JP2000158203A - Surface-covering cemented carbide alloy cutting tool excellent in chipping resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-covering cemented carbide alloy cutting tool excellent in chipping resistance. SOLUTION: This surface-covering cemented carbide alloy cutting tool is composed of a cemented carbide alloy base body made of WC group cemented carbide alloy or TiCN group superalloy and having an outer surface which is covered with a single or a plurality of hard covering layers composed of either or both of a (Ta, Ni)N layer exhibited by the following formula: (Ta, Ni1-x) and a (Ta, Ni)CN layer exhibited by the following formula: (Ta, Ni1-x)CyN1-y wherein x: 0.5 to 0.95, y: 0.01 to 0.5) by a thickness of 0.5 to 10 μm in average through vacuum evaporation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hard coating layer having excellent chipping resistance. Therefore, even when high-speed cutting of difficult-to-cut materials such as stainless steel, chipping (minute chipping) does not occur on the cutting edge. The present invention relates to a surface-coated cemented carbide cutting tool that exhibits excellent wear resistance over a long period of time (hereinafter, referred to as a coated cemented carbide tool).

[0002]

2. Description of the Related Art Conventionally, for example, an arc ion plating apparatus, which is a kind of physical vapor deposition apparatus schematically shown in FIG.
In the state heated to a temperature of ° C., an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which Ta having a predetermined composition is set, and at the same time, nitrogen gas or nitrogen gas is used as a reaction gas in the apparatus. And methane gas,
On the other hand, a substrate made of tungsten carbide (hereinafter, referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter, referred to as TiCN) -based cermet (hereinafter, collectively referred to as a cemented carbide substrate) includes, for example,- Under the condition that a bias voltage of 120 V is applied, a Ta nitride (hereinafter, referred to as TaN) layer or a Ta carbonitride is formed on the surface of the cemented carbide substrate as described in, for example, JP-A-1-225766. It is known to produce coated cemented carbide tools by depositing layers (hereinafter denoted by TaCN) with an average layer thickness of 0.5 to 10 μm. It is also well known that the above-mentioned coated cemented carbide tool is generally used for continuous cutting or interrupted cutting of various steels.

[0003]

On the other hand, in recent years, high performance and high output of cutting equipment have been remarkable, and there is also a demand for labor saving and energy saving of cutting processing. Although there is a tendency, in the case of the above-mentioned conventional coated cemented carbide tools, although it shows excellent wear resistance in continuous cutting and intermittent cutting under normal cutting conditions, it is particularly fast cutting difficult-to-cut materials such as stainless steel. In this case, the TaN layer and the TaCN constituting the hard coating layer are used.
Chipping easily occurs on the cutting edge due to insufficient toughness of the layer,
As a result, at present, the service life is reached in a relatively short time.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoints, attention was paid to the TaN layer and the TaCN layer constituting the hard coating layer of the conventional coated cemented carbide tool, and a study was conducted to improve the toughness thereof.
An N layer and a TaCN layer each containing Ni as a solid solution. A composite nitride of Ta and Ni represented by a composition formula: (Ta _x Ni _1-x ) N [hereinafter, represented by (Ta, Ni) N] ] layer, and / or composition _{formula: (Ta x Ni 1-x} ) C y N represented by Ta by _1-y
And a composite carbonitride of Ni [hereinafter referred to as (Ta, Ni) CN] layer (provided that x: 0.5 to 0.95,
y: 0.01 to 0.5), the hard coating layer is constituted by:
The resulting coated cemented carbide tool is the (Ta, Ni) N
And (Ta, Ni) CN have excellent toughness while maintaining excellent wear resistance, so that not only continuous cutting and intermittent cutting of various steels but also stainless steel which is a difficult-to-cut material is used. Research results have shown that even when used for cutting steel or the like at high speed, chipping does not occur on the cutting edge and excellent wear resistance is exhibited over a long period of time.

The present invention has been made on the basis of the above research results, and has a composition formula: (Ta _x Ni _{1 -x} ) N on the surface of a cemented carbide substrate (Ta, N).
i) N layer, and the composition _{formula: (Ta x Ni 1-x} ) C y N
(Ta, Ni) CN layer represented by _1-y (provided that x: 0.5 to 0.95 and y: 0.01 to 0.
5) Coated cemented carbide with excellent chipping resistance, obtained by depositing a single-layer or multiple-layer hard coating layer composed of either or both of them with an average layer thickness of 0.5 to 10 μm. The tool has features. In the coated cemented carbide tool of the present invention, a titanium nitride layer having a golden color (hereinafter referred to as TiN) having an average thickness of 0.1 to 1 μm is used in order to facilitate identification before and after use. It is good to vapor-deposit with a layer thickness on the surface of the hard coating layer.

