JP2000169965A - Zinc-containing alloy clad member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Zn-containing alloy clad member formed by coating an alloy containing Zn with a dense and excellent film and a process for produc ing the same. SOLUTION: A dezinsification layer forming stage, which forms a dezinsification layer 2 having a lower Zn content than the Zn content of a base material 10 consisting of the alloy containing Zn on the surface of the base material 10 by heating the base material 10 under reduced pressure and evaporating Zn from the surface of the base material 10, is executed. A film forming stage of forming the film 3 under reduced pressure on the dezinsification layer 2 is thereafter executed, by which the Zn-containing alloy clad member 1, which is formed having the dezinsification layer 2 on the surface of the base material 10 and coating the surface of the dezinsification layer 2 with the film 3, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Zn-containing alloy coated member obtained by coating a surface of a Zn-containing alloy with a film formed under reduced pressure, and a method for producing the same.

[0002]

2. Description of the Related Art For example, in order to improve properties such as corrosion resistance of magnesium alloys and aluminum alloys, a method of applying a surface treatment such as painting, wet plating, lining, anodic oxidation treatment, chemical conversion coating treatment, etc. to the surface of these alloys. Is used. The coating and the lining of a polymer material can easily form a coating on a substrate made of a magnesium alloy or an aluminum alloy. However, since these films transmit moisture and oxygen, corrosion may occur on the surface of the base material. Also, the paint and lining are soft,
There is also a disadvantage that it is easily scratched.

[0003] The wet plating, anodic oxidation treatment, conversion coating treatment, etc., have less permeation of moisture and oxygen and higher hardness than painting. However, there is a disadvantage that defects are easily generated in the coating. As a surface treatment of a magnesium alloy, a well-known chromate treatment (DOW7) or the like is often used. However, since this method uses a solution containing chromium, its use is expected to decrease in the future due to environmental problems such as waste liquid treatment.

As described above, since the above-mentioned surface treatment method has various problems, attention has been paid to dry processes such as ion plating, sputtering, and plasma CVD, which can form a more dense and excellent film. . For example,
In JP-A-4-254576, as a surface treatment method of a magnesium alloy, a Si intermediate layer is formed by sputtering on the surface of a base material made of a magnesium alloy, and an Al film is further formed thereon by ion plating to form a thick film. A method for improving the anticorrosion property has been proposed.

In Japanese Patent Application Laid-Open No. 61-276994, an Al intermediate layer is formed on the surface of a base material made of a magnesium alloy by ion plating or an ion beam, and copper, nickel and gold plating are performed thereon. A method has been proposed.

[0006]

However, the base material contains an alloy containing Zn, for example, a magnesium alloy (ZE41, ZE41).
ZK60, EZ33, etc.) or aluminum alloy (A7
000), it is not possible to obtain an excellent coating even if a conventional surface treatment method using a dry process is simply applied.

That is, dry processes such as ion plating, sputtering, and plasma CVD are usually performed by heating under reduced pressure such as vacuum. Therefore, when Zn is contained in the base material, Zn having a high vapor pressure evaporates during film formation by the dry process. Therefore, the desired film cannot be formed because Zn is contained in the obtained film. This phenomenon is caused by the above-mentioned prior art (Japanese Patent Laid-Open No. 4-254576, Japanese Patent Laid-Open No. 61-27699).
No. 4) also occurs when the intermediate layer is formed, and in fact, sufficient anticorrosion cannot be obtained.

This also means that the surface of a substrate made of a magnesium alloy or an aluminum alloy containing Zn has
The same applies to the case of forming a coating such as iN, DLC (diamond-like carbon). Specifically, the evaporation of Zn during the film formation causes a film to be formed in a state containing Zn, thereby hindering the formation of a continuous dense film. Therefore, the above-mentioned Ti with good adhesion and excellent wear resistance
It is difficult to form a film such as N or DLC.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a Zn-containing alloy coated member obtained by coating a Zn-containing alloy with a dense and excellent film, and a method of manufacturing the same. Things.

