JPS6270040A - Multilayer film and forming method thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer coating that modifies the surface of a metal substrate such as a mechanical part to improve its performance, and a method for forming the same.

[Conventional technology]

Conventionally, various compounds with excellent functions such as wear resistance, corrosion resistance, heat resistance, and lubricity are directly coated on the surface of metal base materials such as various mechanical parts by vapor deposition methods such as one-ion blating, and products are produced. Performance is expected to be improved.

[Problem that the invention seeks to solve]

However, the conventional method of directly coating the surface of mechanical parts with metallic properties with a compound with non-metallic properties has poor affinity due to the difference in the properties of the two, and unlike ion blating, it has poor adhesion. Even in the coating method that is said to be used, the coating film of the compound sometimes peels off in a short period of time immediately after coating or during use as a product.

In addition to the above-mentioned differences in physical properties, there are the following causes of peeling. That is, in the metal material that is the base material, mulch, 81. O
Peeling frequently occurs in alloy steels, stainless steels, and the like that contain relatively large amounts of alloy components with strong oxidizing properties (in other words, strong affinity with oxygen) such as r and Mn. This is said to be because the above alloy components are oxidized and exhibit a chemically inert surface.

Therefore, etching is performed using ion bombardment to activate this inert surface, but it is difficult to determine etching conditions that suit the shape and surface roughness of the base material.
It is impossible to completely activate the entire surface of the base material, and poor adhesion of the coating frequently occurs.

[Means for solving problems]

The present invention has been made in order to improve the reduction in product yield or product life due to poor adhesion of conventional coatings.

Briefly speaking, the present invention involves ionizing the vapor of a metal that has a strong affinity for oxygen, depositing it on the surface of a base material while adjusting the application of a bias voltage, and forming a non-metallic component that forms a compound with the metal along the way. Supplying gas while gradually increasing the amount, eventually forming a surface layer in which a compound of the metal and the non-metallic component occupies the majority, and then coating this surface with a new compound having the non-metallic gas component. The present invention provides a multilayer coating and a method for forming the same.

That is, the present invention provides a first coating layer provided on the surface of a metal base material and made of a first metal that has a strong affinity for oxygen; a second coating layer made of a compound of and a non-metal component; and a fifth coating layer provided on the surface of the second coating layer and made of a compound of the non-metal component and a second metal. a first coating layer formed on the surface of the metal base material and made of a first metal having a strong affinity for oxygen; and a first coating layer provided on the surface of the first coating layer. a second coating layer formed of a compound of the first metal and a non-metallic component; and a second coating layer provided on the surface of the second coating layer and made of a compound of the non-metallic component and a second metal. The metal component of each film constituting the multilayer film comprising the third film layer is evaporated and ionized in a vacuum, and is deposited while adjusting the conditions for applying a bias voltage to the metal base material. This is a method for forming a multilayer coating.

[Effect]

The structure of the coating film of the present invention will be explained with reference to FIG. 1 using a cross-sectional model of the film.

Reference numeral 1 indicates a metal base material to be coated, and on the surface of this metal base material 1, a thin film 2 of oxides or hydroxides formed spontaneously by the constituent metals of the metal base material 1 is firmly adhered. Bonded with strength.

3 is Or-?, which has a strong affinity with oxygen. This is a first metal coating that is deposited on the surface of the thin film 20 by ionizing Ti vapor and adjusting the application of a bias voltage. 4 is the coating 5
The coating is made of a compound of the first metal. This coating 4
The first metal of the coating 3 is continuously vapor-deposited, and a reactive gas, which is a non-metal component that reacts with this metal to form a compound, is gradually supplied in an increasing amount, and finally this The film is formed so that most of the film is composed of compounds and there is a concentration gradient of the compounds. For example, in the case of a nitride, if the vapor deposition of the first metal is continued and a gas such as N is supplied while gradually increasing the amount, the first metal nitride such as Or+Ti described above will form a film. Eventually, the surface layer of the film 4 becomes a film with a high concentration of nitrides. Reference numeral 5 denotes a new compound film formed by the reaction gas (N in this case) supplied during the vapor deposition of the first metal compound film 4 and the second metal. For example, if Sl is evaporated without supplying bird gas, B1 nitride is deposited. In this way, coatings 4 and 5 are coatings in which the non-metallic components constituting the metal compound are the same and only the metallic component is different.

