JP3536593B2 - Surface coated cemented carbide cutting tool with excellent wear resistance with hard coating layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hard coating layer having excellent wear resistance, and therefore, exhibits excellent cutting performance over a long period of time in continuous cutting or intermittent cutting of steel, for example, and has a long tool life. The present invention relates to a cutting tool made of a surface-coated cemented carbide (hereinafter, referred to as a coated cemented carbide tool) capable of extending the life.

[0002]

2. Description of the Related Art Conventionally, an arc ion plating apparatus, which is a kind of physical vapor deposition apparatus schematically shown in FIG. 3, is generally used, and the inside of the apparatus is heated to 500 mtorr, for example, by a heater. In the state heated to a temperature of ° C., the anode electrode and Ti-
An arc discharge is generated between the cathode electrode (evaporation source) on which the Al 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 is introduced into the apparatus as a reaction gas, while tungsten carbide is introduced. A substrate made of a base cemented carbide (hereinafter referred to as WC) or a cermet based on titanium carbonitride (hereinafter referred to as TiCN) (hereinafter, these are collectively referred to as a cemented carbide) has a bias voltage of -200 V, for example. Under the conditions of applying, the surface of the cemented carbide substrate,
For example, as described in JP-A-62-56565, a composite nitride of Ti and Al [hereinafter, (Ti, Al) N
It is known to produce a coated cemented carbide tool by depositing a hard coating layer constituted by the following formula with an average layer thickness of 2 to 20 μm. It is also well known that these coated carbide tools are used for continuous cutting or interrupted cutting of steel, for example.

[0003]

On the other hand, in recent years, the use of FA in cutting devices has been remarkable, and there has been a strong demand for lowering the cost of cutting. Accordingly, it has been strongly desired that cutting tools have a longer service life. However, the conventional coated carbide tools described above do not have sufficient wear resistance to meet these requirements, and therefore, there is a demand for the development of coated carbide tools that exhibit a longer service life. ing.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoints, attention was paid to the hard coating layer constituting the above-mentioned conventional coated carbide tool, and in particular, the grinding was carried out to improve the wear resistance thereof. (Ti, Al) N constituting the hard coating layer of the tool is obtained by using the arc ion plating apparatus illustrated in FIG. 3 as described above, the atmospheric pressure (degree of vacuum): 5 to 30 mtorr, and the atmospheric temperature: 300 to 700. C., arc discharge current: 80 to 100 A, arc discharge voltage: 10 to 50 V, bias voltage to the substrate: -150 to -300 V. (B) (Ti, A) formed by the vapor deposition means of (a) above
1) The coated carbide tool in which the N layer constitutes the hard coating layer is Cu
In X-ray diffraction using kα ray as a radiation source, an X-ray diffraction pattern exemplified in FIG. 2 is shown, and as shown in FIG.
5-37.5 degrees, 42.5-44.5 degrees, and 61.
Diffraction peaks appear at diffraction angles (2θ) in the respective ranges of 5 to 64.5 degrees.
The highest diffraction peak height appears at a diffraction angle (2θ) within the range of 5.5 to 37.5 degrees. (C) In the arc ion plating apparatus also illustrated in FIG. 3, the composition of the Ti—Al alloy set on the cathode electrode (evaporation source) of the apparatus is represented by a composition formula: (Ti
_1-X Al _X ) N (where X is an atomic ratio of 0.3 to
0.5 ), and the arc discharge current and the bias voltage were increased in the deposition conditions of the above (a) to 200 to 250 A and −200 A, respectively. 30 to -80 V, and other conditions were the same, that is, atmosphere pressure (degree of vacuum): 5 to 30 mtorr, atmosphere temperature: 300 to 700 ° C, arc discharge current: 200 to 250 A, arc discharge voltage: 10 When a (Ti, Al) N layer is formed on the surface of the cemented carbide substrate at an average layer thickness of 1 to 10 μm under the conditions of 50 V and a bias voltage to the substrate of −30 to −80 V, the (Ti, Al)
The coated carbide tool on which the Al) N layer is formed exhibits excellent wear resistance over a long period of time by cutting. (D) (Ti, A) formed under the vapor deposition conditions of (c) above.
1) When the coated carbide tool having the N layer as the hard coating layer is observed by X-ray diffraction using the Cukα ray as the radiation source as in (b) above, an X-ray diffraction pattern exemplified in FIG. 1 is obtained. As shown in FIG. 1, (Ti, Al) N constituting the hard coating layer has a maximum diffraction peak height at a diffraction angle (2θ) within the range of 42.5 to 44.5 degrees. The research results shown in (a) to (d) above were obtained.

