KR20110105012A - Magnesium alloy structural member - Google Patents

Abstract

It provides a magnesium alloy member having a high metal texture.

A magnesium alloy member comprising a base material made of a magnesium alloy and a coating layer formed on the base material, wherein the base material is provided with at least a portion of a surface-treated portion subjected to fine concavo-convex processing so as to obtain a metal texture. The coating layer is transparent. This member can raise a metal texture effectively by providing a surface process part. Moreover, this member is excellent in anticorrosive property by providing a coating layer, and it is easy to feel the metal texture by a surface processing part because a coating layer is transparent. The said uneven | corrugated process is a hairline process, a diamond cut process, etc. are mentioned.

Description

Magnesium alloy member {MAGNESIUM ALLOY STRUCTURAL MEMBER}

This invention relates to the magnesium alloy member provided with the coating layer on the base material which consists of magnesium alloys. In particular, it relates to a magnesium alloy member having a high metal texture.

BACKGROUND ART Magnesium alloys containing various additional elements in magnesium are used as materials for housings of portable electric devices such as mobile phones and notebook computers, and members for automobile parts. Since magnesium alloy is an active metal, the surface of the said member is surface-treated for the purpose of anticorrosion (for example, refer patent document 1, 2).

In addition, since magnesium alloy has a hexagonal crystal structure (hcp structure), plastic workability at room temperature is insufficient. It is mainstream. In recent years, press forming is performed on the board | plate material which consists of AZ31 alloy by ASTM standard, and forming the said housing is examined. Moreover, patent document 3 is proposed by the board | substrate which consists of an alloy corresponding to the AZ91 alloy in ASTM specification, and was excellent in press workability.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-285361

Patent Document 2: Japanese Patent Laid-Open No. 2004-149911

Patent Document 3: Japanese Patent Application Laid-Open No. 2007-98470

In recent years, for a magnesium alloy member such as the housing, it is required to increase the metal texture to improve the sense of quality. However, Patent Documents 1 and 2 propose a surface treatment agent that does not impair metal gloss, but have not been studied to increase the metal texture. Also, Patent Document 3 does not mention increasing the metal texture.

It is therefore an object of the present invention to provide a magnesium alloy member having a high metal texture.

The present invention achieves the above object by having at least a part of the surface of the base material made of a magnesium alloy, a surface-treated portion which is subjected to processing to increase the metal texture. Specifically, the magnesium alloy member of the present invention includes a substrate made of a magnesium alloy and a coating layer formed on the substrate, and the substrate is subjected to fine concavo-convex processing so that a metal texture is obtained on at least a part of the surface thereof. It has a surface processing part. In addition, the coating layer is transparent.

The magnesium alloy member of the present invention can effectively increase the metal texture by providing the surface-treated portion. Moreover, the member of this invention can have sufficient anticorrosive property by providing a coating layer. In particular, since the coating layer is transparent, light from the outside can easily penetrate the coating layer and be diffusely reflected in the surface processing portion, and the metal texture can be easily felt in any direction. Therefore, the member of the present invention has a high metal texture and excellent design while having the desired anticorrosive property. Hereinafter, the present invention will be described in more detail.

<Description>

"Furtherance"

As the magnesium alloy constituting the base material of the member of the present invention, those having various compositions (additional residues: Mg and impurities) containing additional elements in Mg can be used, and are not particularly limited. For example, Mg-Al system, Mg-Zn system, Mg-RE (rare earth element) system, Y addition alloy, etc. are mentioned. In particular, the Mg-Al-based alloy containing Al is preferable because of its high corrosion resistance. Examples of the Mg-Al-based alloy include, for example, AZ-based alloy (Mg-Al-Zn-based alloy, Zn: 0.2% by mass to 1.5% by mass) in the ASTM standard, AM-based alloy (Mg-Al-Mn-based alloy, Mn: 0.15). Mass% to 0.5 mass%), AS-based alloys (Mg-Al-Si-based alloys, Si: 0.6 mass% to 1.4 mass%), Mg-Al-RE (rare earth element) based alloys, and these Mg-Al based alloys. The alloy which further added 1 or more types of elements chosen from the group which consists of Bi, Sn, Pb, Ca, and Be etc. is mentioned. The content of Al is preferably 1.0% by mass or more and 11% by mass or less, and the mechanical properties such as corrosion resistance and strength are excellent as the amount of Al increases. However, when the amount of Al is excessively high, plastic workability tends to be lowered. In consideration, 8 mass% or more and 11 mass% or less are more preferable. In particular, Mg-Al alloys containing 8% by mass to 11% by mass of Al and 0.2% by mass to 1.5% by mass of Zn, typically AZ80 and AZ91, can be suitably used. These alloys are preferable because the surface of the substrate hardly discolors even after the fine concavo-convex processing is performed, and metal texture such as metallic gloss is easily obtained.

