JP2002144109A - Surface coat cemented carbide cutting tool having excellent chipping resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface coat cemented carbide cutting tool having excellent chipping resistance. SOLUTION: In this surface coat cemented carbide cutting tool, on the surface of a WC cemented carbide base, (a) as a lower layer, a Ti compound layer having the average layer thickness of 0.5 to 15 μm and composed of TiC layer, TiN layer, TiCN layer, TiCO layer and TiCON layer, (b) as an intermediate layer, an Al2O3, layer having the average layer thickness of 1 to 15 μm, (c) as a surface bed layer, a Ti oxide layer having the average layer thickness of 0.1 to 3 μm and satisfying the composition formula: TiOX (X: atom ratio to Ti, ranging from 1.2 to 1.7), and (d) as a surface layer, a Ti nitrogen oxide layer having the average layer thickness of 0.05 to 2 μm and satisfying the composition formula TiN1-Y(O)Y [wherein (O) indicates diffusion oxygen from the above surface bed layer, Y: atom ratio to Ti ranging from 0.01 to 0.4, are chemically and/or physically vapor deposited as a hard coat layer with the whole average layer thickness of 3 to 30 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a cutting tool) in which a hard coating layer exhibits excellent chipping resistance, particularly when used for high-speed cutting of various steels and cast irons. , Coated carbide tools).

[0002]

2. Description of the Related Art Generally, cutting tools include a throw-away tip which is detachably attached to a tip of a cutting tool for turning or planing of various materials such as steel and cast iron. Drills and miniature drills used for drilling and cutting of solids, and solid type end mills used for face milling and grooving of the work material, shoulder machining, and the like, and the detachable tip is detachably attached. In addition, a throw-away end mill tool or the like that performs cutting in the same manner as the solid type end mill is known. Further, conventionally, generally, as the above-mentioned cutting tool, a tungsten carbide-based cemented carbide substrate (hereinafter, referred to as
(A) as a lower layer, on the surface of a cemented carbide substrate).
It has an average layer thickness of 5 to 15 μm and is made of Ti carbide (hereinafter, referred to as Ti carbide).
A TiC layer, a nitride (hereinafter also referred to as TiN) layer, a carbonitride (hereinafter referred to as TiCN) layer, a carbonate (hereinafter referred to as TiCO) layer, and a carbonitride (hereinafter referred to as TiCNO) ), A Ti compound layer composed of one or more of the above-mentioned layers, and (b) an intermediate layer of 1 to 15
Aluminum oxide having an average layer thickness of μm (hereinafter referred to as Al
(Shown as ₂ O ₃ ) layer and (c) surface layer as 0.05 to 2 μm.
TiN layer having an average layer thickness of m, coated carbide tool formed by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of the above (a) to (c) with an average layer thickness of 3 to 30 μm It has been known. In the above-mentioned conventional coated carbide tool, the TiN layer as a surface layer constituting the hard coating layer is:
It is also known that the outermost surface layer of the hard coating layer is composed of a TiN layer in order to facilitate the discrimination between before and after use of the tool, since the tool itself has a golden surface tone.

In general, the Ti compound layer and the Al ₂ O ₃ layer constituting the hard coating layer of the coated carbide tool have a granular crystal structure, and the Al ₂ O ₃ layer has an α-type crystal structure. The Al ₂ O ₃ layer is subjected to X-ray diffraction using, for example, a Cukα ray having a wavelength of 1.5 angstroms as a radiation source. Is carried out, if the layer is an α-Al ₂ O ₃ layer, depending on the conditions for forming the layer, both are 2θ and 2
5.6 degrees (012 crystal plane orientation), 35.1 degrees (104 crystal plane orientation), 37.8 degrees (110 crystal plane orientation), 43.
4 degrees (113 crystal plane orientation), 52.6 degrees (024 crystal plane orientation), 57.5 degrees (116 crystal plane orientation), 66.5 degrees (124 crystal plane orientation), and 68.2 degrees (030 crystal plane). Α-Al ₂ O ₃ layer showing an X-ray diffraction pattern in which the highest diffraction peak height appears at any diffraction angle of (plane orientation), and κ-Al ₂ O ₃ layer In the same manner, depending on the formation conditions, 19.7 is 29.7.
Degrees, 29.4 degrees, 32.1 degrees, 34.9 degrees, 37.3 degrees
Κ-, which shows an X-ray diffraction pattern in which the highest diffraction peak height appears at any of the diffraction angles of degrees, 43.9 degrees, 52.6 degrees, 56.0 degrees, 62.3 degrees, and 65.2 degrees. Al ₂
It is also well known that an O ₃ layer can be formed.

