JPS6036882B2 - Ceramic tip for cutting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an indexable cutting ceramic tip whose surface is coated with a hard colored film.

Tough ceramic chips for cutting are usually made of alumina as a main component, mixed with carbide, carbonitride, etc., and phosphorized by hot pressing or hot isostatic pressure method (Hika method), and are black in color. Therefore, when using a slow-out ceramic tip for precision finishing, the wear width of the used corner is about 200 mm, and if the base is black, it is difficult to tell whether it is used or not. There were disadvantages such as the cutting edge with corners being discarded if used with seven corners or less, or the same corner being used twice, resulting in defective workpieces. In order to eliminate this drawback, the present inventors considered providing a colored thin layer on the surface of black ceramic.

In this case, the thin film is required to satisfy the following conditions. ■
It has hardness and strength similar to ceramic tools, and does not peel off due to slight friction during handling, unlike when paint is applied to the surface.

In addition, if it peels off, only the part where the chip is used will peel off, like when a metal film is formed on the ceramic surface.
Peeling in one area should not spread to other areas. ■ It has a coefficient of thermal expansion close to that of ceramic tools.

However, if the chips have significantly different coefficients of thermal expansion, other parts of the chip may also peel off during use. ■ Bright colors,
It is also preferably a golden color that stands out against the black background color.

As a result of further intensive study, the present inventors found that hard carbide,
The present invention was completed by discovering that a golden-yellow thin layer made of nitride or carbonitride satisfies all of the above requirements.

That is, the gist of the present invention is to provide a throw-away type cutting ceramic characterized in that a golden-yellow thin layer made of hard carbide, nitride, or carbonitride is provided on the surface of a black ceramic chip mainly composed of alumina. It's on the tip.

The present invention will be explained in detail below.
Contains more than The rest contains carbides such as TIC, WC, and carbonitrides such as TICN.There are no restrictions on the bran silk method, whether it is a hot press method or a hot isostatic pressure method, and the black color is sintered at high temperature and high pressure. It is made of ceramic. The present invention is characterized by providing a golden yellow thin layer on this surface. The thin layer is hard and contains carbides such as TaC, TIN, Z
It consists of nitrides such as rN and TaN, and carbonitrides such as TICN. However, if the amount of TICN' or C increases, the color becomes blackish, so it is preferable to use one that satisfies the following formula. NG
Weight) Cq weight) 10 NQ weight) ≧0.5 To coat the surface of the ceramic chip with these, known methods such as vapor phase deposition (CVD) and physical vapor deposition (PVD) may be used. .

When the above components are coated, they are golden in color and hard, and the coefficient of thermal expansion is not much different from that of ceramics. As an example, Table 1 shows the properties when each component was coated using the CVD method. table
1 *I Commercially available black ceramic made by hot pressing 70% AI203 and 30% TIC.

If the thickness of the thin layer, that is, the thickness of the coating, is 1, the surface of the ceramic chip will be colored and the intended purpose of the present invention will be achieved, but if the thickness is 3 to 20, the cutting edge will be reinforced in addition to coloring. Therefore, it is preferable.

If it is thicker than 20 μm, grain growth of the inner layer coating material occurs during coating, making the thin layer brittle, which is not preferable.

As described above, since the ceramic tip of the present invention has a golden thin layer made of hard carbide, nitride, or carbonitride on the surface, when it is used for cutting, the thin layer is only at the corners where it is used. The layer peels off and the other parts do not.

Therefore, the black ceramic is exposed in the corners where it was used, while the other parts remain golden brown. Since the color stands out in contrast to the black and golden yellow, the corners used for cutting can be immediately identified from any angle without surface reflections. Also, since the thin layer is hard, it cannot be easily peeled off other than by cutting, such as during a chip mounting operation. Furthermore, since it is hard, a thin layer of
When the thickness is 20 mm, the cutting edge is strengthened and boundary wear can be prevented. EXAMPLES The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example black ceramic chip SNP433 (square) and RN4
3L circles) were arranged in a reaction container, and the temperature was 1100℃ and the pressure was 3.
Mom, titanium tetrachloride gas 5%, N2 gas 15%
A mixed gas of 80% was flowed for 1 hour, and TIN was coated according to the following reaction formula.

Claims (1)

[Claims] 1. For throw-away cutting, characterized in that a thin golden-yellow layer made of hard carbide, nitride, or carbonitride is provided on the surface of a black ceramic chip mainly composed of alumina. Ceramic chip. 2. The ceramic chip for cutting according to claim 1, wherein the thin layer is made of TiN. 3. The ceramic chip for cutting according to claim 1 or 2, wherein the thin layer has a thickness of 3 to 20 μm.