WO2007023967A1 - Method for production of magnesium alloy molding-processed article, and magnesium alloy molding-processed article - Google Patents

Abstract

Disclosed is a method for production of a magnesium alloy molding-processed article at a high degree of processing and at a low cost. Also disclosed is a magnesium alloy molding-processed article having a glossy surface, which is produced by the method. The method comprises the steps of coating an organic resin (e.g., a water-soluble urethane resin, a water -soluble polyester resin, a water-soluble acrylic resin, a water-soluble epoxy resin, or an organic resin produced by modification of any one of these resins) or an organic resin capable of imparting a processability which is prepared by mixing any one of these resins with a silne coupling agent, colloidal silica, a lubricant, a metal alkoxide or the like onto the surface of an magnesium alloy material, molding-processing the resulting product into a desired shape, and removing the organic resin using a resin coating remover.

Description

 Specification

 Magnesium alloy molding processed body manufacturing method and magnesium alloy molding processed body

 Technical field

 TECHNICAL FIELD [0001] The present invention particularly relates to a method for producing a magnesium alloy molded processed body having a beautiful surface after molding, and a magnesium alloy molded processed body using the manufacturing method.

 [0002] Lightweight magnesium alloys are used for exterior case members of small portable electronic devices such as mopile communication devices and laptop computers, large case members such as travel suitcases and attachments for storing documents, hoods, trunk lids, Application to automotive parts such as doors and fenders has been attempted. However, it is extremely difficult to form a magnesium alloy with a high workability, which is poor in the caulking property. In order to draw such a difficult-caustic magnesium alloy, the temperature of the die, punch, and presser member of the drawing forming apparatus is heated to about 150 to 400 ° C. (for example, drawing process) Patent Document 1), die, punch and blank holder are heated, and magnesium is heated to the recrystallization temperature range through these forming tools. Magnesium is recrystallized and softens easily due to the heating. A method of heating a magnesium alloy to the recrystallization temperature range during forming, such as a magnesium alloy made by hot deep drawing of a magnesium blank in a box shape while inducing an annealing effect (see, for example, Patent Document 2). Has been proposed.

[0003] It has also been proposed to use a lubricant to facilitate processing. For example, a method of forming an ultra-hard film such as titanium nitride or diamond-like carbon on the surface of a press mold by a coating process (see, for example, Patent Document 3), biodegradable oil, anti-fouling lubricant, pole There has been proposed a method (for example, see Patent Document 4) in which a forming force is measured using a pressure additive, a plastic alloy oil for magnesium alloy or aluminum alloy containing an organic zinc compound and an organic molybdenum compound. Yes. However, these can be heated to form, processed with a lubricant, or heated with a lubricant to form. However, it cannot be applied to applications where the surface is wrinkled due to contact with a tool during processing or a beautiful surface appearance is required.

 [0004] To prevent flaws on the surface during molding caulking, a plate made of pure magnesium, pure aluminum, resin, etc., which is softer than magnesium alloy material, is attached to the surface of at least one of the punch and die. A method of processing (see, for example, Patent Document 5) or a method of placing a fluorine resin film sheet as a heat insulating material on the upper and lower surfaces of a heated magnesium thin plate and performing press molding at a high temperature (for example, see Patent Document 6) Has been proposed. But these methods

In addition, soft pure magnesium, pure aluminum, resin, or fluororesin film sheets used as cushioning materials must be replaced and used for each case, resulting in poor continuous productivity.

. In particular, since the fluororesin film sheet is expensive, the molding force body obtained by using these methods must be disadvantageous in terms of cost.

[0005] Prior art documents relating to the present invention include the following.

 Patent Document 1: Japanese Patent Laid-Open No. 2003-290843

 Patent Document 2: Japanese Patent Laid-Open No. 2002-254115

 Patent Document 3: Japanese Patent Laid-Open No. 2003-154418

 Patent Document 4: Japanese Unexamined Patent Publication No. 2003-105364

 Patent Document 5: Japanese Patent Laid-Open No. 2001-300643

 Patent Document 6: Japanese Patent Laid-Open No. 06-328155

 Disclosure of the invention

 Problems to be solved by the invention

[0006] The present invention relates to a manufacturing method for forming a magnesium alloy formed processed body at a high workability and at a low cost, and a magnesium alloy formed processed body having a beautiful surface formed by using the manufacturing method. The purpose is to provide.