Further, as described in, for example, JP-A-6-8010 and JP-A-7-328808, the TiCN layer of the Ti compound layer constituting the hard coating layer of the coated carbide tool is For the purpose of improving the toughness of the layer itself, it is formed by chemical vapor deposition at a medium temperature range of 700 to 950 ° C. using a mixed gas containing an organic carbonitride as a reaction gas in a normal chemical vapor deposition apparatus. It is also known to have a growing crystal structure.

[0005]

On the other hand, in recent years, there has been a strong demand for labor saving and energy saving for cutting, and with this, cutting has tended to be accelerated. In particular, the surface layer of the hard coating layer is composed of a TiN layer formed by vapor deposition for the purpose of identification before and after use. Since the TiN layer has a strong adhesion to various steels as work materials, particularly high heat generation is caused. In the high-speed cutting process with
Strongly adheres to the N layer and acts to locally peel off the TiN layer from the hard coating layer.
Since the N layer has excellent adhesion to both the Ti compound layer and the Al ₂ O ₃ layer, which are the other constituent layers, these constituent layers are also locally localized together with the TiN layer. Peeled off, resulting in chipping (small chipping) on the cutting edge
At the present time, the service life is reached in a relatively short time.

[0006]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoints, the above-mentioned conventional coated cemented carbide tool has a TiN as a surface layer constituting the hard coating layer.
Results focus on the layer, were studied, in the formation of the (a) the hard coating layer, after the formation of the the Al ₂ O ₃ layer as an intermediate layer, by chemical vapor deposition apparatus or physical vapor deposition apparatus, the Al ₂ The surface of the O ₃ layer was made such that the reaction gas composition was TiCl ₄ : 0.05 to 10% by volume, inert gas: remaining, and reaction atmosphere temperature: 800 to 1100 ° C., reaction atmosphere pressure: 4 ～90KPa, when treated with the criteria, Ti from the atmosphere said Al ₂
Penetrate diffuse to the surface portion of the O ₃ layer, it becomes Ti intrusion diffusion zone is formed in the surface portion of the the Al ₂ O ₃ layer.

[0007] (b) the Ti intrusion diffuse band the Al ₂
In the state formed over a depth of 0.1 to ₃ μm from the surface of the O ₃ layer, the composition of the reaction gas is set as
_{In, TiCl 4: 0.2~10%, CO} 2: 0.1~10%, Ar: 5~60%, H 2: remainder, and then, and, Temperature of reaction atmosphere: 800 to 1100 ° C., the reaction atmosphere pressure : 4 to 70 kPa, having an average layer thickness of 0.1 to 3 μm, and a ratio of oxygen to Ti in an atomic ratio of 1.25 to 1.90 as measured by an Auger spectrometer. That is, when represented by the composition formula: TiO _W , a Ti oxide layer satisfying the following atomic ratio with respect to W: Ti: 1.25 to 1.90 is formed. The band acts to firmly adhere to the surface of the Al ₂ O ₃ layer.