"shape"

The base material is typically a rolled material rolled a cast material, a processed material further subjected to heat treatment, leveler processing, polishing, or the like, and press-worked, bent, or forged processed to these rolled materials or processed materials. The plastic working material which gave further plastic working like this is mentioned. Substrates subjected to plastic working, such as rolling and pressing, have a fine grain diameter and are superior in mechanical properties such as strength to cast materials, and also have internal defects such as shrinkage cavities and voids (pores). There are few surface defects and it has a favorable surface property. In addition, since the rolling material has less surface defects than the casting material, it is possible to reduce the putty filling (defect correction) of the defect before forming the coating layer, or may not be performed. In addition, since the occurrence of defective products due to insufficient defect correction can be reduced, it can contribute to the improvement of product yield. Hereinafter, casting conditions and rolling conditions will be described.

<< production method >>

[Casting condition]

The casting material is preferably produced by a continuous casting method such as a twin-roll process, in particular by the casting method described in WO / 2006/003899. Since the continuous casting method enables rapid quench solidification, oxides, segregation, and the like can be reduced, and casting materials excellent in plastic workability such as rolling can be obtained. Also. By rolling this cast material, the defect which adversely affects plastic processing, such as subsequent press work, for example, a coarse and large crystal precipitate like particle diameter of 10 micrometers or more disappears. In particular, in the AZ alloy, a larger amount of Al tends to produce crystal precipitates. However, by rolling the continuous cast material, a rolled material having fewer defects can be obtained regardless of the alloy composition. The obtained cast material may be subjected to heat treatment (solution treatment, heating temperature: 380 ° C to 420 ° C, heating time: 60 minutes to 600 minutes), aging treatment or the like for homogenizing the composition. In particular, in the case of an AZ-based alloy, it is preferable that the high content of Al is performed for a long time. Although the size of a cast material does not have a problem especially, since it is easy to generate segregation when it is too thick, 10 mm or less is preferable.

[Rolling condition]

The rolling is performed by performing a plurality of passes at a heating temperature of 200 ° C. to 400 ° C., a rolling temperature of 150 ° C. to 250 ° C., and a rolling reduction per pass of 10% to 50%. desirable. Moreover, it is preferable to combine each said conditions suitably so that the rolling material of desired thickness may be obtained. By appropriately combining the conditions of the respective temperatures, the reduction ratio per one pass, and the number of passes, for example, the object to be processed having a sheet thickness of 3 mm to 8 mm before rolling is rolled to a thickness of 1 mm or less, specifically 0.2 mm. It is possible. Known conditions such as controlled rolling disclosed in Patent Document 3 may be used.

An intermediate heat treatment (heating temperature: 250 ° C. to 350 ° C., heating time: 20 minutes to 60 minutes) is performed during the rolling process to remove distortion, residual stress, and aggregate structure introduced into the object by the processing up to this heat treatment. When it reduces, it is preferable because it can prevent unexpected crack, distortion, and deformation in subsequent rolling, and can roll more smoothly. In addition, when the final heat treatment is performed after the final rolling, a rolled material having excellent strength can be obtained, which is preferable. The rolled material before the final heat treatment has a crystal structure in which processing distortion is sufficiently accumulated, and the strength can be improved by forming a fine recrystallized structure by the final heat treatment. In addition, in the rolled material after the final heat treatment having such a recrystallized structure, crystal grains hardly coarsen due to heating during press work. The heating temperature of the final heat treatment is, for example, in the case of the AZ alloy, the higher the Al amount, the higher the temperature. When the Al amount is 8% by mass to 11% by mass, 300 ° C to 340 ° C and a heating time of 10 minutes to 30 minutes is preferred. In these heat treatments, when the temperature is too high or the time is too long, the crystal grains are excessively coarsened, thereby degrading plastic workability such as press working.

The rolled rolled material has high plastic workability because of its small variation in grain diameter and little segregation (for example, intermetallic compounds such as Mg ₁₇ Al ₁₂ ), internal defects and surface defects during casting. The occurrence of cracks and cracks is effectively reduced, and has excellent surface properties.

