JP2002160105A - Cutting tool made of surface coating cemented carbide having high chipping resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coating cemented carbide having high surface lubricity against chips. SOLUTION: (a) A Ti compound layer comprising one or more of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, and a TiCNO layer having an average layer thickness of 0.5 to 15 μm as a lower layer, (b) an Al2O3 layer and/or an Al2O3-ZrO2 mixing layer having an average layer thickness of 1 to 15 μm as an intermediate layer, (c) a composite oxide layer of Ti and Al represented by the composition formula (Ti1-WAlW)OX, satisfying W is 0.02 to 0.15 and X is 1.2 to 1.7, and having an average layer thickness of 0.1 to 3 μm as a surface substrate layer, (d) a hard coating layer comprising a Ti nitrogen oxide layer represented by the composition formula TiN1-Y(O)Y, satisfying Y, namely atomic ratio to Ti, is 0.01 to 0.4, and having an average layer thickness of 0.05 to 2 μm as a surface layer are chemically and/or physically deposited on the surface of a WC base cemented carbide substrate with a total 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, as the above-mentioned cutting tool, (a) a lower layer having a thickness of 0.5 to 15 μm
, A carbide layer of Ti (hereinafter, referred to as TiC), a nitride (hereinafter, also referred to as TiN) layer, a carbonitride (hereinafter, referred to as TiCN) layer, a carbonate (hereinafter, referred to as T
iCO) layer and carbonitride (hereinafter TiCN)
O) or one or more of these layers
A compound layer, (b) an intermediate layer having an average layer thickness of 1 to 15 μm, and aluminum oxide (hereinafter referred to as Al ₂ O ₃ )
Layer and zirconium oxide (hereinafter referred to as ZrO ₂ ) phase dispersedly distributed on an Al ₂ O ₃ substrate described in, for example, JP-A-57-39168 and JP-A-61-201778. ₂ O ₃ —ZrO ₂ mixed layer (hereinafter referred to as Al ₂
O ₃ referred to -ZrO ₂ mixed layer) either or both,
(C) As a surface layer, a TiN layer having an average layer thickness of 0.05 to 2 μm, and a hard coating layer composed of the above (a) to (c) with a total average layer thickness of 3 to 30 μm by chemical vapor deposition and / or
Or coated carbide tools made by physical vapor deposition are known,
It is also known that this coated carbide tool is used for continuous cutting or intermittent cutting of various low alloy steels, cast iron, and the like. In the above-mentioned conventional coated carbide tool, the TiN layer constituting the surface layer of the hard coating layer itself has a golden surface tone, so that it is easy to distinguish the tool before and after use. It is also well-known that it is provided in.

In general, a Ti compound layer, an Al ₂ O ₃ layer and an Al ₂ O ₃ -ZrO ₂ mixed layer which constitute a hard coating layer of the above-mentioned coated carbide tool have a granular crystal structure, and As the Al2O3 layer, those having an α-type crystal structure and those having a κ-type crystal structure are widely used for practical use. Further, for example, JP-A-6-8010 and JP-A-7-3288
08, the TiCN layer of the Ti compound layer constituting the hard coating layer of the coated cemented carbide tool
A layer 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 with a normal chemical vapor deposition apparatus for the purpose of improving the toughness of the layer itself. It is also known to have a vertically elongated crystal structure.