(C) On the Ti oxide layer, as a surface layer, under normal conditions, that is, the reaction gas composition is TiCl ₄ : 0.2 to 10% by volume%, N ₂ : 4 to 60. %, H ₂ : remaining, and a reaction atmosphere temperature: 800 to 1100 ° C., a reaction atmosphere pressure: 4 to 90 kPa, and an average layer thickness of 0.05 to 2 μm.
When the iN layer is formed, oxygen of the Ti oxide layer constituting the surface underlayer diffuses during the formation of the surface layer, and a Ti nitride oxide layer is formed. In this case, the Ti nitride oxide layer is formed. The subsequent surface underlayer was measured at the center in the thickness direction with an Auger spectrometer, and the oxygen ratio was expressed as an atomic ratio to Ti of 1.2 to 1.7, that is, a composition formula: TiO _x . In this case, X: a Ti oxide layer satisfying an atomic ratio to Ti of 1.2 to 1.7. On the other hand, the surface layer is formed by diffusing oxygen at the center in the thickness direction using an Auger spectrometer. Is from 0.01 to the atomic ratio to Ti.
0.4, that is, when represented by a composition formula: TiN _1-Y (O) _Y , where (O) indicates oxygen diffused from the surface underlayer]. A Ti nitride oxide layer that satisfies 01 to 0.4.

(D) In the case of the coated cemented carbide tool obtained by chemical vapor deposition and / or physical vapor deposition of the resulting Ti nitride oxide layer and Ti oxide layer as a surface layer and a surface underlayer of the hard coating layer, the above The Ti oxynitride layer is
High-speed cutting with high heat generation because it has a golden surface tone equivalent to that of the N layer so that it can be identified before and after the use of the tool, and has extremely low adhesion to various steels as work materials. The chips heated at a high temperature are not adhered to the processing, and the Al _{2 of the} surface underlayer is further removed as described above.
With adhesion to O ₃ layer is significantly improved by Ti penetration diffusion zone formed in the surface portion of the the Al ₂ O ₃ layer, from becoming those improved toughness of the Al ₂ O ₃ layer itself, the cutting edge Chipping is significantly suppressed, and excellent cutting performance is exhibited over a long period of time. The research results shown in (a) to (d) above were obtained.

The present invention has been made on the basis of the above-mentioned research results, and (a) has an average layer thickness of 0.5 to 15 μm as a lower layer on the surface of a cemented carbide substrate;
Layer, TiN layer, TiCN layer, TiCO layer, and TiC
A Ti compound layer composed of one or more of NO layers, (b) an intermediate layer having an average layer thickness of 1 to 15 μm, and a surface portion having a depth of 0.1 to 3 μm from the surface; the Al ₂ O ₃ layer obtained by forming a Ti intrusion diffusion zone over, as (c) a surface underlayer has an average layer thickness of 0.1 to 3 m, and the composition formula: TiO _X, in case of expressed The central part in the thickness direction is measured with an Auger spectroscopic analyzer, and a Ti oxide layer satisfying an atomic ratio of X: Ti to 1.2 to 1.7 is satisfied. 2 μm
When the average layer thickness is represented by the composition formula: TiN _1-Y (O) _Y ,
(O) indicates the oxygen diffused from the outermost underlayer.) Similarly, the central part in the thickness direction is measured by an Auger spectrometer, and the atomic ratio to Y: Ti satisfies 0.01 to 0.4. A hard nitride layer composed of the above (a) to (d) with a mean thickness of 3 to 30 μm by chemical vapor deposition and / or
Alternatively, it is characterized by a coated carbide tool having excellent chipping resistance, which is obtained by physical vapor deposition.

Next, the constituent layers of the hard coating layer of the coated carbide tool according to the present invention will be described. By forming the Ti intrusion diffusion zone in the surface portion of the Ti intrusion diffusion zone as above the Al ₂ O ₃ layer of (a) the Al ₂ O ₃ layer surface with the adhesion between the surface underlying layer formed to the surface This improves the chipping resistance by improving the toughness of the Al ₂ O ₃ layer itself, but if the depth from the surface is less than 0.1 μm, the desired effect of improving the adhesion and toughness is obtained. On the other hand, if the depth from the surface exceeds 3 μm, the wear resistance at the time of cutting tends to decrease, so the depth from the surface is 0.1 to 3 μm. I decided.

(B) Ti Nitride Layer (Surface Layer) The ratio of the diffusion oxygen (Y
The value) was set to 0.01 to 0.40 in atomic ratio to Ti, if the value was less than 0.01, the desired effect in suppressing the adhesion to cutting chips could not be secured. If it exceeds 0.4, pores are easily formed in the layer, and it is difficult to form a sound surface layer stably.