[0010]

According to the first aspect of the present invention, a base material made of an alloy containing Zn is heated under reduced pressure to evaporate Zn from the surface of the base material. By performing a dezincing layer forming step of forming a dezincing layer having a low Zn content on the surface of the base material, and then performing a film forming step of forming a film under reduced pressure on the dezincing layer, A method for producing a Zn-containing alloy-coated member, comprising: providing a Zn-containing alloy-coated member having the above-described dezincification layer on the surface of a substrate and coating the above-mentioned coating on the dezincification layer.

What is most notable in the present invention is that the dezincing layer forming step is performed before the film forming step is performed.

As the base material, a magnesium alloy (ZE41, ZK60, EZ) may be used as long as the alloy contains Zn.
33), aluminum alloys (A7000 series), iron alloys, copper alloys, and the like. The dezincing layer forming step is performed by heating the substrate under reduced pressure. For the heating temperature and the degree of pressure reduction in this case, suitable conditions are selected according to the components of the base material and the like.

For example, when the substrate is a magnesium alloy containing Zn (ZE41), the heating temperature is set to 200.
C. to a temperature lower than the melting point, and reduced pressure conditions are 1 × 10 ^{−6 to 2} t.
orr is preferred. When the substrate is an aluminum alloy containing Zn, the heating temperature is set at 20.
The temperature should be 0 ° C. to less than the melting point, and the reduced pressure condition should be 1 × 10 ^-8 to
Preferably, the pressure is 2 torr.

As described above, the zinc-free layer obtained by the zinc-free layer forming step is a layer having a lower Zn content than the Zn content in the substrate. Thus, in the film forming step, the evaporation of Zn from the dezincification layer can be suppressed as much as possible.

Although the allowable Zn concentration of the dezincification layer is greatly affected by the components of the base material, the absolute amount is not more than 3% (% by weight, hereinafter the same), more preferably 1%. The following is good. In this case, irrespective of the components of the base material, evaporation of Zn in the film forming step can be suppressed.

The thickness of the dezincing layer is 0.1 μm.
It is preferable that it is above. If it is less than 0.1 μm, Zn may evaporate from the substrate under the dezincification layer through the dezincification layer. On the other hand, the thickness of the dezincing layer is 10
It may be 0 μm or less. If it exceeds 100 μm, there is a problem that the strength is reduced, and more preferably 1 μm or less.

The film forming step is, as described above, a step of forming a film under reduced pressure. Specific means include, for example, a dry process such as ion plating, sputtering, and plasma CVD. Also,
Examples of the type of the obtained film include TiN, CrN, DLC, and Al ₂ O as a film for improving abrasion resistance.
There are ₃ etc. Further, as a film for improving the anticorrosion property, there are a ceramic film, an oxide film and the like which are dense films having high insulation properties and few defects. As the ceramic coating has AlN, BN, SiC, SiN, etc., as the oxide film is _{Al 2 O 3, Cr 2 0} 3 and the like.

When the base material requires heat treatment such as aging treatment, the heat treatment may be performed after the film forming step, or may be combined with heating in the dezincing layer forming step or the film forming step. You may go.

Next, the operation of the present invention will be described. In the present invention, the dezincing layer forming step is performed before the film forming step is performed. As a result, Zn evaporates from the surface of the base material to form a zinc-free layer having a reduced Zn concentration, and the outer surface of the base material is covered with the zinc-free layer.

Next, a film is formed on the dezincing layer in the film forming step. The atmosphere at this time is
Although a reduced-pressure atmosphere is used, the Zn concentration in the dezincification layer is low as described above, so that the evaporation of Zn is suppressed. Therefore, the formation of the coating can avoid the generation of defects due to the influence of Zn vapor. Specifically, it is possible to prevent densification due to the inclusion of unnecessary Zn in the coating component, prevent a decrease in adhesion, and the like, and form a very dense and sound coating. Therefore, the obtained Zn-containing alloy-coated member becomes a member excellent in characteristics such as corrosion resistance and abrasion resistance by the coating.

Thus, according to the present invention, it is possible to provide a method for producing a Zn-containing alloy-coated member in which a Zn-containing alloy is coated with a dense and excellent coating.