 Means for solving the problem

[0007] In order to achieve the object of the present invention, the method for producing a magnesium alloy molded processed body of the present invention is a method of forming a magnesium alloy material by coating an organic resin imparting workability on the surface of the magnesium alloy material into a predetermined shape A magnesium alloy molded processed body manufacturing method characterized in that after the processing, the organic resin is removed using a resin coating removal liquid (claim 1), In the method for producing a magnesium alloy molded article according to the above (Claim 1), after removing the organic resin, the magnesium alloy material molded into a predetermined shape is subjected to surface treatment or

Z and paint (Claim 2), and

 In the method for producing a magnesium alloy molded processed product according to the above (Claim 1 or 2)! As the organic resin, water-soluble urethane resin, water-soluble polyester resin, water-soluble acrylic resin, water-soluble It is characterized by using an epoxy resin or an organic resin that has at least one of these organic resins modified with these organic resins (Claim 3), and

 In the method for producing a magnesium alloy molded article according to (Claim 3) above, any one or two of a silane coupling agent, colloidal silica, a lubricant, and a metal alkoxide are further used as the organic resin. It is characterized by the use of organic coffins containing the above (Claim 4), and

 In the method for producing a magnesium alloy molded article according to (Claim 4) above, an organic resin further containing a heat resistance imparting agent is used as the organic resin (Claim 5). And also

 In any one of the above-mentioned manufacturing methods of a magnesium alloy molded product, a liquid mainly composed of an alkaline aqueous solution having a pH of 10 or more is used as the resin coating removal liquid. (Claim 6).

[0008] Further, the magnesium alloy forming force body of the present invention is a magnesium alloy forming processed body manufactured by using any one of the above methods for manufacturing a magnesium alloy forming processed body (claims 1 to 5). (Claim 7).

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The magnesium alloy material used in the production of magnesium alloy molded mosquito卩E of the present invention, pure magnesium or aluminum 1. as an alloy component from 0 to 9.0 wt _^0/0, zinc from 0.5 to 6.0 % By weight, containing 0.05-2.0% by weight of manganese, the balance being magnesium and inevitable impurity power of mahnesium alloy, crystal grain size of 2-50 / zm, more preferably 2: LO / zm is preferable (hereinafter, in order to simplify the explanation, both pure magnesium and magnesium alloy are combined together. Called gold). These magnesium alloys are applied to the following forming processes as plate materials such as extruded materials, cutting materials, and hot rolled materials. When using plate material, the plate thickness is preferably 0.05 to 2.0 mm. The surface of these magnesium alloy materials is coated with organic resin to obtain magnesium alloy materials for forming.

[0010] The organic resin coated on the surface of the magnesium alloy material is preferably a water-soluble or water-dispersible resin, a water-soluble urethane resin, a water-soluble polyester resin, a water-soluble talyl resin, A water-soluble epoxy resin, a water-soluble acrylic-modified polyester resin obtained by modifying these organic resins, or a silicone-modified acrylic resin is preferable. These organic resin may be used alone or in combination of two or more. The amount of organic resin added is preferably in the range of 20 to 85% by weight. If it is less than 20% by weight, the formed organic resin film is undesirably damaged by processing. If it exceeds 85% by weight, there is no problem in characteristics, but it is not economical. Furthermore, since the processing temperature of the magnesium alloy material preferably exceeds 150 ° C., it is preferable to use an organic resin having excellent heat resistance.

[0011] These organic resins may be used by forming a film by coating the above magnesium alloy material with a water-soluble or water-dispersible resin alone, but in order to improve molding processability and corrosion resistance. In addition, the following substances may be used in an organic resin. When adding other substances, it is desirable to contain at least 20% by weight of water-soluble or water-dispersible fat. If it is less than 20% by weight, the formed organic resin film is undesirably damaged by processing. By including a silane coupling agent, the adhesion of the organic resin film to the magnesium material, particularly the adhesion during molding, is significantly improved. Silane coupling agents are classified according to the type of functional group such as vinylene-based, epoxy-based, styrinole-based, methacryloxy-based, attaryloxy-based, amino-based, ureido-based, black-propyl-based, mercapto-based, and isocyanate groups. All of these can be used effectively. This is presumably because the silane coupling agent has excellent binding properties, that is, adhesiveness to almost all of the resins. Specifically, epoxy-based silane coupling agent KBM403 is excellent in bonding with urethane and epoxy-based resins, and amino-based silane coupling agent KBM903 is excellent in bonding with acrylic-based resins, Excellent adhesion. Also, various urethane-based resins As a result, an amino-based silane coupling agent KBM903, which is more than just an epoxy-based silane coupling agent KBM403, can provide excellent effects. The silane coupling agent is preferably contained in the organic resin film at 5% by weight or less, more preferably 1% by weight or less. Even if it contains more than 5% by weight, the effect of improving the adhesion is saturated and is not economically advantageous.

