WO2011105392A1

WO2011105392A1 - Multilayer film laminate using aluminum or aluminum alloy as substrate, and lamination method therefor

Info

Publication number: WO2011105392A1
Application number: PCT/JP2011/053902
Authority: WO
Inventors: 晃一稲葉; 邦彦渋澤; 佐藤　剛
Original assignee: 太陽化学工業株式会社
Priority date: 2010-02-23
Filing date: 2011-02-23
Publication date: 2011-09-01
Also published as: JP2013091811A; TW201142083A

Abstract

Disclosed is a multilayer film lamination method, by which an amorphous carbon film can be formed at the top of an aluminum or aluminum alloy base with high adhesion and corrosion of a layer below the amorphous carbon film can be suppressed. Specifically, a multilayer film structure with an adequate gradient of hardness can be obtained by forming a zinc substituted film on the surface of a base that is composed of aluminum or an aluminum alloy, forming a nickel plating layer by an electroless plating method using the zinc substituted film as a primer layer, then forming a hard chromium plating layer, and additionally forming, as the uppermost layer, an amorphous carbon film preferably at a temperature of 350˚C or less and preferably by a low-temperature plasma CVD method.

Description

Multilayer film laminate using aluminum or aluminum alloy as substrate and method for laminating the same

The present invention relates to a multilayer film stack using aluminum or an aluminum alloy as a substrate and a method for laminating the multilayer film laminate, and in particular, a multilayer film laminate including an amorphous carbon film or an amorphous carbon film containing silicon as the uppermost layer, and the multilayer film laminate. The present invention relates to a lamination method.

As the surface treatment of machine parts and jigs that are formed by cutting or the like on aluminum or aluminum alloy, those with an anodized film (anodized or hard anodized) on the surface are widely used. In addition, the treatment of impregnating fine holes generated on the surface by this anodic oxide film treatment with a fluorine resin or the like is also widespread. The processed products obtained by these treatments have room for improvement in terms of wear resistance, anti-adhesion properties of soft metals, electrical conductivity corresponding to static electricity, and the like.

As a surface treatment method that replaces this anodizing treatment, a surface treatment using an amorphous carbon film or an amorphous carbon film containing silicon or the like is known. The amorphous carbon film is hard, has excellent wear resistance, has a small coefficient of friction, has an anti-adhesion property for soft metals, and has acid resistance and alkali resistance. Therefore, by coating the surface of a substrate such as a machine part with this amorphous carbon film, the properties of the substrate surface can be improved. For example, a machine part whose surface is coated with an amorphous carbon film can be cleaned with an acidic or alkaline detergent.

There is a disclosed example of a method for forming an amorphous carbon film on the surface of an aluminum alloy substrate. For example, Japanese Patent Application Laid-Open No. 2002-47556 (Patent Document 1) discloses that a base material is subjected to a solution treatment, and an aging treatment and an amorphous carbon film coating treatment are performed on the solution-treated base material. It is disclosed to do at the same time. However, since the base material of aluminum or aluminum alloy is soft, even if a hard amorphous carbon film is thinly formed on the surface, the difference in hardness between the base material and the amorphous carbon film is difficult. Therefore, the adhesion is inferior and the amorphous carbon film is easily peeled off from the substrate. In addition, when a load is applied, there is a problem that the amorphous carbon film cannot follow the deformation of the substrate and breakage easily occurs.

In order to solve these problems, Japanese Patent Application Laid-Open No. 2004-346353 (Patent Document 2) discloses that an electroless Ni—P plating layer or an ion nitride layer is used as an intermediate layer on the surface of aluminum or an aluminum alloy. It is disclosed that a diffusion layer and an electroless Ni—P plating layer are formed, and then an aging treatment of the substrate and a heat treatment of the electroless plating film are performed simultaneously when forming the amorphous carbon film.

JP 2002-47556 A JP 2004-346353 A

In the method of Patent Document 2, the heat treatment of the electroless Ni—P plating layer causes the plating layer to crystallize and improve the hardness, so that the hardness distribution is graded stepwise and the load resistance is improved. The adhesion is also improved. However, it was found that the difference between the hardness of the Ni—P plating layer and the hardness of the amorphous carbon film is still large, and the adhesion is not sufficient.

Therefore, according to various embodiments of the present invention, a multilayer film laminating method capable of forming an amorphous carbon film on the uppermost part of an aluminum or aluminum alloy base material with good adhesion is provided. In addition, according to various embodiments of the present invention, a multilayer film structure in which an amorphous carbon film is provided on the uppermost part of an aluminum or aluminum alloy base material with good adhesion is provided.

The inventor performs electroless nickel plating on a base material made of aluminum or aluminum alloy in which a zinc layer is deposited by substitution reaction with aluminum or aluminum alloy, and further, hard chrome is formed on the electroless nickel plating layer. By performing plating and further forming an amorphous carbon film or an amorphous carbon film containing silicon thereon, the gradient of hardness between layers and the gradient of the thermal linear expansion coefficient are gentle. It was found that a multilayer film structure capable of suppressing the occurrence of corrosion in the lower layer of the amorphous carbon film can be obtained even when pinholes occur in the film.

The multilayer film structure in one embodiment of the present invention obtained based on such knowledge is obtained by providing a zinc-substituted layer, an electroless nickel plating layer, a hard chromium plating layer, and an amorphous material on a base material made of aluminum or an aluminum alloy. A carbonaceous film or a silicon-containing amorphous carbon film is formed in this order.

According to various embodiments of the present invention, a multilayer film laminating method capable of forming an amorphous carbon film on the uppermost part of an aluminum or aluminum alloy base material with good adhesion is provided. Further, various embodiments of the present invention provide a multilayer film structure in which an amorphous carbon film is provided with good adhesion on the uppermost part of an aluminum or aluminum alloy-based substrate.

The figure which shows the relationship between heat processing temperature and film hardness about each of an electroless Ni-P plating layer, an electroless Ni-B plating layer, and a hard chromium plating layer. The graph which shows the change of the friction coefficient according to the frequency | count of wear of the test sample 7. FIG. A surface photograph of the test sample 7 taken after 100 times of wear. The graph which shows the change of the friction coefficient according to the frequency | count of wear of the test sample 8. FIG. Surface photograph of test sample 8 taken after 8 wear cycles. The graph which shows the change of the friction coefficient according to the frequency | count of wear of the test sample 9. FIG. A surface photograph of test sample 9 taken after 100 wears.

As will be described below, according to various embodiments of the present invention, an amorphous carbon film that is hard and has excellent wear resistance on the top of a soft class of aluminum or aluminum alloy base material among metals. Are provided with good adhesion, and a multilayer film structure capable of improving the wear resistance and slidability of aluminum or an aluminum alloy and a method for producing the same are provided.

In the multilayer film laminating method according to one embodiment of the present invention, a zinc layer is deposited on the surface of aluminum or aluminum alloy by a substitution reaction with aluminum or aluminum alloy, and then electroless nickel plating is performed on the zinc substitution layer. Then, hard chrome plating is performed, and further, an amorphous carbon film is formed thereon to form a multilayer film structure having an inclined structure with an appropriate hardness. That is, in the formed amorphous carbon film, the hardness gradually increases from the base material side of the film toward the uppermost amorphous carbon film side.

According to the multilayer film laminating method according to one embodiment of the present invention, since the difference in hardness between the layers is smaller than that described in, for example, Patent Document 2, the amorphous alloy is formed on the uppermost part of the aluminum alloy base material. A carbon film can be formed with good adhesion.

In addition, both electroless nickel plating and hard chrome plating can be mass-produced in the air atmosphere, so compared to the case where solid chrome is used as a target, such as sputtering film deposition or vapor deposition film formation. The method according to an embodiment of the present invention can be realized relatively inexpensively. In addition, the electroless nickel plating and the hard chrome plating according to an embodiment of the present invention can be formed at a low temperature of 0.1 to 40 μm, respectively. In one embodiment of the present invention, the amorphous carbon film or the silicon-containing amorphous carbon film can be formed by a plasma CVD method.

