JPS6365065A - Coated material - Google Patents

Abstract

PURPOSE:To form a coating film which is excellent in both hardness and toughness by forming a hard film by reaction of Si, Ge, B, N, etc., at specific ratios on the surface of a tool material by a plasma CVD method, etc. CONSTITUTION:The inside of a vacuum vessel 8 disposed with an electrode/ holder 12 imposed thereon with a base material 4 consisting of a stock such as sintered hard alloy material, tool steel and other tool materials, silicone or plastic and a counter electrode 6 to face each other is once evacuated to about 10<-7>Torr by a vacuum pump; thereafter, gaseous mixtures G composed of B2H6, NH3, H2 and SiH4 as raw material reactive gases from cylinders 22a-22d are introduced to about 0.01-10Torr into the vessel. A high-frequency voltage is impressed to the two electrodes 12 and 16 by a high-frequency power supply 18 to generate plasma 24. The hard film 6 which consists of the silicon nitride contg. <=50% Si in atomic concn. and the boron nitride and is excellent in both the hardness and toughness is formed on the surface of the base material 4. Ge may be used in place of Si in this case.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the surface of a base material such as a tool material.

This invention relates to a coating material that has a highly hard film formed on its surface.

[Conventional technology]

Conventionally, boron nitride (B N) or silicon nitride (S
Efforts have been made to extend tool life by forming a highly hard film consisting of i 3 N m).

[Problem that the invention seeks to solve]

However, a film made of boron nitride exhibits high hardness but poor toughness, so when a coating material coated with the film is used, for example, in a tool, there is a drawback that the cutting edge tends to chip and fall off. On the other hand, a film made of silicon nitride has good toughness but is inferior in hardness compared to boron nitride, so the use of this film has the drawback of being inferior in terms of lifespan and the like.

Therefore, the main object of the present invention is to provide a coating material having a film formed on its surface that can achieve both high hardness and good toughness.

[Means for solving problems]

The coating material of the present invention is characterized in that a film containing silicon or germanium in addition to boron and nitrogen is formed on the surface of the base material.

[Effect]

The hardness and toughness of the film can be controlled by adjusting the atomic concentration of silicon or germanium contained therein, and both can be achieved simultaneously.

〔Example〕

FIG. 1 is a sectional view schematically showing a coating material according to an embodiment of the present invention. The coating material 2 of this embodiment has a film 6 made of boron, silicon, and nitrogen on the surface of the base material 4.
is formed.

Various materials can be used as the base material 4, such as a cemented carbide association material, a tool material such as a tool net, a silicon substrate, a plastic, and the like. Also, various shapes can be explored.

The film 6 can be formed by, for example, a thermal CVD method, a plasma CVD method, a photo CVD method, an ion blating method, or the like.

In the film 6, its hardness and toughness can be controlled by controlling the atomic concentration of silicon contained therein, and both can be achieved.

As an example of an experiment, using an apparatus as shown in Fig. 2, Si<
A film 6 as described above was formed on a base material 4 made of a carbide chip or the like.

FIG. 2 is a schematic diagram showing an example of a plasma CVD apparatus, in which a vacuum chamber 8 is evacuated by a vacuum pump 10.
A holder 12 that also serves as an electrode and an electrode 16 are opposed to each other, and a high frequency power source 18 is connected between them. Inside the vacuum container 8,
As the reaction gas G, a mixture of gases as described below from gas sources 22a to 22d and adjusted by flow rate regulators 20a to 20d is introduced. The base material 4 is mounted on the holder 12 and heated by the heater 14.

The type of gas used and its flow rate were diborane (BzH&
) is 0 to 50 ml/min, ammonia (NH3)
+Nitrogen (N2) is 0 to 300 II11/min, and monosilane (SiHa) is 0 to 50 ml/ll1n.

During processing, after evacuating the inside of the vacuum container 8 to a level of 10-' Torr, the reaction gas G is introduced to maintain the pressure inside the vacuum container 8 at around 0.01 to 10 Torr, and a high frequency wave is applied between the holder 12 and the electrode 16. High frequency power was supplied from the power source 18 to generate plasma 24, thereby forming the film 6 as described above on the surface of the base material 4. In that case, the temperature of the base material 4 was set to about room temperature to 700°C, and the high frequency power supplied between the holder 12 and the electrode 16 was set to about 0 to 150 W.

An example of the characteristics of the film 6 obtained as described above is shown in FIG. The horizontal axis in the figure is the atomic concentration of silicon in the film 6 [%]
, the vertical axis shows the hardness and toughness values. The hardness was Vickers hardness, and was measured using a micro Pinkers hardness meter at an indenter load of 10 gf. The toughness value was defined as the length of the crank extending from the indentation mark [μ]. Further, in the above case, the atomic concentration of nitrogen was kept almost constant, and the atomic concentration of boron was made almost inversely proportional to that of silicon.

As can be seen from FIG. 3, the hardness and toughness of the film 6 could be controlled by changing the silicon atomic concentration. For example, when the atomic concentration of silicon is brought close to O, the hardness becomes very high, but the toughness becomes somewhat inferior. This is because the film 6 is made of boron nitride (B N
) This is thought to be because it approaches the membrane. On the other hand, as the atomic concentration of silicon increases, the toughness reaches a maximum at a certain stage and becomes saturated, and the hardness gradually decreases. this is,
This is considered to be because the film 6 approaches a silicon nitride (SiNx) film as the atomic concentration of silicon approaches 50%.

In any case, the atomic concentration of silicon in the film 6 is 50%.
In the case of less than (not including 0), a film 6 with good toughness while maintaining high hardness was obtained. In particular, when the silicon atomic concentration was about 1 to 5%, a film 6 with very good hardness and toughness was obtained.

Therefore, the coating material 2 on which the film 6 as described above is formed can be used in various fields by taking advantage of the film 6's high hardness and good toughness. For example, when it is used in tools, it is possible to extend the tool life while preventing chipping and falling off of the cutting edge, which occurs with conventional tools coated with a boron nitride film. In addition, when the coating material 2 is used as a support for an X-ray absorber layer in an X-ray exposure mask and apertures are formed in the base material 4, the film 6 must have both high hardness and good toughness. Therefore, cracking and warping of the film 6 can be prevented. Furthermore, when used in cylinders, bearings, shafts, etc., it is possible to improve their wear resistance and heat resistance. Furthermore, when used in reaction and hot gas piping and their joints, it is possible to improve their heat resistance and chemical resistance.

Incidentally, the film 6 may contain germanium instead of silicon (in that case, according to the same experiment as above,
Compared to the case of silicon, although the hardness was slightly lower, a similar tendency was observed, and the same tendency was observed for toughness.

〔Effect of the invention〕

As described above, in the coating material of the present invention, the hardness and toughness of the film can be controlled by the atomic concentration of silicon or germanium contained in the surface film.
Moreover, it is possible to achieve both high hardness and good toughness.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a coating material according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of a plasma CVD apparatus. FIG. 3 is a diagram showing an example of film characteristics obtained through experiments. 2... Coating material according to the present invention, 4... Base material, 6.
··film.

Claims (2)

[Claims] (1) A coating material characterized in that a film containing silicon or germanium in addition to boron and nitrogen is formed on the surface of a base material. (2) The coating material according to claim 1, wherein the atomic concentration of silicon or germanium in the film is less than 50% (not including 0).