Next, a second aspect of the present invention provides a substrate comprising a Zn-containing alloy, and a coating formed under reduced pressure and covering the surface of the substrate. A Zn-containing alloy-coated member characterized by having a dezincing layer having a lower Zn content than the base material between the material and the material.

The most remarkable point in the present invention is that the dezincing layer is interposed between the substrate and the coating. And, in the presence of the dezincification layer, the coating can be obtained in a very healthy state. Therefore,
The Zn-containing alloy-coated member of the present invention can be made into a member excellent in corrosion resistance, abrasion resistance, sliding characteristics, etc. by the above-mentioned sound coating, and can be used in various fields such as various machine parts and automobile parts. It can be used effectively.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A Zn-containing alloy-coated member and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to FIG. In this embodiment, three types of examples E1 are used as the present invention.
In addition to preparing Zn-containing alloy coated members of E3 to E3, these were compared with Comparative Examples C1 and C2 to evaluate their corrosion resistance and wear resistance.

As shown in FIG. 1, each of the Zn-containing alloy-coated members 1 of Examples E1 to E3 has a base 10 made of an alloy containing Zn and a base 10 formed under reduced pressure. And a coating 3 to be coated. And, between the coating 3 and the substrate 10, there is a zinc-free layer 2 having a lower Zn content than the substrate 10. Hereinafter, these manufacturing methods will be described in detail.

(Example E1) The Zn-containing alloy-coated member of Example E1 was used as the above-mentioned base material 10 with a Zr content of 4% by weight.
Magnesium alloy ZE41 (JIS) was used. After the base material 10 was degreased and washed, it was heated under reduced pressure. Specifically, the substrate 10 was held for several tens of minutes in a furnace at a temperature of 400 ° C., which was reduced to 0.01 torr.
As a result, Zn evaporates from the surface of the substrate 10, and the zinc-free layer 2 having a lower Zn content than the substrate 10 is formed on the surface of the substrate 10, thus completing the zinc-free layer forming step. In addition, the obtained dezincing layer 2 was obtained as a layer in which a portion having a Zn concentration of 0.1% by weight or less was formed over a thickness of 1.0 μm.

Next, a film forming step of forming the film 3 on the dezincification layer 2 under reduced pressure was performed. Specifically, a thickness of 2 μm is formed on the dezincing layer 2 by using a plasma CVD method.
(Diamond-like carbon) film was formed. The plasma CVD conditions were such that the processing temperature was 200 ° C. in accordance with the aging temperature of the magnesium alloy ZE41 as the base material.
The treatment time was 1 hour and the pressure was 4 torr.

Thus, as shown in FIG. 1, the zinc-free layer 2 having a Zr concentration of 0.1% by weight or less is provided on the surface of the substrate 10 made of the magnesium alloy ZE41.
As a result, a Zn-containing alloy-coated member 1 (Example E1) in which a coating 3 made of a DLC film was coated on the dezincification layer 2 was obtained.

(Example E2) The Zn-containing alloy-coated member of Example E2 was used as the above-described base material 10 with a Zr content of 5% by weight.
Aluminum alloy A7075 (JIS) was used. After the base material 10 was degreased and washed, it was heated under reduced pressure. Specifically, Zn was evaporated from the surface of the substrate 10 by holding the substrate 10 for several tens of minutes in a furnace at a temperature of 300 ° C. reduced to 0.002 torr.
This heating was terminated when the dezincing layer 2 having a Zr concentration of 1% by weight or less was formed at 0.1 μm or more.

Next, a film forming step of forming a film 3 on the dezincification layer 2 under reduced pressure was performed. Specifically, a thickness of 2 μm is formed on the dezincing layer 2 by using a plasma CVD method.
(Diamond-like carbon) film was formed. The plasma CVD conditions were a processing temperature of 300 ° C., a processing time of 1 hour, and a pressure of 4 torr.

Thus, as shown in FIG. 1, a zinc-free layer 2 having a Zr concentration of 0.1% by weight or less is provided on the surface of a base material 10 made of aluminum alloy A7075, and a DLC layer is formed on the zinc-free layer 2. As a result, a Zn-containing alloy-coated member 1 (Example E2) coated with the film 3 was obtained.

