JPH08267306A - Hard-coated cutting tool and manufacture thereof - Google Patents

Abstract

PURPOSE: To display its excellent cutting performance for a long period of time by making a TiAl mixed compound layer coated on a base body surface be varied in the base body surface direction at the ratis of titanium to aluminum and becoming the highest in an edge part. CONSTITUTION: In this TiAl mixed compound layer being coated in a hard coated cutting tool, the ratio of titanium to aluminum is varied according to a spot. In brief, at an edge part, the ratio of Ti to Al is larger than that of Ti to Al in a part 2 other than the edge part, and further the ratio of Ti to Al in the edge part 1 becomes the highest, a fact that the ratio of Ti to Al is varied according to the spot concerned means that a color is deep as the ratio of Ti to Al in the TiAl mixed compound layer in the edge part 1, and further it is simulatively shown so as to make the color become lightened as the ratio of Ti to Al in the part 2 other than the edge part is smaller.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a substrate surface containing Ti and A.
l composite nitride layer, Ti and Al composite carbonitride layer, Ti
Cutting tool coated with a hard layer formed by coating a TiAl composite compound layer composed of one single layer or a plurality of two or more layers out of the composite carbide layers of Al and Al (hereinafter collectively referred to as TiAl composite compound layer) It is about.

[0002]

2. Description of the Related Art Generally, a WC-based cemented carbide, a TiCN-based cermet or the like is used as a substrate, and a TiAl composite compound layer is formed on the surface by physical vapor deposition for the purpose of improving wear resistance. A hard layer-coated cutting tool formed by coating is known (see JP-A-62-56565).
Further, in order to improve the adhesion strength of the hard layer of the hard layer-coated cutting tool to the substrate, one of TiN, TiCN, and TiC has an average layer thickness of 1 to 10 μm. Average layer thickness through the adhesion-strengthening layer of:
There is also known a hard layer-coated cutting tool formed by forming a TiAl composite compound layer having a thickness of 0.5 to 5 μm by a physical vapor deposition method (see JP-A-1-252304). Further, a hard layer-covered cutting tool formed by forming a TiAl composite compound layer whose Al content increases in the thickness direction by a physical vapor deposition method is also known (see Japanese Patent Laid-Open No. 3-188264).

[0003]

However, in recent years, with the demand for cost reduction and high efficiency of cutting, there has been a demand for a hard layer coated cutting tool having a longer service life. No cutting tool having a sufficiently long TiAl composite compound layer coated thereon has been obtained.

Therefore, the inventors of the present invention have used a conventional physical vapor deposition method to produce TiAl at a low cost and with a sufficiently long service life.
As a result of research to manufacture a hard-layer coated cutting tool coated with a composite compound layer, TiA coated on the surface of the substrate
A hard layer-coated cutting tool in which the Ti / Al ratio of the composite compound layer changes depending on the location and the Ti / Al ratio at the edge is the highest is formed by coating the conventional TiAl composite compound layer. We have obtained the knowledge that the service life is much longer than that of hard-layer-coated cutting tools.

The present invention was made on the basis of such findings, and in a hard layer-coated cutting tool comprising a substrate surface coated with a TiAl composite compound layer, a TiAl composite compound coated on the substrate surface. The layer is characterized by a hard layer-coated cutting tool in which the Ti / Al ratio of the TiAl composite compound layer changes toward the surface of the substrate and the Ti / Al ratio is highest at the edge.

More specifically, according to the present invention, the Ti / Al ratio in the edge portion of the substrate surface is 30 / atomic ratio.
70 to 80/20, the Ti / Al ratio of the portion other than the edge portion is in the atomic ratio range of 25/75 to 75/25, and the Ti / Al ratio of the edge portion of the substrate is Is characterized by a hard-layer-coated cutting tool coated with a TiAl composite compound layer having a Ti / Al ratio higher than the Ti / Al ratio of the portions other than the edge portion and the highest.

