JPS6033603B2 - High-speed cutting tool coated with a hard layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-speed cutting tool used in lathe cutting, milling, etc., in which a hard coating layer is applied to the surface of the cutting tool. The object of the present invention is to provide a high-speed cutting tool that has superior wear resistance and ballability in high-speed cutting compared to the previous one.

Conventionally, ceramic tools mainly made of aluminum oxide and/or titanium carbide have been used for such high-speed cutting tools, but although these ceramic tools have high wear resistance in high-speed cutting, they have the disadvantage of poor graininess. For example, when a large load is applied to the cutting edge, such as during heavy cutting, there is a problem that the cutting edge is easily chipped.

In contrast, tools coated with wear-resistant titanium carbide or titanium nitride on the surface of cemented carbide, which has toughness but poor wear resistance during high-speed cutting, can replace conventional hard alloys that do not have a coating layer. In contrast, although it is known to have excellent wear resistance, its wear resistance was inferior to that of ceramic tools when cutting at high speeds of 150 to 20 h/min or higher.

In addition, cutting tools with a double coating layer, which is coated with a carbide or nitride such as titanium and further coated with highly wear-resistant aluminum oxide or zirconium oxide, have been developed; Due to the difference in the basic chemical bonding between carbides and nitrides such as titanium coated on the aluminum oxide and aluminum oxide, the chemical affinity is poor and sufficient bonding strength cannot be obtained. When used for heavy cutting, there is a problem that peeling of the coating layer, abnormal wear, etc. occur, and the inherent wear resistance of the oxide cannot be fully demonstrated. The present invention improves the defects of cutting tools provided with a hard coating layer,
This product provides a high-speed cutting tool that has a tough and wear-resistant coating layer on the surface of the cemented carbide tool.It is made of titanium carbide, titanium nitride, and A first coating layer made of one type of titanium carbonitride is provided, and a second coating layer made of one or two types of aluminum nitride and/or aluminum oxynitride with a thickness of 0.5 to 10 μm is provided on the outside thereof, Furthermore, a third coating layer made of aluminum oxide having a thickness of 0.5 to 5 mm is provided on the outside thereof, and the total thickness of these three coating layers is 2 to 15 peaks. This is a summary.

In this case, one of titanium carbide, titanium nitride, or titanium carbonitride was selected as the first coating layer because its chemical properties are the closest to those of cemented carbide among hard materials, so it has a high chemical affinity with cemented carbide. This is because the adhesive strength with the alloy is extremely high, and the chemical affinity with the aluminum nitride or aluminum oxynitride of the second coating layer is also better than the chemical affinity between the cemented carbide and aluminum nitride or aluminum oxynitride. .

The reason why the thickness is set to 1 to 10 mm is that the effect as a bonding layer to the second coating layer does not appear when the thickness is less than 1 layer, but the effect becomes more apparent when the thickness is 1 layer or more. However, if the number of ridges is 10 or more, the heat from the cutting edge during high-speed cutting may be hindered from being dissipated to the base, and the internal stress may increase due to the difference in thermal expansion, making it more likely to peel off, so 3 to 7 ridges is preferable. Next, aluminum nitride and/or aluminum oxynitride were selected as the second coating layer because their chemical compatibility with titanium carbide, titanium nitride, or titanium carbonitride in the first coating layer and aluminum oxide or aluminum in the third coating layer This is because it has high adhesion strength to both aluminum oxynitride and both coating layers.

