JP3430939B2 - Surface-coated cemented carbide cutting tool with excellent chipping resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Aluminum oxide forming the hard coating layer of hard alloy cutting tools
Um (hereinafter, Al_Two O_Three (Indicated by)
Even if the film thickness is increased, the layer thickness becomes uniform and the toughness decreases.
Therefore, continuous cutting of steel and cast iron, for example, is of course
In particular, when used for interrupted cutting, the tip
Excellent over a long period of time with no cracking (micro chipping)
Surface-coated cemented carbide cutting tool (
Below, referred to as coated carbide tools). [0002] 2. Description of the Related Art Conventionally, generally, for example, Japanese Patent Application Laid-Open No. 6-315
No. 03, JP-A-6-316758, and
As described in Japanese Unexamined Patent Publication No. 7-216549,
Tungsten carbide-based cemented carbide substrate (hereinafter referred to as cemented carbide substrate)
A), an average layer thickness of 0.1 to 15 μm
Having a carbide (TiC) layer of Ti, nitrided
(Hereinafter also referred to as TiN) layer, carbonitride (hereinafter, referred to as TiN)
TiCN layer, carbonate (hereinafter TiCO)
) Layer, a nitride oxide (hereinafter referred to as TiNO) layer, and
One of carbonitride (hereinafter referred to as TiCNO) layer
Or a Ti compound layer composed of two or more kinds, and 0.5 to 15
Al with an average layer thickness of μm_Two O_Three Composed of layers and front
Each of the Ti compound layers has a granular crystal structure.
Some TiCN layers have a vertically elongated crystal structure,
Further, the Al_Two O_Three The layer has a crystal structure such as α-type or κ-type.
A hard coating layer having a total average thickness of 3 to 25 μm
ThickChemical vapor depositionA coated cemented carbide tool is known. [0003] On the other hand, cutting in recent years
Is becoming increasingly FA and demand for labor saving is strong
Therefore, coated carbide tools have a longer service life.
Life extension is required, and as a means to respond to this,
Among the constituent hard coating layers, especially oxidation resistance and thermal stability
Al with high hardness_Two O_Three Thicker layer
Has been widely studied, but the Al_Two O_Three The layer
If the thickness is large, the layer thickness becomes locally uneven, and the cutting edge escapes.
Face, rake face, and the intersection of the flank and rake face
So that there is a significant variation in the layer thickness between
Al_Two O_ThreeDecrease in toughness of layer itself
This inevitably results in intermittent interruptions of steel and cast iron, for example.
When used for cutting, chipping is likely to occur on the cutting edge.
At present, the service life is relatively short due to
You. [0004] Means for Solving the Problems Accordingly, the present inventors have
From the viewpoint as described above, the hard coating layer of the coated carbide tool is formed.
Al formed_Two O_Three Pay attention to the layer, especially when the thickness is increased
To reduce local variations in thickness and to suppress toughness
As a result of the research, (A)Chemical vapor depositionAt Reaction gas composition (% by volume, the same applies hereinafter)-TiCl_Four ::
0.4 to 10%, Ar: 1 to 30%, CO: 0.5 to 5
%, CO_Two : 0.5 to 10%, N_Two : 1 to 40%, H
_Two :remaining, Ambient temperature: 800 to 1100 ° C, Atmospheric pressure: 30 to 500 Torr, When deposition is performed under the conditions of_Two O_Three Consists of
Carbon (C) and non-metal elements other than oxygen (O)
Nitrogen (N) is a percentage of the total amount with O (oxygen) in the total amount.
Ti containing 1 to 20 atomic% in total_Two O_Three Main layer, sand
C and N are Ti_TwoO_Three Of the total amount with O that forms
In total, the content is 1 to 20 atomic%, and the balance is substantially T
i_Two O_Three [Including trace amounts of Cl (chlorine) as inevitable impurities.
