JPS6318051A - Cbn coating method - Google Patents

Abstract

PURPOSE:To carry out CBN coating which required extremely high temp. and pressure at low temp. and pressure by coating a base material with an amorphous or microcrystalline BN film and treating the film at high temp. and pressure. CONSTITUTION:The surface of a base material such as a high-speed steel is coated with an amorphous or microcrystalline BN film of about 1mu thickness by reactive high frequency ion plating or high frequency sputtering. The BN film is treated at high temp. and pressure with a high isostatic pressure device to cause a solid phase reaction and CBN is produced by the reaction. Thus, CBN coating is carried out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to OBN coating, which is a super hard coating applied to cutting tools and cutlery such as paper processing machines, and also as an insulating film in the semiconductor field. Concerning possible 0BII coatings.

[Conventional technology]

0BN (cubic boron nitride) is an artificially synthesized compound that does not exist in nature.
-BN) ft was obtained by processing at ultra-high temperature and high pressure (temperature 1600 or more, pressure 40 Kbar or more).

However, conventional methods can only produce powder or granules, and when used as tools such as grinding wheels, resin or metal is used as a binder by sintering, or CBN particles are coated with a metal plating film. A method has been adopted in which electrodeposited tool binders are dispersed in the material.

However, with these methods, (1) OBN is a particle, so its dimensional accuracy is poor (minimum +3000: average particle size 5 to 6 μm) and cannot be used for precision processing; (2) resin or metal is used as a binder. Adhesion force (OBN retention force)
and (3) low productivity and high cost due to ultra-high temperature and high pressure treatment.

For this reason, CBN? If you can coat it,
In order to solve the above problems, OBN coatings using various PVD (physical vapor deposition) methods are being actively researched, but no success has been achieved so far.

[Problem that the invention seeks to solve]

Coating is a new method of using CBN to replace the conventional use of particulate OBN processed at high temperatures and high pressures, and it is especially useful for ultra-precision machining tools on the submicron order.
It is also said that OBN coating is essential. PVD methods, especially ion blasting and sputtering methods, are being studied for this CBN coating, but a complete OEM coating has not yet been completed. That is, these methods attempt to precipitate OBN by gas-phase reaction using B or macrogonal BM as a raw material, but as already mentioned, OBN is synthesized by ultra-high temperature and high pressure treatment. This is thought to be because these methods involve low-temperature processing and are synthesized in a solid phase. Furthermore, in such a vapor phase coating method, the film obtained is basically a film in a non-equilibrium state, which is inherently amorphous and easily damaged, which is also considered to be the reason for the difficulty in synthesizing CBN.

The present invention is a CB that eliminates the drawbacks of the above conventional method.
The present invention seeks to provide a method for forming an N coating.

[Means for solving problems]

In the present invention, amorphous or microcrystalline BM is formed on the base material in advance.
This is an OBN coating method characterized by coating a film and then treating the film at high temperature and high pressure to form OBN'i.

Conventional methods often result in an amorphous BN film, but the present invention utilizes the non-equilibrium energy of this amorphous film to synthesize OBN'i through a solid phase reaction. That is, an amorphous film is created by a vapor phase method, and then this film is treated at high temperature and high pressure to cause a solid phase reaction and form an OB.
It synthesizes N. Also, IPe during this BE.

Addition of catalyst gold such as Ni or Or is more advantageous because the solid phase reaction conditions are relaxed.

[Effect]

Since there is a large nonequilibrium energy in an amorphous film,
Compared to normal synthesis methods, it can be processed at lower temperatures and pressures.

Furthermore, according to the method of the present invention, OBN coating, which was previously impossible, becomes possible.

[Experimental Example 1] A high-speed steel (5KH55) measuring 30 m x 30 m x 5 m thick was used as a substrate, and BE was coated on the surface by reactive high frequency ion blasting and high frequency sputtering. The film thickness was 3 μm, and the coating conditions were as follows.

1) Reactive high frequency ion brating electron gun output:
10K V
High frequency power: 300W Atmosphere gas: N! (20 mTOrr) Substrate temperature: As a result of performing X-ray diffraction analysis of each BE film obtained by the method above room temperature, no diffraction peak was observed from any of the films.
It was amorphous.

[Experiment 912] In the high-frequency sputtering method described in Experimental Example 1, a composite target layer (BN+Ni or BN+Fe)′ft with an area of N1 or Fe′ft1.5 (BN+Ni or BN+Fe)′ft was used as the target.
B under the same conditions as the high frequency sputtering of Experimental Example 1.
N + Ni and BN + Fe composite films were prepared, and their crystal structures were examined by X-ray diffraction analysis. As a result, all films were found to be amorphous.

〔Example〕

Four types of films 1nx created in Experimental Example 1 and Experimental Example 2
After high-temperature and high-pressure treatment (p (high-temperature isostatic pressing apparatus) K), X-ray diffraction analysis was performed to investigate the structure of the film. Table 1 shows the H engineering P conditions and the X-ray diffraction analysis results.

As a result, it became clear that all the films were OBN. It has also been revealed that OBN synthesis can be performed at lower temperatures and pressures by adding catalytic metals.

Table I HIP conditions and X-ray diffraction analysis results Note 1 h
BN: Hexagonal BN wBl+: Wurtzite BM C! BN: Cubic BM Note 2 The holding time is 15 minutes in each case [Effects of the Invention] As described above in detail in the Examples, according to the method of the present invention,
OBN, which could previously only be synthesized at ultra-high temperatures and high pressures, can now be synthesized at low temperatures and low pressures. What's more, OBN, which could previously only be synthesized in granular form, can now be used in the form of a coating, which is industrially significant. It is.

Sub-agent: 1) Akira Sub-agent Ryo Hagi Hara - Sub-agent Atsuo Yasunishi

Claims (1)

[Claims] A CBN coating method characterized by coating a base material with an amorphous or microcrystalline BN film in advance and then subjecting the film to high temperature and high pressure treatment to form CBN.