Next, the (Ta, Ni) N layer and (Ta, Ni) constituting the hard coating layer of the coated cemented carbide tool of the present invention.
The reason why the composition ratio (atomic ratio) of the Ni) CN layer is limited as described above will be described. That is, in the above (Ta, Ni) N and (Ta, Ni) CN, the component Ta
Contributes to the improvement of the wear resistance, while Ni has the effect of improving the toughness. Therefore, the proportion of Ta: x
If the atomic ratio (hereinafter the same) is less than 0.5, the ratio of Ni becomes relatively larger than 0.5, and the desired excellent wear resistance cannot be secured. T
a ratio: When x exceeds 0.95, the Ni ratio becomes 0.0
Since it is too small as less than 5, the desired toughness cannot be secured, and chipping is likely to occur on the cutting edge. Therefore, the ratio of Ta is 0.5 to 0.95, preferably 0.6 to 0.95. 0.9 was set. Further, since the C component in the (Ta, Ni) CN layer has an effect of improving the hardness, the (Ta, Ni) CN layer has a relatively higher hardness than the (Ta, Ni) N layer. In this case, if the ratio of the component C: y is less than 0.01, a predetermined hardness improving effect cannot be obtained, while if the ratio: y exceeds 0.5, the toughness is sharply reduced. Therefore, the ratio of the component C is 0.01
０．５0.5, preferably 0.1０．１0.45. The reason why the average layer thickness of the hard coating layer is set to 0.5 to 10 μm is that if the layer thickness is less than 0.5 μm, the desired wear resistance cannot be secured, while the layer thickness is 10 μm. This is because chipping is more likely to occur on the cutting edge if it exceeds this, and Ti is deposited on the surface of the hard coating layer.
The reason why the average layer thickness of the N layer is set to 0.1 to 1 μm is that when the layer thickness is less than 0.1 μm, a clear golden color cannot be imparted, while the desired golden color requires a layer thickness up to 1 μm. It is because there is.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the coated cemented carbide tool of the present invention will be specifically described with reference to examples. As raw material powders, WC powder, TiC powder, TaC powder, and Co powder each having an average particle size of 0.5 to 3 μm are prepared, and these raw material powders are WC: 92% by weight%, Ti:
C: 1%, TaC: 1%, and Co: 6% were blended, wet-mixed in a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 1.5 ton / cm ^2. This green compact was sintered in vacuum at a temperature of 1400 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to honing processing of R: 0.02 to conform to ISO standard CNMA1204.
A cemented carbide substrate A made of a WC-based cemented carbide having a chip shape of No. 04 was formed. Further, as raw material powders, TiCN (TiC / TiN = 50/50 in weight ratio) powder, TaC powder, and WC each having an average particle size of 0.5 to 2 μm
Powder, VC powder, Co powder, Ni powder, and C powder were prepared, and these raw material powders were added in a weight% of TiCN: 75.
%, TaC: 3%, WC: 9%, VC: 1%, Co: 8
%, Ni: 3%, and C: 1%.
After wet mixing with a ball mill for 24 hours and drying, 1 to
The green compact is press-molded at a pressure of n / cm ² , and the green compact is sintered in a nitrogen atmosphere of 5 torr at a temperature of 1550 ° C. for 1 hour, and after sintering, R is applied to the cutting edge portion. : 0.0
3 Honing process, ISO standard, CNMG16
A cemented carbide substrate B made of TiCN-based cermet having a chip shape of No. 0404 was formed.