May have)_Two O_Three The main layer is formed
This Ti_Two O_Three The main layer is made of Al_Two O_Three Dense against layers
It has excellent toughness and has good toughness
There is. (B) Therefore, basically, Al having a predetermined layer thickness_Two O_Three
After forming the layer, the Ti_Two O_Three Predetermined layer thickness for main layer
And then again with a predetermined layer thickness of Al_Two O_Three Form a layer
Alternately laminated structure layer, that is, Al of a predetermined layer thickness_Two O_Three Layer of
Two or more layers and a predetermined layer thickness of Ti_Two O_Three One or more layers of the main layer
In the case of an alternate layered structure layer, even if this is made thicker,
Al that constitutes_Two O_Three Make each layer relatively thin
Can cause significant local variations in the layer thickness
Less flank, rake face of cutting edge and said flank
The layer thickness at the edge where the rake face intersects the
And in addition to Al_Two O_Three When the layer itself is thickened
The decrease in toughness that occurs in
When. (C) As a result, each of the hard coating layers is
Note Al_Two O_Three Two or more layers and the Ti_Two O_Three Main layer
One or more alternately laminated structure layers, and one or more of a predetermined layer thickness
Super coating composed of two or more Ti compound layers
The hard tool is the Al_TwoO_ThreeDepending on the layer, the hard coating
Outstanding oxidation resistance, thermal stability and high hardness
And the Ti_Two O_Three Alternate lamination by main layer
The structural layer has good toughness and interlayer density even if it is made thicker.
Since the adhesiveness is ensured, for example, continuous
When used for interrupted cutting, as well as cutting,
Excellent cutting performance over a long period without the occurrence of tapping
To be able to demonstrate its function, as shown in (a) to (c) above.
The research results obtained were obtained. [0005] The present invention has been made based on the above research results.
The surface of the super-hard substrate was all subjected to 0.1.
TiC layer, TiN having an average layer thickness of 1 to 15 μm
Layer, TiCN layer, TiCO layer, TiNO layer, and Ti
Ti compound comprising one or more of CNO layers
Hard coating layer composed of a material layer and an alternately laminated structure layer
Coated carbide tool formed with an overall average layer thickness of ~ 25 µm
And the alternate layered structure layer is formed with an average of 0.5 to 7 μm.
Al with layer thickness_TwoO_ThreeTwo or more layers, 0.05 to 2
μm average layer thickness, mainly Ti_Two O_Three Consists of
C and N as nonmetallic elements other than O
Containing 1 to 20 atomic% of the total amount of Ti_Two
O_Three Composed of at least one main layer, particularly Al_TwoO
_ThreeUniform layer thickness and reduced toughness
Control, thereby improving the chipping resistance of the cutting edge.
The feature is that the coated coated carbide tool is raised. [0006] The hard coating of the coated carbide tool of the present invention.
In the alternate laminated structure layers constituting the layers, Al_TwoO_ThreeLayer of
The reason why the average layer thickness of each layer is 0.5 to 7 μm is that the layer thickness is
Is less than 0.5 μm, even if multiple layers are stacked,
Hardened excellent oxidation resistance and thermal stability, and high hardness
Can not be provided in the porous coating layer, while the layer thickness is
If it exceeds 7 μm, uniformity of the thickness of the hard coating layer is impaired.
And the toughness of the hard coating layer is reduced
For reasons, and also Ti_TwoO_Three Subject
The reason why the average thickness of each layer is 0.05 to 2 μm is as follows.
Is less than 0.05 μm, Ti_Two O_Three Of the main layer
One of the above characteristics, namely Al_TwoO_ThreeExcellent for layers
Adhesion and toughness when the alternate layered structure layer is made thicker
Cannot be secured, while its layer thickness exceeds 2 μm
And the wear resistance of the hard coating layer rapidly decreases
The reason is that. In this case, Ti_Two
O_Three The content ratio of C and N in the main layer depends on the C content in the reaction gas.
O, CO_Two , Ar, and N_Two Adjust the content ratio of
And the mutual proportion of C and N is C
O, CO_Two , And N_Two By adjusting the mutual proportion of
And C and N are both layers themselves.
Exerts an equalizing effect on the improvement of the strength. Accordingly
If the ratio is less than 1 atomic%, a desired strength improving effect is obtained.
On the other hand, if the content exceeds 20 atomic%, the toughness of the layer itself is reduced.
From 1 to 20 atomic% in total,
Desirably, the content is set to 2 to 10 atomic%.
Is within a range of 1 to 20 atomic% in total.
If C is present, even if C is relatively larger than N,
However, even if C is smaller than N, the change in the strength improving effect is as follows.
Since there is no such compound, the total amount of C and N is shown. Further, the coated carbide tool of the present invention
Therefore, each layer of the Ti compound layer constituting the hard coating layer is hard
It has the effect of improving the fracture resistance (toughness) of the coating layer,
When the average layer thickness is less than 0.1 μm, the desired effect can be obtained for the above operation.