The present invention is a multilayer film having the above-mentioned film structure, and each of the constituent films has the following effects.

That is, on the surface of the base material 1, a part of the component metal of the base material 1 is oxidized and spontaneously forms a film 2 such as an oxide film and a hydroxide film, and this film Since the material 2 is extremely thin and has a concentration gradient similar to a diffusion state due to the component metal being a constituent component, it adheres to the base material 1 with strong adhesion strength.

The coating 5 is a coating of a first metal that has a strong affinity for oxygen, and since the first metal of this coating 3 has a strong oxidizing property, the coating 2
As soon as it combines with the oxygen constituting the film, it adheres to the coating 2 with strong adhesion strength.

Coating 4 is formed by gradually increasing the amount of a reactive gas, which is a non-metallic component, such as a non-metallic component, starting from the time when the first metal, which is the same as coating 3, is being vapor-deposited. The non-metal component and the first metal having a strong affinity for oxygen form a compound film by supplying the first metal having a strong affinity for oxygen until the amount of evaporation and the first metal are stoichiometrically established. . Therefore, the coating 4 has a concentration gradient in which the concentration of the compound gradually increases from the coating 3 side toward the coating 5 side. Therefore, since the constituent metals between the coatings 4 and 3 are the same and there is a concentration gradient, the adhesion strength is extremely high.

The coating 5 is a compound that has the same non-metal component as the coating 4 but has a different metal component; in this case, the non-metal component is the same as that of the coating 5 and the coating 4.
It enhances the bonding ability with the material and exhibits strong adhesion.

As described above, since the multilayer coating of the present invention has the same metal component or non-metallic component in each of the adjacent coatings, strong adhesion strength can be obtained.

Next, a method for forming a multilayer coating according to the present invention will be described. The boundaries between the respective films constituting the multilayer film have the above-mentioned metal components or non-metal components in common and are reactive. Therefore, as conditions to meet this requirement, it is necessary to increase the reactivity and bonding properties by ionizing the metal vapor forming each film and applying a bias voltage. Regarding the bias voltage, in the case of the present invention, it is practical even when no bias voltage is applied, but when a moderate voltage is applied, fine undulations (on the order of 10''1 to 10-3μ grooves) occur on the surface of the coating, and the specific surface area decreases. Due to the increase in the number of deposition nuclei, which is the root of the adhesion force,
Even stronger adhesion strength can be obtained. In particular, it is effective to apply a bias voltage from coating 3 to coating 4. The bias voltage has different characteristics depending on the coating method and device, so the voltage range cannot be determined. In short, the voltage should be such that fine undulations are formed on the film.

〔Example〕

In order to confirm the adhesion effect of the coating of the present invention, stainless steel (13
Various films were formed on a Cr-based substrate using an ion blating apparatus equipped with a hollow cathode discharge electron gun e under the conditions shown in Table 1.

Example 1 is a multilayer structure in which a bias voltage is applied, a coating 3 is made of Or, a coating 4 of OrN having a concentration gradient in the thickness direction is deposited on the surface of the coating 30, and a coating 5 of 71M is deposited on the surface of the coating 40. It is a membrane.

In Example 2, coatings 3 and 4 are the same as in Example 1, but coating 5
is a multilayer coating with 8111 deposited.

Example 3 is a multilayer coating in which a bias voltage is applied to set the coating 3 to Or, a coating 4 of Ore having a concentration gradient in the thickness direction is deposited on the surface of the coating 30, and 810 is deposited on the surface of the coating 40.

Example 4 is a multilayer coating in which a bias voltage is applied, the coating 3 is set to T1, a TiH coating 4 having a concentration gradient in the thickness direction is deposited on the surface of the coating 30, and a layer K 84N is further deposited on the surface of the coating 4. be.

In Example 5, a bias voltage is applied, the coating 3 is set to 'rl, and the surface of the coating 3 has a concentration gradient in the thickness direction.
This is a multilayer coating in which a coating 4 of 4 is vapor-deposited, and 810 is further vapor-deposited on the surface of this coating 4.

In Example 6, no bias voltage was applied, the film 3 was made of Or, and the surface of this film 30 was made of Or having a concentration gradient in the thickness direction.
A film 4 of H is deposited, and a bias voltage is applied to T.
iM was deposited.

In Example 7, coating 3 and coating 4 were the same as in Example 6, but
This is a multilayer film in which 81N was deposited on the outermost layer by applying a bias voltage.