(C) Ti Oxide Layer (Surface Underlayer) As described above, the Ti nitride oxide layer, which also constitutes the surface layer, first serves as a surface underlayer, in which the proportion of oxygen is represented by the atomic ratio to Ti. Ti with 1.25 to 1.90 (W value)
It is formed by forming an oxide layer, and then depositing a TiN layer on the surface underlayer under normal conditions, so that diffusion of oxygen from the surface underlayer at the time of forming the TiN layer is suppressed. Indispensably, when the W value of the Ti oxide layer constituting the surface underlayer is less than 1.25, the diffusion reaction of oxygen into the TiN layer is rapidly reduced, and the proportion of the diffused oxygen in the surface layer is reduced. (Y value) cannot be not less than 0.01 in atomic ratio with respect to Ti, while when the W value exceeds 1.90, the ratio of diffused oxygen in the surface layer becomes 0.40 in atomic ratio with respect to Ti. Therefore, the W value is determined to be 1.25 to 1.90. In this case, the ratio of oxygen (X value) in the surface underlayer after the surface layer is formed is represented by the atomic ratio to Ti. 1.
When the X value of the surface underlayer after the formation of the surface layer satisfies 1.2 to 1.7, the Y value of the surface layer becomes 2 to 1.7. 0.01-0.4
0 is satisfied.

(D) Average Layer Thickness of Surface Layer and Surface Underlayer Further, the average layer thickness of the surface layer and the surface underlayer also constituting the hard coating layer is 0.05 to 2 μm and 0.1 to 3 μm, respectively. The reason is that the average layer thickness is 0.05μ.
If it is less than 0.1 m, the desired surface tone (golden color) cannot be secured in the former case, and the oxygen supply to the surface layer becomes insufficient in the latter case. Has a color tone imparting effect of 2 μm, and the latter has an oxygen supplying effect of 3 μm.
This is based on the reason that an average layer thickness of μm can be sufficiently satisfied.

(E) Average layer thickness of lower layer and intermediate layer Average layer thickness of lower layer and intermediate layer is 0.5 to 15 respectively.
μm and 1 to 15 μm are the lower layer (T
When the average layer thickness of the (i-compound layer) is less than 0.5 μm, chipping easily occurs on the cutting edge. On the other hand, when the average layer thickness of the latter intermediate layer (Al ₂ O ₃ layer) is less than 1 μm, the cutting When the progress of the flank wear of the blade is accelerated, and when the average layer thickness of the former exceeds 15 μm, the wear resistance rapidly decreases, while when the average layer thickness of the latter exceeds 15 μm, This is because chipping easily occurs in the cutting blade. Further, the reason why the total average layer thickness of the hard coating layer is set to 3 to 30 μm is that if the layer thickness is 3 μm, it is not possible to secure a desired excellent wear resistance, and if the layer thickness exceeds 30 μm, This is because chipping and chipping are likely to occur in the cutting blade.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a coated carbide tool of the present invention
Will be specifically described with reference to examples. (Example 1) As raw material powders, each was 0.5 to 4 μm.
WC powder having a predetermined average particle size in the range of (Ti,
W) C (weight ratio, hereinafter the same, TiC / WC = 30/7)
0) powder, (Ti, W) CN (TiC / TiN / WC =
24/20/56) powder, (Ta, Nb) C (TaC /
NbC = 90/10) powder, Cr_ThreeC_TwoPowder, and Co
Powders are prepared, and these raw material powders are mixed as shown in Table 1.
And wet mixed in a ball mill for 72 hours, dried
9.8 × 10⁷Pa (1 ton / cm^Two) At pressure
It is pressed into a green compact of a predetermined shape, and this green compact is 1.3
Pa (1 × 10 ^-21300 to 15 in a torr) vacuum
Vacuum firing at a predetermined temperature within the range of 00 ° C for 1 hour
Stipulated in ISO / CNMG120408
Carbide substrate (chip)
P) A to F were manufactured respectively.

