JPS5945755B2 - Coated carbide throw-away tip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coated carbide throw-away tip whose cutting edge can be color-coded to indicate whether it is used or not.

Conventionally, a carbide throw-away tip for cutting made of a super-hard alloy is known, and the surface of the carbide throw-away tip is coated with carbides and nitrides of metals from groups 4a, 5a, and 6a of the periodic table. , one type of oxide, and a solid solution of two or more of these types, and coated with a single layer or multiple layers of two or more types with a thickness of up to 20 μm to improve wear resistance. Therefore, a coated carbide throw-away chip that has a longer cutting life is also known, and furthermore, on the coating layer of the coated carbide throw-away chip, a layer of α-alumina with a thickness of 0.2 to 5 μm is coated. Industrially useful coated carbide throw-away tips are also well-known, which are further coated with a coating layer to improve the heat resistance and oxidation resistance of the tips, thereby making it possible to cut both steel and cast metals.

In particular, the coating layer (upper layer) made of α-alumina in the latter coated carbide throw-away chip is formed by chemical vapor deposition, exhibits a translucent black color, and
Because the coated carbide throw-away tip has a surface roughness of micrometers, although the underlying color is slightly visible in appearance, it exhibits an almost black tone, and furthermore, after cutting, It is also well known that no obvious discoloration occurs when the cutting edge has little wear.

For this reason, it is important to reliably distinguish between used and unused cutting edges of the coated carbide indexable insert by color, especially when changing cutting edges in a short period of time inside a machine tool with insufficient lighting. , almost impossible.

Therefore, we developed a coated carbide throw-away tip that takes advantage of the excellent cutting properties of the coating layer made of α-alumina and allows easy discrimination between used and unused cutting edges.
- on the alumina coating layer by chemical vapor deposition with a layer thickness of 0.
A coating with a bright yellow titanium nitride layer of 5 to 5 μm was proposed, but since forming the titanium nitride coating layer by chemical vapor deposition requires a high temperature of nearly 1000°C, the α-alumina coating described above was proposed. The cutting properties of the layer are damaged by the high temperatures mentioned above, resulting in a short cutting life. The problem is that it becomes .

From the above-mentioned viewpoint, the present inventors have proposed that the conventional coated carbide throw-away chip, that is, the surface of the cemented carbide substrate, be coated with 4a, 5a1, and 6a of the periodic table as described above.
Coated with a single layer or a multilayer of two or more of metals with a thickness of 1 to 20 μm selected from the group consisting of carbides, nitrides, and oxides of group metals, and solid solutions of two or more of these metals. In order to distinguish between a used cutting edge and an unused cutting edge in a coated carbide throw-away tip which is further coated with an α-alumina layer having a layer thickness of 0.2 to 5 μm as an upper layer, by forming a coating layer, In particular, (a) the discoloration before and after use is large;

(b) It has a bright and beautiful color tone before use.

(c) It has a rust-preventing effect. (d) There is no significant apparent discoloration due to oil, especially cutting oil.

(e) The properties of the coated carbide throw-away tip are not impaired.

(f) Low cost.

As a result of conducting research to find a coating layer that satisfies the requirements (a) to (f) above, we found that TiCxNyOz (0.01≦X≦0.3, 0.6≦y≦0. 98, 0
．． It has been found that a coating layer having a thickness of 0.01 to 0.5 μm and having a composition of 01≦z≦0.1, x+y+z≦1.0 has characteristics that satisfy all of the above requirements.

That is, a part of or the vicinity of the cutting edge of the conventional coated carbide throw-away tip, or the entire cutting edge, is coated with a coating of 0.01 to 0.
．． TiCxNyOz layer with a thickness of 5 μm (however, 0.0
1≦x≦0.3, 0.6≦y≦0.98, 0.01≦z
≦0.1, x+y+z≦1.0), the coated part has a bright and beautiful yellow to orange color tone before use, and has good corrosion resistance and does not rust during storage. In addition, there is no apparent discoloration even when contaminated with cutting oil; on the other hand, after use, the color changes to black due to the high temperatures generated during cutting, resulting in the bright yellow to orange color of an unused cutting edge. They discovered that it is very easy to distinguish the black color of a used cutting blade even in a dark place.

This invention has been made based on the above findings, and the reason why the composition and thickness of the TiCxNyOz coating layer are limited as described above will be explained below.

(a) Composition of TiCxNyOz coating layer TiCxNyO
X in the z coating layer, . The relative proportions of yl and z are determined empirically, and are 0.01≦Z≦0.3,
0.6≦y≦0.98, 0.01≦z≦0.1, and x+y+z≦1.0), it has a clear yellow to orange color, and this yellow to orange color When exposed to high temperatures during cutting, it changes color to black, which is easy to distinguish.