[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, since the TiN layer that constitutes the surface layer of the hard coating layer has a strong adhesiveness to various types of steel as a work material, the chip is heated to a high temperature, particularly in high-speed cutting with high heat generation. Combined with the TiN
Strongly adheres to the layer and acts to locally peel off the TiN layer from the hard coating layer;
Layer is an intermediate layer the Al ₂ O ₃ layer and Al ₂ O ₃ -ZrO ₂
Since it has excellent adhesion to the mixed layer, these intermediate layers are included, and the other constituent layers are also made of the Ti.
At present, the chip is locally peeled off together with the N 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
From the above viewpoint, the surface layer of the hard coating layer is T
Focusing on the conventional coated carbide tool composed of the iN layer, a study was carried out to improve the chipping resistance especially under high-speed cutting conditions. As a result, (a) the conventional coated carbide tool In forming the hard coating layer, an Al ₂ O ₃ layer and an Al ₂ O ₃
After forming the -ZrO ₂ mixed layer, first, as a surface undercoat layer, by chemical vapor deposition apparatus, the reaction gas composition, by _{volume%, TiCl 4: 0.2~10%,} AlCl 3: 0.05~ _{1%, CO 2: 0.1~10%} , Ar: 5~60%, H2: rest, and then, and, temperature of reaction atmosphere: 800 to 1100 ° C., reaction atmosphere pressure: 4～70KPa, between the conditions, When it has an average layer thickness of 0.1 to 3 μm and is represented by the composition formula: (Ti _{1 -W} AlW) O _Z , the central part in the thickness direction is measured by an Auger spectroscopic analyzer, Forming a composite oxide layer of Ti and Al satisfying the following atomic ratios: W: 0.02 to 0.15 and Z: 1.25 to 1.90. Then, as a surface layer, the usual conditions, that is, the reaction gas composition is
And TiCl ₄ : 0.2 to 10%, N ₂ : 4 to 60%, H ₂ : remaining, and the reaction atmosphere temperature: 800 to 1100 ° C., and the reaction atmosphere pressure: 4 to 90 kPa. , T with an average layer thickness of 0.05 to 2 μm
When the iN layer is formed, oxygen of the composite oxide layer of Ti and Al 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 layer is formed. surface underlayer after the oxide layer forming the composition _{formula: (Ti 1-W Al W} ) O X, in the case where expressed, by measuring the thickness direction central portion Auger spectrometer, both in terms of atomic ratio W: 0.02 to 0.15, X: 1.2 to 1.7, and a composite oxide layer of Ti and Al is satisfied. On the other hand, in the surface layer, the central part in the thickness direction is also subjected to Auger spectroscopy. When the ratio of the diffusion oxygen is 0.01 to 0.4 in atomic ratio with respect to Ti as measured by an apparatus, that is, when represented by the composition formula: TiN _1-Y (O), where (O) is the above surface Shows oxygen diffused from the underlayer], Y: 0.01 to 0.4 in atomic ratio to Ti, And a Ti oxynitride layer satisfying
In a coated carbide tool in which a nitrided oxide layer and a composite oxide layer of Ti and Al are chemically and / or physically deposited as a surface layer and a surface underlayer of a hard coating layer, the surface underlayer is materially Not to mention the same kind of surface layer,
Due to the action of Al contained therein, it adheres firmly also to the Al ₂ O ₃ layer and the Al ₂ O ₃ -ZrO ₂ mixed layer constituting the intermediate layer of the hard coating layer, and in particular, the Ti nitride oxide layer It has a golden surface tone equivalent to that of the above-mentioned TiN layer, which makes it possible to identify before and after the use of a tool, and has extremely low adhesiveness to various steels as a work material, thus causing high heat generation. Chips heated at a high temperature are not adhered to high-speed cutting, so that chipping of the cutting edge is significantly suppressed and excellent cutting performance is exhibited over a long period of time. (B) In the composite oxide layer of Ti and Al constituting the surface underlayer of the hard coating layer of the coated cemented carbide tool of (a),
Al ₂ O ₃ layer and Al ₂ O ₃ —ZrO ₂ constituting an intermediate layer
At the interface with the mixed layer, the content of Al is relatively higher than that of Ti, and at the interface with the TiN layer constituting the surface layer, the content of Ti is higher than that of Al. , since it becomes adhesion to the intermediate layer and the surface layer further further improved, compared with Ti at the interface portion between the the Al ₂ O ₃ layer and Al ₂ O ₃ -ZrO ₂ comprising a mixed layer intermediate layer In the thickness direction, a component concentration gradient is formed which continuously and / or intermittently increases the content ratio of Ti at the interface with the surface layer. It is desirable to do. The research results shown in (a) and (b) above were obtained.

The present invention has been made based on the results of the above-mentioned research, and comprises: (a) a lower layer having an average layer thickness of 0.5 to 15 μm 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) as an intermediate layer, an Al ₂ O ₃ layer and an Al ₂ O ₃ -ZrO ₂ mixed layer having an average layer thickness of 1 to 15 μm;
(C) When the surface underlayer has an average layer thickness of 0.1 to 3 μm and is represented by a composition formula: (Ti _{1 -W} Al _W ) O _x , the central part in the thickness direction is Auger spectroscopy. A composite oxide layer of Ti and Al satisfying the following atomic ratios: W: 0.02 to 0.15, X: 1.2 to 1.7, as measured by an analyzer, and (d) a surface layer , Having an average layer thickness of 0.05 to 2 μm, and represented by a composition formula: TiN _1-Y (O), wherein (O) represents oxygen diffused from the surface underlayer. Similarly, the central part in the thickness direction is measured by an Auger spectrometer, and the Ti nitride oxide layer satisfies the following expression: an atomic ratio of Y to Ti: 0.01 to 0.4, which is composed of the above (a) to (d) Excellent chipping resistance, obtained by chemically and / or physical vapor-depositing a coated hard coating layer with a total average layer thickness of 3 to 30 μm. The characteristics of the coated coated carbide tool are as follows.