The multilayer film structure according to one embodiment of the present invention includes, for example, a primary layer on an aluminum or aluminum alloy-based base material (in this specification, sometimes simply referred to as an aluminum base material). The secondary layer, the tertiary layer, and the uppermost layer are laminated in this order. In one embodiment of the present invention, the primary layer is a zinc-substituted film having good adhesion to aluminum or an aluminum alloy, and the secondary layer is an electroless nickel (Ni—P or Ni—B) plating layer. The third layer is a hard chrome plating layer, and the uppermost layer is an amorphous carbon film or an amorphous carbon film containing silicon (in this specification, simply referred to as “amorphous carbon film”). Yes.)

When the hardness of the aluminum substrate is approximately Hv100 and the hardness of the electroless nickel is amorphous or when the P content in the Ni—P plating film is precipitated as fine crystals with a low phosphorus type of approximately 1 to 4 wt% The hardness of Hv is approximately 500 to 700, the hardness of hard chrome plating is approximately Hv 1000, and the hardness of the amorphous carbon film formed by the plasma CVD apparatus is approximately Hv 1300 to 2000. In this way, by forming the hard chrome plating layer under the amorphous carbon film, it is possible to realize a multilayer structure in which the hardness increases in a gradient from the primary layer to the uppermost layer. Thereby, an amorphous carbon film can be formed with good adhesion on the uppermost layer of the aluminum substrate. The zinc-substituted film is very thin compared to other films. For example, the influence of a zinc-substituted film of about 200 nm on the adhesion of an amorphous carbon film can be ignored. In various embodiments of the present invention, when the secondary layer is formed on the primary layer, the secondary layer is formed directly on the primary layer (without any other film). Alternatively, as long as the adhesion of the amorphous carbon film is not substantially deteriorated, a secondary layer may be provided on the primary layer via another film that is not specified in this specification.

For example, between the primary layer and the secondary layer, for the purpose of improving adhesion and smoothness, a strike copper plating film having a thickness of about 10 to 300 nm, a copper film of the same thickness by a sputtering apparatus or a vapor deposition apparatus is used. A film, a strike electrolytic Ni plating film having a thickness of about 10 nm to 300 nm, a Ni film having a thickness of 10 nm to 300 nm by a sputtering apparatus or a vapor deposition apparatus, and the like. An electrolytic Ni plating film, a Ni film formed by a sputtering apparatus or a vapor deposition apparatus has a hardness of about Hv 200 to 500, so it may be harder than the secondary layer, but it is very thin compared to other films, so There is no substantial effect on the adhesion of the crystalline carbon film. Similarly, when the tertiary layer is formed on the secondary layer, the tertiary layer may be formed directly on the secondary layer (without any other film), or it may be amorphous. As long as the adhesion of the carbonaceous film is not substantially deteriorated, a tertiary layer may be provided on the secondary layer via another film. Further, when the uppermost layer is formed on the tertiary layer, the uppermost layer may be formed directly on the tertiary layer (without passing through another film), or the amorphous carbon film may be adhered. The uppermost layer may be provided on the tertiary layer through another film as long as the property is not substantially deteriorated.

The multilayer film structure thus formed also has a gradual change in the coefficient of thermal expansion from the base material to the uppermost layer. That is, the thermal linear expansion coefficient of each layer is approximately 23 × 10 ⁻⁶ / ° C. in the base material aluminum, and approximately 13 × 10 ⁻⁶ / ° C. in the secondary electroless nickel layer, and the hard chromium plating of the tertiary layer. The layer is approximately 7 × 10 ⁻⁶ / ° C., and the uppermost amorphous carbon film is approximately 2 × 10 ⁻⁶ / ° C. Thus, the thermal expansion coefficient decreases stepwise from the aluminum base toward the uppermost layer. Thereby, even if it is a case where a multilayer film structure is a case where it is manufactured or used in an environment with a large temperature change, the adhesiveness between each layer can be improved. The coefficient of thermal expansion of the zinc-substituted film is 26 × 10 ⁻⁶ / ° C., which is higher than that of the aluminum base material. However, the zinc-substituted film is much thinner than other layers, for example, about 50 to 200 nm. Therefore, the influence on the adhesion between layers can be ignored.

In one embodiment of the present invention, the adhesion between the zinc-substituted layer and the aluminum or aluminum alloy base material can be improved by roughening the surface of the aluminum or aluminum alloy base material by sandblasting or the like.
When an amorphous carbon film is directly formed on top of the electroless nickel plating, the carbon particles necessary for bonding the amorphous carbon film do not easily react with Ni to form carbides. And the bond between the amorphous carbon film is weakened. Therefore, in one embodiment of the present invention, a hard chrome plating layer is interposed between the electroless nickel plating layer and the amorphous carbon film. The amorphous carbon film is formed with good adhesion to the electroless nickel plating layer and its lower layer through this hard chrome plating layer.

Hereinafter, a multilayer stacking method according to an embodiment of the present invention will be described. First, a zinc replacement film as a primary layer is formed on the surface of a base material (aluminum base material) made of aluminum or an aluminum alloy. This zinc replacement film is performed as a base treatment for electroless nickel plating described later, and includes a degreasing process, an acidic etching process, a nitric acid dipping process, a first zinc replacement process, a zinc nitrate stripping process, A dizinc replacement step. In one example, the aluminum substrate is immersed in a weak alkaline solution for degreasing, then immersed in an acid solution such as sulfuric acid, etched, and then immersed in nitric acid, and then a strong alkali containing NaOH as a main component. A zinc substitution layer is deposited with a zinc substitution solution (primary substitution). Next, the aluminum substrate after the primary substitution is immersed in nitric acid to remove the smut, and further zinc substitution (secondary substitution) is performed with the same zinc substitution solution as before. The zinc substitution layer functions as a primer layer. In various embodiments of the present invention, the zinc-substituted layer can be formed by any known method.

In one embodiment of the present invention, it is preferable to form an anodized film on the aluminum base material in order to insulate the aluminum base material from the upper layer structure. The anodized film is made of, for example, anodized or hard anodized. A zinc-substituted film can be formed on the aluminum substrate on which the anodized film is formed. When forming a zinc-substituted film on an aluminum substrate provided with an anodized film, the processing time for each step of forming the zinc-substituted film may be adjusted. Thereby, in the completed multilayer film structure, it is possible to electrically insulate between the aluminum base portion and the portion above the anodized film.

On the other hand, when a zinc-substituted film is formed on an aluminum substrate on which an anodized film is formed, the anodized film is dissolved in the above-described nitric acid dipping step and zinc replacement using a strong alkaline solution. It can also be removed from the material. For example, in the case of an alumite layer having a thickness of 10 μm, the steps of degreasing, etching, acid soaking, primary zinc substitution, acid soaking and secondary zinc substitution are performed in approximately 30 seconds to 1 minute 30 seconds, Can be dissolved. Thus, when it is not necessary to electrically insulate an aluminum base material and its upper layer, formation of a zinc substitution film and resurface treatment of aluminum or aluminum alloy in which an alumite layer was formed can be performed at a time. Therefore, the anodized aluminum or aluminum alloy base material can be reused.

Further, in the above-described zinc-substituted layer forming step, the aluminum base material is immersed in an alkaline and acidic solution, so that burrs and cutting powder generated during processing of the base material can be removed. Thus, by providing the zinc-substituted layer on the aluminum base material by the above-described method, the base treatment of electroless nickel plating and the removal of burrs and cutting powder can be performed at once. Leaving burrs or cutting powder generated during the processing of an aluminum base material may cause the upper amorphous carbon film to peel off. By forming a zinc-substituted layer on the base material, the adhesion between the layers can be reduced. In addition to the improvement, the effect of preventing peeling of the amorphous carbon film by removing burrs and cutting powder can be obtained.