Comparative Example 1 is a multilayer film in which the coating 4 is not present, and 'riN to which a bias voltage is applied is deposited on the surface of the Or coating 30 to which no bias bias pressure is applied.

Comparative Example 2 is a conventional method, and is a film in which TiN is deposited directly on the surface of the base material by applying a bias voltage.

In order to evaluate the adhesion of the various films mentioned above, a comparative adhesion test was conducted using an electrostrictive ultrasonic vibration tester under constant test conditions. The results are shown in FIG. Although Examples 4, 5, and 7 of the present invention are not described, they are similar to other described examples of the present invention, and if described, they would be confusing, so they were excluded.

According to the results, there was no peeling of the multilayer film of each example of the present invention, and weight loss due to erosion of the film 5 due to erosion was confirmed, and there was no peeling from the boundary between the films constituting the multilayer film. Adhesion was good. However, in Comparative Examples 1 and 2, the coating peeled off in a short time, and then the surface of the Or layer and the surface of the base material were eroded by erosion, resulting in weight loss, and poor adhesion was confirmed. That is, Comparative Example 1 is T
The iN coating was peeled off and the Or layer was eroded by erosion. In Comparative Example 2, the TiN coating was peeled off and the base material was eroded by erosion.

[Effects of the Invention] According to the above evaluation results, in Comparative Example 1, the TiH coating 5 on the surface layer peeled off because the compound layer of the coating 4 was not present. Therefore, the effectiveness of the coating 4 of the present invention is recognized. Furthermore, in the case of Example 2, the coating 5 was in strong contact with the base material, and the effect of the coating 3 of the present invention (having a strong affinity for oxygen) was also recognized. Comparative Example 2 is a conventional grading method, and it is recognized that it lacks compatibility with stainless steel surfaces. Therefore, the present invention was effective in terms of adhesion. Among the present invention, Examples 1 to 5 in which a bias voltage was applied to coatings 3 and 4 had slightly better results than Examples 6 and 7 in which no bias voltage was applied, and the effect of applying the bias voltage was recognized.

The effects of bias voltage application are shown in FIGS. 3 and 4.

FIG. 3 shows the coating a (O
4 is a microscopic photograph of the surface of coating 4 (Orb) of Example 6 in which the bias voltage of FIG. 4 is not applied, both at a magnification of 5000 times. The one in Figure 5 has countless fine undulations on its surface.
These undulations improve the adhesion of the coating 5.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the cross-sectional structure of the multilayer coating of the present invention, and FIG. 2 is a graph showing the evaluation results of the coating of the example of the present invention.
FIGS. 3 and 4 are micrographs (magnification: 000x) showing the state of the surface layer of the coating with and without applying a bias voltage. Sub-agent 1) Clearance agent Ryo Hagiwara - Sub-agent Atsuo Anzai 11B + 111141 To Taka - ≧ Figure 3 Figure 71 Procedural amendment form (method) % formula % 1. Display of case Showa 60 pr 'f,' + Application No. 210323 2,
';a'JI'5 Masters 81' Multilayer coating and its formation method 3, person making correction>1;Relationship with 't,'? Patent applicant 1iIili
2-5-1-4 Marunouchi, Chiyoda-ku, Tokyo, posterity
Rinto ICpli Toranomon-chome, Minato-ku, Tokyo 16-2 No. 2 Corrected to ``Metallic structure in the column ``Brief explanation of drawings'' of the specification subject to amendment.''

Claims (2)

[Claims] (1) A first coating layer provided on the surface of a metal base material and made of a first metal that has a strong affinity for oxygen, and a first coating layer provided on the surface of the first coating layer and made of a first metal and a non-metal. a second coating layer made of a compound of the non-metallic component and a second metal, and a third coating layer provided on the surface of the second coating layer and made of a compound of the non-metallic component and a second metal. A multilayer film characterized by: (2) A first coating layer provided on the surface of the metal base material and made of a first metal that has a strong affinity for oxygen, and a first metal and non-metal component provided on the surface of the first coating layer. and a third coating layer provided on the surface of the second coating layer and made of a compound of the non-metallic component and a second metal. A method for forming a multilayer film, which comprises evaporating and ionizing component metals of each film constituting the multilayer film in a vacuum, and depositing them while adjusting conditions for applying a bias voltage to a metal base material.