JPH11254208A - Milling tool excellent in wear and abrasion resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a milling tool excellent in wear and abrasion resistance. SOLUTION: With regard to a milling tool of a type having a surface coated cemented carbide made cutting blade tip formed of a hard coated layer on the surface of a cemented carbide base substance fitted to it in a detachable manner, the cemented carbide base substance is of 75 to 95 weight % dispersed phase and the remainder of a bonded phase and an unavoidable unpurity, the dispersed phase composed of WC and containing 5 to 20 weight % of Co as a bonded phase forming component, and includes a high temperature heat formed surface layer having a reaction product Com Wn C distributed on the surface covering in the depth of 1 to 2 μm from the utmost surface. Besides composing it with the cemented carbide base substance, the hard coated payer is composed of a Ti compound layer consisting of one or two or more kinds of either a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, a TiNO layer, or TiCNO layer, all of which are formed by applying an MT-CVD method, or of such Ti compound layer and a Al2 O3 layer formed by applying the MT- CVD method or an HT-CVD method, and the average layer thickness is to be 0.5 to 4.5 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard coating layer constituting a cutting edge tip, which has excellent adhesion to the surface of a cemented carbide substrate, and therefore can be used even in high-speed cutting under severe cutting conditions. The present invention relates to a milling (milling) tool that exhibits excellent wear resistance over a long period of time because no peeling occurs.

[0002]

2. Description of the Related Art Conventionally, as shown in a plan view of FIG. 1 (a), for example, a notch formed on a side surface of a tip portion of a rotating shank body made of steel or cemented carbide has the same shape as that shown in FIG. ), A surface-coated cemented carbide cutting edge tip (hereinafter simply referred to as a cutting edge tip) illustrated in a plan view and a longitudinal sectional view.
That is, there is known a milling tool of a type in which a cutting edge tip having a hard coating layer formed on the surface of a cemented carbide substrate is detachably mounted by fixing means such as screwing. Further, the hard coating layer constituting the cutting edge tip is formed by a normal high temperature chemical vapor deposition method (hereinafter, referred to as an HT-CVD method),
1000 to 115, which is the deposition temperature of the HT-CVD method.
It is also known that it is formed by a medium temperature chemical vapor deposition method (hereinafter, referred to as an MT-CVD method) in which vapor deposition is performed at 700 to 980 ° C., which is relatively lower than 0 ° C.

[0003]

On the other hand, labor saving and energy saving of cutting work have been remarkable in recent years, and accordingly, cutting conditions have tended to be further increased. When used under high speed conditions,
Due to the insufficient adhesion of the hard coating layer constituting the cutting edge tip to the surface of the cemented carbide substrate, the hard coating layer is liable to peel off, which significantly accelerates the progress of wear and is relatively short. At present, the service life is reached.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoints, attention was paid to a milling tool, and a study was conducted to improve the adhesion of the hard coating layer to the surface of the cemented carbide substrate in the cutting edge tip constituting the milling tool. Has an internal composition consisting of: dispersed phase: 75 to 95% by weight; binder phase and unavoidable impurities: remaining; and the dispersed phase is composed of tungsten carbide (hereinafter referred to as WC) or WC, Ti, T
a, Nb, and Zr carbides, nitrides, and carbonitrides (hereinafter, TiC, TiN, TiCN, and Ta, respectively)
C, TaN, TaCN, NbC, NbN, NbCN, Z
rC, ZrN, and ZrCN), and two or more of these solid solutions (hereinafter collectively referred to as metal charcoal.
(Hereinafter referred to as nitride), and when the above-mentioned metal carbon / nitride is contained, the content ratio is 0.1 to 5% by weight, and the binder phase is formed. A cemented carbide substrate containing 5-20% by weight of Co as a component. In this case, the average particle size of WC in the cemented carbide substrate is 0.1 to 1.5 μm from the viewpoint of the substrate strength.
m is desirable. (B) The cemented carbide substrate of (a) is placed in a hydrogen atmosphere containing carbon dioxide gas or titanium tetrachloride, and the atmosphere pressure is 5
When a high-temperature heat treatment is performed at a temperature of 900 to 1000 ° C. for 5 to 15 minutes at a temperature of 0 to 550 torr, a complex carbide of Co and W or Co and W is coated on the surface over a predetermined depth from the outermost surface. Composite carbides (mainly
(Represented by _Com W _n C). (C) the reaction product Co _m W _n C is the surface of the cemented carbide substrate having a high-temperature heat forming surface layer distribution of the (b) in the surface portion, both using the MT-CVD method, a carbide layer of Ti , Nitride layer, carbonitride layer, carbonate layer, nitride layer,
And a carbonitride layer (hereinafter referred to as TiC layer and TiN layer, respectively)
Layer, TiCN layer, TiCO layer, TiNO layer, and Ti
A CNO layer), an aluminum oxide (hereinafter referred to as Al ₂ O ₃₎ formed by MT-CVD or HT-CVD if necessary. When the hard coating layer composed of the above-described layers is formed with an average thickness of 0.5 to 4.5 μm, the Ti
The adhesion of the compound layer to the surface of the cemented carbide substrate is significantly improved by the high-temperature heat-formed surface layer formed on the surface of the cemented carbide substrate, and therefore, the resulting milling tool equipped with a cutting edge tip Is to exhibit excellent wear resistance over a long period of time since the hard coating layer of the cutting edge tip does not peel even when used for high-speed cutting. The research results shown in (a) to (c) above are shown.