That is, the aluminum oxide of the third coating layer has a chemical affinity with the titanium carbide, titanium nitride, or titanium carbonitride of the first coating layer, which is quite different from the atomic bonding style of the carbide or nitride of the cemented carbide or titanium. However, aluminum nitride and aluminum oxynitride have a similar atomic bonding pattern to that of titanium carbide and nitride, and have a high chemical affinity, making it possible to easily obtain tight adhesion. On the other hand, aluminum oxide, which is the third coating layer, has good bonding properties because it can be bonded via aluminum ions, and in combination with its own strong properties, it is possible to obtain an extremely strong adhesive layer. be. In addition, its thermal conductivity is considerably higher than that of alumina, so it can effectively disperse the heat from the cutting edge to other parts, lowering the temperature of the cutting edge. And its thickness is 0
．． 5 to 10. Below 0.5 French, the effect of bonding the third coating layer to the first coating layer as described above will not be sufficiently achieved, and above low, the internal stress between the layers will increase due to the difference in thermal expansion. If the size is too large, it may actually cause peeling, so preferably
~5 Buddhas are desirable. Next, we chose aluminum oxide for the third coating layer, which is the outermost layer.As can be seen from the fact that aluminum oxide is used in high-speed cutting tools as the main component of ceramic tools, it has excellent hardness, heat resistance, and wear resistance at room temperature. Of course, this is because the wear resistance during high-speed cutting is extremely high even at high temperatures.

If the thickness is less than 0.5, the effect of improving wear resistance is poor, and if it is more than 5, peeling or abnormal wear may occur due to interlayer internal stress resulting from the difference in thermal expansion, so a thickness of 1 to 3 is preferable. The total thickness of the first to third coating layers is 2 to
The reason why 15A is set is that if it is less than 2 degrees, the effect of improving wear resistance is poor, and if it is more than 15 degrees, it may cause peeling or abnormal wear due to interlayer internal stress caused by the difference in coefficient of thermal expansion between the base and coating layer. , preferably 7 to 12 Buddhas.

For coating with these hard coating materials, for example, in the case of coating titanium carbide, a method is used in which a mixed gas of titanium chloride, hydrogen, and hydrocarbons is introduced onto the surface of a cemented carbide substrate heated to 1000 to 1100 oo, that is, known chemical vapor deposition. law (hereinafter abbreviated as CV)
(referred to as method D). In that case, the following reaction occurs on the surface of the cemented carbide substrate, depositing a thin layer of titanium carbide on the substrate. TICL4 10 (Sun 2) 10 CH4 → TIC+
To coat other titanium nitrides, titanium carbonitrides, aluminum nitrides, aluminum oxynitrides, or aluminum oxides, follow the reactions of the following formulas.

TIC14 12th 21st/Su 21 TIN+4HCI Fox C
l3 10 thin 20 N2 1 fox N + side I fox CI 30 × 02 10 Nada 1 N2 → 2 AI 〇 N 10 phrases HCI 12 C 〇 2 NC 13 3 C0 2 13 days 20 CO → AI 2 0 3 10 days CI + 4 C 〇 The details will be more clearly understood from the examples described below.

Example 1 An example of the present invention will be described with reference to FIG.
After loading NP432)2 and heating to about 1100°C,
A mixed gas of CH2 and CH2 led from the gas cylinders 3a and 3b and a mixed gas of TIC14 evaporated by the evaporator 4 were flowed into the reaction vessel for 1 hour.

At this time, the pressure inside the container was 30 tons, and the mixing ratio of the three components of the mixed gas was 87% ratio, 45% CH, and 148% TIC. As a result, an inner layer of titanium nitride having a thickness of approximately 3Y could be deposited on the surface of the cemented carbide substrate. After that, the flow of the mixed gas is stopped, and then the temperature of the coated cemented carbide substrate is set to 1050 qo in the same container,
3. Replace the gas cylinder and add a mixed gas of 245% N2, 45% N2, and 10% MCI3 gas evaporated in the evaporator to the reaction vessel. A thin layer of aluminum nitride with a thickness of 5 mm was deposited over a period of time. Next, the inflow of the mixed gas was stopped and the cylinder was replaced.
%, and a mixed gas with a mountain CI of 38% was introduced for 2 hours. The temperature and pressure at this time were 110,000 and 30 tons, and as a result,
It was possible to apply a coating of AI203 with a thickness of 1.5 mm.
With the above, this chip has a hard coating layer of TIC3↓ on the first coating layer, AIN5 on the second coating layer, and AI2031.5 on the third coating layer, and is confirmed by X-ray diffraction and line analysis with a Y-ray microanalyzer. did. Note that there was an intermediate layer of AION between the second coating layer and the *3rd coating layer. This tool is M. Set to 1. A partially cutaway perspective view is shown in FIG.
2 is a cemented carbide base, 2a is a first coating layer, 2b is a second coating layer, and 2c is a third coating layer.

