tungsten carbide (WC) -based cemented carbides, cemented carbides containing Co in addition to WC, cemented carbides containing additionally carbonitrides of Cr, Ti, Ta, Nb, and the like in addition to WC); cermet (mainly including TiC, TiN, TiCN, etc.), high-speed steel, ceramic (e.g., titanium carbide, silicon nitride, aluminum nitride, or alumina), cubic boron nitride sintered body (cBN sintered body), and diamond sintered body, and more preferably includes one selected from the group consisting of cemented carbide, cermet, and cBN sintered body.

Among these various types of base materials, a WC-based cemented carbide or a cermet (particularly a TiCN-based cermet) is particularly preferably selected. This is because these base materials are excellent in balance between hardness and strength at high temperatures, and have excellent characteristics as base materials for surface-coated cutting tools used for the above-mentioned applications.

When the substrate is a cemented carbide, the substrate preferably contains 7 mass% or more and 12 mass% or less of cobalt, more preferably 8 mass% or more and 11 mass% or less of cobalt, and still more preferably 9 mass% or more and 10.5 mass% or less of cobalt, relative to the total mass of the substrate. The content ratio of cobalt can be determined by, for example, titration.

The substrate has a rake face and a relief face. "rake surface" means a surface that scratches chips cut from a workpiece material. "flank" means the face of a portion that is in contact with the workpiece material. The substrate is divided into the following two cases: "the rake face and the flank face are continuous with each other by the cutting edge face located therebetween", and "the rake face and the flank face are continuous with each other by the ridge line located therebetween". This will be described below with reference to fig. 1 to 6.

Fig. 1 is a perspective view showing one aspect of a cutting tool, and fig. 2 is a sectional view taken along line X-X in fig. 1. The cutting tool having such a shape is used as a replaceable cutting insert for turning.

The surface of the cutting tool 10 shown in fig. 1 and 2 includes an upper surface, a lower surface, and four side surfaces, and the cutting tool 10 has a quadrangular prism shape which is slightly thinner as a whole in the vertical direction. The cutting tool 10 also has a through hole penetrating its upper and lower surfaces, and adjacent side surfaces are connected to each other by an arc surface at each boundary of the four side surfaces.

In the cutting tool 10, the upper surface and the lower surface form a rake face 1a, four side faces (and an arc face connecting the side faces to each other) form a flank face 1b, and each arc face connecting the rake face 1a and the flank face 1b forms a cutting edge face 1 c.

Fig. 3 is a partially enlarged view of fig. 2. Fig. 3 shows an imaginary plane a, a boundary AA, an imaginary plane B, a boundary BB, and an imaginary edge line AB'.

The imaginary plane a corresponds to a plane obtained by extending the rake face 1 a. The boundary AA is a boundary between the rake face 1a and the cutting edge face 1 c. The imaginary plane B corresponds to a plane extended from the flank face 1B. The boundary BB is a boundary between the flank face 1b and the cutting edge face 1 c. The imaginary edge line AB 'is an intersection line of a plane (imaginary plane a) extended from the rake face 1a and a plane (imaginary plane B) extended from the flank face 1B, and the imaginary plane a and the imaginary plane B intersect with each other to define the imaginary edge line AB'.

In the case shown in fig. 3, the cutting edge face 1c is a curved face (ground). The rake face 1a and the flank face 1b are continuous with each other with the cutting edge face 1c therebetween, and the portion of the rake face 1a and the flank face 1b adjacent to the cutting edge face 1c and the cutting edge face 1c form a cutting edge portion of the cutting tool 10.

In fig. 3, the imaginary plane a and the imaginary plane B are respectively shown in the form of lines, and the boundary AA, the boundary BB, and the imaginary ridgeline AB' are all shown in the form of points.

