JP2002120104A - Cutting tool made of surface coated cemented carbide alloy having chipping resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool made of a surface coated cemented carbide alloy having high chipping resistance. SOLUTION: This cutting tool made of the surface coated cemented carbide alloy is formed by physically depositing a hard coating layer made of a single layer formed of one of formulas (Ti1-XAlX)N and (Ti1-XAlX)C1-YNY (where, X is 0.1 to 0.7 and Y is 0.5 to 0.99 in atomic ratio) or a double layer formed of both of them, with an average layer thickness of 1 to 10 μm, onto a surface of a tungsten carbide-based cemented carbide alloy substrate or a titanium carbonitride-based cermet substrate. A Ti oxide layer having average thickness of 0.1 to 3 μm represented by the formula TiOV (where, V is atomic ratio to Ti and satisfies 1.2 to 1.7) as the outermost ground layer, and a Ti oxynitride layer having average thickness of 0.05 to 2 μm represented by the formula TiN1-Z (O)Z (where, (O) is diffusion oxygen from the outermost ground layer and Z is atom ratio to Ti and satisfies 0.01 to 0.4) as the outermost layer are chemically and/or physically deposited.

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.

In general, for example, an arc ion plating apparatus which is a kind of physical vapor deposition apparatus schematically shown in FIG. 1 is used, and the inside of the apparatus is heated to 500 ° C. by, for example, reducing the atmosphere to a vacuum of 20 mtorr. While heated to a temperature, an anode electrode and Ti-A having a predetermined composition
An arc discharge is generated between the cathode electrode (evaporation source) on which the alloy is set, for example, under the conditions of a voltage: 35 V and a current: 90 A, and at the same time, nitrogen gas or nitrogen gas and methane gas as a reaction gas in the apparatus. On the other hand, a substrate made of a tungsten carbide (hereinafter, referred to as WC) -based cemented carbide or a cermet based on titanium carbonitride (hereinafter, referred to as TiCN) (hereinafter, these are collectively referred to as a super-hard substrate) include: For example, under the condition that a bias voltage of -200 V is applied, the surface of the cemented carbide substrate is
No. 6565, the composition formula: (Ti
_1-X Al _X ) N and (Ti _1-X Al _X ) C _{1 -Y} N _Y (where X is 0.1 to 0.7 and Y is 0.5 to 0.
99)), and a composite nitride of Ti and Al having
(Ti, Al) N] and composite carbonitride [hereinafter, referred to as
(Ti, Al) CN], or a single or multilayer hard coating layer composed of one or both of them.
It is known to produce coated carbide tools by vapor deposition with an average layer thickness of 10 μm.

In the above-mentioned conventional coated carbide tool,
In order to facilitate the discrimination between before and after use of the tool, a titanium nitride (hereinafter referred to as TiN) layer having a golden color tone is replaced with the (Ti, Al) N layer and / or the (Ti, A) layer.
1) Chemical vapor deposition or physical vapor deposition is performed on the surface of a hard coating layer composed of a CN layer with an average layer thickness of 0.05 to 2 μm as an outermost surface layer.

[0005]

On the other hand, in recent years, there has been a strong demand for labor saving and energy saving for cutting work, and with this, cutting work tends to be accelerated. In particular, when a TiN layer is deposited on the surface of the hard coating layer as the outermost surface layer for the purpose of identification before and after use, the TiN layer has a strong adhesiveness to various steels as work materials. In high-speed cutting with particularly high heat generation, the chips are strongly adhered to the TiN layer in combination with the high temperature heating, and act to locally peel the TiN layer from the hard coating layer. In this case, the TiN layer is a hard coating layer (Ti, Al) N
Layer and the (Ti, Al) CN layer, the hard coating layer is also made of the TiN
At present, the chip is locally peeled off together with the layer, and as a result, chipping (small chipping) occurs at the cutting edge, which results in a relatively short service life.

