JPH09277104A - Cutting tool made of surface-coated cemented carbide having hard coating layer excellent in inter-layer adhesiveness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool made of a surface-coated cemented carbide having a hard coating layer excellent in inter-layer adhesiveness. SOLUTION: This cutting tool made of a surface-coated cemented carbide chemically deposited and/or physically deposited with a hard coating layer containing an Al2 O3 compound layer mainly made of Al2 O3 on the surface of a WC group cemented carbide substrate at the average layer thickness of 3-20μm. The Al2 O3 compound layer contains Zr and/or Hf of 0.5-10wt.% and N of 0.001-0.1wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an Al ₂ O ₃ -based compound layer containing aluminum oxide (hereinafter referred to as Al ₂ O ₃ ) as a main component which constitutes a hard coating layer and has excellent interlayer adhesion. Therefore, for example, when used for high-speed cutting of steel or cast iron, a cutting tool made of surface-coated cemented carbide that exhibits excellent cutting performance for a long period of time without chipping or chipping (fine chipping) in the cutting edge ( Hereinafter, it will be referred to as a coated cemented carbide tool).

[0002]

2. Description of the Related Art Conventionally, on a surface of a tungsten carbide based cemented carbide substrate (hereinafter referred to as a cemented carbide substrate), a hard coating layer containing an Al ₂ O ₃ layer, for example, a Ti carbide (hereinafter referred to as TiC) layer. , Nitride (hereinafter also referred to as TiN) layer, carbonitride (hereinafter referred to as TiCN) layer, oxide (hereinafter referred to as T)
iO ₂ ) layer, carbonate (hereinafter referred to as TiCO)
One or two of a layer, a nitric oxide (hereinafter, referred to as TiNO) layer, and a carbonitride oxide (hereinafter, referred to as TiCNO, and collectively referred to as Ti carbon / nitrogen / oxide) layer.
_{3 to 2} hard coating layer consisting of Al ₂ O ₃ layer and above
Coated carbide tools made by chemical vapor deposition and / or physical vapor deposition with an average layer thickness of 0 μm are known. Further, particularly, the formation of the Al ₂ O ₃ layer constituting the hard coating layer of the above-mentioned coated cemented carbide tool is carried out by reacting gas with a volume% of aluminum trichloride (hereinafter referred to as AlCl ₃ ): 1 to 20%, dioxide carbon (hereinafter, indicated by CO _2): 0.5~30%, [CO optionally (CO) or hydrogen chloride (HCl): 1
.About.30%], hydrogen: remainder, and a hydrogen-based reaction gas having a composition of reaction temperature: 950 to 1100.degree. C. and atmospheric pressure: 20 to 200 torr.

[0003]

On the other hand, in recent years, high performance and high output of a cutting device have been remarkable, and there is a strong demand for labor saving. With this, cutting tends to be performed at a high speed. In the conventional coated cemented carbide tool, among the hard coating layers constituting the same, the Al ₂ O ₃ layer is particularly excellent in oxidation resistance and thermal stability, and has higher hardness,
When the material is used for high-speed cutting of steel or cast iron, the cutting edge is likely to be chipped or chipped due to insufficient interlayer adhesion with other constituent layers, such as Ti carbon, nitrogen, and oxide layers. Due to this, it is the current situation that the service life is reached in a relatively short time.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoint, the hard coating layer of the coated cemented carbide tool is constructed.
Al formed_Two O_Three Focus on layers and compare them to other constituent layers
As a result of conducting research to improve interlayer adhesion,
Method and / or physical vapor deposition method
Instead of the conventional hydrogen-based reaction gas described above, the
AlCl_Three 1 to 10%, hydrogen (hereinafter, H_Two Indicated by
): 6 to 15%, nitrogen oxides (hereinafter referred to as NO):
16-30%, zirconium tetrachloride (hereinafter ZrCl_Four
And / or hafnium tetrachloride (hereinafter referred to as Hf)
Cl_Four:): 0.1 to 0.6%, for example, Ar or He
Inert gas having a composition consisting of:
The reaction temperature and atmospheric pressure are
Under the following conditions, that is, reaction temperature: 850 to 1100 ° C,
Layer formation under conditions of atmospheric pressure: 20 to 200 torr
When done, Zr and / or Hf in the formed layer,
N is contained, and Zr and / or Hf
And the content ratio of N mainly in the above-mentioned inert gas type reaction gas
Weight% by adjusting composition and reaction atmosphere
And Zr and / or Hf: 0.5 to 10%, N:
If it becomes 0.001-0.1%,
Al_TwoO_ThreeAnd Zr and / or Hf
And Al containing N_TwoO_ThreeThe system compound layer is a hard coating layer
To other layers that make up, such as the Ti carbon / nitride / oxide layer
Shows excellent adhesion to Al and_TwoO _ThreeThe main
Minutes, so Al_TwoO_ThreeHas the following characteristics:
It has excellent oxidation resistance, thermal stability, and high hardness,
Therefore, this Al_TwoO_ThreeHard coating including a compound layer
Layered coated carbide tools can be used for high-grade materials such as steel and cast iron.
When used for fast cutting, chipping and chipping occur on the cutting edge.
It has excellent cutting performance over a long period of time.
I got the research results.