Although fig. 1 to 3 show the case where the cutting edge face 1c is a curved face (ground), the shape of the cutting edge face 1c is not limited thereto. For example, as shown in fig. 4, the cutting facet 1c may have a planar shape (negative margin). Alternatively, as shown in fig. 5, the cutting facet 1c may have a shape including both a flat surface and an arc surface (a shape combining a ground and a negative margin).

As in the case shown in fig. 3, in the case shown in fig. 4 and 5, too, the rake face 1a and the flank face 1B are continuous with each other with the cutting edge face 1c therebetween, and define an imaginary plane a, a boundary AA, an imaginary plane B, a boundary BB, and an imaginary ridge AB'.

In other words, all cases shown in fig. 3 to 5 are included in the "case where the rake face and the flank face are continuous with each other with the cutting edge face located therebetween".

In the case where the base material 1 has the shape as shown in fig. 3 to 5 as described above, the cutting edge face 1c may be determined only according to the shape thereof. This is because in this case, the cutting edge face 1c is not included in the imaginary plane a or the imaginary plane B, and thus can be visually distinguished from the rake face 1a and the flank face 1B.

The cutting facet 1c is generally the surface of the substrate 1 and may include a face formed by machining the edges of the intersecting faces. In other words, the substrate 1 is obtained by machining at least a part of the surface of a substrate precursor formed of, for example, a sintered body, and the cutting edge face 1c may include a face formed by chamfering with machining.

In contrast, the case where the base material 1 has a sharp edge shape as shown in fig. 6 is included in the "case where the rake face and the flank face are continuous with each other with the ridge line therebetween".

In the case shown in fig. 6, the cutting edge face 1c shown in fig. 3 to 5 does not exist, the rake face 1a and the flank face 1b are adjacent to each other, the boundary between the rake face 1a and the flank face 1b defines an edge line AB, and the portion adjacent to the edge line AB and the edge line AB in the rake face 1a and the flank face 1b form a cutting edge portion of the cutting tool 10.

Although the shape of the base material 1 and the names of the respective portions have been described with reference to fig. 1 to 6, the shapes and the names of the respective portions corresponding to the base material described above may be similarly used for the surface-coated cutting tool according to the present embodiment. That is, the surface-coated cutting tool has a rake surface and a flank surface.

< coating film >

The "coating film" according to the present embodiment means a film that covers at least a part of the rake face and at least a part of the flank face in the base material. This is within the scope of the present embodiment even if the composition is partially different in a part of the base material.

The thickness of the coating is preferably 6.5 μm to 14 μm, and more preferably 8 μm to 11 μm. Herein, the "thickness of the coating film" refers to a layer constituting the coating film (e.g., TiCN layer, Al described below)₂O₃Layer and any other layers). The thickness of the coating can be measured by measuring the cross section of the surface-coated cutting tool at a magnification of 1000 times using, for example, an optical microscope. Specifically, the thickness may be obtained by measuring any three points in the cross section and averaging the thicknesses of the measured three points. For TiCN layer, Al, described below₂O₃The same applies to the measurement of the thickness of each of the layer and any other layer.

The coating includes a TiCN layer. "TiCN layer" refers to a layer made of TiCN. The TiCN layer may contain inevitable impurities within a range that does not impair the effects obtained by the surface-coated cutting tool according to the present embodiment. The same applies to "any other layer" described below.

The thickness of the TiCN layer is preferably 6 μm to 10 μm, and more preferably 7 μm to 9 μm. For example, the thickness of the TiCN layer can be measured by measuring the cross section of the surface-coated cutting tool at a magnification of 1000 times using an optical microscope.

The coating film may further include any other layer within a range not to impair the effects of the present embodiment. Examples of any other layer include TiN layer, TiBNO layer, TiCNO layer, TiB₂Layer, TiAlN layer, TiAlCN layer, TiAlON layer, TiAlONC layer and Al₂O₃And (3) a layer. Further, there is no particular limitation on the stacking order of these layers. That is, the TiCN layer may be the outermost layer in the coating film.

