JPH111764A - Cutting tool made of surface coated cemented carbide, having hard coating layer excellent in wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide, having a hard coating layer excellent in wear resistance. SOLUTION: The coated cemented carbide tool is formed by coating, by physical vapor deposition, the surface of a base material of tungsten-carbide-base cemented carbide or a base material of titanium-carbonitride-type cermet, to 1-10 μm average layer thickness, with a hard coating layer of sigle or double layer constituted of either or both of a (Ti, Al)N layer and a (Ti, Al)CN layer which have formulae (Ti1-x Alx )N and (Ti1-x Alx )C1-y Ny [where the symbols (x) and (y) stand, respectively, for 0.3-0.7 and 0.5-0.99, by atomic ratio], respectively, for the formation of arc ion plating. At this time, an oxygen-implanted layer irradiated with oxygen ion is formed at least on the ridgeline of cutting edge of the coated cemented carbide tool, over the depth in the range between a position at a depth of 0.5 μm from the surface and a position at a depth of 50% of the average layer thickness of the hard coating layer, measured by the depth on the cutting face side and/or the depth on the flank side.

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 interrupted cutting of, for example, steel, 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, in general, for example, an arc ion plating apparatus, which is a kind of physical vapor deposition apparatus schematically shown in FIG. 1, is used, and the inside of the apparatus is heated to 500 mtorr, for example, with a heater at 500 mtorr. 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 or nitrogen gas and methane gas as a reaction gas in the apparatus. On the other hand, a substrate made of a tungsten carbide (hereinafter, referred to as WC) -based cemented carbide or a cermet based on titanium carbonitride (hereinafter, referred to as TiCN) (hereinafter, these are collectively referred to as a cemented carbide substrate) include: For example, under the condition that a bias voltage of -200 V is applied, the surface of the cemented carbide substrate is
As described in Japanese Patent No. 6565, any one of a composite nitride of Ti and Al [hereinafter, referred to as (Ti, Al) N] and a composite carbonitride [hereinafter, referred to as (Ti, Al) CN] It is known to produce coated cemented carbide tools by depositing a single or multiple hard coating layers composed of one or both, with an average layer thickness of 1 to 10 μm. Also,
It is 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 above-mentioned conventional coated carbide tools do not have sufficient wear resistance to meet these requirements, and therefore, there is a demand for the development of a coated carbide tool having a longer service life. ing.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
In view of the above, attention was paid to the hard coating layer constituting the above-mentioned conventional coated carbide tool, and as a result of conducting a study especially to improve the wear resistance of the hard coating layer, the hard coating layer of the above-mentioned conventionally coated carbide tool was obtained. (Ti, Al) N layer and (Ti, A)
l) When forming the CN layer using the arc ion plating apparatus illustrated in FIG. 3 as described above, the conditions are as follows: atmosphere pressure (degree of vacuum): 5 to 30 mtorr, atmosphere 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, and the composition formula: (Ti _1-x Al _x ) N and (Ti _1-x Al _x ) N
_1-x Al _x ) C _1-y N _y (where x is 0.
(Ti, Al) N layer and (Ti, Al) CN layer satisfying 3 to 0.7, y indicates 0.5 to 0.99, and then satisfying the above composition formula (Ti , Al) N layer and / or (Ti, Al) CN layer, at least a rake face of a coated carbide tool formed by depositing a single or multiple hard coating layers with an average layer thickness of 1 to 10 μm. Cutting edge ridge line where the flank intersects (hereinafter simply referred to as cutting edge ridge line),
In other words, an electron impact type (hot cathode type, Kaufman type, bucket type) or Oxygen ion irradiation is performed using an ion gun such as a cold cathode type or a high frequency discharge type, and measured at the rake face side depth and / or the flank side depth, and 0.5
Forming the oxygen-implanted oxygen implanted layer over a depth in the range of from .mu.m to 50% of the average layer thickness of the hard coating layer, the resulting coated carbide tool will have excellent wear resistance. , And obtained research results that demonstrate excellent cutting performance 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 of (Ti _1-x Al _x ) N and (Ti _1-x Al _x ) N for forming an arc ion plating on the surface of a cemented carbide substrate. (Ti, Al) N layer having _1-x Al _x ) C _1-y N _y (where x represents 0.3 to 0.7 and y represents 0.5 to 0.99 in atomic ratio) And (Ti, Al)
A hard coated layer consisting of a single layer or multiple layers composed of one or both of the CN layers is physically coated with an average layer thickness of 1 to 10 μm to form a coated carbide tool, and the coated carbide tool is provided. 0.5 μm from the surface, measured at least on the rake face side and / or the flank face depth
The hard coated layer has excellent wear resistance, and is formed by forming an oxygen-implanted oxygen-implanted layer over a depth ranging from m to 50% of the average thickness of the hard coated layer. It is characterized by the following.