 [0012] Further, by containing colloidal silica, the hardness of the organic resin film is improved, the abrasion resistance is improved, and the corrosion resistance is also improved. The colloidal silica is preferably contained in the organic resin film at 50% by weight or less. When the content exceeds 50% by weight, the organic resin film becomes too hard, the workability of the organic resin film deteriorates, and cracks are likely to occur in the organic resin film during molding.

 [0013] Further, by including a lubricant, the moldability of the magnesium alloy material for forming, in which the organic resin film is formed on the magnesium alloy material, is improved. Lubricants include higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, calcium salts of these higher fatty acids, aluminum salts, zinc salts, barium salts, magnesium salts, these higher fatty acid esters, Polyolefin wax such as polyethylene wax and polypropylene wax, fluorinated wax such as polytetrafluoroethylene, polytetrafluoroethylene, polyfluorinated vinylidene and polyfluoride butyl, graphite, molybdenum disulfide, Inorganic powders such as boron nitride can be used. These lubricants are preferably contained in the organic resin film in an amount of 20% by weight or less. If it exceeds 20% by weight, the adhesion of the organic resin film to the magnesium alloy during molding will deteriorate.

 [0014] Furthermore, the heat resistance of the magnesium alloy material for forming, in which the organic resin film is formed on the magnesium alloy material, is improved by containing the metal alkoxide. Metal alkoxides include boron, aluminum, titanium, vanadium, manganese, iron, and cobalt.

Among them, titanium-based alkoxides can be suitably used, among them, which can include alkoxides of copper, yttrium, zirconium, niobium, lanthanum, cerium, tantalum and tungsten. These metal alkoxides are preferably contained at 10% by weight or less in the organic resin film. If it contains more than 10% by weight, it is useful for magnesium alloy materials. The forming processability of the magnesium alloy material for forming with the machine resin film formed decreases. Each of the above silane coupling agents, colloidal silica, lubricants, and metal alkoxides may be used alone or in combination in the organic resin film! Good.

 [0015] The organic resin obtained as described above is applied to the surface of the magnesium alloy material and dried to form an organic resin film. The thickness of the organic resin film is preferably 0.1 to 50; ζ ΐη as the thickness after drying, and more preferably 1 to LO / z m. The surface friction coefficient at the working temperature at which the magnesium alloy material for forming force can be obtained in this way is preferably 0.2 or less. The friction coefficient at the processing temperature is the friction coefficient at the temperature at which the magnesium alloy material for forming force is covered, and is a HEIDON ball contact friction coefficient measuring device (Dynamic St rain Amplifer 3K-34D, Peeling / Slipping / This is the value measured using Scratching TESTER HEIDON—14).

[0016] The magnesium alloy material for forming force obtained as described above has a coefficient of friction of 0.2 or less at the processing temperature, and is excellent in formability, drawing, forging, rolling, press working. It can be suitably formed without using a solid lubricant such as lubricating oil or molybdenum disulphide, which has been conventionally used for applications such as aging. In addition, a conventional method for producing a magnesium alloy material that requires the application of a lubricating oil can also be suitably formed by using a solid lubricant such as a lubricating oil or molybdenum disulfide molybdenum that has been conventionally used. It is also possible to use the manufacturing method of the present invention capable of oil-free processing in combination and to process continuously in the conventional oil coating manufacturing process. Furthermore, when the magnesium alloy material for forming is heated to a temperature range of 350 ° C or lower, preferably 200 to 350 ° C, and further processed, compared to a temperature range of less than 200 ° C. And the molding calorie can be performed at a high degree of processing. However, when the molding process is performed in a temperature range exceeding 200 ° C, the organic resin film is decomposed and discolored or cracks are formed in the film, which deteriorates the appearance and makes it difficult to improve the calorie degree. Therefore, by adding a heat resistance-imparting agent to the organic resin film that only improves the heat resistance of the organic resin alone, the organic resin can be used in a high temperature processing temperature range of 200 to 350 ° C or lower. It is possible to stably perform molding without causing discoloration of the oil film or generation of cracks, and improving the degree of processing. it can. As a result, in a molding alloy of a magnesium alloy material for forming force, a processing temperature at which the same workability as that obtained when a conventional lubricating oil is used is obtained in a temperature range of 350 ° C. or lower. It is possible to lower the temperature, and there is an advantage that unnecessary heat treatment is unnecessary. Needless to say, it is not necessary to apply lubricant during molding.