In the coating film according to the present embodiment, Al may be provided on the TiCN layer₂O₃And (3) a layer. The expression "providing Al on the TiCN layer₂O₃Layer "means that only the upper side of the TiCN layer needs to be provided with Al₂O₃Layers and no contact between these layers is required. In other words, it is possible to form a TiCN layer and Al₂O₃Any other layers are disposed between the layers. In the coating, Al may be directly provided on the TiCN layer₂O₃And (3) a layer. Al (Al)₂O₃The thickness of the layer is preferably 0.5 μm to 4 μm, more preferably 0.5 μm to 3 μm, and still more preferably 1 μm to 2 μm.Al can be measured by measuring the cross section of the surface-coated cutting tool at a magnification of 1000 times, for example, using an optical microscope₂O₃The thickness of the layer.

< orientation of TiCN layer in region d1 of rake face >

In the surface-coated cutting tool according to the present embodiment, the TiCN layer has the (311) orientation in the region d1 of the rake face 1 a.

In the case of "the rake face 1a and the flank face 1b are continuous with each other with the cutting edge face 1c located therebetween" as shown in fig. 3 to 5, the region D1 is "a region between an imaginary line D1 and a boundary AA, wherein the imaginary line D1 is located on the rake face 1a and is spaced 500 μm from the imaginary ridge line AB', and the boundary AA is located between the rake face 1a and the cutting edge face 1 c".

In contrast, in the case of "the rake face 1a and the flank face 1b are continuous with each other with the ridge line AB therebetween" as shown in fig. 6, the region D1 is "a region between the ridge line AB and an imaginary line D1, wherein the imaginary line D1 is located on the rake face 1a and is spaced 500 μm from the ridge line AB".

In this embodiment, in addition to the region d1, the TiCN layer may also have a (311) orientation in other regions of the rake face than the region d 1. For example, the TiCN layer may have (311) orientation in the entire rake face.

The expression "the TiCN layer has (311) orientation" means that, in the texture coefficient TC (hkl) defined by the following equation (1), the texture coefficient TC (311) of the (311) plane in the TiCN layer is larger than that of any other crystal orientation plane. In other words, this means that the texture coefficient TC (311) is the largest among those of the other crystal orientation planes. In this equation, I (hkl) and I (h)_xk_yl_z) Respectively, the measured diffraction intensities of the (hkl) plane and (h)_xk_yl_z) Measured diffraction intensity of the surface. I is_o(hkl) represents the average value of the powder diffraction intensity of TiC (card No. 32-1383) at the (hkl) plane and the powder diffraction intensity of TiN (card No. 38-1420) at the (hkl) plane according to the powder diffraction Standard Commission database (JCPDS database). I is_o(h_xk_yl_z) Representing (h) according to JCPDS database_xk_yl_z) Powder diffraction intensity of TiC (card number 32-1383) of the surface and (h)_xk_yl_z) Average value of powder diffraction intensities of TiN (card No. 38-1420) of the face. (hkl) and (h)_xk_yl_z) Each represents any one of eight surfaces including a (111) surface, a (200) surface, a (220) surface, a (311) surface, a (331) surface, a (420) surface, a (422) surface, and a (511) surface ".

[ mathematical formula 2]

The texture coefficient tc (hkl) can be obtained by, for example, X-ray diffraction measurement performed under the following conditions. Specifically, when the base material 1 (i.e., the cutting tool 10) has a sharp edge shape as shown in fig. 6, X-ray diffraction measurement is performed on any three points in the region D1 between the ridge line AB and the imaginary line D1 spaced 500 μm from the ridge line AB, and the average of the texture coefficients of the (hkl) plane obtained at these three points according to the above equation (1) is taken as the texture coefficient tc (hkl) in the region D1 of the rake face 1a (fig. 7). Although three points on the imaginary line D1 are selected as arbitrary three points in fig. 7, any three points may be selected as long as they are within the region D1. In the case where the base material 1 has the shape shown in fig. 3 to 5, X-ray diffraction measurement is performed on any three points in the region D1 between the boundary AA and the virtual line D1, and the average of the texture coefficients of the (hkl) plane obtained at these three points is taken as the texture coefficient tc (hkl) in the region D1 of the rake face. Hereinafter, the texture coefficient in the region d1 of the rake face is referred to as "TC_rake(hkl) "and the like.