[0006] In the coated carbide tool of the present invention,
(Ti, Al) N and (Ti,
Al increases the hardness against TiCN in Al) CN, has been is intended to be formed as a solid solution in order to improve the wear resistance, thus the composition _{formula: (Ti 1-x Al x} ) N and the (Ti _{1- If the x value of} xAl _x ) C _1-y N _y is less than 0.3, the desired wear resistance cannot be ensured. On the other hand, if the value exceeds 0.7, chipping or chipping of the cutting edge may occur. The x value was determined to be 0.3 to 0.7 (atomic ratio) for the reason that it is likely to occur. In addition, since the C component in the (Ti, Al) CN layer has an effect of improving hardness,
The (Ti, Al) CN layer has a relatively high hardness as compared with the (Ti, Al) N layer. In this case, the ratio of the C component is less than 0.01, that is, the y value is 0.99. If it exceeds, the predetermined hardness improving effect cannot be obtained, while the proportion of the C component is 0.5%.
When the y value exceeds 0.5, that is, when the y value is less than 0.5, the toughness rapidly decreases.
99, preferably 0.55 to 0.9. The reason why the average layer thickness of the hard coating layer is 1 to 10 μm is that the layer thickness is 1
If the thickness is less than μm, the desired excellent wear resistance cannot be ensured, while if the thickness exceeds 10 μm, chipping or chipping is likely to occur in the cutting edge. Similarly, the depth of the oxygen ion-irradiated oxygen-implanted layer formed in the hard coating layer is set to 0.5 μm to 50% of the average layer thickness of the hard coating layer. If the effect of improving the abrasion cannot be obtained, and if the depth exceeds 50% of the average thickness of the hard coating layer, the hard coating layer tends to become brittle and chipping or chipping of the cutting edge occurs. This is because it becomes easier. further,
In order to facilitate the discrimination before and after use of the coated carbide tool of the present invention, a titanium nitride (TiN) layer having a golden color tone as an outermost surface layer has an average layer thickness of 0.1 to 1 μm. May be deposited.

[0007]

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 having an average particle diameter of 1 to 3 μm,
Powder, ZrC 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 composition shown in Table 1 to form a ball mill. For 72 hours,
After drying, it is pressed into a green compact at a pressure of 1.5 ton / cm ² , and the green compact is sintered in a vacuum at a temperature of 1400 ° C. for 1 hour, and after sintering, the cutting edge is cut. R in part:
Honing process of 0.05 and ISO standard / SPG
Carbide substrates A1 to A10 made of a WC-based cemented carbide having a chip shape of A120408 were formed. In addition, as raw material powder, Ti having an average particle size of 0.5 to 2 μm is used.
CN (TiC / TiN = 50/50 by weight ratio) powder, M
o ₂ C powder, ZrC powder, NbC powder, TaC powder, W
A C powder, a Co powder, and a Ni powder were prepared, and these raw material powders were blended in the blending composition shown in Table 2, wet-mixed in a ball mill for 24 hours, dried, and then dried at 1 ton / cm.
Press molding into a green compact at a pressure of ²
In a nitrogen atmosphere of orr, sintering is performed at a temperature of 1540 ° C. for 1 hour, and after sintering, a honing process of R: 0.03 is performed on a cutting edge portion, and ISO standard SEKN1203A is applied.
Carbide substrates B1 to B6 made of TiCN-based cermet having a chip shape of FEN1 were formed.