[0006]

Means for Solving the Problems Accordingly, the present inventors have
In view of the above, attention has been paid to a conventional coated carbide tool in which a TiN layer is formed as the outermost surface layer on the surface of the hard coating layer for the purpose of identification, and in particular, the chipping resistance under high-speed cutting conditions. As a result of conducting research to improve the surface roughness, the surface of the above-mentioned conventional coated carbide tool was firstly provided with a reactive gas composition in the form of TiCl ₄ : 0.2 to
_{10%, CO 2: 0.1~10%} , Ar: 5~60%,
H ₂ : remaining, reaction atmosphere temperature: 800 to 1100 ° C., reaction atmosphere pressure: 4 to 70 kPa (30 to 525 torr)
r) under the following conditions, an average layer thickness of 0.1 to 3 μm, and the ratio of oxygen to Ti is 1.25 to 1.90 in atomic ratio, as measured by an Auger spectrometer, that is, In the case of the composition formula: TiO _W , a Ti oxide layer satisfying an atomic ratio of W: Ti to 1.25 to 1.90 is formed, and a top surface layer is formed on the Ti oxide layer. Under normal conditions, that is, when the reaction gas composition is TiCl ₄ : 0.2 to 10% by volume, N ₂ : 4
６０60%, H ₂ : remaining, and reaction atmosphere temperature: 800 to 1100 ° C., reaction atmosphere pressure: 4 to 90 kPa (30 to 675 torr)
r) T having an average layer thickness of 0.05 to 2 μm under the following conditions:
When the iN layer is formed, oxygen of the Ti oxide layer constituting the outermost surface underlayer diffuses when the outermost surface layer is formed, and T
An i-nitride oxide layer is formed.
The outermost surface underlayer after the formation of the i-nitrogen oxide layer was measured by an Auger spectrometer at the center in the thickness direction, and the oxygen content was
When the atomic ratio with respect to _V is 1.2 to 1.7, that is, when represented by the composition formula: TiO _V , the Ti oxide layer satisfies the following: 1.2 to 1.7 with V: Ti. The outermost layer,
Similarly, the central part in the thickness direction is measured by an Auger spectrometer, and the ratio of the diffused oxygen is 0.01 to
0.4, that is, when represented by the composition formula: TiN _1-Z (O) _Z , (where (O) indicates oxygen diffused from the outermost underlayer), the atomic ratio of Z to Ti is 0. .01 to 0.4, and a Ti nitride oxide layer satisfying
A nitrided oxide layer and a Ti oxide layer are formed on the surface of the hard coating layer by chemical vapor deposition and / or as an outermost surface layer and an outermost surface underlayer.
Or, in the case of a coated carbide tool subjected to physical vapor deposition, the Ti nitride oxide layer as the outermost surface layer has a golden surface tone equivalent to that of the TiN layer, so that it is possible to identify before and after use of the tool. And extremely low adhesion to various types of steel, which is the work material, so that high-temperature heated chips do not adhere to high-speed cutting with high heat generation. Have been remarkably suppressed, and a study result has been obtained that exhibits excellent cutting performance over a long period of time.

The present invention has been made on the basis of the above research results, and has a composition represented by the following formula: (T
i _1-X Al _X ) N and (Ti _1-X Al _X ) C _1-Y N _Y (where X is 0.1 to 0.7 and Y is 0.5 to
(Indicating 0.99) (Ti, Al) N and (T
(i, Al) CN, in a coated cemented carbide tool obtained by physical vapor deposition of a single-layer or multiple-layer hard coating layer composed of one or both of them, with an average layer thickness of 1 to 10 μm. 0.1 to 3 as the outermost surface underlayer
When it has an average layer thickness of μm and is represented by the composition formula: TiO _V , the center in the thickness direction is measured by an Auger spectroscopic analyzer, and the atomic ratio to V: Ti is 1.2 to 1. 7, a Ti oxide layer that satisfies
When it has an average layer thickness of 2 μm and is represented by the composition formula: TiN _1-Z (O) _Z , (where (O) indicates oxygen diffused from the outermost underlayer), the same thickness The central part in the direction is measured by an Auger spectroscopic analyzer, and a Ti nitride oxide layer satisfying the following: 0.01 to 0.4 in atomic ratio with respect to Z: Ti is formed by chemical vapor deposition and / or physical vapor deposition. It is characterized by a coated carbide tool having excellent chipping properties.