The present invention has been made on the basis of the above-mentioned research results, and has a notch formed in a side surface of a tip portion of a steel or cemented carbide rotary shank body, and has a surface of a cemented carbide substrate. In a milling tool of a type in which a cutting edge tip having a hard coating layer formed thereon is removably mounted, the cemented carbide substrate in the above cutting edge tip is formed by dispersing phase: 75 to 95% by weight, binder phase and inevitable impurities: And a dispersed phase comprising WC or one or more of WC and a metal charcoal / nitride, and one of the metal charcoal / nitride. When containing two or more species, the content ratio is 0.1 to
5% by weight, and Co: 5-2 as a binder phase forming component.
0% by weight, and 0.1 to 0.1%
Having a high-temperature heating forming the surface layer of the reaction product Co _m W _n C is distributed over a depth of 2 [mu] m, as well as composed of a cemented carbide substrate, the hard coating layer, either by using a MT-CVD method is formed TiC layer, TiN layer, TiCN layer, Ti
A Ti compound layer comprising one or more of a CO layer, a TiNO layer, and a TiCNO layer;
constituted by i compound layer and MT-CVD method or the Al ₂ O ₃ layer formed by HT-CVD method, and has an average layer thickness thereof and 0.5～4.5Myuemu, wear resistance superior milling tool It is characterized by the following.

[0006] Next, in the milling tool of the present invention, the composition of the cemented carbide substrate in the cutting edge tip to configure this, Co _m W _n C distribution depth, and as a mean layer thickness of the hard coating layer of the The reason for the limitation is explained. (A) Proportion of dispersed phase If the proportion is less than 75% by weight, not only the proportion of the binder phase becomes relatively too large, so that the wear resistance sharply decreases, but also the formation of _Com W _n C. There will be suppressed, whereas when the ratio exceeds 95 wt%, the proportion of the binder phase is too small not avoid decrease in strength, and formed in this case it is also Co _m W _n C is suppressed Therefore, the ratio was determined to be 75 to 95% by weight. In addition,
In this case, with respect to the average particle size of the WC particles constituting the dispersed phase, if the average particle size is less than 0.1 μm, a decrease in wear resistance is inevitable, while if the average particle size exceeds 1.5 μm. The thickness is desirably 0.1 to 1.5 μm as described above because a desired strength improving effect cannot be obtained.

(B) Content ratio of metal carbon / nitride Since these components have a function of forming a dispersed phase to increase the hardness of the cemented carbide substrate and thereby improve the wear resistance, these components are necessary. Depending on the content, but the content ratio is 0.1
If the amount is less than about 10% by weight, the desired effect of improving wear resistance cannot be obtained.
On the other hand, if the content exceeds 5% by weight, the strength of the cemented carbide substrate tends to decrease, so the content is set to 0.1 to 5% by weight.