Next, these super-hard substrates (chips) A to F
Table 2 (l-TiCN in Table 1 was obtained by using a conventional chemical vapor deposition apparatus)
No. 010, which has a vertically elongated crystal structure
It shows the conditions for forming the CN layer, and the other conditions show the conditions for forming a normal granular crystal structure. The “target diffraction angles” of α-Al ₂ O ₃ and κ-Al ₂ O _{3 in} the table are X
Under the conditions shown in the target diffraction angle (2θ) at which the highest diffraction peak height appears in the X-ray diffraction pattern).
A compound layer and an Al ₂ O ₃ layer are formed. Then, the reaction gas composition is set as follows: TiCl ₄ : 5% by volume, Ar: remaining, and a reaction atmosphere temperature: 950 ° C., a reaction atmosphere pressure: 50 kPa, Under the conditions described above, the Al ₂ O ₃ layer was treated for a predetermined period of time to form a Ti intrusion diffusion band over the target depth from the surface shown in Table 4 (“Ti diffusion depth” in Table 4). (The unit is “μm”, the same applies to Tables 8 and 10 below.)
And a surface underlayer consisting of a diffusion oxide supply Ti oxide layer having a target layer thickness also shown in Table 4 under the conditions shown in Table 3 as a constituent layer of the hard coating layer, and also shown in Table 2 By forming a surface layer composed of a diffusion oxygen-containing Ti oxynitride layer having a target layer thickness also shown in Table 4 under the same conditions as the TiN (other layer) formation conditions, FIG.
FIG. 1A is a schematic perspective view and FIG. 2B is a schematic longitudinal sectional view of the present invention. Carbide chips) 1 to 15 were manufactured respectively.
As shown in Table 5, the same conditions were used except that no Ti intrusion diffusion zone was formed on the surface of the Al ₂ O ₃ layer and a TiN layer was formed instead of the surface layer and the surface underlayer. Thus, conventional surface-coated cemented carbide throwaway tips (hereinafter, referred to as conventionally-coated cemented carbide tips) 1 to 15 as conventional coated cemented carbide tools were manufactured, respectively.

The coated carbide tip 1 of the present invention obtained as a result
Surface layer and surface underlayer constituting hard coating layer of No. 15 to 15
About the oxygen content ratio at the center in the thickness direction (Y value and
And X value) were measured using an Auger spectrometer.
At this time, the values shown in Table 6 were shown. In addition,
Bright coated carbide tips 1-15 and conventional coated carbide tips 1
15 to 15, the α-
Al_TwoO_ThreeLayer and κ-Al _TwoO_Three1.5 on layers
Uses Cukα ray with gustrom wavelength as the source
Observed by X-ray diffraction
The highest diffraction peak height is at substantially the same diffraction angle as (2θ).
It shows the X-ray diffraction pattern that appears, and expands as a surface layer.
Both the oxygen-dispersed Ti nitride oxide layer and the TiN layer
It has a golden surface tone and the thickness of its constituent layers
And Al_TwoO_ThreeDepth of Ti intrusion diffusion zone at layer surface
The cross section was measured using a scanning electron microscope.
The average layer thickness and the average depth are substantially the same as the target values, respectively.
(Average of 5 points each). In addition, the present invention
In the hard chips 11 to 15, a hard coating layer is formed.
Vacancies are formed along the interface between the surface layer and the surface underlayer.
Scattering was observed. Note that the above target value and actual measurement value (surface
(Excluding measured values of X value of underlayer and Y value of surface layer)
The staff also showed the same results in Examples 2 and 3 below.

Next, the coated carbide tips 1 to 1 according to the present invention will be described.
5 and the conventional coated carbide tips 1 to 15 were screwed to the tip of a tool steel tool with a fixing jig. Work material: JIS SCM440 round bar, Cutting speed: 300 m / min . Infeed: 1.5 mm Feed: 0.2 mm / rev. , Cutting time: 10 minutes, Dry high-speed continuous turning test of alloy steel under the following conditions: Work material: JIS SNCM439 Lengthwise equally spaced round bar with four longitudinal grooves, Cutting speed: 350 m / min . Infeed: 1.5 mm Feed: 0.25 mm / rev. , Cutting time: 10 minutes, dry high-speed intermittent turning test of alloy steel under the conditions of
In each turning test, the flank wear width of the cutting edge was measured. Table 6 shows the measurement results.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

