JP2001341005A - Coated hard tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated hard tool with excellent wear resistance in also a high speed cutting. SOLUTION: This tool is provided with a base material 2 and a coating film 1 containing TiCN formed on the base material 2. In a color tone of the coating film 1, chromaticity a* (a red direction) is 0<=a*<=10, chromaticity b* (a yellow direction) is 0<=b*<=20 and brightness L* is 0<=L*<=100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated hard tool, and more particularly to a coated hard alloy tool used as a cutting tool or other wear-resistant tool requiring wear resistance. The present invention relates to a coated hard alloy tool having excellent welding resistance.

[0002]

2. Description of the Related Art Conventionally, as a cutting tool, a cemented carbide (an alloy obtained by adding a carbon nitride of Ti (titanium), Ta (tantalum), or Nb (niobium) to a WC-Co alloy) has been used. Was. However, with the recent increase in cutting speeds, cemented carbide, cermet, or alumina-based or silicon nitride-based ceramics are used as base materials, and PVD (Physic
al Vapor Deposition) method of the periodic table of elements IVa, V
a, The use ratio of hard alloy tools in which a film made of carbide, nitride, carbonitride, boronitride, or oxide such as Group VIa metal or Al (aluminum) is coated to a thickness of 3 to 20 μm is increasing. I have.

[0003] In particular, coating by the PVD method can be used for cutting tools requiring high strength, such as drills, end mills and indexable inserts for milling, because the wear resistance can be increased without deteriorating the strength of the base material. ing.

[0004]

In recent years, the cutting speed has been increased in order to further improve the machining efficiency. Accordingly, tools are required to have higher wear resistance and oxidation resistance. It is becoming. In particular, in high-speed cutting, since the wear resistance of the base material cannot be expected much due to the high temperature, the wear resistance of the coating film has become very important.

It is therefore an object of the present invention to provide a coated hard tool having good wear resistance even at high speed cutting.

[0006]

Means for Solving the Problems The present inventors have studied stress strain in order to improve the wear resistance of a coating film. In general, a material containing many lattice defects and dislocations becomes hard because the movement of the dislocations is restricted. Therefore, it was considered that the introduction of a defect into the coating film would improve the wear resistance.

[0007] Then, various types of TiCN (titanium carbonitride) were coated on the cemented carbide, and dislocations and lattice defects were introduced into the coating to examine wear resistance. As a result, it was found that when dislocations and lattice defects were introduced, the wear resistance was improved. Interestingly, it was also found that the color tone of the coating film changes when dislocations and lattice defects increase.

[0008] In TiCN, it is generally known that the color tone changes when the content ratio of C (carbon) and N (nitrogen) changes. And chromaticity a only when lattice defects
^* 0 to 10 (red), chromaticity b ^* (yellow) 0
It was found that the lightness L ^* was 0 or more and 100 or less and 20 or less. Among them, particularly, those having a chromaticity a ^* (red direction) of 0 or more and 5 or less, a chromaticity b ^* (yellow direction) of 0 or more and 10 or less, and a lightness L ^* of 10 or more and 50 or less have significantly improved performance. Was.

Therefore, the coated hard tool of the present invention includes a base material and a coating film containing TiCN formed on the base material, and has a chromaticity a ^* of 0 to 10 in the color tone of the coating film. Chromaticity b ^* is 0 or more and 20 or less, and lightness L ^* is 0 or more and 100.
It is as follows.

As a result, dislocations and lattice defects are sufficiently introduced into the coating film, and good wear resistance can be obtained even in high-speed cutting.

The color display method based on the chromaticity a ^* , the chromaticity b ^*, and the lightness L ^* conforms to JIS Z8730.
3. of SZ 8722 (Spectral colorimetric method)
When measuring by the stimulus value direct reading method, JIS Z
8722-5. (Stimulus value direct reading method). However, the photoelectric colorimeter used for measurement is L
^* a ^* b ^* may be obtained.

In the above coated hard tool, preferably,
In the color tone of the coating film, chromaticity a ^* is 0 or more and 5 or less, chromaticity b ^* is 0 or more and 10 or less, and lightness L ^* is 10 or more and 50 or less.

As a result, better wear resistance can be obtained in high-speed cutting. In the above coated hard tool, preferably, the thickness of the coating film is 0.5 μm or more and 10 μm or more.
m or less.