The present invention was made based on the above research results, and a hard coating layer containing an Al ₂ O ₃ based compound layer containing Al ₂ O ₃ as a main component on the surface of a superhard substrate,
For example, a hard coating layer composed of one or more of the Ti carbon / nitride / oxide layers and the Al ₂ O ₃ based compound layer is chemically and / or physically vapor-deposited with an average layer thickness of 3 to 20 μm. In the coated cemented carbide tool, the Al ₂ O ₃ -based compound layer is contained in a weight percentage of Zr and / or Hf: 0.5.
10%, N: 0.001 to 0.1%, improves the adhesion of the hard coating layer to other constituent layers, and thus has excellent chipping resistance in high-speed cutting of, for example, steel or cast iron. It is characterized by a coated cemented carbide tool that exerts its properties.

[0006] As described above, Zr and / or Hf and N in the Al ₂ O ₃ compound layer constituting the hard coating layer of the coated cemented carbide tool of the present invention coexist with other components as described above. It has the effect of improving the adhesion to the constituent layers, for example, Ti carbon, nitrogen, and oxide layers,
Therefore, among these components, Zr and / or H
Even if the content of f is less than 0.5%, the content of N is 0.
If it is less than 001%, the desired excellent interlayer adhesion cannot be ensured. On the other hand, if the content of Zr and / or Hf in these components exceeds 10%, the content of N is 0.1% or less. %, The characteristics of the Al ₂ O ₃ -based compound layer will be impaired.
r and / or Hf: 0.5 to 10%, N: 0.00
It was set at 1 to 0.1%. Further, the average layer thickness of the hard coating layer is set to 3 to 20 μm, because the desired excellent wear resistance cannot be secured when the layer thickness is less than 3 μm, and when the layer thickness exceeds 20 μm, This is because the chipping resistance is lowered.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide tool of the present invention will be specifically described with reference to examples. Medium-sized WC powder having an average particle diameter of 2.8 μm, 4.9 μm as the raw material powder
m of coarse WC powder, 1.5 μm of (Ti, W) C (the same in weight ratio, hereinafter, 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 and Co powder of 1.1 μm were prepared, and these raw material powders were compounded in the composition shown in Table 1, wet-mixed for 72 hours in a ball mill, and dried. After that, ISO / CNMG12040
8 (for carbide substrates A to D) and SEEN42AFTN
Press molded into a green compact having the shape defined in No. 1 (for the super hard substrate E), and the green compact was vacuum-sintered under the conditions shown in Table 1 to produce super hard substrates A to E, respectively. Further, with respect to the carbide substrate B, 100 torr CH
After maintaining at a temperature of 1400 ° C. for 1 hour in a ₄ gas atmosphere, a gradual cooling carburizing treatment is performed, and after the treatment, carbon and Co adhering to the surface of the cemented carbide substrate are removed by acid and barrel polishing. Maximum Co content at 11 μm position: 1
A Co-rich zone of 5.9 wt% and depth: 42 μm was formed on the surface of the substrate. Further, the above-mentioned cemented carbide substrates A and D include
As-sintered, a Co-rich zone having a maximum Co content of 9.1 wt% and a depth of 23 μm was formed on the surface at a position of 17 μm from the surface, and the remaining superhard substrates C and E were formed. Had no overall formation of the Co-enriched zone and had a homogeneous structure throughout. Table 1 shows the internal hardness (Rockwell hardness A scale) of each of the carbide substrates A to E.

Then, the surfaces of these super-hard substrates A to E are honed, and a conventional chemical vapor deposition apparatus is used. Table 1 (1-TiCN in the table corresponds to JP-A-6-8010
Which has a vertically elongated crystal structure, and the p-TiCN has a normal granular crystal structure) and Table 3 [Al ₂ O ₃ (a)-
(I) represents the Al ₂ O ₃ compound layer, Al ₂ O
₃ (j) shows an Al ₂ O ₃ layer. The same applies to Tables 4 and 5] under the conditions shown in Tables 4 and 5 to form a hard coating layer having the composition and target layer thickness (layer thickness at the flank wear width of the cutting edge) shown in Tables 4 and 5. According to the present invention coated carbide tool 1
13 and conventional coated carbide tools 1 to 10 were manufactured.

Regarding the above-mentioned various coated carbide tools obtained as a result, Al ₂ O in the hard coating layers constituting the
_For the purpose of evaluating the interlayer adhesion between the ₃ type compound layer and the Al ₂ O ₃ layer, for the coated carbide tools 1 to 4 of the present invention and the conventional coated carbide tools 1 and 2, the work material is JIS / FCD.
450 round bar, cutting speed: 300 m / min. , Depth of cut: 2 mm, feed: 0.4 mm / rev. , Cutting time:
A dry continuous cutting test of ductile cast iron was performed under the condition of 15 minutes, and the flank wear width of the cutting edge was measured.