In the hard layer coated cutting tool of the present invention,
The "edge portion" means a cutting blade and a strip-shaped portion having a width of 3 mm or less from the cutting blade, and the other portion is called "a portion other than the edge portion". The hard layer-coated cutting tool of the present invention will be specifically described with reference to the drawings. FIG. 1 is a perspective explanatory view for easily understanding the hard layer-coated cutting tool of the present invention, where 1 is an edge portion and 2 is a portion other than the edge portion. TiAl coated on hard layer coated cutting tool of this invention
In the composite compound layer, the Ti / Al ratio changes depending on the location, the Ti / Al ratio in the edge portion 1 is higher than the Ti / Al ratio in the portion 2 other than the edge portion, and the edge portion 1 The highest Ti / Al ratio is. The fact that the Ti / Al ratio differs depending on the location is shown in FIG.
In the TiAl composite compound layer of the edge portion 1
It is simulated that the color becomes darker when the Al ratio is large and the color becomes lighter when the Ti / Al ratio of the portion 2 other than the edge portion is small.

The TiAl composite compound layer formed on the hard layer-coated cutting tool according to the present invention in which the Ti / Al ratio changes depending on the location, the substrate is loaded into an ordinary ion plating apparatus which is one of physical vapor deposition apparatuses. Then, while flowing nitrogen gas, the absolute value of the negative bias voltage is changed within the range of 20 to 300 V so as to be gradually increased from the initial stage to the end of the reaction. The absolute value of the negative bias voltage is set in the range of 20 to 300 V. The reason is that if the absolute value of the negative bias voltage is less than 20 V, the crystallinity of the film deteriorates and a sound film cannot be formed. However, if the voltage exceeds 300 V, Al on the coating surface
Is sputtered, and a film having a target Ti / Al ratio cannot be obtained, which is not preferable. A more preferable range of the absolute value of the negative bias voltage is 40 to 2
It is 50V.

[0009]

【Example】

Example 1 As a substrate, an ISO standard SEEN1203AFTN-shaped throwaway tip made of WC-based cemented carbide corresponding to P30 was prepared, and this throwaway tip was chemically cleaned using an organic solvent with an ultrasonic cleaner. Furthermore, Ti target and Ti / Al ratio of 70/30, 65/3
5, 60/40, 55/45, 50/50, 45/5
5, 40/60, 35/65, 30/70, 25/7
A target composed of a mixture of Ti and Al of 5 and 20/80 (referred to as TiAl target) was prepared. After the throw-away tip, the Ti target and the TiAl target were both charged and installed in an arc ion plating device, the pressure in the arc ion plating device was maintained at 1 × 10 ⁻⁵ torr and temperature: 700 ° C. Ar gas is supplied to make an Ar gas atmosphere of 1 × 10 ⁻² torr, and the throwaway tip is set to −1000.
A V-charge was applied to perform bombard cleaning.

Next, the surface of the throwaway tip is shown in Table 1.
To TiC layer, TiN layer, and TiCN layer having an average layer thickness shown in 3 to 3, or with or without forming an adhesion-strengthening layer composed of one or more of the TiC layer, the edge portion of Ti / Al ratio (A), Ti / Al ratio (B) of portions other than the edge portion, and Ti having an average layer thickness
By forming an Al composite compound layer and further forming a TiN outermost layer having an average layer thickness shown in Tables 1 to 3 on the TiAl composite compound layer, the hard layer-coated cutting tool of the present invention (hereinafter Referred to as the coated cutting tool of the present invention) 1
˜20, comparative hard layer coated cutting tools (hereinafter referred to as comparative coated cutting tools) 1 to 6 and conventional hard layer coated cutting tools (hereinafter referred to as conventional coated cutting tools) 1 to 4 were produced. The Ti / Al ratio (B) of the portion other than the edge portion is a measured value of the Ti / Al ratio at the center of the rake face of the throwaway tip.