In the coated carbide tool of the present invention, the ratio (Z value) of the diffusion oxygen of the Ti nitride layer constituting the outermost surface layer is set to 0.01 to 0.40 in atomic ratio to Ti.
If the value is less than 0.01, the desired effect cannot be ensured in suppressing the adhesion to chips, while the value is 0.4
If it exceeds 0, pores are easily formed in the layer, and it is difficult to stably form a sound outermost surface layer.

Further, as described above, the Ti nitride oxide layer also constituting the outermost surface layer first serves as an outermost surface underlayer so that the oxygen ratio is 1.25 to 1.90 in atomic ratio to Ti.
(W value) is formed by forming a Ti oxide layer and then depositing a TiN layer on the outermost surface underlayer under ordinary conditions. Diffusion of oxygen from the surface underlayer is indispensable, but if the W value of the Ti oxide layer constituting the outermost surface underlayer is less than 1.25, the diffusion reaction of oxygen into the TiN layer rapidly increases. When the W value exceeds 1.90, the ratio (Z value) of the diffused oxygen in the outermost surface layer cannot be made 0.01 or more in atomic ratio with respect to Ti.
Since the atomic ratio of diffused oxygen in the outermost surface layer exceeds 0.40 in atomic ratio to Ti, W
The value is set to 1.25 to 1.90. In this case, the ratio of oxygen (V
Value) takes on a value in the range of 1.2 to 1.7 in atomic ratio with respect to Ti. In other words, the V value of the outermost underlayer after the outermost layer is formed is 1.2 to 1.7. If you are satisfied,
The Z value of the outermost surface layer satisfies 0.01 to 0.40.

Further, the average layer thickness of the outermost surface layer and the outermost surface underlayer is 0.05 to 2 μm and 0.1 μm, respectively.
If the average layer thickness is less than 0.05 μm or less than 0.1 μm, the desired surface color (golden color) cannot be secured in the former case, and Means that the oxygen supply to the outermost surface layer is insufficient, whereas the former provides a color tone of 2 μm and the latter provides an oxygen supply of 3 μm.
This is based on the reason that an average layer thickness of m can be performed sufficiently satisfactorily. Further, the reason why the average layer thickness of the hard coating layer is set to 1 to 10 μm is that if the layer thickness is 1 μm, the desired excellent wear resistance cannot be secured, while if the layer thickness exceeds 10 μm, the cut-off occurs. This is because chipping and chipping easily occur in the blade.

Further, the Ti oxide layer of the outermost surface underlayer is formed on the surface of the hard coating layer composed of the (Ti, Al) N layer and / or the (Ti, Al) CN layer, The condition where the value is on the low side in the range of 1.25 to 1.90, for example, in the range of 1.25 to 1.50, or the thin side in which the average layer thickness is in the range of 0.1 to 3 μm, for example, 0.1
When the film is formed under conditions within the range of 1 to 1 μm, sufficient interlayer adhesion with the hard coating layer may not be obtained (of course, depending on the formation conditions of the Ti oxide layer, In such a case, sufficient interlayer adhesion can be obtained). In this case, after forming the Ti oxide layer, the following atmosphere, that is, the atmosphere gas composition is changed to TiCl ₄ :
0.05 to 10% by volume, inert gas: remaining, ambient temperature: 800 to 1100 ° C., atmospheric pressure: 4 to 90 kPa (30 to 675 Torr)
r) for a predetermined period of time, for example, about 5 minutes to 5 hours, in the atmosphere described above, and at the interface between the Ti oxide layer and the hard coating layer,
Desirably, an interdiffusion layer is formed with an average layer thickness of 0.05 to 2 μm so as to improve interlayer adhesion. Further, the treatment for improving the interlayer adhesion between the Ti oxide layer and the hard coating layer is performed as follows. Even when the W value and the average layer thickness of the Ti oxide layer are values other than the values on the low side and the thin side, it may be performed for the purpose of further improving interlayer adhesion.