That is, if the above conditions are not met, the color tone changes to dark red and the reflectance decreases, making it dark, making it difficult to distinguish between used and unused. (b)
Thickness of TiCxNyOz If the thickness is less than 0.01 μm, yellow to orange colors that can be easily distinguished cannot be imparted, and the black change after cutting is not clear. If this happens, the excellent heat resistance, oxidation resistance, and wear resistance of the α-alumina coating layer will be impaired, reducing the cutting life, so the thickness is set to 0.01 to 0.5 μm. Established.

Further, the TiCxNyOz coating layer in the coated carbide throw-away chip of the present invention can be formed at low cost by applying the sputtering method, and although the deposition rate is slow, it is very dense and is made of α-alumina. Since the surface roughness of the coating layer is 1 to 2 μm, it has practically sufficient adhesion strength.

Further, the TiCzNyOz coating layer is preferably formed in an atmosphere containing nitrogen, using Ti as a cathode, and at a temperature of 700° C. or lower. That is, if the reaction temperature exceeds 700°C, the properties of the α-alumina coating layer will be impaired, resulting in a reduction in cutting life. Next, the coated carbide throw-away chip of the present invention will be explained with reference to examples.

Example 1 First, a normal chemical vapor deposition method was applied to the surface of a carbide throw-away chip made of JISP3O with dimensions of inscribed circle: 12.7 mm, thickness 4.76 mm, and nose radius 0.8 mm. Thickness: 5 μMf) TiC layer, layer thickness: 2 μm TiCO. 5OO. Lower layer consisting of 5 layers and layer thickness:
A conventionally coated carbide throw-away chip with a dark red appearance and a black tone at first glance was manufactured by coating the upper layer with a 2 μm α-alumina layer, and then placed in a vacuum chamber. The Ar:N2:H2-1:
By performing glow discharge for 30 minutes while flowing a gas mixture in a 1:1 ratio at a rate of 100 ml per minute, the entire cutting edge has a bright, slightly orange-yellow color. :0.2 μm TiCO. O5NO
．． ,OO. EXAMPLE 1 A coated carbide throw-away chip according to the invention, which was covered with an O2 layer, was manufactured.

Next, the coated carbide throwaway tip of the present invention,
When the above-mentioned conventional coated carbide throw-away tip was used in an automatic lathe for cutting automobile parts, it reached the end of its life after cutting 200 parts. This shows that the cutting characteristics are not impaired in any way by the TiCxNyOz coating layer. In addition, in the coated carbide throw-away tip of the present invention, the bright, slightly orange-yellow color changes to black after use, making it possible to clearly and extremely easily distinguish before and after use. In contrast, with conventional coated carbide throw-away chips, there is almost no change in the dark red (almost black) color tone of the α-alumina coating layer, so it is difficult to use, especially inside machine tools with insufficient lighting. Color classification in a short period of time was almost impossible.

Example 2 The lower layer was composed of only a TiC layer (layer thickness: 5 μMf), and the composition of the mixed gas introduced into the vacuum chamber was Ar:N2:
A coated carbide throw-away chip of the present invention was manufactured under the same conditions as in Example 1 except that H2:CH4 = 1:1:1:0.1.

The TiCxNyOz layer in the coated carbide throwaway chip of the present invention obtained as a result has an orange color and a composition of Ti.
C.O. l5NO. 83OO. . 2. Thickness: 0.3 μm.

Next, the coated carbide throwaway tip of the present invention,
TiCxNyOz for color-coding used/unused cutting blades
Regarding the conventional coated carbide throw-away tip that does not form a coating layer, workpiece material: JIS: SNCM-8 round bar, cutting speed: 180 m/Mi! t, depth of cut: 0.5mm, feed: 0.1mm/Revl, cutting conditions: 10mm, When cutting tests were conducted under the following conditions, both chips were 0.
．． It showed flank wear of 3 mm.

However, with the coated carbide throw-away tip of the present invention, the color changes from bright orange before use to black after use, making it very easy to distinguish by color, whereas with the conventional coated carbide throw-away tip, It was extremely difficult to distinguish because it remained black both before and after use. As mentioned above, TiCxNyO is formed at a low cost by applying a low temperature of 700'C or less by a normal sputtering method.
According to the coated carbide throw-away chip of the present invention having the Z coating layer, the bright yellow to orange color tone before use changes to black after use, so it is possible to distinguish between used and unused chips even inside a machine tool with insufficient lighting. This allows the cutting edges to be clearly and easily distinguished by color.

Claims (1)

[Claims] 1. On the surface of the super hard alloy substrate, 4a, 5a,
and one type of carbide, nitride, and oxide of group 6a metal, and a single layer or a multilayer of two or more types with a layer thickness of 1 to 20 μm selected from the group consisting of a solid solution of two or more types of these metals. In a coated carbide throw-away tip that is coated with an upper layer of α-alumina with a layer thickness of 0.2 to 5 μm through a lower layer of A yellow to orange TiCxNyOz layer with a thickness of 0.01 to 0.5 μm to distinguish between used and unused blades (0.01≦x≦
0.3, 0.6≦y≦0.98, 0.01≦z≦0.1
, z+y+z≦1.0).