In the coated cemented carbide tool of the present invention, the ratio (Y value) of diffused oxygen in the Ti nitride layer constituting the surface layer of the hard coating 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 of suppressing adhesion to chips cannot be secured, while if the value exceeds 0.40, pores are easily formed in the layer, This is because it is difficult to stably form a sound surface layer.

As described above, the Ti nitride oxide layer, which also forms the surface layer, first serves as a surface underlayer, in which the ratio of oxygen to (Ti + Al) is 1.25 to 1.
Forming a composite oxide layer of Ti and Al having a Z value of 90 and then depositing a TiN layer on the surface underlayer under normal conditions. At this time, diffusion of oxygen from the surface underlayer becomes indispensable.
When the value is less than 1.25, the diffusion reaction of oxygen into the TiN layer is rapidly reduced, and the ratio (Y value) of diffused oxygen in the surface layer is set to 0.01 or more in atomic ratio with respect to Ti. On the other hand, if the Z value exceeds 1.90, the proportion of diffused oxygen in the surface layer increases to more than 0.40 in atomic ratio with respect to Ti. In this case, the ratio (X value) of oxygen in the surface underlayer after the formation of the surface layer is set to a value within the range of 1.2 to 1.7 in atomic ratio to (Ti + Al). In other words, when the X value of the surface base layer after the formation of the surface layer satisfies 1.2 to 1.7,
The Y value of the surface layer satisfies 0.01 to 0.40. Furthermore, in the surface underlayer composed of the composite oxide layer of Ti and Al, as described above, Al ₂ O ₃
At the interface between the layer and / or the intermediate layer of the Al ₂ O ₃ —ZrO ₂ mixed layer, the content of Al is relatively high.
Conversely, by increasing the content of Ti at the interface between the nitrided oxide layer and the surface layer, the adhesion to the intermediate layer and the surface layer is further improved. With the W value of 0.02 to 0.15 as the center, a component concentration gradient in which the lower side has a relatively higher W value and the upper side has a relatively lower W value is continuously and / or in the thickness direction. It is desirable to form it intermittently.

Further, the average layer thickness of each of the surface layer and the surface base layer also constituting the hard coating layer is set to 0.05 to 0.05.
When the average layer thickness is less than 0.05 μm or less than 0.1 μm, the desired surface tone (golden color) cannot be secured in the former case, and the average thickness is less than 0.1 μm. The latter is based on the reason that the oxygen supply to the surface layer is insufficient, while the former provides a color tone of 2 μm and the latter provides an oxygen supply of 3 μm with an average layer thickness of sufficiently satisfactory. It is.

The reason why the average layer thickness of the lower layer and the intermediate layer is 0.5 to 15 μm and 1 to 15 μm, respectively, is that the average layer thickness of the lower layer (Ti compound layer) is 0.5
When the thickness is less than μm, chipping tends to occur on the cutting edge, while the latter intermediate layer (Al ₂ O ₃ layer and Al ₂ O ₃ −
When the average layer thickness of the ZrO ₂ mixed layer) is less than 1 μm, the progress of the flank wear of the cutting edge in particular is accelerated, and when the former average layer thickness exceeds 15 μm, the wear resistance rapidly decreases. And the average layer thickness of the latter is 15 μm
Is exceeded, chipping is likely to occur on the cutting edge. 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.

[0012]

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, 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, Cr3 C2 powder, and Co
Powders are prepared, and these raw material powders are blended in the composition shown in Table 1, wet-mixed in a ball mill for 72 hours, dried, and then pressed into a green compact having a predetermined shape at a pressure of 100 MPa. The body is placed in a vacuum of 6 Pa, 1300 to 15
Vacuum sintering was performed at a predetermined temperature in the range of 00 ° C. for one hour to produce superhard substrates (chips) A to F having a throw-away chip shape specified in ISO • CNMG120408.