Next, an electroless nickel plating layer as a secondary layer is formed on the above-described zinc replacement film. The electroless nickel plating layer is, for example, an electroless Ni—P plating layer or an electroless Ni—B plating layer. When forming an electroless Ni-P plating layer, the aluminum substrate with the zinc replacement film as the primary layer is immersed in a plating solution containing nickel ions and hypophosphite ions to replace the zinc. Electroless Ni—P plating is formed on the film. In electroless Ni—P plating, the plating proceeds continuously by the autocatalytic action of nickel. By this self-catalytic action, if there is a void through which the plating solution flows on the surface of the zinc-substituted film of the aluminum base, a plating film is uniformly formed on the surface of the zinc-substituted film. Further, since the thickness of the plating film is proportional to the plating time, the thickness of the plating film can be managed through the control of the plating time.

The electroless Ni—B plating layer is formed on the same principle as the electroless Ni—P plating layer using an electroless plating solution containing nickel ions and a boron-based agent such as amine borane which is a reducing agent. The In the case of electroless Ni—B plating, the decomposition and deterioration of the plating solution is severe and must be made disposable each time. Therefore, electroless Ni—P plating may be more suitable for actual production.

Furthermore, the electroless nickel plating layer of the present invention may have a two-layer structure in which an electroless Ni—B plating layer is formed on an electroless Ni—P plating layer. In this case, generally, the hardness of the electroless Ni—B plating layer is higher than the hardness of the electroless Ni—P plating layer and lower than the hardness of the hard chrome plating layer, so that an inclined structure having a more preferable hardness is formed. it can.
The thickness of the plating layer varies depending on the use and usage of the substrate, but is usually 0.1 to 40 μm, preferably 3 to 20 μm. However, the thickness of the plating layer is not limited to these.
As the secondary layer, an electrolytic nickel plating layer may be formed on the electroless nickel plating layer. The electrolytic nickel plating layer is formed by energizing the base material on which the primary layer and the secondary layer are formed in a solution containing Ni sulfamate, Ni chloride and boric acid and maintained at about 55 ° C. Is done. This solution may contain an additive (glossy material) as necessary. The electrolytic nickel plating layer can be formed to have a hardness of about Hv 500 equivalent to that of the electroless nickel plating layer by adjusting the amount of additive (glossy material) added.

Electrolytic nickel plating has less plating waste liquid and is more environmentally friendly than electroless nickel plating. Therefore, part of the thickness of electroless nickel plating can be supplemented by electrolytic nickel plating. Depending on the film forming conditions, the hardness of the electrolytic Ni—P plating layer may be slightly smaller than the hardness of the electroless Ni—P plating layer. However, since the difference in hardness is slight, even if the hardness is reversed, the adhesion of the amorphous carbon film is not substantially adversely affected.

In one embodiment of the present invention, when the amorphous carbon film is formed, for example, by using a low temperature plasma CVD method, a portion below the amorphous carbon film, that is, an aluminum base, a zinc substitution layer, An amorphous carbon film can be formed with the electroless nickel layer and the hard chromium plating layer kept at 300 ° C. or lower. In another embodiment of the present invention, when an amorphous carbon film is formed, for example, by using a low temperature plasma CVD method, the portion below the amorphous carbon film is kept at 260 ° C. or lower. An amorphous carbon film can be formed as it is.

An electroless nickel plating layer having a phosphorus (P) content of approximately 8 wt% or more (in this specification, nickel plating containing phosphorus may be referred to as “Ni—P plating”) is approximately 260 ° C. or less. Although it is an amorphous structure, when it exceeds 260 degreeC, the transition from this amorphous structure to a crystal structure will begin. In this crystal structure, since hard Ni ₃ P crystals are dispersed and precipitated, the electroless Ni—P plating layer begins to harden, and when heated to approximately over 300 ° C., in electroless Ni—P plating, The property as a crystal structure containing hard Ni ₃ P becomes dominant. Thus, the hardness of the electroless nickel plating layer (Ni—P plating layer) changes according to the progress of crystallization. For example, the hardness of an electroless nickel plating layer (Ni-P plating layer) heated at a temperature exceeding 300 ° C. may reach Hv 900 to Hv 1000, and may be similar to or slightly higher than the hardness of a hard chrome plating layer. is there.

An electroless nickel plating layer having a boron (B) content of approximately 3 wt% or more (in this specification, nickel plating containing boron may be referred to as “Ni—B plating”) is heated at 300 ° C. or more. The transition from the amorphous structure to the crystal structure begins. Hard Ni ₃ B crystals are dispersed and precipitated in this crystal structure. The nature of the crystal structure containing heated by the hard Ni 3 _B is dominant until approximately greater than 400 ° C.. Thus, the hardness of the electroless nickel plating layer (Ni—B plating layer) changes according to the progress of crystallization of the amorphous structure of nickel. For example, the hardness of an electroless nickel plating layer (Ni—B plating layer) heated at a temperature exceeding 400 ° C. may reach Hv 1200 to Hv 1400, which may exceed the hardness of the hard chrome plating layer.

Therefore, in one embodiment of the present invention, the hardness of the electroless nickel plating (Ni—P plating or Ni—B plating) layer is produced by manufacturing the multilayer film structure with the workpiece always kept at 300 ° C. or lower. Does not exceed the hardness of the hard chrome plating layer, and the gradient structure of the hardness in the multilayer structure is maintained. In addition, by producing a multilayer film structure with the workpiece always kept at 260 ° C. or lower, the amorphous nature is dominant in the electroless nickel plating (Ni—P plating, Ni—B plating) layer. Thus, the gradient structure of hardness can be maintained.
In one embodiment of the present invention, by adjusting the concentration of phosphorus (P) in the plating solution used when forming the electroless nickel plating (Ni—P plating) layer, the electroless nickel plating layer is not made amorphous. It can be precipitated as crystals. For example, when the mass percentage concentration of phosphorus in the plating film is 1 to 4 wt%, the nickel plating layer is deposited as fine crystals. The hardness of this nickel-plated layer of fine crystals is approximately Hv 650 to 700. Also in this case, as described above, the secondary layer becomes harder than the hard chromium plating layer of the tertiary layer by forming the film while keeping the workpiece at 300 ° C. or lower or 260 ° C. or lower at all times. Can be prevented.
As described above, the multilayer film structure is manufactured so that the electroless nickel plating layer has an amorphous structure by adjusting the heating temperature when forming the multilayer film structure of the present application to 300 ° C. or lower or 260 ° C. or lower. Can do. Since the electroless nickel plating layer does not have crystallinity, the progress of corrosion from crystal defects can be further prevented.

Next, a hard chromium plating layer as a tertiary layer is formed on the secondary layer. The hard chrome plating layer as the third layer is formed by energizing the base material on which the first layer and the second layer are formed, for example, in a sulfuric acid aqueous solution containing chromic acid.
The thickness of the hard chrome plating layer to be formed varies depending on the use and usage of the substrate, but is usually 0.1 to 40 μm, preferably 0.2 to 20 μm. Hard chromium of about 0.2 μm is called flash. However, the thickness of the hard chrome plating layer is not limited to these.
The hard chromium plating to be formed is energized at a high current density during film formation, so that a large amount of hydrogen generated as a by-product is taken into the film. As a result, when heated after plating, hydrogen embrittlement becomes obvious and the hardness decreases. For example, the hard chrome plating immediately after the formation has a hardness of Hv 1000 or more, but the hardness of the hard chrome plating subjected to the heat treatment of 300 ° C. or more is reduced to about Hv 800. However, it is possible to maintain a hardness sufficiently higher than the hardness Hv 500 to 600 of chromium formed by sputtering.