[0012] In the coated carbide tool of the present invention,
(Ti, Al) N and (Ti,
Al in Al) CN increases the hardness with respect to TiCN and thus forms a solid solution in order to improve the wear resistance. Therefore, the composition formulas: (Ti _1-x Al _x ) N and (Ti _{1- If} the X value of _X Al _X ) C _{1-Y NY} is less than 0.1, the desired abrasion resistance cannot be ensured, while the value is not more than 0.1.
When the value exceeds 7, the X value is determined to be 0.1 to 0.7 (atomic ratio) because chipping or chipping is likely to occur in the cutting edge, and the (Ti, Al) CN layer Since the C component has an effect of improving hardness, (T
The (i, Al) CN layer has a relatively high hardness as compared with the above (Ti, Al) N layer.
When the value is less than 01, that is, when the Y value exceeds 0.99, the predetermined hardness improving effect cannot be obtained. On the other hand, when the ratio of the C component exceeds 0.5, that is, when the Y value is less than 0.5, the toughness sharply increases. Since the value decreases, the Y value is set to 0.5 to 0.9.
9, preferably 0.55 to 0.9.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide tool of the present invention will be specifically described with reference to examples. (Example 1) As raw material powders, WC powder, TiC powder, ZrC powder, V
C powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, T
An iN powder, a TaN powder, and a Co powder were prepared, and these raw material powders were blended in the blending composition shown in Table 1, wet-mixed in a ball mill for 72 hours, dried, and then dried.
a into a green compact at a pressure of
a. Sintering is performed in a vacuum at a temperature of 1400 ° C. for 1 hour, and after sintering, the cutting edge is subjected to a honing process of R: 0.05 to obtain a WC having a chip shape of ISO standard CNMG120408. Substrates A1 to A10 made of base cemented carbide
Was formed.

Further, as raw material powders,
TiCN having an average particle size of 2 μm (by weight ratio TiC /
(TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder, Co powder, and Ni powder were prepared, and these raw material powders were blended into the composition shown in Table 2. After wet-mixing with a ball mill for 24 hours and drying, the mixture is pressed into a green compact at a pressure of 100 MPa, and the green compact is heated in a nitrogen atmosphere of 2 kPa at a temperature of:
Sintered under the condition of holding at 1500 ° C. for 1 hour, and after sintering, the cutting edge portion is subjected to a honing process of R: 0.03 to form a TiC having a chip shape of ISO standard CNMG120408.
Carbide substrates B1 to B6 made of N-based cermet were formed.

Then, these super-hard substrates A1 to A10 and B1 to B6 are ultrasonically cleaned in acetone, dried, and charged into a usual arc ion plating apparatus illustrated in FIG. 1, respectively. On the other hand, after mounting the Ti-Al alloys having various component compositions as a cathode electrode (evaporation source), and evacuating the inside of the apparatus to maintain a vacuum of 0.5 Pa, the inside of the apparatus was heated to 500 ° C. by a heater. Ar gas was introduced into the apparatus to form an Ar atmosphere of 10 Pa. In this state, a bias voltage of -800 V was applied to the super-hard substrate to clean the surface of the super-hard substrate with Ar gas bombardment. Nitrogen gas or nitrogen gas and methane gas were introduced to make a reaction atmosphere of 6 Pa, and the bias voltage applied to the superhard substrate was reduced to -200 V, and the cathode voltage was lowered. Arc discharge is generated between the substrate and the anode electrode, and a hard coating layer having a target composition and a target layer thickness shown in Tables 3 and 4 is deposited on the surfaces of the super-hard substrates A1 to A10 and B1 to B6. Then, using a conventional chemical vapor deposition apparatus, the surface of the hard coating layer is coated with a reaction gas composition in TiCl 4:
4.2%, N2: 35%, H2: remaining, reaction atmosphere temperature: 1040 ° C., reaction atmosphere pressure: 30 kPa.
By forming with the target layer thickness shown in FIG.
(A) is a schematic perspective view, and (b) is a conventional coated cemented carbide throwaway tip as a conventionally coated cemented carbide tool having a shape shown in a schematic longitudinal sectional view (hereinafter referred to as a conventionally coated cemented carbide tip). ) Were prepared respectively.