If the average layer thickness exceeds 15 μm
The wear of the hard coating layer itself will rapidly progress
Therefore, the average layer thickness was determined to be 0.1 to 15 μm. Ma
In addition, the total average layer thickness of the hard coating layer was set to 3 to 25 μm.
Has a desired wear resistance if the average layer thickness is less than 3 μm.
Cannot be maintained, while its average layer thickness exceeds 25 μm.
Chipping and chipping easily occur
For that reason. [0008] DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a coated carbide tool of the present invention
Will be specifically described with reference to examples. As raw material powder,
Average particle size: Medium WC powder having 2.8 µm, 4.9 µm
m of coarse WC powder and 1.5 μm of (Ti, W) C (weight
The same in the following, TiC / WC = 30/70) powder,
1.2 μm (Ti, W) CN (TiC / TiN / W
C = 24/20/56) powder, 1.2 μm (Ta,
Nb) C (TaC / NbC = 90/10) powder;
2 μm Cr_ThreeC_TwoPowder and 1.1 μm Co powder
Powders, and mix these raw material powders as shown in Table 1.
And wet-mixed in a ball mill for 72 hours and dried.
After that, ISO • CNMG120408 (Carbide substrates A to D)
SEEN42AFTN1 (for carbide substrate E)
Into a green compact of the shape specified in
In the end, vacuum sintering under the conditions shown in Table 1
Substrates A to E were respectively manufactured. In addition, the above-mentioned carbide substrate
A, B and C are bonded to the surface as they are sintered
The content of Co, which is a phase forming component, is lower than that of the inside of the carbide substrate.
On the other hand, a high Co-enriched zone is formed,
Substrates D and E have no formation of the Co-rich zone,
It had an overall homogeneous structure. Table 1
Is the internal hardness (Rockwell hardness) of the above-mentioned carbide substrates A to E
A scale). Next, the surfaces of these super-hard substrates A to D
Then, with the honing applied, a normal chemical vapor deposition
Table 2 and Table 3 (l-TiCN in Table 2 is
The figure shows the conditions for forming a TiCN layer having a long crystal structure.
All of the layers formed under other conditions
Under the conditions shown in Tables 4 and 5
Hardness of composition and target layer thickness (flank of cutting edge) shown in
By forming a coating layer, the coated carbide tools of the present invention 1 to 1
0, and Ti_Two O_Three Conventional coated carbide without formation of main layer
Tools 1 to 10 were manufactured respectively. In addition, the present invention coating
Regarding the hard tools 1 to 10, the flank of each cutting edge is C
X-ray diffraction using ukα-ray as a source
The observation of the_Two O_Three Diffraction angle of
(2θ) 24.0 ± 1 degree, 34.5 ± 1 degree, 6
Diffraction peaks at 1.0 ± 1 ° and 63.0 ± 1 °
, This allows Ti _Two O_Three The main layer is made of Ti_Two
O_Three It can be confirmed that the tool consists of
Polished and finished on the tool rake and flank
Ti_Two O_Three Auger the C and N contents of the main layer
When measured using an electron spectroscopy analyzer,
i_Two O_Three C in the total amount of C, N, and O in the main layer
And the ratio of the total amount of N is substantially the same as the target content in Table 3.
The same values. In addition, the constituent layers constituting the hard coating layer
The deviation also has substantially the same layer thickness as the target layer thickness.
Was. Next, the coated carbide tools 1 and 2 of the present invention will be described.