(Embodiment E3) The Zn-containing alloy-coated member of this embodiment E3 is an example using amorphous SiC instead of the DLC film as the coating 3 in the embodiment E2. That is, first, in the same manner as in Example E2, a dezincing layer 2 having a Zr concentration of 0.1% by weight or less and a thickness of 0.1 μm or more was formed on the surface of the base material 10 made of the aluminum alloy A7075.

Next, a film forming step of forming a film 3 on the dezincification layer 2 under reduced pressure was performed. Specifically, a thickness of 2 μm is formed on the dezincing layer 2 by using a sputtering method.
Was formed. The sputtering conditions were a processing temperature of 250 ° C., a processing time of 3 hours, and a pressure of 0.007 torr.

As a result, as shown in FIG. 1, the dezincing layer 2 having a Zr concentration of 0.1% by weight or less is provided on the surface of the base material 10 made of the aluminum alloy A7075. As a result, a Zn-containing alloy-coated member 1 (Example E3) coated with the coating 3 made of an amorphous SiC film was obtained.

(Comparative Examples C1 and C2) Each of the above Examples E1 to E1
For comparison with E3, the above substrate was used as it was.
That is, Comparative Example C1 is a comparative material with respect to Example E1, and is a magnesium alloy ZE41. Comparative Example C
2 is a comparative material for Examples E2 and E3, which is aluminum alloy A7075.

Next, a corrosion test was performed on each of Examples E1 to E3 and Comparative Examples C1 and C2 to evaluate corrosion prevention. The corrosion test is a salt spray test (JIS Z237)
It was carried out by measuring the corrosion weight loss according to 1).
Table 1 shows the measurement results. As can be seen from Table 1, the products of the present invention (Examples E1 to E3) were found to have significantly improved anticorrosion effects as compared with Comparative Examples C1 and C2, which are the base materials.

[0037]

[Table 1]

Next, in this example, a wear test was performed to evaluate the sliding characteristics. The wear test was performed by a ball-on-disk wear test, and the wear resistance was evaluated by measuring the wear depth. Table 2 shows the measurement results. Table 2
As is better known, the product of the present invention (Examples E1 to E3)
In each case, it was found that the abrasion resistance was greatly improved as compared with the base materials of Comparative Examples C1 and C2, and that the sliding characteristics were improved.

[0039]

[Table 2]

From the above results, it was found that the product of the present invention, Example E,
The Zn-containing alloy coated members 1 to E3 have the excellent coating 3 described above.
It can be seen that excellent corrosion resistance and abrasion resistance are exhibited by obtaining.

[0041]

As described above, according to the present invention, it is possible to provide a Zn-containing alloy-coated member obtained by coating a Zn-containing alloy with a dense and excellent coating, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration of a Zn-containing alloy-coated member in an embodiment.

[Explanation of symbols]

 1. . . 9. Zn-containing alloy coated member, . . Substrate, 2. . . 2. Dezincing layer, . . Coating,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kawahara 41-cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. No. 41, Yokomichi, 1st place, Toyota Central R & D Laboratories, Inc. F-term (reference) 4K029 AA02 BA34 BA56 BB10 BC01 BC02 CA03 CA05 FA06 4K030 BA21 BA28 BA37 BB05 CA02 DA02 FA01 LA01

Claims (2)

[Claims] 1. A dezincing layer having a lower Zn content than the base material is formed by heating a base material made of an alloy containing Zn under reduced pressure to evaporate Zn from the surface of the base material. Performs a dezincing layer forming process to form on the surface of the base material,
After that, by performing a film formation step of forming a film under reduced pressure on the dezincification layer, the substrate is provided with the dezincification layer on the surface and the coating is coated on the dezincification layer. A method for producing a Zn-containing alloy-coated member, characterized by obtaining a Zn-containing alloy-coated member as follows. 2. A base material comprising an alloy containing Zn and a coating formed under reduced pressure and covering the surface of the base material, wherein a base material is provided between the coating and the base material. Z than
Zn having a zinc-free layer having a low n content
Containing alloy coated member.