[Preliminary Machining Before Plastic Processing After Rolling]

It is preferable to perform the grinding | polishing process for smoothing the surface of a rolling material, and the leveler process for correcting the undulation of a rolled material, the orientation of a crystal grain, etc. to the obtained rolled material. Leveler processing is performed by, for example, passing a rolled material through a roller leveler, and the polishing processing is typically wet belt type polishing. The abrasive grains are preferably # 240 or more, more preferably # 320 or more, particularly # 600. The rolled material to which the said preliminary processing was given and the plastic working material which gave this rolling material the plastic working like press work are easy to perform the uneven | corrugated processing mentioned later.

[Plastic processing]

Plastic working such as press working, deep drawing processing, forging processing, blow processing, and bending processing have a temperature range in which the structure of the rolled material is recrystallized and the mechanical properties of the rolled material do not change significantly. Specifically, the temperature is preferably performed at a temperature of 250 ° C or lower, particularly at a temperature of 200 ° C to 250 ° C. When the plastic working is carried out on the rolled material at such a temperature, since the size of the crystal grains of the site which is not plastically deformed hardly changes, the strength of this part is hardly changed before and after the plastic working, and the high strength can be maintained, and the high strength plastic Work material is obtained.

The plastic working may be performed at any stage after the coating layer is formed, before the coating layer is formed, and after the processing of the uneven processing, which will be described later, after the processing of the uneven processing.

The heat treatment may be performed after the plastic working to remove the distortion introduced by the plastic working, to remove the residual stress, and to improve the mechanical properties. As for heat processing conditions, heating temperature: 100 degreeC-450 degreeC, heating time: 5 minutes-about 40 hours are mentioned.

<< surface processing part >>

The member of this invention is equipped with the surface process part by which the fine unevenness | corrugation process was given to at least one part of the said base material surface, It is one of the characteristics. This uneven | corrugated process is a process which contributes to raising a metal texture, Specifically, at least 1 sort (s) of a cutting process, a grinding process, a spray process, and the corrosion process using an acid is mentioned. More specifically, at least 1 sort (s) of a hairline process, a diamond cut process, a spin cut process, a shot blast process, and an etching process is mentioned. The member of this invention may be one of these processes, and the uneven | corrugated process which combined multiple types may be given.

The fine unevenness | corrugation specifically mentions that surface roughness is 1 micrometer or more and 200 micrometers or less by Rmax (maximum height: distance from a minimum position to a maximum position). If the unevenness satisfying the above range is obtained, light from the outside directed toward the member of the present invention is diffusely reflected on the surface of the member of the present invention, so that the metal texture can be sufficiently felt even when the member of the present invention is viewed from any direction. In a relatively smooth state of less than 1 mu m, excellent metallic luster is obtained in the same manner as in the case where mirror processing is substantially performed, but it is difficult to increase the metal texture, and in the rough state exceeding 200 mu m, the metal texture is difficult to be obtained. It is more preferable that surface roughness is 1 micrometer or more and 50 micrometers or less in Rmax. Moreover, in order to improve the adhesiveness of a base material and a coating layer, a base material may be roughened, but this roughening is performed so that it may not impair metal gloss, and it is thought that a metal texture does not become high.

Only a part of the surface of the base material may be sufficient as the said surface processing part, and when there is front and back in the member of this invention, only the surface side (one surface side whole surface) may be sufficient, and may reach the whole (front and back surface). However, when the above-mentioned plastic working is performed after the uneven processing, when the unevenness may be crushed by the plastic working and the metal texture may decrease, it is preferable to perform the uneven working after the above-mentioned plastic working. In particular, when the surface processing portion reaches one surface or the front and back surfaces, the unevenness is likely to be crushed by the plastic working. Therefore, the uneven processing is preferably performed after the plastic working. Or when devising the lubricating agent etc. at the time of the said plastic working, and performing plastic processing so that the unevenness | corrugation of a surface processing part may not be crushed, you may perform plastic processing after uneven | corrugated processing. For example, press-processing etc. are interposed between the raw material to which the uneven | corrugated process was performed, between sheets made of fluororesins like Teflon (trademark). When such plastic working is performed, the surface shape of the member obtained after plastic working can almost maintain the surface shape of the raw material before plastic working. Therefore, for example, the member whose base surface whole surface is a surface process part can be manufactured easily by using what the uneven process was given to the whole surface as a raw material.