(conditions for X-ray diffraction measurement)

X-ray output: 45kV and 200mA

The X-ray source, wavelength CuK α,

a detector: D/teX Ultra 250

Scanning shaft: 2 theta/theta

Longitudinally limiting slit width: 2.0mm

Scanning mode: CONTINUOUS

Scanning speed: 20 DEG/min

Here, the diffraction intensity of the X-ray is calculated from the integrated intensity measurement.

The (311) texture coefficient in the region d1 of the rake face is preferably 3 or more, and more preferably 4 or more.

< orientation of TiCN layer in region d2 of flank face >

In the surface-coated cutting tool according to the present embodiment, the TiCN layer has a (422) orientation in the region d2 of the flank face 1 b.

Here, in the case of "the rake face 1a and the flank face 1b are continuous with each other with the cutting edge face 1c interposed therebetween" as shown in fig. 3 to 5, the region D2 is "a region interposed between an imaginary line D2 on the flank face 1b and spaced 500 μm from the imaginary ridge line AB', and a boundary BB between the flank face 1b and the cutting edge face 1 c".

In contrast, in the case of "the rake face 1a and the flank face 1b are continuous with each other with the ridge line AB therebetween" as shown in fig. 6, the region D2 is "a region between the ridge line AB and an imaginary line D2, wherein the imaginary line D2 is located on the flank face 1b and is spaced 500 μm from the ridge line AB".

In this embodiment, in addition to region d2, the TiCN layer may also have a (422) orientation in other regions in the flank surface than region d 2. For example, the TiCN layer may have a (422) orientation throughout the flank face.

The expression "the TiCN layer has (422) orientation" means that, in the texture coefficient TC (hkl) defined by the above equation (1), the texture coefficient TC (422) of the (422) plane in the TiCN layer is larger than that of any other crystal orientation plane. In other words, this means that the texture coefficient TC (422) is the largest among those of the other crystal orientation planes. The above texture coefficient tc (hkl) can be obtained by a method similar to that described in the above < orientation of TiCN layer in the region d1 of the rake face >.

That is, in the case of "the rake face 1a and the flank face 1b are continuous with each other with the cutting edge face 1c interposed therebetween" as shown in fig. 3 to 5, the region D2 is "a region interposed between an imaginary line D2 on the flank face 1b and spaced 500 μm from the imaginary ridge line AB', and a boundary BB between the flank face 1b and the cutting edge face 1 c".

In contrast, in the case of "the rake face 1a and the flank face 1b are continuous with each other with the ridge line AB therebetween" as shown in fig. 6, the region D2 is "a region between the ridge line AB and an imaginary line D2, wherein the imaginary line D2 is located on the flank face 1b and is spaced 500 μm from the ridge line AB".

Hereinafter, the texture coefficient in the region d2 of the flank face is referred to as "TC_flank(hkl) "and the like.

The texture index (422) in the region d2 of the flank face is preferably 3 or more, and more preferably 4 or more.

In the present embodiment, in the region d1 of the rake face, the ratio TC of the (311) texture coefficient to the (422) texture coefficient_rake(311)/TC_rake(422) Preferably greater than 1, more preferably 1.2 or greater, and still more preferably 1.5 or greater. Here, when TC_rake(422) Is zero and TC_rake(311) When more than zero, TC_rake(311)/TC_rake(422) Determined to be greater than 1. TC (tungsten carbide)_rake(311)/TC_rake(422) Above 1, the effect according to the present embodiment is achieved.