Further, as shown in Table 5, in the conventional coated carbide tips 1 to 24, Ti
In the state where the N layer was not formed, the conditions shown in Table 6 were applied to the surface of the hard coating layer composed of the (Ti, Al) N layer and / or the (Ti, Al) CN layer using a normal chemical vapor deposition apparatus. To form an outermost surface underlayer comprising a Ti oxide layer having a target composition also shown in Table 6 and a target layer thickness shown in Table 5, and subsequently as the outermost surface layer in the conventional coated carbide tips 1 to 24 described above. Under the same conditions as the formation of the TiN layer
The surface-coated cemented carbide of the present invention as the coated cemented carbide tool of the present invention also having the shape shown in FIG. 2 by forming the outermost surface layer composed of the N (O) layer with the target layer thickness also shown in Table 5. Slow-away tips (hereinafter referred to as coated carbide tips) 1 to 24 were manufactured.

Also, the above-mentioned coated carbide tips 1-2 of the present invention
4, the coated super hard tip 6 of the present invention and the coated super hard tip 19 of the present invention were prepared immediately after the formation of the outermost surface underlayer composed of the Ti oxide layer.
Cl ₄ : 1% by volume, Ar: Remaining, ambient temperature is 10
At 20 ° C., an atmosphere pressure of 7 kPa (50 Torr) was maintained for 1 hour in an atmosphere. In the latter, the atmosphere gas composition was TiCl ₄ : 0.2 vol%, Ar: the balance, and the atmosphere temperature was 1000 ° C. Atmospheric pressure is 20 kPa
(Ti, Al) N layer and / or (Ti, Al) under the condition of holding for 2 hours in an atmosphere of (150 Torr).
An interlayer adhesion improving treatment for forming an interdiffusion layer was performed on the interface between the hard coating layer composed of the CN layer and the outermost surface underlayer composed of the Ti oxide layer. As a result, according to a cross-sectional measurement using a scanning electron microscope and an Auger spectroscopic analyzer, the average layer thickness (average of five points) of the coated superhard chip 3 of the present invention was 0.6 μm at the interface between the hard coating layer and the outermost underlayer. On the other hand, in the coated super-hard tip 7 of the present invention, formation of an interdiffusion layer having an average layer thickness (average of 5 points) of 0.8 μm was observed.

Further, in the coated superhard chips 1 to 24 of the present invention obtained as described above, the oxygen content ratio at the center in the thickness direction of the outermost surface layer and the outermost surface underlayer formed on the surface of the hard coating layer When (Z value and V value) were measured using an Auger spectrometer, the values shown in Tables 7 and 8 were shown. In addition, the above-mentioned coated carbide tips 1 of the present invention
24 and the conventional coated carbide tips 1 to 24, the composition of the hard coating layer was measured using an Auger spectrometer, and the thicknesses of the hard coating layer, the outermost underlayer, and the outermost layer were determined by scanning electron beam. When the cross section was measured using a microscope, the values were substantially the same as the target composition and the target layer thickness, respectively (the layer thickness was compared with the average layer thickness of the five-point average). The relationship between the target composition, the target layer thickness, and the measured value showed the same results in Examples 2 and 3 below.

Next, the coated carbide tips 1-2 of the present invention will be described.
4 and the conventional coated carbide tips 1 to 24 were screwed to the tip of a tool steel tool with a fixing jig. Work material: JIS SCM440 round bar, Cutting speed: 250 m / min . Infeed: 2.0 mm Feed: 0.3 mm / rev. , Cutting time: 10 minutes, Dry high-speed continuous turning test of alloy steel under the following conditions: Work material: JIS SNCM439 Longitudinal four equally-rounded round bars, Cutting speed: 200 m / min . Infeed: 2.0 mm Feed: 0.25 mm / rev. , Cutting time: 5 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. The measurement results are shown in Tables 7 and 8.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

[0026]

[Table 7]

[0027]

[Table 8]