Next, these super-hard substrates (chips) A to F
Table 2 and Table 3 (l-TiCN in Table 2 is a TiCN having a vertically-grown crystal structure described in JP-A-6-8010) using a conventional chemical vapor deposition apparatus with the surface of Under the conditions shown in Table 4), the Ti compound layer (lower portion) having the composition and the target layer thickness shown in Table 4 was obtained under the conditions shown in Table 4. Layer), an Al ₂ O ₃ layer and / or A
l ₂ O ₃ -ZrO ₂ mixed layer (an intermediate layer), further composite oxide layer (surface preparation layer) diffusion oxygenating Ti and Al and a diffusion of oxygen-containing Ti oxynitride layer (surface layer) hardcoat FIG. 1A is a schematic perspective view showing the formation of a layer.
(B) a throw-away tip made of a surface-coated cemented carbide of the present invention as a coated carbide tool of the present invention having a shape shown in a schematic longitudinal sectional view (hereinafter, referred to as a coated carbide tip of the present invention).
1 to 10 were manufactured respectively.

For comparison purposes, as shown in Table 5, as shown in Table 5, a composite oxide layer of Ti and Al for supplying diffusion oxygen (surface underlayer) and a titanium nitride oxide layer containing diffusion oxygen (surface layer)
Under the same conditions, except that a TiN layer is formed as a surface layer instead of a conventional coated carbide tool as a conventional coated carbide tool (hereinafter referred to as a conventional coated carbide chip). 1 to 10 were manufactured respectively.

The coated carbide tip 1 of the present invention obtained as a result
The oxygen content ratio (Y value and X value) at the center in the thickness direction of the surface layer and the surface underlayer constituting the hard coating layer of Nos. 10 to 10 were measured using an Auger spectrometer. Value shown. When the Al content ratio (W value) of the center portion in the thickness direction of the surface underlayer was measured using an Auger spectrometer, the Al values were substantially the same as the target values shown in Table 3. Further, the thickness of each of the constituent layers of the hard coating layer of each of the coated carbide tips 1 to 10 of the present invention and the conventional coated carbide tips 1 to 10 was measured in cross section using a scanning electron microscope. The average layer thickness was substantially the same as the thickness (average at 5 points). The relationship between the target value and the actually measured value showed the same result in Examples 2 and 3 below.

Next, the coated carbide tips 1 to 1 according to the present invention will be described.
0 and the conventional coated carbide tips 1 to 10 were screwed to the tip of a tool steel tool with a fixing jig. Work material: JIS SCM440 round bar, Cutting speed: 350 m / min . Infeed: 1.5 mm Feed: 0.25 mm / rev. , Cutting time: 5 minutes, Dry high-speed continuous turning test of alloy steel under the following conditions: Work material: JIS SNCM439 Lengthwise equally spaced four round bar with longitudinal grooves, Cutting speed: 300 m / min . Infeed: 1.5 mm Feed: 0.3 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. Table 6 shows the measurement results.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

[0022]

[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
m3 Cr2 powder, 1.5 μm VC powder, 1.0
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 compositions shown in Table 7,
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 7, 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 super-hard substrates (end mills)
With the honing applied to the surfaces a to h, a Ti compound layer (lower portion) having a composition and a target layer thickness shown in Table 8 was obtained using an ordinary chemical vapor deposition apparatus under the same conditions shown in Tables 2 and 3. Layer), an Al2O3 layer and / or an Al2O3-Zr
O2 mixed layer (intermediate layer), and Ti and A for diffusion oxygen supply
By forming a hard coating layer composed of a composite oxide layer (surface underlayer) and a diffusion oxygen-containing Ti oxynitride layer (surface layer), a schematic front view in FIG. ) End mills (hereinafter, referred to as coated carbide end mills) 1 to 8 of the surface coated cemented carbide alloy of the present invention as coated carbide tools of the present invention having the shape shown in the schematic cross-sectional view of the cutting edge portion. Manufactured.

For comparison purposes, as shown in Table 9, the diffusion oxygen-containing Ti oxynitride layer (surface layer) and the Ti / Ai composite oxide layer for supplying diffusion oxygen (surface underlayer) are shown in Table 9. ) In place of forming a TiN layer (surface layer) under the same conditions except that a conventional surface-coated cemented carbide end mill (hereinafter referred to as a conventional coated carbide end mill) as a conventional coated carbide tool is provided. Was 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: 80 m / min. , Groove depth (cut): 2 mm, Table feed: 550 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): 5 mm, Table feed: 600 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): 10 mm, table feed: 600 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.

[0027]

[Table 7]

[0028]

[Table 8]

[0029]

[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
With the honing applied to the surface of '~ h', using a conventional chemical vapor deposition apparatus, under the same conditions as shown in Tables 2 and 3, the Ti compound layer having the composition and target layer thickness shown in Table 10 ( Lower layer), Al2O3 layer and / or Al2O3-Z
rO2 mixed layer (intermediate layer), and Ti for supplying diffusion oxygen
By forming a hard coating layer composed of a composite oxide layer of Al and Al (a surface underlayer) and a diffusion oxygen-containing Ti oxynitride layer (a surface layer), a schematic front view in FIG. b) A drill made of a surface-coated cemented carbide of the present invention as a coated carbide tool of the present invention having a shape shown in a schematic cross-sectional view of a groove forming portion (hereinafter referred to as a coated carbide drill of the present invention) 1 to 8
Was manufactured respectively.