In the present embodiment, the ratio TC of the (422) texture coefficient in the region d1 of the rake face to the (422) texture coefficient in the region d2 of the flank face_rake(422)/TC_flank(422) Preferably 1 or less, more preferably 0.8 or less, and still more preferably 0.7 or less. TC (tungsten carbide)_rake(422)/TC_flank(422) At 1 or less, the effect according to the present embodiment is achieved.

Method for producing surface-coated cutting tool

A method of manufacturing a surface-coated cutting tool according to the present embodiment is a method of manufacturing the above-described surface-coated cutting tool, the method including:

a substrate preparation step of preparing a substrate;

a TiCN layer coating step of coating at least a part of the rake face and at least a part of the flank face with a TiCN layer; and

a shot blasting step of shot blasting the TiCN layer in the rake face,

wherein the TiCN layer coating step is performed by chemical vapor deposition and includes discontinuously supplying a raw material gas of the TiCN layer. The steps will be described below.

< step of preparing substrate >

In the substrate preparation step, a substrate is prepared. The substrate may be any substrate generally known as a substrate of this type, as described above. For example, when the base material is made of cemented carbide, first, raw material powders having a mixture composition (mass%) shown in table 1 below are uniformly mixed using a commercially available milling machine, and then the powder mixture is compression-molded into a predetermined shape (e.g., CNMG120408 NUX). Subsequently, the compact of the raw material powder is sintered at 1300 ℃ to 1500 ℃ or less for 1 to 2 hours in a predetermined sintering furnace, thereby obtaining a base material made of cemented carbide.

< TiCN layer coating step >

In the TiCN layer coating step, at least a portion of the rake face and at least a portion of the flank face are coated with a TiCN layer.

Here, "at least a part of the rake face" is an area in the rake face 1a, and includes an area D1 between an edge line AB, which is an edge line at the intersection between the rake face 1a and the flank face 1b, and an imaginary line D1 spaced 500 μm from the edge line AB (e.g., fig. 6). Similarly, at least a part of the "flank face" is a region in the flank face 1b, and includes a region D2 between an edge line AB and an imaginary line D2, wherein the edge line AB is an edge line at the intersection between the rake face 1a and the flank face 1b, and the imaginary line D2 is spaced 500 μm from the edge line AB (for example, fig. 6).

In one aspect of the present embodiment, the "at least a portion of the rake face" is an area in the rake face 1a and includes an area D1 between a boundary AA and an imaginary line D1, wherein the boundary AA is located between the rake face 1a and the cutting edge face 1c, and the imaginary line D1 is spaced 500 μm apart from an imaginary edge line AB' at an intersection between an imaginary plane a including the rake face 1a and an imaginary plane B including the flank face 1B (e.g., fig. 3 to 5). Similarly, at least a part of the "flank face" is a region in the flank face 1b, and includes a region D2 between a boundary BB and an imaginary line D2, wherein the boundary BB is located between the flank face 1b and the cutting edge face 1c, and the imaginary line D2 is spaced 500 μm from the imaginary ridge AB' (for example, fig. 3 to 5).

A method of coating at least a portion of a rake surface and at least a portion of a flank surface with a TiCN layer is performed by Chemical Vapor Deposition (CVD), and includes discontinuously supplying a raw material gas of the TiCN layer to form the TiCN layer. That is, the TiCN layer coating step is performed by chemical vapor deposition, and includes discontinuously supplying a raw material gas of the TiCN layer.

Specifically, first, TiCl is mixed₄、CH₃CN、N₂And H₂Used as a raw material gas. For example, the mixing amounts are as follows: TiCl (titanium dioxide)₄In an amount of 2 to 10 vol%, CH₃The amount of CN is 0.4 to 2.5 vol%, N₂In an amount of 15% by volume, the balance being H₂。

The temperature in the reaction chamber during the reaction by CVD is preferably 800 to 850 ℃.