(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 (Ti, W) C powder, 1.8 μm Co powder,
And 1.2 μm carbon (C) powder were prepared, and these raw material powders were respectively blended into the blending composition shown in Table 9;
Further, the wax was added, and the mixture was ball-milled in acetone for 24 hours, dried under reduced pressure, and press-molded into various compacts having a predetermined shape at a pressure of 100 MPa. 13 ° C / min.
The temperature was raised to a predetermined temperature in the range of 70 to 1470 ° C., maintained at this temperature for 1 hour, and then sintered under furnace cooling conditions to obtain a diameter of 8 mm.
mm, 13 mm, and 26 mm to form three types of round bar sintered bodies for forming a cemented carbide substrate, and from the three types of round bar sintered bodies, by grinding, in a combination shown in Table 9, The diameter x length of the cutting edge is 6mm x 13mm, 10mm x
Carbide substrates (end mills) a to h having dimensions of 22 mm and 20 mm × 45 mm were produced, respectively.

Next, these carbide substrates (end mills)
Honing was performed on the surfaces of a to h, ultrasonic cleaning was performed in acetone, and the dried state was charged into a normal arc ion plating apparatus also illustrated in FIG. Under the conditions, a hard coating layer having a target composition and a target layer thickness shown in Table 10 was formed by vapor deposition, and subsequently, using a general chemical vapor deposition apparatus, the same conditions as in Example 1 were used. By vapor-depositing a TiN layer as the outermost layer having the target layer thickness shown,
FIG. 3 (a) is a schematic front view, and FIG. 3 (b) is a conventional surface-coated cemented carbide end mill (hereinafter, referred to as a conventional coated carbide end mill) as a conventional coated carbide tool having a shape shown in a schematic cross-sectional view. 1 to 8 were manufactured respectively.

Also, as shown in Table 11, in the conventional coated carbide end mills 1 to 8 described above, the (Ti, Al) N layer and / or the (Ti, Al) N layer was formed without forming the TiN layer as the outermost surface layer. On the surface of the hard coating layer composed of the (Ti, Al) CN layer, the Ti oxide having the target composition shown in Table 6 and the target layer thickness shown in Table 11 was also formed under the conditions shown in Table 6 by using a conventional chemical vapor deposition apparatus. The outermost surface layer made of a TiN (O) layer is formed under the same conditions as the formation of the TiN layer as the outermost layer in the conventional coated carbide tips 1 to 24 of Example 1 above. Table 1
3 by forming with the target layer thickness shown in FIG.
The surface-coated cemented carbide end mills (hereinafter, referred to as the present invention coated carbide end mills) 1 to 8 as the inventive coated cemented carbide tools having the shapes shown in FIG.

Next, in the coated superhard end mills 1 to 8 of the present invention obtained as described above, the outermost surface layer and the outermost underlayer formed on the surface of the hard coating layer have the oxygen content at the center in the thickness direction. When the ratios (Z value and V value) were measured using an Auger spectrometer, the values shown in Table 11 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: 80 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: 90 m / 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: 90 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 10 and 11, respectively.

[0032]

[Table 9]

[0033]

[Table 10]

[0034]

[Table 11]

(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
The surface of '~ h' was honed, ultrasonically cleaned in acetone, dried and charged in a usual arc ion plating apparatus also illustrated in FIG. Under the same conditions, a hard coating layer having a target composition and a target layer thickness shown in Table 12 was formed by vapor deposition, and subsequently, using a conventional chemical vapor deposition apparatus, under the same conditions as in Example 1 above. By evaporating and forming a TiN layer as the outermost layer having the target layer thickness shown in Table 12, the shape shown in the schematic front view in FIG. Drills made of conventional surface-coated cemented carbide (hereinafter referred to as conventional coated carbide drills) 1 to 8 as conventional coated cemented carbide tools were manufactured.