(C) Co Content The Co component has the effect of improving the sinterability and thus the strength of the cemented carbide substrate, but if the content is less than 5% by weight, the desired strength improvement is achieved. No effect is obtained and Co
look like the formation of _m W _n C is suppressed, whereas when the ratio exceeds 20 wt%, decreases the wear resistance of the cemented carbide substrate, in particular a rake face wear of the cutting edge portion proceeds rapidly not only is that way, since in this case the formation of Co _m W _n C is to be suppressed, the ratio 5-2
It was determined to be 0% by weight.

(D) Distribution depth of Co _m W _n C If the distribution depth is less than 0.1 μm, the distribution ratio in the high-temperature heat-formed surface layer is too small, and the hard coating layer has a desired excellent distribution. can not be ensured adhesion, whereas when the distribution depth exceeds 2 [mu] m, the distribution ratio of Co _m W _n C in the cemented carbide substrate outermost surface becomes too much, chipping the cutting edge tip which causes (Micro chipping) is likely to occur, so the distribution depth is set to 0.1 to 2 μm, preferably 0.3 to 0.6 μm.

(E) Average layer thickness of the hard coating layer If the average layer thickness is less than 0.5 μm, it is not possible to secure desired excellent wear resistance to the cutting edge tip, while the average layer thickness is 4 μm. If it exceeds 0.5 μm, chipping and chipping easily occur in the cutting edge tip, so the average layer thickness is set to 0.5 to 4.5 μm, preferably 1.0 to 2.0 μm.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A milling tool according to the present invention will be specifically described with reference to embodiments. First, as raw material powder,
Various WC powders having an average particle diameter changed in the range of 0.1 to 1.5 μm, each having a mean particle diameter of 0.5 μm
C powder, TiN powder, TiCN powder, TaC powder, Ta
N powder, TaCN powder, NbC powder, NbN powder, Nb
CN powder, ZrC powder, ZrN powder, ZrCN powder, (Ti _0.5 Ta _0.5 ) C powder, (Ta _0.8 N
b _0.2) C powder, (Ta _0.4 Zr _0.6) C powder, (Ti
_0.8 Zr _0.2 ) N powder, (Ti _0.9 Nb _0.1 ) C _0.8 N
_0.2 powder, (Ta _0.4 Zr _0.6 ) C _0.5 N _0.5 powder,
(Ti _0.2 Ta _0.8 ) C _0.4 N _0.6 powder, (Ti _0.3 T
a _0.3 Zr _0.4 ) C powder, (Ti _0.1 Zr _0.8 N)
b _0.1 ) C powder, (Ta _0.7 Nb _0.1 Zr _0.2 ) C powder, (Ti _0.3 Nb _0.3 Zr _0.4 ) N powder, (Ti _{0.1
Ta 0.8 Nb 0.1) C 0.9 N} 0.1 powder, (Ti _0.2 Ta
_0.2 Zr _0.4 Nb _0.2 ) C _0.7 N _0.3 powder (the numerical values of the solid solution powder indicate the molar ratio) and Co powder of 0.5 μm were prepared, and these raw material powders were mixed in the mixing ratio shown in Table 1. The mixture was wet-mixed with a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 1 ton / cm ² , and the green compact was pressed in a vacuum of 1 × 10 ⁻³ torr.
Vacuum sintering at a predetermined temperature in the range of 50 to 1500 ° C. for one hour, having substantially the same composition as the composition shown in Table 1, and also having the average composition shown in Table 1. Cemented carbide base materials a to z constituting a cutting edge tip made of WC having a particle size were formed.

Next, the surface of each of the cemented carbide substrate materials a to z was also applied to the surface of each of the materials under the conditions shown in Table 2.
Cemented carbide substrate A~Z by Co _m W _n C over the depth is shown to form a high-temperature heating the forming surface layer distributed in
Was manufactured.