This is because if the thickness of the coating film is less than 5 μm, the effect of the coating is small, and if it exceeds 10 μm, the coating film is easily peeled off.

In the above coated hard tool, preferably,
TiN (titanium nitride), TiC between base material and coating film
(Titanium carbide), ZrN (zirconium nitride), ZrC
(Zirconium carbide), CrN (chromium nitride) and C
There is further provided an adhesion enhancing layer made of at least one selected from the group consisting of rC (chromium carbide).

As a result, the adhesion strength between the coating film and the base material is improved, and higher performance is expected.

In the above coated hard tool, preferably,
The material of the base material has Co (cobalt) of 8% by mass or more and 12% by mass or less.

As described above, by appropriately selecting the Co content of the base material as the cemented carbide, the wear resistance is remarkably improved. When the content of Co is less than 8% by mass, the wear resistance of the cemented carbide itself is good, so that the effect of coating is not sufficiently exhibited. On the other hand, when the content of Co exceeds 12% by mass,
The base material itself becomes too soft, and film peeling occurs because the Young's modulus is too different from the hard coating film of the present invention,
The effect of coating is not exhibited.

In the above coated hard tool, preferably,
The material of the base material is 0.05 mass% or more and 1 mass% or less of Cr.
(Chromium) and / or V (vanadium) of 0.05% by mass or more and 0.5% by mass or less.

By adding Cr or V to the cemented carbide as the base material, the effect of improving the performance becomes remarkable.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view of a coated hard tool according to an embodiment of the present invention. Referring to FIG.
A coating film 1 made of CN is formed on a surface of a base material 2 made of a cemented carbide. The base material 2 includes, for example, WC
-Co alloy or an alloy obtained by adding Cr or V to this alloy is used. In the color tone of the coating film 1, the chromaticity a ^* (in the red direction) is from 0 to 10 and the chromaticity b ^* (in the yellow direction) is from 0 to 2.
0 or less, and the lightness L ^* is 0 or more and 100 or less. In particular, the chromaticity a ^* (in the red direction) is from 0 to 5, and the chromaticity b ^* (in the yellow direction) is 0.
It is preferable that the brightness L ^* is 10 or more and 10 or less and 50 or less.

The thickness of the coating film 1 is preferably 0.5 μm or more and 10 μm or less in consideration of the effect of coating and prevention of peeling.

Preferably, an adhesion reinforcing layer 3 is formed between the coating film 1 and the base material 2 as shown in FIG. 2, and the adhesion reinforcing layer 3 is made of TiN, TiC, ZrN, Z
It may be made of any material of rC, CrN, and CrC, or may be made of any combination of these materials.

The material of the base material 2 is not less than 8% by mass and not more than 12% by mass.
It preferably has the following Co, and further has 0.0
5 mass% or more and 1 mass% or less of Cr and / or 0.0
It is preferable to have V of 5% by mass or more and 0.5% by mass or less.

[0026]

Embodiments of the present invention will be described below in detail.

(Experimental Example 1) Shape I of model number SDKN42
Various TiCN coatings shown in Table 2 were applied to the SOP30 cemented carbide base material (containing 11% by mass of Co and the balance being WC). Further, using each of the coated samples, a block of alloy steel was cut under the conditions shown in Table 1, and the abrasion loss of each sample after cutting was measured. Table 2 also shows the results of the wear amount.

[0028]

[Table 1]

[0029]

[Table 2]

From the results shown in Table 2, the chromaticity a ^* (in the red direction) is 0.
Not less than 10 and chromaticity b ^* (yellow direction) is not less than 0 and not more than 20;
Samples 1 to 5 of the present invention having a lightness L ^* having a color tone in the range of 0 to 100 have less flank wear and higher abrasion resistance than Samples 6 to 8 having a color tone outside the range. You can see that. Further, chromaticity a ^* (red direction) is 0 or more and 5 or less, chromaticity b ^* (yellow direction) is 0 or more and 10 or less,
It can be seen that Samples 1, 2, and 5 having a color tone with a lightness L ^{* in} the range of 10 or more and 50 or less can obtain higher abrasion resistance than Samples 3 and 4 having a color tone outside the range.