(Example 2) As raw material powder, average particle size:
Medium coarse WC powder having 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, 1.2 μm
NbC powder, 1.2 μm ZrC powder, 2.3 μm
m Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm
μm of (Ti, W) C powder and 1.8 μm of Co
Powders were prepared, and each of these raw material powders was blended in the composition shown in Table 7, and further added with wax, and ball-mixed in acetone for 24 hours, and dried under reduced pressure.
It is press-molded into various compacts of a predetermined shape at a pressure of 0 MPa, and these compacts are compacted in a vacuum atmosphere of 6 Pa at 7 ° C. /
The temperature is raised to a predetermined temperature in the range of 1370 to 1470 ° C. at a heating rate of 1 minute, held at this temperature for 1 hour, and then sintered under the condition of furnace cooling to obtain a 3 mm diameter of 8 mm, 13 mm, and 26 mm. Kinds of round bar sintered bodies for forming a cemented carbide substrate are formed, and the above three kinds of round bar sintered bodies are further subjected to grinding processing in a combination shown in Table 7 to obtain a diameter x length of a cutting edge portion. Is 6mm × 1 each
3mm, 10mm x 22mm, and 20mm x 45m
Carbide substrates (end mills) a to h each having a size of m were manufactured.

Next, these super-hard substrates (end mills)
With the honing applied to the surfaces of a to h, using a normal chemical vapor deposition apparatus, under the same conditions as shown in Table 2, the target layer thickness of Ti as a constituent layer of the hard coating layer shown in Table 8 was obtained.
A compound layer and an Al ₂ O ₃ layer are formed. Then, the reaction gas composition is set as follows: TiCl ₄ : 4% by volume, Ar: remaining, and a reaction atmosphere temperature: 900 ° C., a reaction atmosphere pressure: 50 kPa, Under the conditions described above, a Ti intrusion diffusion zone is formed on the surface portion of the Al ₂ O ₃ layer over a target depth from the surface also shown in Table 8, and a hard coating layer is formed. Under the conditions shown in Table 3 under the same conditions as the surface underlayer consisting of the diffusion oxide supply Ti oxide layer having the target layer thickness shown in Table 3 and the TiN (other layer) similarly shown in Table 2 By forming a surface layer composed of a diffusion oxygen-containing Ti oxynitride layer having a target layer thickness also shown in Table 8, FIG. 2A is a schematic front view, and FIG. Inventive coated super with shape shown in cross-sectional view End mills made of the surface-coated cemented carbide of the present invention (hereinafter, referred to as coated carbide end mills of the present invention) 1 to 8 as hard tools were produced.

For the purpose of comparison, as shown in Table 9, the formation of the Ti intrusion diffusion zone on the surface of the Al ₂ O ₃ layer was not performed, and the surface made of the Ti oxide layer for supplying diffusion oxygen was not formed. A conventional surface-coated cemented carbide end mill (hereinafter, referred to as a conventional coated carbide tool) under the same conditions except that a TiN layer is formed instead of the surface layer composed of the underlayer and the diffusion oxygen-containing Ti oxynitride layer. Conventionally called coated carbide end mills) 1 to 8 were manufactured respectively.

The oxygen content ratio (Y value and X value) at the center in the thickness direction of the surface layer and the surface base layer constituting the hard coating layer of the coated carbide end mills 1 to 8 of the present invention obtained as a result is shown below. When measured using an Auger spectrometer, the values shown in Table 8 were shown. Next, of the coated carbide end mills 1 to 8 of the present invention and the coated carbide end mills 1 to 8 of the present invention, the coated carbide end mills 1 to 3 of the present invention and the conventionally coated carbide end mills 1 to 3 are: Plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 100 m / min. , Groove depth (cut): 3 mm, Table feed: 500 mm / min, Dry high-speed grooving test of alloy steel, coated carbide end mills 4 to 6 of the present invention and conventional coated carbide end mills 4 to 6 , Work material: Plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 110 min. , Groove depth (cut): 6 mm, Table feed: 500 mm / min, Dry high-speed grooving test of alloy steel, coated carbide end mills 7 and 8 of the present invention and conventional coated carbide end mills 7 and 8 , Work material: Plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM415 plate, Cutting speed: 110 m / min. , Groove depth (cut): 15 mm, table feed: 500 mm / min, dry high-speed grooving test of alloy steel under the following conditions. The length of the cutting groove up to a reduction of 0.2 mm, which is a measure of the service life, was measured. The measurement results are shown in Tables 8 and 9, respectively.