Further, as shown in Table 13, in the conventional coated carbide drills 1 to 8 described above, Ti
In the state where the N layer was not formed, the conditions shown in Table 6 were applied to the surface of the hard coating layer composed of the (Ti, Al) N layer and / or the (Ti, Al) CN layer using a normal chemical vapor deposition apparatus. In the same manner, the outermost surface underlayer composed of the Ti oxide layer having the target composition shown in Table 6 and the target layer thickness shown in Table 13 was formed.
Under the same conditions as in the formation of the TiN layer as the outermost layer in 24, the outermost layer made of the TiN (O) layer was also formed with the target layer thickness shown in Table 13 to have the shape shown in FIG. Drills made of the surface-coated cemented carbide of the present invention (hereinafter referred to as the coated carbide drills of the present invention) 1 to 8 as the coated carbide tools of the present invention were manufactured.

The coated carbide drill 1 of the present invention obtained as a result
In Nos. To 8, the oxygen content ratio (Z value and V value) of the center portion in the thickness direction of the outermost surface layer and the outermost surface underlayer formed on the surface of the hard coating layer was measured using an Auger spectroscopic analyzer. However, the values shown in Table 13 were shown. Next, among the above coated carbide drills 1 to 8 of the present invention and conventional coated carbide drills 1 to 8, the coated carbide drills 1 to 3 of the present invention and the conventionally coated carbide drills 1 to 3 are as follows. Plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 50 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: 60 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: 75 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. Table 13 shows the measurement results.

[0039]

[Table 12]

[0040]

[Table 13]

[0041]

From the results shown in Tables 3 to 13, it can be seen that the outermost surface layer of the hard coating layer is formed of a Ti oxynitride layer formed by reacting with oxygen diffused from the outermost underlayer at the time of forming the TiN layer. The coated carbide tool according to the present invention is characterized in that the Ti nitride oxide layer has an extremely low affinity for high-temperature heated chips even in high-speed cutting of steel with high heat generation.
Since it does not adhere to the i-nitride oxide layer, it exhibits excellent wear resistance without chipping on the cutting edge, whereas the outermost layer of the hard coating layer is made of a TiN layer. In the case of coated carbide tools, the chips
Since the TiN layer easily adheres to the N layer and the TiN layer is peeled off together with the other constituent layers by the cutting powder, chipping easily occurs in the cutting blade, and it is apparent that this causes a service life in a relatively short time. It is. 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. 1 is a schematic explanatory view of an arc ion plating apparatus.

FIG. 2A 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. 3A is a schematic front view of a coated carbide end mill,
(B) is a schematic cross-sectional view of the cutting blade portion.

FIG. 4A 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.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C23C 16/30 C23C 16/30 16/40 16/40 (72) Inventor Takashi Oga 1-Kitabukurocho, Omiya City, Saitama Prefecture 297 Mitsubishi Materials Co., Ltd. Research Laboratory F-term (reference) JA06 LA22

Claims (1)

[Claims] 1. A tungsten carbide based cemented carbide substrate or
On the surface of the titanium carbonitride-based cermet substrate, the composition formula: (T
i_1-XAl_X) N and (Ti)_1-XAl_X) C _1-YN_Y(T
However, X is 0.1 to 0.7 and Y is 0.5 to
0.99) and a composite nitride of Ti and Al having
And one of the composite carbonitrides of Ti and Al
Hard coating consisting of a single layer or multiple layers composed of both
The surface coating formed by physical vapor deposition of the layer with an average layer thickness of 1 to 10 μm
In the case of coated hard metal cutting tools, the surface of the hard coating layer
In addition, an average layer thickness of 0.1 to 3 μm is used as the outermost underlayer.
Having the composition formula: TiO_V When represented by,, the center in the thickness direction is
A Ti oxide layer that satisfies the following: V: Ti in an atomic ratio of 1.2 to 1.7, and has an average layer thickness of 0.05 to 2 μm as a top surface layer,
And a composition formula: TiN_1-Z(O)_Z(Where (O) is the outermost underlayer)
The diffused oxygen is shown).
A Ti oxynitride layer that satisfies the following formula: an atomic ratio to Z: Ti of 0.01 to 0.4, as measured by a spectroscopic analyzer, by chemical vapor deposition and / or
Excellent chipping resistant surface coating by physical vapor deposition
Cemented carbide cutting tool.