The present invention has been made based on the results of the above-mentioned research, and is based on the conditions of vapor deposition on the surface of a superhard substrate.
200-250 A of arc discharge current to the substrate
Is formed under the condition of a bias voltage of −30 to −80 V , and a composition formula: (Ti
_{1-X Al} X) N (provided that, X is 0. 3 in atomic ratio
0.5 ) and a hard coating layer made of (Ti, Al) N having an average layer thickness of 1 to 10 μm to form a coated carbide tool, and using the Cukα ray as a radiation source. Among the diffraction peaks of (Ti, Al) N constituting the hard coating layer by X-ray diffraction of a carbide tool, 42.5 to
Characterized by a coated carbide tool having a hard coating layer with excellent wear resistance, showing an X-ray diffraction pattern in which the highest diffraction peak height appears at a diffraction angle (2θ) within the range of 44.5 degrees. It is.

[0006] In the coated carbide tool of the present invention,
Al of (Ti, Al) N constituting the hard coating layer is TiC
N to form a solid solution in order to increase the hardness with respect to N and thereby improve the wear resistance.
_If the X value of _1-X Al _X ) N is less than 0.3, the desired wear resistance cannot be secured, while if the X value exceeds 0.5 , chipping tends to occur on the cutting edge. For this reason, the X value was determined to be 0.3 to 0.5 (atomic ratio). Also, the average thickness of the hard coating layer is 1 to 10 μm.
The reason why m is that if the layer thickness is less than 1 μm, the desired excellent wear resistance cannot be secured, while the layer thickness is 1 μm.
This is because if it exceeds 0 μm, chipping and chipping of the cutting edge are likely to occur. Furthermore, in order to facilitate the discrimination before and after use of the coated cemented carbide tool of the present invention, a titanium nitride (TiN) layer having a golden color tone as an outermost surface layer has an average thickness of 0.1 to 1 μm. It may be deposited with a layer thickness.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide tool of the present invention will be specifically described with reference to examples. WC powder, TiC, each having an average particle size of 1 to 3 μm, as raw material powders
Powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂
Powder, TiN powder, TaN powder, and Co powder were prepared, and these raw material powders were blended in the blending composition shown in Table 1, wet-mixed for 72 hours in a ball mill, and dried.
Press molding into a green compact with a pressure of 1.5 ton / cm ² ,
This green compact is sintered in a vacuum at a temperature of 1400 ° C. for one hour, and after sintering, the cutting edge portion is subjected to a honing process of R: 0.05 to obtain ISO standard SPGA120408.
Carbide substrate A- made of WC-based cemented carbide with a chip shape of
1 to A-7 were formed. As raw material powders, TiCN (TiC / TiN = 50/50 by weight) powder, Mo ₂ C powder, each having an average particle size of 0.5 to 2 μm,
A TaC powder, a WC powder, a Co powder, and a Ni powder were prepared, and these raw material powders were blended in the composition shown in Table 2, wet-mixed in a ball mill for 24 hours, and dried.
A green compact is press-formed at a pressure of 1 ton / cm ² , and the green compact is pressed in a nitrogen atmosphere of 10 torr at a temperature of 1540.
Sintering under the condition of holding at 1 ° C. for 1 hour. After sintering, the cutting edge is subjected to a honing process of R: 0.03 to conform to ISO standard S
TiC with chip shape of EKN1203AFEN1
Carbide substrates B-1 to B-3 made of N-based cermet were formed.