Next, these cemented carbide substrates A and B are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. 1, respectively. ), A Ta—Ni alloy or a metal Ti having various component compositions was mounted, and the inside of the apparatus was heated to 500 ° C. with a heater while the inside of the apparatus was evacuated and kept at a vacuum of 1 × 10 ⁻⁵ torr. In this state, a bias voltage of −100 V is applied to the cemented carbide substrate, and then arc discharge is caused between the cathode electrode and the anode electrode while introducing nitrogen gas or nitrogen gas and methane gas as a reaction gas into the apparatus. And forming a hard coating layer on each surface of the cemented carbide substrates A and B with a target composition and a target layer thickness shown in Tables 1 to 4. Alloy tool 18 and a conventional coated cemented carbide tools 1 to 4 were produced, respectively. The composition and layer thickness of each of the constituent layers of the hard coating layer in the above-mentioned coated cemented carbide tools 1 to 18 of the present invention and the conventionally coated cemented carbide tools 1 to 4 were measured using an electron probe X-ray microanalyzer. Tables 1-4
The composition and the average layer thickness were substantially the same as the target composition and the target layer thickness shown in FIG.

[0009] Of the various coated cemented carbide tools obtained as a result, the coated cemented carbide tools 1 to 9 of the present invention and the conventional coated cemented carbide tools 1 and 2 are as follows: Work material: JIS SUS304 circle Bar, Cutting speed: 320m / min, Feeding: 0.2mm / rev, Cutting depth: 1.5mm, Cutting time: 10min. Perform dry continuous high-speed cutting test of stainless steel under the following conditions. For tools 10 to 18 and conventional coated cemented carbide tools 3 and 4, work material: JIS SUS316 round bar, cutting speed: 350 m / min, feed: 0.15 mm / rev, cutting depth: 1.5 mm, cutting A dry continuous high-speed cutting test was also performed on stainless steel under the conditions of time: 10 minutes, and the flank wear width of the cutting edge was measured in each cutting test. The measurement results are shown in Tables 2 and 4.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

From the results shown in Tables 1 to 4, all of the coated cemented carbide tools 1 to 18 of the present invention are excellent in continuous high-speed cutting of stainless steel, which is a difficult-to-cut material, without chipping of the cutting edge. The conventional coated cemented carbide tools 1 to 4 have the following wear resistance, and the cutting blade wear condition is normal.
It is clear that any continuous high-speed cutting of stainless steel due to lack of toughness of the hard coating layer causes chipping of the cutting edge, resulting in a relatively short service life. As described above, the coated cemented carbide tool of the present invention provides the (Ta, Ni) N layer and the (Ta, N) layer constituting the hard coating layer.
i) Since the CN layer has excellent wear resistance and toughness, it is possible to cut or cut various steels under normal conditions, as well as stainless steel, which can be cut under more severe conditions. No chipping occurs in the cutting edge even during continuous high-speed cutting, and exhibits excellent wear resistance for a remarkably long period of time. High-performance and high-power cutting equipment, and labor-saving and energy-saving cutting work Can be sufficiently satisfied.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an arc ion plating apparatus.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C23C 28/04 C23C 28/04 F term (reference) 3C046 FF03 FF05 FF10 FF16 FF19 FF25 FF32 FF34 FF40 FF48 FF53 4K029 AA04 AA21 BA54 BA58 BA60 BB02 BC00 BD05 EA01 4K044 AA09 BA18 BB02 BC01 CA07 CA13

Claims (2)

[Claims] To 1. A surface of the tungsten carbide based cemented carbide substrate or titanium carbonitride-based cermet substrate, the composition _{formula: (Ta x Ni 1-x} ) composite nitride layer of Ta and Ni represented by N, and the composition _{formula: (Ta x Ni 1-x} ) C y
A composite carbonitride layer of Ta and Ni represented by N _1-y (where x: 0.5 to 0.95 and y: 0.
01 to 0.5), a single-layer or multiple-layer hard coating layer composed of any one or both of
Cutting tool made of surface coated cemented carbide with excellent chipping resistance, deposited with an average layer thickness of m. 2. A composite nitride layer of Ta and Ni represented by a composition formula: (Ta _x Ni _1-x ) N on the surface of a tungsten carbide-based cemented carbide substrate or a titanium carbonitride-based Samet substrate, and a composition _{formula: (Ta x Ni 1-x} ) C y
A composite carbonitride layer of Ta and Ni represented by N _1-y (where x: 0.5 to 0.95 and y: 0.
01 to 0.5), a single-layer or multiple-layer hard coating layer composed of any one or both of
m, and a titanium nitride layer of 0.1 m on the hard coating layer.
A cutting tool made of a surface-coated cemented carbide with excellent chipping resistance, which is deposited with an average layer thickness of １1 μm.