And conventional coated carbide tools 1 and 2 Work material: Square material of JIS / FCD450, Cutting speed: 250 m / min. , Notch: 2mm, Feed: 0.3 mm / rev. , Cutting time: 5 minutes, A dry interrupted cutting test of ductile cast iron was conducted under the conditions
The flank wear width of the blade was measured. The coated carbide tools 3 and 4 of the present invention and the conventional
For coated carbide tools 3, 4, Work material: JIS S45C square material, Cutting speed: 300 m / min. , Cut: 1.5 mm. , Feed: 0.3 mm / rev. , Cutting time: 5 minutes, Under dry cutting conditions of carbon steel under the conditions of
The surface wear width was measured. The above-mentioned coated carbide tools 5, 6 according to the present invention and the conventional ones
For coated carbide tools 5, 6, Work material: JIS SCM415 square material, Cutting speed: 250 m / min. , Cut: 2 mm. , Feed: 0.3 mm / rev. , Cutting time: 5 minutes, Intermittent cutting test of alloy steel under the conditions of
The surface wear width was measured. The coated carbide tools 7, 8 according to the present invention and the prior art
Regarding coated carbide tools 7 and 8, Work material: JIS FC200 square material, Cutting speed: 300 m / min. , Cut: 2 mm. , Feed: 0.3 mm / rev. , Cutting time: 5 minutes, Under the conditions described above, a dry intermittent cutting test was performed on cast iron, and the flank
The wear width was measured. Similarly, the coated carbide tools 9 and 10 of the present invention and
For the conventional coated carbide tools 9, 10, Work material: 100 mm wide x 500 mm long
JIS SCM440 square lumber, Usage conditions: Single blade attached to a 125mm diameter cutter, Rotation speed: 640 r. p. m. , Cutting speed: 250 m / min. , Cut: 2 mm. , Feed: 0.2mm / blade, Cutting time: 2 passes (1 pass cutting time: 4.3 minutes), Milling (intermittent cutting) test of alloy steel under the following conditions
The flank wear width of the cutting blade was measured. These measurement results
The results are shown in Table 6. [0015] [Table 1] [0016] [Table 2][0017] [Table 3] [0018] [Table 4][0019] [Table 5] [0020] [Table 6][0021] According to the results shown in Tables 4 to 6, the hard coating
The layer is Al_TwoO_ThreeLayer and Ti_Two O_ThreeAlternate lamination of main layers
The coated carbide tool of the present invention comprising a structural layer and a Ti compound layer
10 is the Ti_Two O_Three By the action of the main layer, A
l_TwoO_ThreeThe toughness of the hard coating layer is low even when the thickness of the layer is increased
Is significantly suppressed, and local variations in layer thickness are noticeable.
Flank, rake, and flank of the cutting edge
Even though the layer thickness at the edge where the rake faces intersect is uniform
On the other hand, the hard coating layer_TwoO_ThreeLayer and Ti compound layer
Conventional coated carbide tools 1 to 10_Two
O_ThreeWhen the thickness of the layer is increased, the toughness of the hard coating layer is avoided.
Is not possible, and the thickness of the layer varies greatly.
The coated carbide tools 1 to 10 according to the present invention are the same as the conventional coated carbide tools.
1 step compared to 1 to 10 with intermittent cutting of steel and cast iron
It is evident that it exhibits loose chipping resistance. Above
As shown in FIG.
Al constituting the layer _TwoO_ThreeThe layer is Ti_Two O_Three Alternate with main layer
Since the film thickness is increased by lamination, the toughness of the hard coating layer does not decrease.
And local variations in layer thickness are extremely small
Therefore, not only continuous cutting of steel and cast iron, for example,
Excellent chipping resistance in interrupted cutting
Cutting performance because it exhibits excellent cutting performance over the period
Can respond satisfactorily to FA and labor saving
It is.

──────────────────────────────────────────────────続 き Continued on the front page (72) Kunihiro Endo, Inventor 1-297 Kitabukurocho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation General Research Laboratory (56) References JP-A-11-77405 (JP, A) Special Table 2002 -526654 (JP, A) Patent 3718223 (JP, B2) Patent 3353675 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23B 27/14 C23C 14/06 C23C 16/30 C23C 28/04

Claims (1)

(57) [Claim 1] A tungsten carbide-based cemented carbide substrate having a surface having a mean layer thickness of 0.1 to 15 μm,
i, a Ti compound layer composed of one or more of a carbide layer, a nitride layer, a carbonitride layer, a carbonate layer, a carbonitride layer, and a carbonitride layer; chemical in the hard coating layer composed of a total average layer thickness of 3~25μm
In a cutting tool made of a surface-coated cemented carbide obtained by vapor deposition , the alternate layered structure layer is composed of two or more aluminum oxide layers having an average layer thickness of 0.5 to 7 μm and an average layer of 0.05 to 2 μm. It has a thickness, the main component is dititanium trioxide, and carbon and nitrogen as nonmetal elements other than oxygen, in a total amount, 1 to 1 in the total amount with oxygen.
A cutting tool made of a surface-coated cemented carbide having excellent chipping resistance, comprising at least one layer of a dititanium trioxide main layer containing 20 atomic%.