Subsequently, a hard coating layer having a composition and an average thickness shown in Table 4 is formed on the surface of each of the cemented carbide substrates AZ under the conditions shown in Table 3 to obtain a length: 28 .9mm x width: 11.2mm x thickness: 5m
Cutting blade tips A to Z for the present invention having the dimensions of m and the shape shown in FIG. 1B were formed.

Furthermore each of these present invention for cutting inserts A~Z, JIS · SCM440 (hardness: H _R C4
0) or a composition of WC-6% Co;
C is made of a cemented carbide having an average particle size of 1.5 μm, and has a total length of 200 mm × front half length: 120 mm × rear half length: 80 mm × front half diameter: 30 mm × rear half diameter: 32 mm. The milling tool 1 according to the present invention is obtained by screwing in a combination shown in Table 6 into a notch formed on a side surface of a tip portion of a rotating shank body having dimensions and a shape shown in a plan view in FIG. ~ 26 were each manufactured.

For the purpose of comparison, as shown in Table 5, in place of the cemented carbide substrates A to Z having the surface layer formed by heating at a high temperature, cemented carbide substrates a to z without the formation thereof were used. Comparative milling tools 1 to 1 shown in Table 6 under the same conditions except that the comparative cutting edge tips a to z formed by using
26 were each manufactured.

Then, the resulting milling tools 1-26 and comparative milling tools 1-26 of the present invention were prepared as follows: Work material: FCD400, angled material: 10 degrees, Cutting speed: 1000 m / min, 1 blade Per-cut feed: 0.4 mm / tooth, axial cut: 0.2 mm, radial cut: 0.35 mm, dry high-speed contour milling of cast iron under the following conditions: The cutting time to 0.2 mm 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]

[0023]

From the results shown in Table 6, all of the milling tools 1 to 26 of the present invention exhibit excellent wear resistance because the hard coating layer of the cutting edge tip constituting them does not peel off. On the other hand, in the comparative milling tools 1 to 26, it is apparent that the hard coating layer of the cutting edge chip is peeled off during the cutting, and that the peeling significantly promotes wear. is there. As described above, according to the milling tool of the present invention, the adhesiveness of the hard coating layer of the cutting edge tip constituting the cutting tool to the surface of the cemented carbide substrate is distributed in the high-temperature heat-formed surface layer formed on the substrate surface. _m W _n C has been significantly improved, so that it can be used not only under normal cutting conditions, but also in high-speed cutting, without causing peeling of the hard coating layer of the cutting edge tip and excellent wear resistance. For a long time.

[Brief description of the drawings]

FIG. 1A is a plan view of a milling tool and FIG. 1B is a plan view and a vertical cross-sectional view of a cutting edge tip constituting the milling tool.

Claims (4)