[0030]

[Table 7]

[0031]

[Table 8]

[0032]

[Table 9]

(Example 3) The diameters of 8 mm (for forming the super-hard substrates a to c), 13 mm (for forming the super-hard substrates d to f), and 26 mm (for the super-hard substrate g) produced in Example 2 described above. h
(For forming), the diameter x length of the groove forming portion was 4 mm x 13 mm (the carbide substrate a ') by grinding from the three types of round rod sintered bodies. ~ C '), 8mm
× 22 mm (carbide substrate d ′ to f ′) and 16 mm ×
Carbide substrates (drills) a 'to h' each having a size of 45 mm (carbide substrates g 'and h') were manufactured.

Next, these carbide substrates (drills) a
In the state where honing was performed on the surface of '~ h', using a normal chemical vapor deposition apparatus, also under the conditions shown in Table 2,
As the constituent layers of the hard coating layer, a Ti compound layer and an Al ₂ O ₃ layer having the target layer thicknesses shown in Table 10 were formed, and then the reaction gas composition was set as follows: TiCl ₄ : 3% by volume, Ar: remaining, And a reaction atmosphere temperature: 850 ° C., a reaction atmosphere pressure: 50 kPa, and a predetermined time, and a target depth from the surface similarly shown in Table 10 on the surface portion of the Al ₂ O ₃ layer. And a surface layer formed of a diffusion oxygen supply Ti oxide layer having a target layer thickness shown in Table 10 under the conditions shown in Table 3 as a constituent layer of the hard coating layer. , And TiN (other layers) also shown in Table 2
By forming a surface layer composed of a diffusion oxygen-containing Ti oxynitride layer having a target layer thickness also shown in Table 10 under the same conditions as the formation conditions, a schematic front view in FIG.
First, a drill made of a surface-coated cemented carbide of the present invention (hereinafter referred to as a coated carbide drill of the present invention) 1 to 8 as a coated carbide tool of the present invention having a shape shown in a schematic cross-sectional view of a groove forming portion is manufactured, respectively. did.

For the purpose of comparison, as shown in Table 11, the formation of the Ti intrusion diffusion zone on the surface of the Al ₂ O ₃ layer was not performed, and the surface made of the diffusion oxygen supply Ti oxide layer was not formed. Instead of a surface layer consisting of an underlayer and a diffusion oxygen-containing Ti oxynitride layer, a conventional surface-coated cemented carbide drill (hereinafter, referred to as a conventionally coated cemented carbide tool) under the same conditions except that a TiN layer is formed. Conventional coated carbide drill) 1
To 8 were each manufactured.

The coated carbide drill of the present invention obtained as a result 1
The oxygen content ratio (Y value and X value) at the center in the thickness direction of the surface layer and the surface base layer constituting the hard coating layers of Nos. To 8 were measured using an Auger spectrometer. Value shown. Next, the coated carbide drills 1 to 8 of the present invention and the conventional coated carbide drills 1 to 8
Among them, the coated carbide drills 1 to 3 of the present invention and the conventionally coated carbide drills 1 to 3 are: work material: plane dimension: 100 mm × 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 60 m / min. , Feed: 0.2 mm / min, Wet high-speed drilling test of alloy steel under the following conditions: coated carbide drills 4 to 6 of the present invention and conventional coated carbide drills 4 to
About 6, work material: plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 70 m / min. , Feed: 0.2 mm / min, wet high-speed drilling test of alloy steel under the following conditions: coated carbide drills 7 and 8 of the present invention and coated carbide drills 7 of the prior art.
For No. 8, Work material: Plane dimensions: 100 mm × 250 mm, thickness: 5
0 mm JIS SCM415 plate, Cutting speed: 90 m / min. , Feed: 0.35 mm / min, Wet cutting high-speed drilling test of alloy steel under the following conditions, and the flank of the cutting edge at the tip of any wet type (using water-soluble cutting oil) high-speed drilling cutting test. Wear width is 0.
The number of drilling processes up to 3 mm was measured. The measurement results are shown in Tables 10 and 11, respectively.