Next, these super-hard substrates A1 to A10 and B1 to B6 are ultrasonically cleaned in acetone and dried, and each is charged into a usual arc ion plating apparatus illustrated in FIG. On the other hand, Ti-Al alloys having various component compositions were mounted as a cathode electrode (evaporation source), and the inside of the apparatus was evacuated and kept at a vacuum of 1 × 10 ^-5 torr while the inside of the apparatus was heated to 500 ° C. After heating, an Ar gas was introduced into the apparatus to form an Ar atmosphere of 1 × 10 ⁻³ torr, and in this state, a −800 V bias voltage was applied to the superhard substrate to clean the surface of the superhard substrate by Ar gas bombardment. Then, nitrogen gas or nitrogen gas and methane gas are introduced into the apparatus as a reaction gas to supply 5 × 10 ⁻³ torr.
r and reducing the bias voltage applied to the cemented carbide substrate to -200 V to generate an arc discharge between the cathode electrode and the anode electrode, thereby forming the cemented carbide substrates A1 to A10 and B1. Conventionally coated carbide tools 1 to 24 were produced by depositing a hard coating layer having the composition and average layer thickness shown in Tables 3 and 4 on the surfaces of B6 to B6, respectively.

Then, an electron impact type (bucket type) ion gun is applied to each of the cutting edge ridges of the conventional coated carbide tools 1 to 24 or the rake face and / or flank of the cutting edge. The present invention is carried out by forming an oxygen ion-irradiated oxygen-implanted layer having a depth shown in Table 5 by performing oxygen ion irradiation to measure the rake face side depth and / or flank side depth using Coated carbide tools 1 to 24 were manufactured respectively. The depth of the oxygen-injected layer was determined by using an Auger analyzer and measuring the oxygen concentration distribution at a right angle with the longitudinal section of the tool directed from the surface toward the inside.

Next, the coated carbide tools 1 to 18 of the present invention and the conventional coated carbide tools 1 to 18 obtained as a result are as follows: work material: square material of JIS S45C; cutting speed: 200 m / min. , Depth of cut: 2.5 mm, feed: 0.25 mm / tooth, a dry interrupted cutting (milling) test of carbon steel was performed, and the coated carbide tools 19 to 24 of the present invention and the conventionally coated carbide tools 19 Work material: square bar of JIS SNCM439, Cutting speed: 330 m / min. , Depth of cut: 2 mm. , Feed: 0.15 mm / tooth, a dry intermittent cutting (milling) test of alloy steel was performed under the following conditions. In any cutting test, the cutting time until the flank wear width of the cutting edge reached 0.2 mm was determined. It was measured. Table 6 shows the measurement results.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

[0014]

[Table 4]

[0015]

[Table 5]

[0016]

[Table 6]

[0017]

From the results shown in Tables 3 to 6, all of the coated carbide tools 1 to 24 of the present invention are superior to the conventional coated carbide tools 1 to 24 due to the formation of the oxygen ion-irradiated oxygen implanted layer. It is evident that it exhibits excellent wear resistance and exhibits 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, and therefore sufficiently satisfies the use of FA in a cutting device and a reduction in the cost of cutting. Is what you can do.

[Brief description of the drawings]

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

Claims (1)

[Claims] 1. A composition formula for forming an arc ion plating on the surface of a tungsten carbide-based cemented carbide substrate or a titanium carbonitride-based cermet substrate: (Ti _1-x Al _x ) N and (Ti _1-x Al _x) ) Ti and Al composite nitride and Ti and Al having C _1-y N _y (where x represents 0.3 to 0.7 and y represents 0.5 to 0.99 in atomic ratio)
Hard coating layer consisting of a single layer composed of any one of the composite carbonitrides or a multilayer composed of both
A surface-coated cemented carbide cutting tool formed by physical vapor deposition with an average layer thickness of μm, and at least the cutting edge ridge line where the rake face and the flank intersect, the rake face side depth of the surface-coated cemented carbide cutting tool. 0.5 μm from the surface, measured at the flank and / or flank depth
A hard coating layer having excellent wear resistance, characterized in that the oxygen coating layer is formed by oxygen ion irradiation over a depth ranging from 50 to 50% of the average layer thickness of the hard coating layer. Hard alloy cutting tool.