The electrolytic hard chrome plating layer and the electrolytic nickel plating layer are characterized in that they are deposited thicker than the other flat portions at the end portions (in the vicinity of corners and edges) of the base material. Since stress concentrates on the edge of the base material and damage is likely to occur, forming an electrolytic hard chromium plating layer or electrolytic nickel plating layer thick on the edge of the base material results in the edge of the base material being easily damaged. The part can be reinforced intensively. For example, when the base material is formed in a gear shape, an electrolytic hard chrome plating layer or an electrolytic nickel plating layer can be formed thickly on a tooth portion that is easily damaged.
Furthermore, since the electrolytic hard chrome plating layer is excellent in weather resistance, it contributes to prevention of corrosion of the base material even if the amorphous carbon film provided in the upper layer has some defects.

FIG. 1 shows the heat treatment temperature and film hardness for each of the electroless Ni-P plating layer (-■-), the electroless Ni-B plating layer (-◆-), and the hard chrome plating layer (-▲-). It is a figure which shows the relationship. The graph of FIG. 1 shows a primary layer, a secondary layer (electroless Ni—P plating layer or electroless Ni—B plating layer), and a tertiary layer (hard chrome plating) on the substrate by the method described above. The layered product in which the layer was formed was subjected to heat treatment at a plurality of temperatures between room temperature and 400 ° C., and the hardness of each layer was measured after the heat treatment. Each heating time was 1 hour. The thickness of each of the electroless Ni—P plating layer, the electroless Ni—B plating layer, and the hard chrome plating layer was 35 μm. As a measuring instrument, MVK-H3 manufactured by Akashi Co., Ltd. was used, and the load was set to 25 gf (loading time: 20 seconds).

As shown in FIG. 1, the hard chromium plating layer of the third layer is softened by heating. On the contrary, the Ni—P plating layer is hardened by heating. As a result, the hardness of the hard chrome layer and the Ni—P plating layer are approximately the same at around 350 ° C. Therefore, in order to obtain a preferable hardness gradient structure, it is desirable to avoid heating at a temperature higher than 350 ° C. after the formation of the electroless Ni—P plating layer and the hard chrome plating layer. In particular, when an amorphous carbon film is formed on the hard chrome plating layer, it is desirable to form at 350 ° C. or lower. For example, an amorphous carbon film can be formed at 350 ° C. or lower by using a low temperature plasma CVD method.
Similarly to the Ni—P plating layer, the Ni—B plating layer is hardened by heating, and the hardness of the hard chromium layer and the Ni—B plating layer is approximately the same at about 320 ° C. After forming the electroless Ni—B plating layer and the hard chromium plating layer, it is desirable to avoid heating at a temperature higher than 320 ° C. In particular, when forming an amorphous carbon film on the hard chrome plating layer, it is desirable to form it at 320 ° C. or lower. For example, an amorphous carbon film can be formed at 320 ° C. or lower by using a low temperature plasma CVD method.

An amorphous carbon film or a silicon-containing amorphous carbon film that is the uppermost layer is formed on the tertiary layer. The amorphous carbon film is formed by various methods such as a CVD (chemical vapor deposition) method such as a plasma CVD method or a physical vapor deposition (PVD) method such as an ion plating method or a sputtering method. The amorphous carbon film according to one embodiment of the present invention is formed using a low temperature plasma CVD method at 350 ° C. or lower or 320 ° C. or lower depending on the type of the electroless nickel layer as the secondary layer.
As described above, the hardness of the hard chrome plating layer is reduced by heating. Therefore, by selecting a method for forming an amorphous carbon film or a silicon-containing amorphous carbon film in which the hard chrome plating layer does not reach a high temperature, it is possible to prevent a decrease in the hardness of the hard chrome plating layer. For example, when the PVD method is used, the hard chrome plating layer may be heated to 350 to 500 ° C. Therefore, instead of the PVD method, a plasma CVD method capable of forming a film at a low temperature of 350 ° C. or less can be used. . The hard chrome plating layer contains a large amount of hydrogen in the film. Hydrogen contained in the hard chromium plating layer is not preferable for the film forming process by the PVD method. Furthermore, the heat generated by the PVD method may cause warpage and distortion in the aluminum or aluminum alloy base material. In one embodiment of the present invention, since the amorphous carbon film is formed using the plasma CVD method, the problems associated with the manufacturing method using the PVD method do not occur.

In one embodiment of the present invention, an amorphous carbon film can be formed by low temperature sputtering. In addition, by providing a cooling device for the workpiece, the amorphous carbon film can be formed by keeping the workpiece at 350 ° C. or lower even by a method in which the workpiece becomes a high temperature of 350 ° C. or higher without the cooling device.

As described above, it may be desirable to form the amorphous carbon film according to an embodiment of the present invention by the plasma CVD method rather than the PVD method. The plasma CVD method can form a film under a low temperature condition. Plasma CVD methods used in various embodiments of the present invention include high pressure pulse plasma CVD, high frequency plasma CVD using high frequency discharge, direct current plasma CVD using direct current discharge, and microwave using microwave discharge. A plasma CVD method is included. Since the direct current plasma CVD method is energized continuously, it is desirable to control the temperature of the substrate with a cooling device.
In one embodiment of the present invention, it is desirable to use a high-pressure pulse plasma CVD method to form an amorphous carbon film. In the high-pressure pulse plasma CVD method, the duty ratio of the power source can be controlled from 2% to 10% by increasing / decreasing the pulse frequency, so that the film forming temperature can be easily lowered as compared with other film forming methods. In addition, since carbon ions and the like can be implanted into a lower layer than the amorphous carbon film at a high pressure, adhesion between the lower layer and the amorphous carbon film is easily obtained.

The formed amorphous carbon film or the amorphous carbon film containing silicon is formed in various thicknesses depending on the use of the substrate, but is usually formed to 10 nm to 10 μm, preferably 0.1 μm. Formed to ˜3 μm. However, the thickness of the amorphous carbon film is not limited to these.
In order to further improve the adhesion between the hard chromium plating layer and the amorphous carbon film, an amorphous carbon film containing silicon can be used as the intermediate adhesive layer. In this case, the thickness of the intermediate adhesive layer varies depending on the use and usage of the substrate, and it is not necessary to particularly limit it, but it is usually 10 nm to 1 μm, preferably 0.1 μm to 0.5 μm. .

Amorphous carbon film can use hydrocarbon gas, such as methane, acetylene, and benzene, as a reaction gas in the case of forming using the CVD method. For the formation of the amorphous carbon film containing silicon, a silicon compound gas such as Si (CH ₃ ) ₄ or SiH ₄ can be used as a reaction gas when the CVD method is used. Argon gas can be used as the carrier gas. A mixture of argon gas and hydrocarbon gas can also be used as the carrier gas.

Hereinafter, examples of multilayer film structures and multilayer film stacking methods according to various embodiments of the present invention will be described. In the examples of the present invention, the measurement of the thickness and hardness of each film formed on the base material is performed by forming a single film on a silicon (100) substrate juxtaposed with the base material, It is measured.

The following nine (1) to 3 (3) test samples were subjected to adhesion tests. In order to produce a test sample, a base material (hereinafter referred to as “cylindrical base material”) in which a 5000 series aluminum alloy base material (5052 material) was formed into a cylindrical shape having a diameter of 10 mm and a height of 10 mm was prepared. By forming the base material in a cylindrical shape, the surface-treated film is easily peeled off by stress. Therefore, such a cylindrical base material is suitable for the adhesion test.
A zinc-substituted film was formed on the side surface of this cylindrical substrate by the method described above. Specifically, the cylindrical substrate was immersed in a weak alkaline solution and degreased at 70 ° C., and then immersed in a sulfuric acid solution at 70 ° C. to etch the substrate surface. Further, the substrate was acid-immersed with 50% nitric acid at room temperature, and a zinc-substituted layer was deposited at room temperature with a strong alkaline zinc-substituted solution mainly composed of NaOH. Subsequently, in order to remove the smut, it was immersed in 50% nitric acid at room temperature. Furthermore, the second zinc substitution was performed with the same zinc substitution solution as before.