The adhesion strengthening layer and the outermost TiN layer in the coated cutting tools 1 to 20 of the present invention, the comparative coated cutting tools 1 to 6 and the conventional coated cutting tools 1 to 4 have a Ti target in an arc ion plating apparatus as a cathode. A TiC layer is formed by applying a bias voltage to the throwaway chip substrate while flowing a nitrogen gas, and a TiC layer is formed by applying a bias voltage to the throwaway chip substrate by using a Ti target in the arc ion plating device as a cathode and flowing a methane gas. Furthermore, the TiCN layer is formed by using a Ti target in an arc ion plating apparatus as a cathode while flowing a nitrogen gas and a methane gas by applying a bias voltage to a throwaway chip substrate, and both are formed under normal physical vapor deposition conditions. However, the TiAl composite compound layer is shown in Table 4 to Using the reaction gas shown in, it was formed while applying a gradually varying bias voltage between the end time from the physical vapor deposition initial.

The coated cutting tools 1 to 20 of the present invention, the comparative coated cutting tools 1 to 6 and the conventional coated cutting tools 1 to 4 thus obtained were used. Work material: SCM440 (HB 220) Cutting speed: 200 m / Min, Feed per blade: 0.3 mm / blade, Depth of cut: 2.0 mm, Cutting time: 30 minutes, Wet milling cutting test is performed, flank wear width of cutting edge is measured, and damage is done at the same time. The morphology was observed and the results are shown in Table 7.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

[Table 4]

[0017]

[Table 5]

[0018]

[Table 6]

[0019]

[Table 7]

Example 2 As a substrate, by weight%, TiCN-15% WC-10%
_{TaC-9% Mo 2 C-} 6% Ni-12% of the composition consisting of Co ISO standards SEEN1203AFTN1 shape of T
Ti target and Ti / A prepared in Example 1 except that the iCN-based cermet throwaway tip is used
Using a TiAl target having an L ratio, the adhesion strengthening layer having the average layer thickness shown in Tables 8 to 10, the Ti / Al ratio (A) of the edge portion, and the portion other than the edge portion were used in the same manner as in Example 1. The coated cutting tool of the present invention 2 having a TiAl composite compound layer having a Ti / Al ratio (B) and a TiN outermost layer.
1-37, comparative coated cutting tools 7-12 and conventional coated cutting tools 5-7 were produced. The adhesion-strengthening layer was formed under normal physical vapor deposition conditions.
It was formed under the conditions shown in.

These coated cutting tools 21 to 37 of the present invention, comparative coated cutting tools 7 to 12 and conventional coated cutting tools 5 to 7
Work material: SCM440 (HB 220) Cutting speed: 200 m / min, Feed per blade: 0.2 mm / blade, Depth of cut: 1.5 mm, Cutting time: 30 minutes, Wet milling test Then, the flank wear width of the cutting edge was measured, and at the same time, the damage form was observed, and the results are shown in Table 14.

[0022]

[Table 8]

[0023]

[Table 9]

[0024]

[Table 10]

[0025]

[Table 11]

[0026]

[Table 12]

[0027]

[Table 13]

[0028]

[Table 14]

Example 3 As a substrate, commercially available, twist angle: 30 degrees, blade length: 24 m
m, diameter: 10 mm, a square-type two-blade high-speed tool steel end mill was prepared, and the Ti target and TiAl having a Ti / Al ratio prepared in Example 1 were used except that this high-speed tool steel end mill was used. Using the target, the adhesion strengthening layer having the average layer thickness shown in Tables 15 to 17, the Ti / Al ratio (A) of the edge portion, and the Ti / Al ratio of the portion other than the edge portion ( Inventive coated cutting tools 38-54 having a TiAl composite compound layer with B) and a TiN outermost layer, comparative coated cutting tool 13
-18 and conventional coated cutting tools 8-10 were made. The adhesion-strengthening layer was formed under normal physical vapor deposition conditions.
The Al composite compound layer was formed under the conditions shown in Tables 18 to 20.