<Coating layer>

The member of the present invention is characterized by having a transparent coating layer on its surface. By providing a transparent coating layer on a base material, it is easy to visually confirm the surface processing part provided in the base material surface, and it is easy to feel a metal texture. Although the coating layer may be colored and transparent, if it is colorless and transparent, the color tone and touch of the base itself of a base material are also felt, and it is thought that a metal texture is more easy to feel. On the other hand, transparent means the degree which can visually confirm a base material.

It is preferable that a coating layer has at least anticorrosiveness, and if it is equipped with a decorative property, product value can be raised and it is preferable. For example, the coating layer has a multilayer structure provided with the anticorrosive layer which has anticorrosive property, and the coating layer which functions as a protection or decoration. The anticorrosive layer is disposed on the substrate side, and the coating layer is disposed on the anticorrosive layer.

The anticorrosive layer is not particularly problematic as long as it has a desired anticorrosive property. Typical examples include those formed by anticorrosive treatment (chemical conversion treatment or anodization treatment). When the anticorrosive treatment is performed, magnesium on the surface of the substrate is oxidized to produce an oxide of magnesium, and the layer made of this oxide functions as an anticorrosive layer. This anticorrosive layer may be formed before plastic working, such as press working, or may be formed after plastic working. If an anticorrosive layer is provided before plastic working, this layer tends to function as a lubricant during plastic working. Moreover, since this anticorrosive layer is in the state which the minute crack (gold) generate | occur | produced, since the structural material of a coating layer enters into a crack, adhesiveness with a coating layer is high, and it is preferable.

If the anticorrosive layer has a small surface resistivity, specifically, 0.2 Ω · cm or less, the member of the present invention can be grounded, which is preferable. In order to make surface resistivity small, the thickness of a coating layer is mentioned, for example. If the thickness of an anticorrosive layer is 2 micrometers or less, it will become a low resistance layer. Moreover, when the said anticorrosive layer is made thin in thickness to 2 micrometers or less, especially 0.5 micrometer or less, transparency is easy to be obtained. In addition, since the surface which takes a ground (in many cases, it is the back surface of a housing) in the said housing etc. is not required to decorate in many cases, you may use only an anticorrosive layer, without forming a coating layer. What is necessary is just to mask, etc., to form the coating layer only in a desired site | part in the site | part used only for an anticorrosive layer (for example, the site | part where a low surface resistance is desired).

In addition, an anticorrosive layer can be formed using the transparent surface treating agent as described in patent document 1.

If the said coating layer is transparent, and it is excellent in adhesiveness with an anticorrosive layer, and excellent in corrosion resistance and surface hardness to some extent, it will not cause a problem in particular. For example, a known clear coating using a resin such as a transparent acrylic resin or a transparent fluorine resin can be used. In order to form a coating layer using the said resin etc., you may use any of a wet method (immersion method, spray coating, electrodeposition coating, etc.), and dry type (PVD method, CVD method). By providing such a transparent coating layer, the member of this invention can raise a metal texture and can also raise a merchandise value. When a coating layer may be damaged by plastic working, it is preferable to form after a plastic working. Moreover, when the coating layer considers the favorable display property of the metal texture in a surface processing part, the ease of manufacture, etc., it is preferable that thickness is 30 micrometers or less. When the thickness of the coating layer becomes thick, the reflected light of the light from the outside interferes with each other, the sharpness of the surface processing portion may be blurred, and the metal texture may be reduced.

Effect of the Invention

The magnesium alloy member of the present invention can increase the product value due to the high metal texture.

Hereinafter, embodiments of the present invention will be described.

[Test Example 1]

The press-formed body provided with the base material which consists of magnesium alloys, and the coating layer which coat | covers the surface was produced, and the panel test was done about the external appearance.

A base material is produced as follows. A casting material having a thickness of 5.0 mm obtained by a twin roll continuous casting method having a composition (composition corresponding to AZ91 alloy) of Mg-9.0% Al-1.0% Zn (all mass%) is prepared. Casting is carried out under the conditions described in WO / 2006/003899. This casting material is rolled. The rolling is performed by passing a plurality of passes on the heating temperature of the object to be processed (rolling object) at a temperature of 200 ° C to 400 ° C, a heating temperature of 150 ° C to 250 ° C, and a rolling reduction rate per pass of 10% to 50%. Rolled plate having a thickness of 0.5 mm. Leveler processing and grinding | polishing process are given to the obtained rolled board in order, a warm press work is given to the cut piece cut | disconnected to desired size, and a box-shaped press material is obtained. Press work is performed by placing the said cutting piece in the die which has a cuboid-shaped recessed part so that this recessed part may be covered, and pressing it with a rectangular parallelepiped punch. The punch has a rectangular parallelepiped shape of 60 mm x 90 mm, and the four corners contacting the cut pieces have a predetermined rounded shape. In addition, a heater and a thermocouple are embedded in the die and the punch, so that the temperature at the time of pressing can be adjusted to a desired temperature. Here, it heats at 200 degreeC-300 degreeC.