The cylindrical substrate after the zinc substitution layer was formed in this way was further subjected to the following treatment to obtain each sample. That is, an electroless Ni—P plating layer having a thickness of 5 μm is formed on the cylindrical substrate after the zinc substitution layer is formed, and an amorphous carbon film (including an intermediate layer containing silicon of 0.1 μm) is formed thereon. Was formed to a thickness of 0.4 μm to obtain test sample 1 (1). In addition, an electroless Ni—P plating layer is formed to a thickness of 5 μm on the cylindrical base material after the zinc-substituted layer is formed, and an amorphous carbon film (including the intermediate layer of 0.1 μm) thereon is 0.8 μm. A film was formed with a thickness to obtain Test Sample 1 (2). Further, an electroless Ni—P plating layer having a thickness of 5 μm is formed on the cylindrical base material after the zinc-substituted layer is formed, and an amorphous carbon film (including the intermediate adhesive layer of 0.1 μm) is formed thereon. A film was formed with a thickness of 6 μm to obtain Test Sample 1 (3). Since test samples 1 (1) to 1 (3) do not have a hard chrome plating layer, all are comparative examples.

An electroless Ni—P plating layer is formed on the cylindrical base material after the zinc substitution layer is formed to a thickness of 5 μm, and a hard chromium plating layer is formed thereon to a thickness of 5 μm. A carbon film (including an intermediate layer of 0.1 μm) was formed to a thickness of 0.4 μm to obtain Test Sample 2 (1). Further, an electroless Ni—P plating layer is formed on the cylindrical base material after the zinc substitution layer is formed to a thickness of 5 μm, and a hard chromium plating layer is formed thereon to a thickness of 5 μm. A crystalline carbon film (including 0.1 μm of the intermediate layer) was formed to a thickness of 0.8 μm to obtain Test Sample 2 (2). Further, an electroless Ni—P plating layer having a thickness of 5 μm is formed on the cylindrical substrate after the zinc-substituted layer is formed, and a hard chrome plating layer is formed thereon with a thickness of 5 μm. A crystalline carbon film (including the intermediate layer of 0.1 μm) was formed to a thickness of 1.6 μm to obtain Test Sample 2 (3). Test samples 2 (1) to 2 (3) are examples of the present invention.

5 μm of electrolytic Ni plating layer is formed on the cylindrical substrate after the zinc substitution layer is formed, and an amorphous carbon film (including the intermediate adhesive layer of 0.1 μm) is formed thereon with a thickness of 0.4 μm. Test sample 3 (1) was obtained. Further, an electrolytic Ni plating layer having a thickness of 5 μm is formed on the cylindrical base material on which the zinc replacement layer has been formed, and an amorphous carbon film (including the intermediate adhesive layer 0.1 μm) is formed thereon with a thickness of 0.8 μm. Film was obtained to obtain test sample 3 (2). Furthermore, 5 μm of electrolytic Ni plating layer is formed on the cylindrical substrate after the zinc substitution layer is formed, and an amorphous carbon film (including the intermediate layer of 0.1 μm) is formed thereon with a thickness of 1.6 μm. As a result, test sample 3 (3) was obtained. Test samples 3 (1) to 3 (3) are comparative examples because they do not have an electroless nickel layer and a hard chromium plating layer.

In the production of test samples 1 (1) to 3 (3), a high-pressure DC pulse plasma CVD apparatus was used to form the amorphous carbon film. In this high-pressure DC pulse plasma CVD apparatus, after evacuating to 7 × 10 ⁻⁴ Pa, the substrate was cleaned with argon gas plasma for about 5 minutes, and then using tetramethylsilane at a flow rate of 30 SCCM, gas pressure of 2 Pa, applied voltage An intermediate layer containing silicon was formed under the conditions of −5 kV, a pulse frequency of 10 kHz, and a pulse width of 10 μs. Then, using acetylene as the source gas, an amorphous carbon film is formed by high-pressure DC pulse plasma CVD under the conditions of applied voltage -5 kV, pulse frequency 10 kHz, pulse width 10 μs, gas flow rate 40 SCCM, gas pressure 2 Pa. did. The film formation time was adjusted so that a desired film thickness was obtained in each test sample. Further, the amorphous carbon film was formed so that the intermediate layer had the same thickness in each sample. The temperature of the deposition chamber at the end of deposition was less than 160 ° C. for all samples. An amorphous carbon film having a thickness of 1.6 μm has the outermost layer having the largest internal stress.

In all the test samples, after the amorphous carbon film was formed, the temperature was naturally lowered without introducing the substrate cooling gas, and the thermometer attached to the inner periphery of the film formation chamber showed 60 ° C. Each test sample was taken out from the film forming chamber.
In this state after film formation, test samples 1 (2), 1 (3), and test samples 3 (1), 3 (2), and 3 (3), which are comparative examples, are based on an amorphous carbon film. It was confirmed that it peeled from the material. In particular, it was confirmed that peeling progressed from the site where the amorphous carbon film was formed thick.
Here, exfoliation in the description of the present invention means a portion where the amorphous carbon film disappears or a state where the amorphous carbon film is turned up. This peeling was confirmed by 20 times observation with a CCD camera.
For test sample 1 (1) and Examples 2 (1), 2 (2), and 2 (3), the peeling of the amorphous carbon film could not be confirmed. Test sample 1 (1), which is a comparative example, was not confirmed to be peeled off, but test samples 1 (2) and 1 (3) manufactured by changing only the thickness of the amorphous carbon film under the same conditions. About peeling, as above-mentioned, peeling was confirmed. Therefore, in a multilayer film structure having no hard chrome plating layer, peeling may occur depending on the film thickness of the amorphous carbon film, and the adhesion of the amorphous carbon film is not sufficient. On the other hand, in test samples 2 (1) to 2 (3) which are examples of the present invention, no peeling occurred regardless of the film thickness of the amorphous carbon film. Thus, in the examples of the present invention, improvement in the adhesion of the amorphous carbon film was observed.

Moreover, the comparison verification of the base-material adhesive force by a heat cycle was performed as follows. Similar to the adhesion test described above, a base material (hereinafter referred to as “cylindrical base material”) in which a 5000 series aluminum alloy base material (5052 material) was formed into a cylindrical shape with a diameter of 10 mm and a height of 10 mm was prepared. A zinc-substituted film was formed on the cylindrical substrate by the method described above, and an electroless Ni—P plating layer was formed on the zinc-substituted film by 5 μm. Further, a hard chrome plating layer formed thereon with a thickness of 5 μm and a film formed with a thickness of 0.5 μm were prepared.
Next, the cylindrical base material on which these two kinds of hard chromium plating layers are formed and the cylindrical base material on which neither the electroless nickel plating layer nor the hard chromium plating layer is formed are put into a high-pressure DC pulse plasma CVD apparatus. Then, an amorphous carbon film was formed on these cylindrical substrates by the following method. First, the reaction vessel of the CVD apparatus was evacuated to 7 × 10 ⁻⁴ Pa, and then the surface of the charged cylindrical substrate was cleaned with argon plasma for 10 minutes. An intermediate adhesive layer was formed on the surface of the cylindrical substrate under the conditions of a pressure of 2 Pa, an applied voltage of −5 kV, a pulse frequency of 10 kHz, and a pulse width of 10 μs. The intermediate adhesive layer was formed for 10 minutes. The intermediate adhesive layer is formed between the amorphous carbon film and the lower layer in order to improve the adhesion of the amorphous carbon film. Subsequently, an amorphous carbon film made of acetylene as a raw material is formed on the intermediate adhesive layer for 20 minutes under the conditions of an applied voltage of −5 kV, a pulse frequency of 10 kHz, a pulse width of 10 μs, a gas flow rate of 40 SCCM, and a gas pressure of 2 Pa. The amorphous carbon film having a thickness of 1.2 μm and a hardness of Hv 1500 including the intermediate adhesive layer (0.4 μm) was formed on each cylindrical substrate. The temperature of the film formation chamber at the end of film formation was 125 ° C.