These coated cutting tools 38 to 54 of the present invention, comparative coated cutting tools 13 to 18 and conventional coated cutting tools 8 to
Work material: S50C (HB 230), Cutting speed: 30 m / min, Feed per blade: 0.07 mm / blade, Depth direction cut: 15 mm, Cut: 1 mm, Cutting length: 20 mm, The dry upward cutting test under the conditions of No. 2 was performed, the flank wear width of the cutting edge was measured, and at the same time, the damage form was observed, and the results are shown in Table 21.

[0031]

[Table 15]

[0032]

[Table 16]

[0033]

[Table 17]

[0034]

[Table 18]

[0035]

[Table 19]

[0036]

[Table 20]

[0037]

[Table 21]

[0038]

From the results shown in Tables 1 to 7, the coated cutting tools 1 to 20 of the present invention are all conventional coated cutting tools 1 to 4.
Is superior in wear resistance and exerts excellent cutting performance over a long period of time. From the results shown in Tables 8 to 14, the coated cutting tools 21 to 37 of the present invention are all conventional coated cutting tools 5 to 7 It is found that the coated cutting tool 3 of the present invention is superior in wear resistance and exhibits excellent cutting performance over a long period of time, and from the results shown in Tables 15 to 21.
8 to 54 are all more than the conventional coated cutting tools 8 to 10,
It can be seen that it has excellent wear resistance and exhibits excellent cutting performance over a long period of time. However, it is also understood that unfavorable characteristics appear when the conditions of the present invention are not satisfied. As described above, the hard layer-coated cemented carbide cutting tool of the present invention exerts excellent cutting performance for a long period of time, and therefore brings industrially excellent effects.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of a hard layer-coated cutting tool of the present invention.

[Explanation of symbols]

 1 Edge part base 2 Parts other than edge part

Claims (6)

[Claims] 1. A single nitride layer of a composite nitride layer of Ti and Al, a complex carbonitride layer of Ti and Al, and a composite carbide layer of Ti and Al, or a plurality of layers of two or more species on the surface of a substrate. A compound compound layer of Ti and Al consisting of
In a hard layer-coated cutting tool coated with a composite compound layer), the TiAl composite compound layer coated on the surface of the substrate is T
A hard layer-coated cutting tool characterized in that the Ti / Al ratio of the iAl composite compound layer changes in the surface direction of the substrate and is highest at the edge portion. 2. The TiAl composite compound layer coated on the surface of the substrate has a Ti / Al ratio of 3 in atomic ratio at the edge portion.
It is in the range of 0/70 to 80/20, and the Ti / Al ratio of the portion other than the edge portion is 25/75 to 75/2 in atomic ratio.
The hard layer-coated cutting tool according to claim 1, wherein the ratio Ti / Al in the edge portion is larger than the Ti / Al ratio in a portion other than the edge portion. 3. T between the substrate and the TiAl composite compound layer
The hardened layer according to claim 1 or 2, wherein an adhesion-strengthening layer having a layer thickness of 1 to 10 µm, which is a single layer of iN, TiCN, or TiC, or a plurality of two or more layers is formed. Layer coated cutting tool. 4. The outermost layer of the TiAl composite compound layer coated on the surface of the substrate is coated with a TiN layer having a layer thickness of 1 to 10 μm as the outermost layer. Hard layer coated cutting tool. 5. The TiAl composite compound layer has a layer thickness: 1
It is in the range of -10 μm.
The hard layer-coated cutting tool according to 2, 3, or 4. 6. The TiAl composite compound layer in which the Ti / Al ratio changes toward the surface of the substrate and has the highest Ti / Al ratio at the edge portion is formed by a normal physical vapor deposition method. In the method for forming a layer, the layer is formed by changing the absolute value of the negative bias voltage so as to gradually increase within the range of 20 to 300 V between the initial stage and the end of the reaction. The method for manufacturing a hard layer-coated cutting tool according to 2, 3, 4 or 5.