[0037]

[Table 10]

[0038]

[Table 11]

[0039]

From the results shown in Tables 4 to 11, the surface layer of the hard coating layer is composed of a Ti oxynitride layer formed by reacting with oxygen diffused from the surface underlayer when forming the TiN layer. In the coated carbide tool of the present invention, even in high-speed cutting of steel with high heat generation, the Ti nitride oxide layer has a very low affinity for high-temperature heated chips, and the chip has the Ti nitride oxide. not adhere to the layer, and adhesion to the Al ₂ O ₃ layer of Ti oxide layer is a surface underlayer is the Al ₂
The remarkable improvement by the Ti intrusion diffusion zone formed on the surface portion of the O ₃ layer and the improvement of the toughness of the Al ₂ O ₃ layer itself are also achieved. In the conventional coated cemented carbide tool in which the outermost surface layer of the hard coating layer is formed of a TiN layer, the chips tend to adhere to the TiN layer. Is peeled off by the cutting powder together with the other constituent layers, so that chipping easily occurs on the cutting blade, and it is apparent that the use life of the cutting blade can be shortened in a relatively short time. As described above, the coated cemented carbide tool of the present invention enables the practical use of the identification tool before and after use, particularly in high-speed cutting of various steels and cast irons. No wear is exhibited, and excellent wear resistance is exhibited over a long period of time.

[Brief description of the drawings]

FIG. 1A is a schematic perspective view of a coated carbide tip, and FIG.
1 is a schematic longitudinal sectional view of a coated carbide tip.

FIG. 2 (a) is a schematic front view of a coated carbide end mill,
(B) is a schematic cross-sectional view of the cutting blade portion.

FIG. 3A is a schematic front view of a coated carbide drill, and FIG.
FIG. 3 is a schematic cross-sectional view of the groove forming portion.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C23C 16/32 C23C 16/32 16/34 16/34 16/36 16/36 16/40 16/40 ( 72) Inventor Toshiaki Ueda 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Real Research Institute, Inc. Terms (reference) 3C037 CC02 CC04 CC09 3C046 FF03 FF10 FF13 FF16 FF17 FF19 FF22 FF25 4K030 AA03 AA10 AA14 AA16 AA18 BA18 BA35 BA36 BA38 BA41 BA43 BA46 BB12 CA03 JA01 LA22

Claims (1)

[Claims] 1. A surface of a tungsten carbide-based cemented carbide substrate comprising: (a) a lower layer having an average layer thickness of 0.5 to 15 μm, a Ti carbide layer, a nitride layer, a carbonitride layer, A carbonate compound layer, a Ti compound layer composed of one or more of a carbonitride compound layer, (b) an intermediate layer having an average layer thickness of 1 to 15 μm,
On the surface part, Ti is spread over a depth of 0.1 to 3 μm from the surface.
(C) an aluminum oxide layer having an intrusion diffusion zone, (c) a surface underlayer having an average layer thickness of 0.1 to 3 μm and, when represented by a composition formula: TiO _x , a center in the thickness direction Part is measured with an Auger spectrometer, and X: a Ti oxide layer satisfying an atomic ratio to Ti of 1.2 to 1.7, (d) an average layer thickness of 0.05 to 2 μm as a surface layer And having the composition formula: TiN _1-Y (O) _Y ,
(O) indicates oxygen diffused from the outermost surface underlayer.] Similarly, the central part in the thickness direction is measured by an Auger spectroscopic analyzer, and satisfies an atomic ratio of 0.01 to 0.4 with respect to Y: Ti. A surface having excellent chipping resistance, obtained by subjecting a hard coating layer composed of the above (a) to (d) to chemical vapor deposition and / or physical vapor deposition with an average layer thickness of 3 to 30 μm. Coated cemented carbide cutting tool.