In this way, three types of samples were obtained. Of these three types of samples, a sample containing a hard chromium plating layer of 5 μm is a test sample 4, a sample containing a hard chromium plating layer of 0.5 μm is a test sample 5, and an amorphous carbon film is directly applied to a cylindrical substrate. A sample obtained by film formation is designated as test sample 6.
About these

test samples

4, 5, and 6, the comparative test of the adhesive force by a heat cycle was done. First, each of

test samples

4, 5, and 6 was heated to 260 ° C. with a hot plate and held at 260 ° C. for 10 minutes. Then, it was immersed in water at 17 ° C. and rapidly cooled. This heating to 260 ° C. and cooling with water at 17 ° C. are defined as one cycle. This cycle was repeated a plurality of times, and the peeled state of the film was observed at 20 times the CCD camera in the same manner as the other sample methods described above.
As a result, it was observed that in Sample 6, the amorphous carbon film was partially peeled off at the third cycle. After 10 cycles, no peeling was observed for Samples 4 and 5.
As described above, the adhesion to the lower layer of the amorphous carbon film is such that a zinc-substituted layer, an electroless Ni—P layer (5 μm), a hard chromium plating (5 μm), and an amorphous carbon film are formed on an aluminum substrate. The multilayer film structure formed in this order is more than the multilayer film structure in which an amorphous carbon film containing silicon is directly formed on an aluminum substrate as an intermediate adhesive layer, and an amorphous carbon film is formed thereon. However, it was confirmed that it could be improved for practical use.

Next, a frictional wear test was performed on the test samples 7 to 9 as follows.
Test samples 7 and 9 are an embodiment of the present invention, and test sample 8 is a comparative example. For the test, a friction wear tester according to JIS K 7218 was used, and a hard ball (ball) with a diameter of 2 mm was used as the other party. Was measured.

Test sample 7 was manufactured by the following method. First, plate-like aluminum alloy 5052 having a length and width of 100 mm × 40 mm and a thickness of 1 mm is dipped in a weak alkaline solution and degreased at 70 ° C., and then dipped in a sulfuric acid solution at 70 ° C. Etched. The substrate after etching was acid-immersed with 50% nitric acid at room temperature. Next, a zinc substitution layer was deposited on the surface of the base material after the acid immersion treatment at room temperature with a strong alkali zinc substitution solution mainly composed of NaOH. Subsequently, it was immersed in 50% nitric acid at room temperature to remove the smut. Finally, zinc replacement was performed again with the same zinc replacement solution as before.
Subsequently, an electroless Ni—P plating treatment was performed for 40 minutes on the base material on which the zinc-substituted layer was formed to deposit an electroless Ni—P plating layer with a thickness of 10 μm. Further, a hard chromium plating layer having a thickness of 10 μm was formed on the upper layer by performing electrolytic chromium plating for 35 minutes. The substrate on which the hard chrome plating layer was formed was ultrasonically cleaned and then put into a high-pressure DC pulse plasma CVD apparatus. Then, the high-pressure DC pulse plasma CVD apparatus was depressurized to 1 × 10 ⁻³ Pa, and the substrate charged with argon gas plasma was cleaned for about 5 minutes. Next, using trimethylsilane with a gas flow rate of 30 SCCM, a gas pressure of 2 Pa, an applied voltage of −4.5 kV, a pulse frequency of 10 KHz, a pulse width of 10 μs, and an intermediate carbon adhesive layer of silicon containing silicon on the cleaned substrate. Formed. On this intermediate adhesive layer, an acetylene with a gas flow rate of 40 SCCM is used as a source gas, and an amorphous carbon film is formed under the conditions of an applied voltage of −5 kV, a pulse frequency of 10 kHz, a pulse width of 10 μs, and a gas pressure of 2 Pa. did. Film formation was performed such that the thickness of the intermediate adhesive layer was 25% of the total thickness of the intermediate adhesive layer and the amorphous carbon film. The time required for the step of depositing the amorphous carbon film was about 20 minutes including the step of forming the intermediate adhesive layer.
In the step of forming the intermediate adhesive layer and the amorphous carbon film, the temperature of the aluminum substrate was made not to exceed 350 ° C. The thermolabel which can confirm the temperature change to 200 degreeC was attached to the aluminum base material, and it confirmed that the base material temperature did not reach 200 degreeC. When the amorphous carbon film was formed, the film was formed for 10 minutes, then stopped for 10 minutes, and the temperature of the substrate was lowered. Thereafter, the film formation was resumed to form an amorphous carbon film.
The amorphous carbon film had a thickness of 0.4 μm and a hardness of Hv1500. The temperature of the film formation chamber at the end of film formation was 86 ° C.

Test sample 8 was produced by the following method. First, a plate-shaped aluminum alloy 5052 base material having a length and width of 100 mm × 40 mm and a thickness of 1 mm is prepared, and silicon is directly applied on the base material using the high-pressure DC pulse plasma CVD method under the same conditions as the test sample 7. An intermediate adhesion layer of amorphous carbon film and an amorphous carbon film were formed.
Next, a test sample 9 was produced. An electroless Ni—P plating layer was deposited to a thickness of 5 μm on an aluminum substrate on which a zinc replacement layer was formed in the same manner as in test sample 7. The electroless Ni—P plating treatment was performed for 20 minutes. Further, 5 μm of an electrolytic nickel plating layer was deposited, and on this electrolytic nickel plating layer, a hard chromium electrolytic plating treatment was performed for 35 minutes so that the thickness of the electrolytic hard chromium plating layer was 10 μm. Further, an intermediate adhesion layer and an amorphous carbon film of an amorphous carbon film containing silicon were formed under the same conditions as in the test sample 7 by using a high-pressure DC pulse plasma CVD method.

The results of frictional wear tests performed on these test samples 7 to 9 are shown in FIGS.
FIG. 2 is a graph showing the change in the coefficient of friction according to the number of wears of the test sample 7, and FIG. 3 is a surface photograph of the test sample 7 taken after 100 times of wear. The horizontal axis in FIG. 2 represents the number of wears, and the vertical axis represents the measured coefficient of friction. A square point is a friction coefficient in the case of 502g, and a triangular point is a friction coefficient of 700g. As described above, the frictional wear test was performed by using a frictional wear tester according to JIS K 7218 and reciprocating a super hard ball with a predetermined indentation load on the test sample. The number of times the hard balls reciprocate on the test sample is defined as the number of wear. The photograph in FIG. 3 was taken at a magnification of 200 times using a CCD camera.
As shown in FIG. 2, the test sample 7 maintains a friction coefficient of approximately 0.04 μm or less until the number of frictions reaches 100. Further, as shown in FIG. 3, the trajectory of the ball is hardly visible on the surface of the test sample 7 even after the test of 100 times of wear is performed. From these test results, it was found that the test sample 7 showed good frictional wear resistance.

FIG. 4 is a graph showing a change in the coefficient of friction according to the number of wears of the test sample 8. In the figure, the square point represents the friction coefficient at 700 g, and the triangular point represents the friction coefficient at 502 g. FIG. 5 is a photograph of the surface of the test sample 8 taken after 8 times of wear. The photograph in FIG. 5 was taken in the same manner as test sample 7.
As shown in FIG. 4, the friction coefficient of the test sample 8 rapidly increased when the number of wear was 2. Further, as shown in FIG. 5, the trajectory of the ball clearly appeared as a white band extending in the left-right direction on the surface of the test sample 8. From these test results, it was confirmed that the surface of the test sample 8 was greatly sharpened and the surface of the aluminum alloy was exposed.