Next, No. The rudder was made by coating the same cemented carbide base as used in No. 1 with a hard material as shown in Table 1. 2~enemy. I gave it a 5.
In this case, the titanium nitride coating is applied to the ship's side. Using the same equipment and principle as in 1, a mixed gas of 145% TIC, 80% ratio, and 15% N2 was used, and the temperature was maintained at 110,000 °C for 1 hour at a pressure of 30 Tom. The thus obtained tool according to the present invention was used as a conventional cemented carbide tool of the same shape and material without a coating layer.
6 and a cemented carbide tool boat coated with a titanium nitride coating with a thickness of 5 mm and an aluminum oxide coating with a thickness of 1.5 mm using the above method. 7 and the conventionally used ceramic tool boat. 8
A comparative cutting test was also conducted under the following conditions, and Table 1 shows the results of comparing the tool life expressed as the time until the maximum flank wear, chipping, or chipping damage reached 0.3 ribs. Table 1 Cutting conditions Work material JISFC-20 Cast iron rod (120 side × 4
Cutting speed: 30 cuts/min Depth of cut: 2 side feed: 0.35 side rev As shown in Table 1, No. 1 without conventional coating layer. No. 6 was subject to severe wear, and its lifespan expired in just 3 minutes.The first coating layer was coated with titanium nitride and the second coating layer was coated with aluminum oxide using the conventional method. 7 has less wear and 0 in 21 minutes
．． Although it showed some wear on the 3 side, it was still not satisfactory as there was some abnormal wear. No. 8 caused chipping in just 2 minutes, resulting in 0.0% flank damage.
It became the third side and the lifespan was exhausted.

In contrast, the present invention further includes a first coating layer made of one type of titanium carbide, titanium nitride, or titanium carbonitride, and a second coating layer made of one or two types of aluminum nitride and/or aluminum oxide on the outside thereof. A third coating layer made of aluminum oxide is provided on the outside. 1 to 5 indicate that the present invention can provide a cutting tool that has little wear, no chipping, and no abnormal wear, and has a cutting life that is more than twice that of conventional products, and that can be used extremely advantageously in cutting processing. This was confirmed. In this embodiment, only the coating method using the CVD method is shown, but the present invention is not limited to the CVD method, and the coating can also be performed using a physical vapor deposition method called PVD, sputtering, or the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a CVD apparatus used in an embodiment of the present invention, and FIG. 2 is a cutaway perspective view of a tool of the present invention. DESCRIPTION OF SYMBOLS 1... Stainless steel CVD reaction vessel, 2... Cemented carbide substrate, 3a, 3b, 3c... Gas cylinder used for vapor deposition, 4... Vapor deposition layer of vapor deposition substance, 5... Heating of reaction vessel 1 Furnace, 6...vacuum pump. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A high-speed cutting tool in which the surface of a base made of cemented carbide is coated with a hard material, made of one of titanium carbide, titanium nitride, or titanium carbonitride having a thickness of 1 to 10 μm on the base. A first coating layer of 0.5 to 10μ is provided on the outside.
A second coating layer made of one or two of aluminum nitride and/or aluminum oxynitride is provided with a thickness of A high-speed cutting tool characterized in that the total thickness of the three coating layers is 2 to 15μ. 2. The high-speed cutting tool according to claim 1, wherein the first coating layer provided on the surface of the base made of cemented carbide is titanium carbide. 3. The high-speed cutting tool according to claim 1, wherein the first coating layer provided on the surface of the base made of cemented carbide is titanium nitride or titanium carbonitride.