In addition, the intermediate heat treatment may be performed during the rolling, or the final heat treatment may be performed after the rolling to remove distortions or the like introduced into the rolling target by rolling before the heat treatment. In addition, rolling may be performed after performing a solution treatment on the cast material.

(Test Material 1-A)

In the obtained box-shaped press material, a diamond cut process of a processing radius of 50 mm, a depth of 0.02 mm (20 μm), and a pitch of 0.05 mm is performed on the entire surface (about 60 mm x 90 mm) on the protruding side. do. This processing is performed with a commercially available diamond cut machine. By this process, the surface whole denier base material (press material (firing material)) by the diamond cut process of the surface whole surface of the side which protruded is obtained.

The base material is subjected to a base treatment to form a multilayer coating layer (anticorrosive layer, coating layer), thereby obtaining a magnesium alloy member having a substrate having a surface-treated portion and a coating layer. The basic treatment is performed in the order of degreasing → acid etching → desmutting → surface adjustment. Thereafter, chemical conversion treatment → drying is performed to form an anticorrosive layer (thickness: about 0.5 m). Water washing is performed between each process from degreasing to drying. Formation of a coating layer (thickness: about 20 micrometers) takes place in order of spray application to baking. The coating layer is formed only on the outer surface side (outside of the box) of the base material, and is not formed on the inner surface side (inside of the box). Therefore, the inner surface side is masked before forming a coating layer. Hereinafter, each process is explained in full detail (concentration of each solution shows the mass%). What was obtained by this process is used as test material 1-A. In addition, when there is a defect in the surface of the substrate, putty embedding and polishing may be appropriately performed.

Degreasing: 60 ° C., 10 minutes under stirring of 10% KOH and 0.2% solution of nonionic surfactant

Acid etching: 40 ° C., 1 minute, under stirring of 5% organic phosphoric acid solution

Dismuting: 60 ° C., 5 minutes under ultrasonic stirring of 10% KOH solution

Surface adjustment: 60 degreeC, 5 minutes under stirring of the carbonic acid aqueous solution adjusted to pH8

Chemical conversion treatment: P system treatment liquid + 1% KOH made by A company which has 10% phosphoric acid as a main component is used as a processing liquid, 30 degreeC, 2 minutes, stirring

Drying: 150 ° C., 5 minutes

Spray application: Spray colorless transparent acrylic paint

Baking: 150 ° C., 10 minutes

(Test Material 1-B)

Except not performing the said diamond cut process on the obtained box-shaped press material, the sample in which the base material and the coating layer were formed similarly is set as test material 1-B.

As a result of performing a panel test with respect to the obtained test materials 1-A and 1-B, it was found that 9 out of 10 test materials 1-A had high metal texture and excellent design. I got an answer. From this result, it turns out that the magnesium alloy member which has the surface process part to which the diamond cut process was given to the surface of the base material, and is equipped with a transparent coating layer becomes high in metal texture. In addition, the object of a panel test can also be selected according to the target layer (for example, group which likes 20 personal computers, etc.) of the product using magnesium alloy members, such as a personal computer and a mobile telephone. The same applies to the following test examples.

[Test Example 2]

Except having changed the diamond cut process of the test material 1-A of the test example 1 into the hairline process, the sample produced similarly to the test material 1-A was used as the test material 2-A, and a panel test is performed about the external appearance. It was.

In this test, the hairline process whose surface roughness was 10 micrometers at Rmax (maximum height) was implemented. As a result of performing a panel test with respect to the obtained test material 2-A and the test material 1-B produced without the hairline process or the diamond cut process produced by the test example 1, about 10 arbitrary people, Eight out of ten people answered that the test material 2-A had a high metal texture and excellent design. From this result, it turns out that the magnesium alloy member which has the surface process part to which the hairline process was given to the surface of a base material, and is equipped with a transparent coating layer becomes high in metal texture.