FIG. 6 is a graph showing a change in the coefficient of friction according to the number of wears of the test sample 9, and FIG. 7 shows a surface photograph of the test sample 9 taken after 100 times of wear.
As shown in FIG. 6, the test sample 9 maintains a friction coefficient of approximately 0.15 μm or less until the number of frictions reaches 100. In addition, as shown in FIG. 7, the surface of the test sample 9 can be confirmed with a ball trajectory even after 100 wear tests, but there is no abnormality such as peeling on the amorphous carbon film. Not observed. From these test results, it was found that the test sample 9 showed good frictional wear resistance.

From the above, it was confirmed that the test samples 7 and 9 which are the examples of the present invention have a higher frictional wear resistance than the comparative examples. Since this excellent frictional wear resistance is due to the nature of the amorphous carbon film formed in the uppermost layer, the test samples 7 and 9 which are examples of the present invention are tested through a test for measuring the number of wears. It was shown that the amorphous carbon film did not peel off. Test sample 8 was unable to observe good frictional wear resistance. The reason why good frictional wear resistance was not obtained for test sample 8 was that the uppermost amorphous carbon film was peeled off and the friction coefficient of the softer substrate portion was measured. Thus, it was shown that the adhesion of the amorphous carbon film was improved in the examples of the present invention.

Subsequently, it was confirmed by the following experiment that burrs and cutting powder could be removed in the film forming process of the zinc-substituted layer.
First, an aluminum alloy (5052) base material having a 100 mm square and a plate thickness of 5 mm is prepared, and a portion for forming a concave portion for storing components and a bottom of the concave portion is formed on one surface of the base material by three-dimensional countersink processing. A part alignment pallet was created by forming a large number of part alignment holes like meshes. Six pallets for aligning the same parts were prepared. After cutting, heat treatment for warping correction was performed at 270 ° C. for 7 hours without cleaning in order to leave burrs and cutting powder in the vicinity of the hole and in the hole wall.
A zinc-substituted film was formed on the surface of three of the six component alignment pallets after the heat treatment thus obtained as follows. First, the three parts alignment pallets were degreased with an aluminum cleaner NE-6 manufactured by Meltex Co., Ltd., a Japanese company. Unless otherwise specified, the chemicals for plating were those from Meltex Co., Ltd. Specifically, the parts alignment pallet was immersed in an aluminum cleaner NE-6 solution having a concentration of 60 g / L and degreased at 70 ° C. for 180 seconds. The parts pallet after degreasing was washed with tap water for 30 seconds. Then, the tap water washing for 30 seconds was performed again.
Next, the surface of the pallet for parts alignment after the water washing was immersed and etched using an acidic solution. Specifically, a mixed solution of Actan E-10 having a concentration of 100 ml / L and Actan 70 having a concentration of 10 g / L was used as the acidic solution, and the component alignment palette was etched at 70 ° C. for 60 seconds. Then, tap water washing for 30 seconds was performed twice on the parts alignment pallet.
Next, the pallet for parts alignment was placed in a mixed solution of 67.5% nitric acid with a concentration of 500 ml / L, 98% sulfuric acid with a concentration of 250 ml / L, and actin 70 with a concentration of 120 g / L at room temperature for 30 seconds. Soaked. Then, tap water washing for 30 seconds was performed twice on the parts alignment pallet.
Next, the component alignment pallet after the acid immersion treatment was immersed in a zinc replacement solution containing Almon EN having a concentration of 200 ml / L as a main component at 25 ° C. for 90 seconds to deposit a zinc replacement layer on the surface of the component alignment pallet. . Then, tap water washing for 30 seconds was performed twice on the parts alignment pallet.
Next, the component alignment pallet on which the zinc replacement layer was formed was immersed in 67.5% nitric acid having a concentration of 500 ml / L at room temperature for 30 seconds, and the smut was dropped. Then, tap water washing for 30 seconds was performed twice on the parts alignment pallet.
Finally, the parts alignment pallet was immersed in a zinc replacement solution mainly composed of Almon EN having a concentration of 200 ml / L for 60 seconds at 25 ° C., and a second zinc replacement treatment was performed.
As described above, the zinc replacement layer was formed on the three parts alignment pallets by the method according to the embodiment of the present invention.

Subsequently, each of the three parts alignment pallets on which no film was formed was placed in a mixed solution of Melplate NI-2280LF M1 and Melplate NI-2280LF M2 having a concentration of 55 ml / L at 90 ° C. for 40 minutes. It was immersed, 10 μm of electroless nickel plating was deposited on the zinc-substituted layer, and electrolytic hard chromium plating was further performed for 35 minutes to form a hard chromium plating layer having a thickness of 10 μm.
Subsequently, an amorphous carbon film was formed by the following method on the three component alignment pallets and the three component alignment pallets on which only the zinc replacement layer was formed. Prior to the formation, each of these six component alignment palettes was immersed in isopropyl alcohol and subjected to ultrasonic cleaning for 5 minutes.

The six parts alignment palettes after the ultrasonic cleaning were respectively put into a high-pressure DC pulse plasma CVD apparatus, and a carbon film was formed under the following conditions.
Deposition chamber vacuum: 7 × 10-4 Pa
Argon base material cleaning: Gas flow rate 30 SCCM, gas pressure 2 Pa,
Applied voltage: -3.5 Kv Pulse frequency 10 kHz, Pulse width 10 μs, 5 minutes Trimethylsilane intermediate adhesion layer: Gas flow rate 30 SCCM, Gas pressure: 2 Pa
Applied voltage: −4.5 Kv Pulse frequency 10 kHz, pulse width 10 μs, 15 minutes Carbon film layer with acetylene: gas flow rate: 30 SCCM, gas pressure: 2 Pa
Applied voltage: −5 Kv, pulse frequency 10 kHz, pulse width 10 μs, 35 minutes. Thereby, an amorphous carbon film of about 1 μm was formed on each of the six component alignment pallets. The three parts alignment pallets on which the zinc replacement layer, the electroless nickel plating layer, the hard chrome plating layer, and the amorphous carbon film are formed in this way are referred to as test samples 10, 11, and 12, respectively. Further, the remaining three component alignment pallets on which the amorphous carbon film is formed directly on the substrate are referred to as test samples 13, 14, and 15, respectively.

Test samples 10 to 15 were allowed to stand at room temperature and normal pressure for 3 days after the formation of the amorphous carbon film. Holes for aligning parts of the test samples 10 to 15 were observed at a magnification of 200 times using a CCD camera. As a result, no peeling of the amorphous carbon film was observed in the test samples 10, 11, and 12. On the other hand, in each of the test samples 13, 14 and 15, peeling was observed in the amorphous carbon film formed on the vicinity of the hole or on the part where the burr or cutting powder was attached to the hole wall. In addition, swell of the amorphous carbon film was observed.
From the above, it can be confirmed that in the film-forming process of the zinc-substituted film according to one embodiment of the present invention, peeling of the amorphous carbon curtain due to burrs and cutting powder attached to the aluminum or aluminum alloy substrate is prevented. It was.

Next, according to the experiment shown below, the anodic oxide film formed on the aluminum substrate by the step of forming the zinc-substituted film according to one embodiment of the present invention can be removed, and the anodic oxide film was left. It was confirmed that a zinc-substituted film can be formed as it is.
First, an aluminum alloy base material (5052 material) of 30 mm square and 1 mm thickness was prepared. The aluminum alloy base material was subjected to an anodic acid treatment to form an anodic oxide film having a thickness of 30 μm, and an anodic oxide film sample 1 was obtained. Also, an anodic acid treatment was performed on the aluminum alloy substrate to form an anodized film having a thickness of 10 μm, and an anodized film sample 2 was obtained.