[Claims] 1. A surface coated cemented carbide cutting in which a hard coating layer is formed on a surface of a cemented carbide substrate in a notch formed on a side surface of a tip portion of a rotating shank body made of steel or cemented carbide. In a milling tool of a type in which a blade tip is detachably mounted, a cemented carbide substrate in the surface-coated cemented carbide cutting blade tip is composed of: dispersed phase: 75 to 95% by weight; binder phase and unavoidable impurities: remaining; It has an internal composition, the dispersed phase is composed of tungsten carbide, and Co: 5 to 20 as a binder phase forming component.
% By weight, and 0.1 to 0.1%
A cemented carbide substrate having a high-temperature heat-formed surface layer in which a reaction-formed composite carbide of Co and W is distributed over a depth of 2 μm, and the hard coating layer is formed by a medium-temperature chemical vapor deposition method. A Ti compound layer composed of one or more of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer, carbonitride layer, and carbonitride layer, A milling tool with excellent wear resistance, characterized in that the average layer thickness is 0.5 to 4.5 μm. 2. A surface-coated cemented carbide cutting tool in which a hard coating layer is formed on a surface of a cemented carbide substrate in a notch formed in a side surface of a tip portion of a steel or cemented carbide rotary shank main body. In a milling tool of a type in which a blade tip is detachably mounted, a cemented carbide substrate in the surface-coated cemented carbide cutting blade tip is composed of: dispersed phase: 75 to 95% by weight; binder phase and unavoidable impurities: remaining; It has an internal composition, the dispersed phase is composed of tungsten carbide, and Co: 5 to 20 as a binder phase forming component.
% By weight, and 0.1 to 0.1%
A cemented carbide substrate having a high-temperature heat-formed surface layer in which a reaction-formed composite carbide of Co and W is distributed over a depth of 2 μm, and the hard coating layer is formed by a medium-temperature chemical vapor deposition method. A Ti compound layer composed of one or more of a Ti carbide layer, a nitride layer, a carbonitride layer, a carbonate layer, a nitride oxide layer, and a carbonitride layer, An aluminum oxide layer formed by a vapor deposition method or a high-temperature chemical vapor deposition method and having an average layer thickness of 0.5 to 4.5.
Milling tool with excellent wear resistance, characterized by having a thickness of μm. 3. A surface coated cemented carbide cutting in which a hard coating layer is formed on a surface of a cemented carbide substrate in a notch formed on a side surface of a tip end portion of a rotating shank body made of steel or cemented carbide. In a milling tool of a type in which a blade tip is detachably mounted, a cemented carbide substrate in the surface-coated cemented carbide cutting blade tip is composed of: dispersed phase: 75 to 95% by weight; binder phase and unavoidable impurities: remaining; Having an internal composition, and forming the dispersed phase into tungsten carbide, carbides, nitrides, and carbonitrides of Ti, Ta, Nb, and Zr, and a solid solution of two or more of these (hereinafter, collectively referred to as Metal carbon / nitride) and the above-mentioned metal charcoal / nitride.
The content ratio of one or more of the nitrides is 0.1
To 5% by weight, and Co: 5 to 5% as a binder phase forming component.
20% by weight, and 0.1% from the outermost surface on the surface.
Having a high-temperature heat-formed surface layer in which reaction-formed composite carbides mainly composed of Co and W are distributed over a depth of 1 to 2 μm,
The hard coating layer is formed of a cemented carbide substrate, and the hard coating layer is formed of a Ti carbide layer, a nitride layer, a carbonitride layer, a carbonitride layer, a carbonitride layer, Excellent wear resistance, characterized in that it is composed of a Ti compound layer composed of one or more of carbon oxynitride layers and has an average layer thickness of 0.5 to 4.5 μm. Milling tools. 4. A surface-coated cemented carbide cutting tool in which a hard coating layer is formed on a surface of a cemented carbide substrate in a notch formed in a tip side surface of a steel or cemented carbide rotating shank main body. In a milling tool of a type in which a blade tip is detachably mounted, a cemented carbide substrate in the surface-coated cemented carbide cutting blade tip is composed of: dispersed phase: 75 to 95% by weight; binder phase and unavoidable impurities: remaining; It has an internal composition, and the dispersed phase is made of tungsten carbide, carbides, nitrides, and carbonitrides of Ti, Ta, Nb, and Zr, and two or more solid solutions thereof (hereinafter, collectively referred to as metal Or one or more of the above-mentioned carbon / nitrides, and
The content ratio of one or more of the nitrides is 0.1
To 5% by weight, and Co: 5 to 5% as a binder phase forming component.
20% by weight, and 0.1% from the outermost surface on the surface.
Having a high-temperature heat-formed surface layer in which reaction-formed composite carbides mainly composed of Co and W are distributed over a depth of 1 to 2 μm,
The hard coating layer is formed of a cemented carbide substrate, and the hard coating layer is formed of a Ti carbide layer, a nitride layer, a carbonitride layer, a carbonitride layer, a carbonitride layer, And a Ti compound layer composed of one or more of carbon oxynitride layers, and an aluminum oxide layer formed by a medium temperature chemical vapor deposition method or a high temperature chemical vapor deposition method, and an average layer thereof 0.5-4.5 thickness
Milling tool with excellent wear resistance, characterized by having a thickness of μm.