For comparison purposes, as shown in Table 11, the diffusion oxygen-containing Ti oxynitride layer (surface layer) and the Ti / Al composite oxide layer for supplying diffusion oxygen (surface underlayer) are shown in Table 11. ) In place of forming a TiN layer (surface layer) under the same conditions except that a drill made of a conventional surface-coated cemented carbide as a conventional coated carbide tool (hereinafter referred to as a conventional coated carbide drill)
1 to 8 were produced respectively.

The coated carbide drill 1 of the present invention obtained as a result
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: 50 m / min. , Feed: 0.3 mm / min, Wet high-speed drilling test of alloy steel under the following conditions: coated carbide drills 4 to 6 according to the present invention and conventional coated carbide drills 4 to 4
About 6, work material: plane dimensions: 100 mm x 250 mm, thickness: 5
0 mm JIS SCM440 plate, Cutting speed: 60 m / min. , Feed: 0.3 mm / min, wet high-speed drilling test of alloy steel under the following conditions: coated carbide drills 7 and 8 according to the present invention and conventional coated carbide drills 7 and 8
For No. 8, Work material: Plane dimensions: 100 mm × 250 mm, thickness: 5
0 mm JIS SCM415 plate, Cutting speed: 70 m / min. , Feed: 0.4mm / min, Welding high-speed drilling cutting test of alloy steel under the following conditions, and the flank surface of the tip cutting surface in any wet (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.

[0034]

[Table 10]

[0035]

[Table 11]

[0036]

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, the composite oxide layer (surface underlayer) of Ti and Al also constituting the hard coating layer is mixed with Al2O3 layer and Al2O3-ZrO2 even in high-speed cutting of steel with high heat generation. Layer (intermediate layer) and the Ti nitride oxide layer (surface layer), and the Ti nitride oxide layer (surface layer) has extremely low affinity for high-temperature heating chips. Since the powder does not adhere to the Ti oxynitride layer, it exhibits excellent wear resistance without chipping on the cutting edge, whereas the surface layer of the hard coating layer is composed of a TiN layer. Conventional coated carbide tools, Since the cutting powder easily adheres to the TiN layer, and the TiN layer is peeled off by the cutting powder together with other constituent layers, chipping easily occurs in the cutting blade, which causes a relatively short service life. It is clear that 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.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23P 15/28 B23P 15/28 A C04B 41/89 C04B 41/89 J C23C 16/30 C23C 16/30 16 / 32 16/32 16/34 16/34 16/36 16/36 16/40 16/40 F term (reference) 3C037 CC02 CC04 CC09 3C046 FF03 FF10 FF13 FF16 FF19 FF22 FF25 4K018 AD06 BA04 BA11 DA11 FA24 KA15 4K030 AA03 AA06 AA14 BA24 BA36 BA38 BA41 BA42 BA43 BB12 CA03 LA01 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, (B) an aluminum oxide layer having an average layer thickness of 1 to 15 μm as an intermediate layer, and / or a Ti compound layer comprising one or more of a carbon oxide layer and a carbonitride oxide layer. Or an aluminum oxide-zirconium oxide mixed layer in which a zirconium oxide phase is dispersed and distributed on an aluminum oxide substrate; (c) a surface underlayer having an average layer thickness of 0.1 to 3 μm, and a composition formula: ( Ti _1-W Al _W ) O _x , where the central part in the thickness direction was measured with an Auger spectrometer, and all were represented by atomic ratios of W: 0.02 to 0.15 and X: 1.2. ~ 1.7, complex oxidation of Ti and Al satisfying Layer, as (d) the surface layer has an average layer thickness of 0.05 to 2 [mu] m, and the composition _{formula: TiN 1-Y (O)} Y, in the case where expressed [However, (O) under the surface Shows the oxygen diffused from the stratum], and also measures the central part in the thickness direction with an Auger spectroscopic analyzer, and the atomic ratio of Y to Ti is 0.01 to 0.4. A cutting tool made of a surface-coated cemented carbide having excellent chipping resistance, wherein the hard coating layer composed of (a) to (d) is chemically vapor-deposited and / or physically vapor-deposited with an overall average layer thickness of 3 to 30 μm.