Next, a zinc-substituted film was formed on the anodized film sample 1 as follows. First, the anodized film sample 1 was immersed in an aluminum cleaner NE-6 having a concentration of 60 g / L for 180 seconds at 70 ° C. to be degreased. Next, the anodic oxide film sample 1 after degreasing was etched by immersing it in a mixed solution of 100 ml / L Actan E-10 and 10 g / L Actan 70 at 70 ° C. for 150 seconds. Next, the etched anodic oxide film sample 1 was immersed in 50% nitric acid at room temperature for 30 seconds. Next, the anodic oxide film sample 1 after the acid immersion treatment is immersed in a zinc-substituting liquid mainly composed of Almon EN having a concentration of 200 ml / L at room temperature for 100 seconds to deposit a zinc-substituting layer on the surface of the anodic oxide film sample 1. It was. Next, the anodized film sample 1 on which the zinc substitution layer was deposited was again immersed in 50% nitric acid at room temperature for 30 seconds. Next, the anodic oxide film sample 1 after the acid immersion was immersed in a zinc replacement solution mainly composed of Almon EN having a concentration of 200 ml / L at room temperature for 70 seconds to perform a second zinc replacement treatment. Next, the anodized film sample 1 after the second zinc substitution treatment was energized in a standard composition of pH 4.1 elpilite GS-6 at a current density of 55 ° C. and 3 A / dm ² for 9 minutes. A test sample 16 was prepared as a sample.

The photograph of the test sample 16 produced in this manner was photographed at a magnification of 3000 times using a CCD camera. As a result, there was no anodic oxide film that was 30 μm before the step of forming the zinc-substituted film. As a result, it was confirmed that the 30 μm anodic oxide film disappeared during the zinc substitution film forming step.

Further, a zinc-substituted film was formed on the anodized film sample 2 as follows. First, the anodized film sample 2 was immersed in an aluminum cleaner NE-6 having a concentration of 60 g / L at 70 ° C. for 14 seconds to degrease. Next, the degreased anodic oxide film sample 2 was etched by being immersed in a mixed solution of 100 ml / L of Actane E-10 and 10 g / L of Actan 70 at 70 ° C. for 14 seconds. Next, the etched anodic oxide film sample 2 was immersed in 50% nitric acid at room temperature for 14 seconds. Next, the anodic oxide film sample 2 after the acid immersion treatment is immersed in a zinc-substituting liquid mainly composed of Almon EN having a concentration of 200 ml / L at room temperature for 14 seconds to deposit a zinc-substituting layer on the surface of the anodic oxide film sample 2. Thus, a test sample 17 was produced.

When a photograph of the test sample 17 produced in this way was taken at a magnification of 3000 times using a CCD camera, the anodized film remained on the aluminum substrate. Thus, it was confirmed that at least a part of the 10 μm anodic oxide film initially remained on the base material by the above-described zinc-substituted film forming step.

As described above, the removal amount of the anodic oxide film on the aluminum substrate can be adjusted by controlling the treatment time and the number of times of each step included in the zinc substitution treatment. For example, the removal amount of the anodized film can be increased by increasing the treatment time with an acidic or alkaline solution, and the anodized film can be completely removed as described above. By removing the anodized film, the aluminum substrate and the upper layer portion can be electrically connected. On the other hand, an anodic oxide film can be left on the aluminum substrate by reducing the treatment time with an acidic or alkaline solution. The anodized film can insulate the aluminum substrate from the upper layer portion.

The multilayer structure according to various embodiments of the present invention can be applied to an index carrier. The index carrier is configured by rotatably supporting a disk-shaped guide member on a rack. A plurality of pockets for accommodating two sides of the square electronic component are formed at equal intervals on the outer periphery of the disc-shaped guide member. Since a negative pressure is applied to the pocket in the direction of the rotation center of the guide member, the electronic component can be accommodated in the pocket and transported in the rotation direction. A CCD camera can be disposed outside the outer periphery of the guide member in the radial direction. The guide member can accommodate an electronic component in a pocket and carry the electronic component to a photographing area of the CCD camera. With this CCD camera, it is possible to inspect the appearance of the electronic components being transported. The index carrier itself is known and disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-307269.

In one embodiment of the present invention, the multilayer structure according to various embodiments of the present invention described above is formed on the surface of an index carrier. The pockets of the guide member are susceptible to damage due to frequent contact with the electronic components. By forming the multilayer structure according to various embodiments of the present invention on the surface of such a part that is easily damaged, the frictional wear resistance of the part can be improved, and the life of the index carrier can be increased. Can be extended.

According to various embodiments of the present invention described above, an amorphous carbon film that is hard and excellent in wear resistance is formed on the top of a soft aluminum or aluminum alloy-based substrate as a metal with good adhesion. Or the multilayer film structure which can improve the abrasion resistance of aluminum alloy, and sliding property, and its manufacturing method are provided. According to the multilayer film laminating method according to various embodiments of the present invention, all layers from the base material to the hard chrome plating can be wet-plated, so that the temperature during film formation is suppressed to 150 ° C. or lower. be able to. Thereby, film-forming of each layer can be made into less than 250 degreeC which is the recrystallization temperature of aluminum or an aluminum alloy base material. When the amorphous carbon film or the amorphous carbon film containing silicon according to various embodiments of the present invention is formed by the CVD method, it is not necessary to prepare an expensive solid target such as titanium, tungsten, or chromium. In addition, according to the multilayer structure according to various embodiments of the present invention, even if pinholes are generated in the uppermost amorphous carbon film, the surface of the aluminum base material is hard chrome plated with excellent weather resistance. Since it is covered with a layer and a nickel plating layer, the aluminum substrate can be protected even if foreign matter enters from the pinhole.

Each multilayer film structure and multilayer film laminating method described in this specification is an exemplification, and various changes can be made to the configuration, material, and manufacturing method without departing from the spirit of the present invention. In addition, various modifications can be made to the above-described embodiment without departing from the spirit of the present invention. The examples are also given as examples, and the present invention is not limited to the examples described above.

Claims

A multilayer film structure in which a zinc substitution layer, an electroless nickel plating layer, a hard chromium plating layer, and an amorphous carbon film are formed in this order on a base material made of aluminum or an aluminum alloy.
The multilayer film structure according to claim 1, wherein the amorphous carbon film is formed at 350 ° C or lower.
The multilayer film structure according to claim 1, wherein the amorphous carbon film is formed at 300 ° C or lower.
The multilayer film structure according to claim 1, wherein the amorphous carbon film is formed at 260 ° C or lower.
The multilayer film structure according to claim 1, wherein the electroless nickel plating layer is amorphous.
The multilayer film structure according to claim 1, wherein an electrolytic nickel plating layer is formed between the electroless nickel plating layer and the hard chrome plating layer.
The multilayer film structure according to claim 1, wherein an intermediate adhesive layer is formed on the hard chrome plating layer, and the amorphous carbon film is formed on the intermediate adhesive layer.
The multilayer film structure according to claim 1, wherein an anodized layer is formed on the substrate, and the zinc-substituted layer is formed on the anodized layer.
Forming a zinc substitution layer on the surface of the substrate made of aluminum or an aluminum alloy;
Forming an electroless nickel layer on the zinc-substituted layer by an electroless plating method;
Forming a hard chromium layer on the electroless nickel layer by a plating method;
Forming an amorphous carbon film at 350 ° C. or lower on the hard chromium layer.
The multilayer film structure according to claim 9, further comprising a step of forming an electrolytic nickel plating layer on the electroless nickel plating layer by a plating method, wherein the hard chromium plating layer is formed on the electrolytic nickel plating layer. body.
The multilayer film laminating method according to claim 9, further comprising a step of forming an intermediate adhesive layer on the hard chrome plating layer, wherein the amorphous carbon film is formed on the intermediate adhesive layer.
The multilayer film laminating method according to claim 9, further comprising a step of forming an anodized layer on the base material, wherein the zinc substitution layer is formed on the anodized layer.
The multilayer film stacking method according to claim 9, wherein the amorphous carbon film is formed by a plasma CVD method.
The multilayer film stacking method according to claim 13, wherein the plasma CVD method is a DC pulse plasma CVD method.
The multilayer film stacking method according to claim 9, wherein the amorphous carbon film is formed at 300 ° C. or lower.
The multilayer film stacking method according to claim 9, wherein the amorphous carbon film is formed at 260 ° C. or lower.