[Test Example 3]

Except having changed the structural material of the coating layer in the test material 1-A of the test example 1, the sample produced similarly to test material 1-A was used as the test material 3-A, and the panel test was performed about the external appearance. .

In this test, a base treatment and an anticorrosive layer are formed on a base material in the same procedure as in Test Example 1, and then a colorless transparent fluororesin (Smiflon: Sumitomo Denki Kogyo Co., Ltd.) is applied and dried. By this step, Test Material 3-A having a transparent coating layer having a thickness of 25 μm is obtained.

As a result of performing a panel test with respect to the obtained test material 3-A and the test material 1-B produced in Test Example 1 (without hairline processing or diamond cut processing), an arbitrary ten people were Nine out of ten people answered that the test material 3-A had a high metal texture and excellent design.

[Test Example 4]

Except having changed the diamond cut process of the test material 1-A of the test example 1 into the etching process, the sample produced similarly to the test material 1-A was made into test materials 4-1A and 4-2A, and it showed the panel about an external appearance. The test was conducted.

The surface treatment part by the etching process of the test material 4-1A was formed as follows. After applying a resist to the surface of the box-shaped press material, a mask of a predetermined shape was placed on the surface, and the uncured portion was peeled off with a solvent to pattern a predetermined shape. Thereafter, a dry etching having a depth of 10 µm was applied to a portion where the press material (material) was exposed by an ion milling device, and finally, the resist was removed to obtain a surface on the protruding side of the press material (about 60 mm x 90 mm). Unevenness of a predetermined shape was formed in the.

The surface treatment part by the etching process of the test material 4-2A was formed as follows. After printing a predetermined shape on the surface of the box-shaped press member by screen printing, the unprinted portion is etched with a depth of 20 µm by acid, and finally, the printed portion is removed, and the surface of the protruding side of the press member is removed. Unevenness | corrugation of a predetermined | prescribed shape was formed in (about 60 mm x 90 mm).

Panel test was conducted for 10 random persons on the obtained test specimens 4-1A and 4-2A and the test specimen 1-B produced in Test Example 1 (not subjected to irregularities such as etching). It was. As a result, 7 out of 10 people answered that test material 4-1A had high metal texture and excellent design. Moreover, the answer that the test material 4-2A had high metal texture and was excellent in design from eight out of ten people was obtained.

In addition, embodiment mentioned above can be suitably changed, without deviating from the summary of this invention, It is not limited to the structure mentioned above. For example, the composition of the magnesium alloy, the conditions of casting, rolling, and plastic working, the plate thickness after casting and rolling, the method of forming the uneven processing, the forming conditions, the forming material of the coating layer, the forming method, and the like can be appropriately changed.

Since the magnesium alloy member of the present invention has a high metal texture, the magnesium alloy member can be suitably used in a field where it is desired to have excellent design properties such as housings of portable electric devices.

Claims (11)

In a magnesium alloy member comprising a base material made of a magnesium alloy and a coating layer formed on the base material, The said base material is equipped with the surface process part in which the fine unevenness | corrugation process was performed so that the metal texture may be obtained in at least one part of the surface, The magnesium alloy member, characterized in that the coating layer is transparent. The magnesium alloy member according to claim 1, wherein the base material is made of a rolled material made of Mg-Al-based magnesium alloy, and contains 8% by mass to 11% by mass of Al. The magnesium alloy member according to claim 2, wherein the base material is a press material on which the rolling material is pressed. The magnesium alloy member according to claim 1, wherein the unevenness is at least one of a cutting process, a grinding process, a spray process, and a corrosion process using an acid. The magnesium alloy member according to claim 4, wherein the uneven processing is at least one of hairline processing, diamond cut processing, spin cut processing, shot blast processing, and etching processing. The magnesium alloy member according to claim 1, wherein the surface roughness of the surface-treated portion is 1 µm or more and 200 µm or less in Rmax. The magnesium alloy member according to claim 1, wherein the coating layer includes an anticorrosive layer disposed on the substrate side and a coating layer disposed on the anticorrosive layer. The magnesium alloy member according to claim 7, wherein the anticorrosive layer comprises an oxide of magnesium. The magnesium alloy member according to claim 7 or 8, wherein the anticorrosive layer has a thickness of 2 m or less (except for 0 m). The magnesium alloy member according to claim 7, wherein the coating layer has a thickness of 30 µm or less (except for 0 µm). The magnesium alloy member according to claim 7, wherein the coating layer is made of a transparent resin.