[0008] Next, these super-hard substrates A-1 to A-7 and B-1 to B-3 are ultrasonically cleaned in acetone and dried, and each of the conventional arcs illustrated in FIG. Ti-Al having various component compositions as a cathode electrode (evaporation source) was charged into an ion plating apparatus.
After mounting the alloy and evacuating the inside of the apparatus to maintain a vacuum of 1 × 10 ⁻⁵ torr, the inside of the apparatus was heated to 500 ° C. with a heater, and then Ar gas was introduced into the apparatus to obtain 1 × 10 ^−3. to
rr in an Ar atmosphere, and in this state, -800
Applying a bias voltage of v to clean the surface of the cemented carbide substrate with Ar gas bombardment, then introducing nitrogen gas as a reaction gas into the apparatus, and while maintaining the reaction atmosphere temperatures shown in Tables 3 and 4, respectively, In addition to the reaction atmosphere (degree of vacuum) shown in Tables 3 and 4, the bias voltage applied to the carbide substrate was lowered to the voltage shown in Tables 3 and 4,
The arc discharge current and the arc discharge voltage are set to the conditions shown in Tables 3 and 4, respectively, and arc discharge is generated between the cathode electrode and the anode electrode, whereby the carbide substrates A-1 to A-7 and By coating a hard coating layer of (Ti, Al) N having an X value and an average layer thickness also shown in Tables 3 and 4 on the respective surfaces of B-1 to B-3, the coating of the present invention is superposed. Hard tools 1 to 10 and conventional coated carbide tools 1 to 10 were produced, respectively. When the surface of the hard coating layer of each of the coated carbide tools obtained as a result was observed by X-ray diffraction using a Cukα ray as a radiation source, the arc discharge current and the bias voltage among the deposition conditions were relatively determined. The coated carbide tools 1 to 10 of the present invention in which the (Ti, Al) N layer was
Among the diffraction peaks of i, Al) N, 42.5 to 44.5
5 shows an X-ray diffraction pattern in which the highest diffraction peak height appears at a diffraction angle (2θ) within a range of degrees, while the arc discharge current and the bias voltage of the deposition conditions are relatively low, and the conventional deposition conditions (Ti, The conventional coated cemented carbide tools 1 to 10 on which the Al) N layer is formed have diffraction angles (2, 35.5 to 37.5 degrees) of the diffraction peaks of (Ti, Al) N.
The X-ray diffraction pattern at which the highest diffraction peak height appears at θ) was shown. FIG. 1 shows an X-ray diffraction pattern of the coated carbide tool 2 of the present invention, and FIG. 2 shows an X-ray diffraction pattern of the conventionally coated carbide tool 2.

[0009] Next, the present invention coated cemented carbide tool 1-7 and the conventional coated cemented carbide tools 1 to 7 in which the results obtained are Workpiece: SCM440 (hardness: HB 220) square bar of cutting speed: 120 m / min. , Depth of cut: 2.5 mm, feed: 0.25 mm / tooth, a dry interrupted cutting (milling) test of alloy steel was performed, and the coated carbide tools 8 to 10 of the present invention and the conventionally coated carbide tools 8 About 10 to 10 , Work material: Square material of SNCM440 (hardness: HB220), Cutting speed: 300 m / min. , Notch: 2 mm. , Feed: 0.15mm / tooth, dry intermittent cutting (milling) test of alloy steel under the conditions of: In any cutting test, the cutting time until the flank wear width of the cutting edge reaches 0.2mm It was measured. Tables 3 and 4 show the measurement results.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

According to the results shown in Tables 3 and 4, all of the coated carbide tools 1 to 10 of the present invention are the same as those of the conventional coated carbide tools 1 to 10 .
It is evident that it exhibits excellent wear resistance as compared to No. 10 and has a long service life. As described above, the coated carbide tool of the present invention has a longer service life than this type of conventional coated carbide tool. Is what you can do.

[Brief description of the drawings]

FIG. 1 is a view showing an X-ray diffraction pattern of a coated carbide tool 1 of the present invention.

FIG. 2 is a view showing an X-ray diffraction pattern of a conventional coated carbide tool 1.

FIG. 3 is a schematic explanatory view of an arc ion plating apparatus.

Continuation of front page (72) Inventor Keiichi Sakurai 1511 Furamaki, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works (56) References JP-A-8-209333 (JP, A) JP-A-8- 127862 (JP, A) JP-A-6-122959 (JP, A) JP-A-6-322517 (JP, A) Ikeda et al., High-temperature oxidation characteristics of Ti-Al-N-based hard films produced by PVD method And abrasion resistance, Journal of the Japan Institute of Metals, Japan, 1993, Vol. 57 / No. 8, p. 919 −925 (58) Field surveyed (Int.Cl. ⁷ , DB name) C23C 14/00-14/58 B23B 27/14 B23P 15/28

Claims (1)

(57) [Claims] 1. The method according to claim 1, wherein the surface of a tungsten carbide-based cemented carbide substrate or a titanium carbonitride-based cermet substrate is subjected to vapor deposition conditions.
200-250 A of arc discharge current to the substrate
Is formed under the condition of a bias voltage of −30 to −80 V , and a composition formula: (Ti
_1-X Al _X ) N (where X is an atomic ratio of 0.3 to
0.5 ) and a hard coating layer made of a composite nitride of Ti and Al having a mean thickness of 1 to 10 μm as a surface coated cemented carbide cutting tool. X of the above surface-coated cemented carbide cutting tool used as
The highest diffraction peak height appears at a diffraction angle (2θ) in the range of 42.5 to 44.5 degrees among the diffraction peaks of the composite nitride of Ti and Al constituting the hard coating layer by line diffraction. A cutting tool made of a surface-coated cemented carbide having a hard coating layer exhibiting an X-ray diffraction pattern and having excellent wear resistance.