Similarly, for the coated carbide tools 5 and 6 of the present invention and the conventional coated carbide tools 3 and 4, the work material is JI.
S ・ SNCM439 round bar, cutting speed: 300m / mi
n. , Cut: 2 mm. , Feed: 0.4 mm / re
v. , Cutting time: 15 minutes, the dry continuous cutting test of the alloy steel was performed, and the flank wear width of the cutting edge was measured.

Similarly, for the coated carbide tools 7 and 8 of the present invention and the conventional coated carbide tools 5 and 6, the work material is JIS S.
45C round bar, cutting speed: 300 m / min. , Cut: 2 mm. , Feed: 0.4 mm / rev. , Cutting time: 15 minutes, a dry continuous cutting test of carbon steel was performed, and the flank wear width of the cutting edge was measured.

Similarly, for the coated carbide tools 9 to 11 of the present invention and the conventional coated carbide tools 7 and 8, the work material is JIS:
FC300 round bar, cutting speed: 350 m / min. , Cut: 2 mm. , Feed: 0.4 mm / rev. , Cutting time: 15 minutes, a dry continuous cutting test of cast iron is performed,
The flank wear width of the cutting blade was measured.

For the coated cemented carbide tools 12 and 13 of the present invention and the conventional coated cemented carbide tools 9 and 10, the work material: width 1
JIS / SC with dimensions of 00 mm x 500 mm length
Square bar of M440, usage condition: single blade attached to a cutter with a diameter of 125 mm, rotation speed: 510 r. p. m. , Cutting speed: 200 m / min. , Cut: 2 mm. , Feed:
Dry milling (intermittent cutting) test of alloy steel is performed under the conditions of 0.15 mm / blade, cutting time: 3 passes (1 pass cutting time: 7.1 minutes), and the flank wear width of the cutting edge is measured. did. Table 6 shows the measurement results.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

[Table 5]

[0019]

[Table 6]

[0020]

From the results shown in Table 6, the results are inactive.
Zr and / or positively by using a reactive gas based reaction gas
Is Hf and Al containing N_TwoO_ThreeIncluding system compound layer
The coated carbide tools 1 to 13 of the present invention formed by forming a hard coating layer
Is the Al_TwoO_ThreeTi whose compound layer is another constituent layer
Has excellent interlayer adhesion to carbon / nitride / oxide layers
Therefore, there is no chipping or chipping on the cutting edge, and
The Al_TwoO_ThreeAl-based compound layer_TwoO_ThreeAs good as
It has excellent oxidation resistance, thermal stability, and high hardness.
Combined with excellent wear resistance in high speed cutting of steel and cast iron
In contrast, it is formed using a hydrogen-based reaction gas.
Al_TwoO_ThreeConventional coated carbide whose layer constitutes a hard coating layer
In tools 1-10, Al_TwoO_ThreeLayer of Ti charcoal / nitrogen /
Due to insufficient interlayer adhesion to the oxide layer, the cutting edge is
Injuries and chipping occur, leading to a relatively short service life.
It is clear that As mentioned above, the coating of this invention
The cemented carbide tool is made of Al that constitutes the hard coating layer of this. _TwoO_Threesystem
The compound layer is another constituent layer, such as Ti charcoal / nitrogen / oxidation
Since it has excellent adhesion to material layers, etc.
Delicate interlayer adhesion is required, such as steel and cast iron
Even when used for high-speed cutting, the cutting edge is not chipped or chipped.
It produces excellent cutting performance for a long time without
Sufficiently supports high-speed machining and high performance, and
It also greatly contributes to labor saving.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takatoshi Oshia 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Material Co., Ltd.

Claims (2)

[Claims] 1. A hard coating layer containing an aluminum oxide-based compound layer containing aluminum oxide as a main component is chemically and / or physically deposited on the surface of a tungsten carbide-based cemented carbide substrate with an average layer thickness of 3 to 20 μm. A surface-coated cemented carbide cutting tool comprising the following: the aluminum oxide-based compound layer, in% by weight, Zr and / or Hf: 0.5 to 10%, N: 0.001 to 0.1%, A surface-coated cemented carbide cutting tool having an excellent interlaminar adhesion with a hard coating layer characterized by containing. 2. A Ti carbide layer, a nitride layer, a carbonitride layer, an oxide layer, a carbonate layer, a oxynitride layer, and a oxycarbonitride layer are formed on the surface of a tungsten carbide based cemented carbide substrate. A surface-coated super layer obtained by chemical vapor deposition and / or physical vapor deposition of a hard coating layer consisting of one or more of these and an aluminum oxide-based compound layer containing aluminum oxide as a main component with an average layer thickness of 3 to 20 μm. A hard alloy cutting tool,
An excellent hard coating layer characterized in that the aluminum oxide compound layer contains, by weight%, Zr and / or Hf: 0.5 to 10%, N: 0.001 to 0.1%. A surface-coated cemented carbide cutting tool with interlayer adhesion.