(Experimental Example 2) Next, TiN, TiC, ZrN, ZrC, and Cr were used as an adhesion strengthening layer at the interface between the base material and the coating film.
An experiment was performed to confirm the effect of providing the N and CrC thin films. As the experiment, samples 11 to 16 in which the above-mentioned respective adhesion strengthening layers were formed between the interface between the same coating film and the base material as the sample 2 of the experimental example 1 were produced, and were cut under the same conditions as in the experimental example 1 to withstand resistance. Abrasion was evaluated. Table 3 shows the results.

[0032]

[Table 3]

From the results shown in Table 3, it can be seen that the flank wear amount is further reduced and the wear resistance is improved by disposing the adhesion reinforcing layer.

(Experimental Example 3) Next, as an experiment for confirming the effect when the composition of the base material is different, a sample prepared by the same method as in Experimental Example 1 was prepared, and cut under the same conditions as in Experimental Example 1 to reduce wear resistance. evaluated. Table 4 shows the results.

[0035]

[Table 4]

Although not explicitly shown in the results of Table 4,
Samples 22 and 23 were not usable as a tool because the chipping occurred and the work was damaged, though the wear was small.

From these results, it can be seen that when the amount of Co contained in the base material is 8% by mass or more and 12% by mass or less, the color tone falls within the range of the present invention and excellent cutting performance can be obtained.

Further, by adding 0.05% to 1% by mass of Cr and / or 0.05% to 0.5% by mass of V in addition to Co to the base material, the cutting performance is further improved. It turns out that it improves.

The embodiments and examples disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0040]

As described above, in the coated hard tool of the present invention, the chromaticity a ^* is 0 or more and 10 or more in the color tone of the coating film.
Hereinafter, the chromaticity b ^* is 0 or more and 20 or less, and the lightness L ^* is 0 or more and 10 or less.
Since it is 0 or less, dislocations and lattice defects are sufficiently introduced into the coating film, and good wear resistance can be obtained even in high-speed cutting. Thereby, the coated hard tool of the present invention is a drill, an end mill, a throw-away insert for milling, a replaceable cutting edge for cutting, a metal saw, a cutting tool, a reamer,
The present invention can be favorably applied to cutting tools such as taps, metal press working having a wear-resistant coating film formed on the surface thereof, metal forging, die casting, plastic molding dies, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a partial cross-sectional view of a coated hard tool according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a configuration in which an adhesion strengthening layer is provided between a coating film and a base material in the coated hard tool according to one embodiment of the present invention.

[Explanation of symbols]

 1 coating film, 2 base material, 3 adhesion strengthening layer.

Continuation of the front page (72) Inventor Haruyo Fukui 1-1-1, Konokita, Itami-shi, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works (72) Inventor Akihiko Ikegaya 1-1-1, Kunyokita, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works F term (reference) 3C046 FF03 FF10 FF25 FF32 FF37 FF39 FF50 4K029 AA04 BA55 BA58 BA60 BB02 BC02 BC07 BD05 EA01

Claims (7)

[Claims] 1. A base material, and a coating film containing TiCN formed on the base material, wherein in the color tone of the coating film, chromaticity a ^* is 0 or more and 10 or less, and chromaticity b ^* is 0 to 20 and brightness L ^* is 0 to 100
The following is a coated hard tool. 2. In the color tone of the coating film, chromaticity a ^* is 0 or more and 5 or less, chromaticity b ^* is 0 or more and 10 or less, and lightness L ^* is 1 or more.
The coated hard tool according to claim 1, wherein the number is 0 or more and 50 or less. 3. The thickness of the coating film is 0.5 μm or more and 10 μm or more.
The coated hard tool according to claim 1, wherein the thickness is not more than μm. 4. A method according to claim 1, wherein Ti is provided between said base material and said coating film.
The coated hard tool according to any one of claims 1 to 3, further comprising an adhesion strengthening layer made of at least one selected from the group consisting of N, TiC, ZrN, ZrC, CrN and CrC. 5. The coated hard tool according to claim 1, wherein the material of the base material includes Co in an amount of 8% by mass or more and 12% by mass or less. 6. The coated hard tool according to claim 5, wherein the material of the base material contains 0.05% by mass or more and 1% by mass or less of Cr. 7. The material of the base material is V at 0.05% by mass.
The coated hard tool according to claim 5, which has a content of 0.5% by mass or more.