The pressure in the reaction chamber during the reaction by CVD is preferably 6kPa to 7kPa, and more preferably 6kPa to 6.7 kPa.

The total gas flow rate during the reaction by CVD is preferably 80L/min to 120L/min, and more preferably 80L/min to 100L/min.

An example of a method of discontinuously supplying the raw material gas is to alternately supply the raw material gas and H at predetermined time intervals₂Gas (100 vol%). More specifically, the supply of the source gas is stopped every 15 minutes, and H equal in volume to the source gas is supplied₂Gas for 1 minute. Thus, the TiCN is atomized, which makes it possible toTo form a TiCN layer more likely to be changed to have an orientation of (311) by shot blasting.

Any other layers, such as Al, may be stacked after forming the TiCN layer₂O₃And (3) a layer.

< shot blasting step >

In the shot blasting step, the TiCN layer of the rake face is shot blasted. "shot blasting" refers to a process of colliding (projecting) a large amount of small balls (media) of steel, nonferrous metals, etc. with the surface of a rake face, etc. at high speed to change the properties of the surface such as orientation and compressive stress. In the present embodiment, the shot peening of the rake face reduces the proportion of (422) faces in the TiCN layer of the rake face and increases the proportion of (311) faces. Therefore, the TiCN layer has higher toughness and has excellent defect resistance. The medium may be projected by any means as long as the orientation of the TiCN layer is changed, and the medium may be projected directly onto the TiCN layer or onto any other layer disposed on the TiCN layer (e.g., Al₂O₃Layer) on the substrate. The projection may be performed by any means as long as the medium is projected onto the area d1 of the rake surface, for example, the medium may be projected onto the entire rake surface.

A distance between the projection unit of the projection medium and the surface of the rake face or the like (hereinafter, also referred to as "projection distance") is preferably 80mm to 120mm, and more preferably 80mm to 100 mm.

The pressure applied to the medium at the time of projection (hereinafter, also referred to as "projection pressure") is preferably 0.1 to 0.5MPa, and more preferably 0.1 to 0.3 MPa.

The treatment time of the shot blast is preferably 10 seconds to 60 seconds, and more preferably 10 seconds to 30 seconds.

Various conditions of the shot blasting can be appropriately adjusted according to the composition of the coating film.

< other steps >

In the manufacturing method according to the present embodiment, in addition to the above steps, another step may be appropriately performed as long as the effect of shot peening is not impaired.

This embodiment preferably further comprises Al₂O₃Layer stackA step in which Al is added after the TiCN layer coating step or the shot blasting step₂O₃The layers are stacked on top of a TiCN layer. For example when stacking Al by CVD₂O₃When layers are used, the layers may be stacked as described below. Firstly, the AlCl is added₃、HCl、CO₂、H₂S and H₂Used as a raw material gas. For example, the mixing amount may be as follows: AlCl₃In an amount of 1.6 vol%, HCl in an amount of 3.5 vol%, CO₂In an amount of 4.5 vol%, H₂The amount of S is 0.2 vol%, and the balance is H₂。

The CVD conditions at this time were 1000 ℃ C, 6.7kPa, and the gas flow rate (total gas amount) was 56.3L/min.

When any other layer is formed as described above, the layer can be formed by a conventional method.

< accompanying notes >

The above description includes the embodiments listed below.

(attached note 1)

A surface-coated cutting tool comprising: a base material and a coating film for coating the base material, wherein

The base material includes a rake face, a flank face, and a cutting edge portion connecting the rake face and the flank face to each other,

the coating film comprises a TiCN layer,

the TiCN layer has (311) orientation in region D1, region D1 is a region in the rake face and between the ridge line, which is the ridge line at the intersection between the rake face and the flank face, and an imaginary line D1, which is the line D1 is 500 μm away from the ridge line, and

the TiCN layer has a (422) orientation in region D2, region D2 being a region in the flank face and between the ridge line and an imaginary line D2, the imaginary line D2 being spaced 500 μm from the ridge line.