 [0017] As the heat resistance-imparting agent, it is preferable to use a heat-resistant resin such as polyimide or a siloxane compound. Examples of the siloxane compound include polymers and monomers of organosiloxanes such as dimethylsiloxane, jetylsiloxane, methylethylsiloxane, diphenylsiloxane, and methylphenylsiloxane, or polyalkyleneoxide groups, hydroxyl groups in these organosiloxane molecules. , An amide group, a carboxyl group, a sulfone group, and an amino group, those having one or more substituents of two or more are preferably used. These heat resistance imparting agents are preferably contained in the organic resin film at 5 to 80% by weight, more preferably 10 to 60% by weight. Thus, by including a heat resistance-imparting agent in the organic resin film, the magnesium alloy material for forming is heated to a warm working temperature range of 200 to 350 ° C., and a molding case is formed at a high degree of processing. It is possible to do this. The heat resistance imparting agent may be contained alone in the organic resin, but may be contained in combination with one or more of the above silane coupling agent, colloidal silica, and lubricant. Good.

[0018] On the surface of the magnesium alloy molded casing thus molded, the organic resin film remains and adheres. Depending on the application, it may be used as it is, or may be further coated on the organic resin film as required. However, when applied to applications where a beautiful metal surface itself is required, the organic resin remaining on the surface must be removed. The organic resin can be removed by spraying abrasive particles onto the surface using a shot blasting method, but the surface shape changes, so it is preferable to remove it using a removing solution. As the removing liquid, it is preferable to use a liquid mainly composed of an alkaline aqueous solution having a pH of 10 or more, to which a surfactant or the like imparting wettability or wettability is added. If the pH is 10 or less, it takes a long time to remove. The alkaline aqueous solution is inexpensive, and the remaining alkaline aqueous solution after removing the organic resin is easily washed away with water. Since post-drying can be performed, the cost required for the process of removing the organic resin can be reduced.

 [0019] The magnesium alloy forming force body of the present invention can be obtained as described above. In order to impart corrosion resistance and aesthetics, the formed processed body is further subjected to known anodizing treatment, chemical conversion treatment, plating. A surface treatment such as, or a transparent or colored coating may be applied. Or, after applying any of these surface treatments, apply a transparent or colored paint on top of it.

 [0020] A magnesium alloy molded article produced using the production method of the present invention as described above has a beautiful metal surface, and is a small portable electronic device such as a mopile communication device or a notebook computer. The present invention can be suitably applied to exterior case members for equipment, large case members such as suitcases for travel and attaché cases for storing documents, and automotive members such as hoods, trunk lids, doors, and fenders.

 Example

 Hereinafter, the present invention will be described in detail with reference to examples.

 (Making magnesium alloy materials for forming)

 As magnesium alloy material for forming, the silane coupling shown in Table 1 on the resin solution shown in Table 1 or the resin shown in Table 1 on both sides of a 0.4 mm thick magnesium alloy plate having the following alloy components: A resin solution containing an agent, colloidal silica, lubricant, metal alkoxide, and heat resistance imparting agent is dried so that each additive has the content shown in Table 1 in the dried state. The resin film was coated with a bar coater so that the thickness of the resin film was as shown in Table 1 and dried to prepare a magnesium alloy material for molding for testing.

 <Alloy composition>

 Al: 3.1 wt%, Zn: l. 1 wt%, Mn: 0.31 wt%, balance: Mg and inevitable impurity elements

 <Average crystal grain size>

 8 ^ m

[0022] [Table 1]

(Making of magnesium alloy molding case)

The magnesium alloy material for forming force obtained as described above is squeezed under the following conditions. Thus, a magnesium alloy molded casing was obtained. The processing temperature was the same as that of the die and blank holder, and only the punch temperature was room temperature. In addition, the friction coefficient at the processing temperature was measured with a HEIDON friction coefficient measurement device with a holder heating device. During measurement, after the magnesium alloy material for forming force fixed to the holder was heated to the temperature at the time of the caulking, the contact ball was a SUS ball with a diameter of 10 mm attached to the device, a measuring load of 200 g, and a measuring time 1. Measurement was performed under conditions of 6 mmZsec.

 <Punch shoulder R>

 5mm

 <Punch temperature>

 Hanging iini

 <Dice temperature>

 200. C, 250 ° C

 <Blank holder temperature>

 200. C, 250 ° C

 <Aperture speed>

 ImmZ seconds

 <Lubricating oil and lubricant>

 No lubricating oil or lubricant is used when processing the magnesium alloy material of the present invention

 [0024] As a comparative example, a sample obtained by applying commercially available plastic cask oil G3080 (manufactured by Nippon Tool Oil Co., Ltd.) on both sides of the above magnesium alloy material was applied to both sides of sample number 17 and the magnesium alloy material. A sample attached with a 50 μm thick fluororesin film was drawn under the same conditions as Sample No. 18 to obtain a magnesium alloy molded body for comparison.

[0025] (Removal of organic resin film)

 From the magnesium alloy molded casing of the present invention obtained as described above, the remaining organic resin film was removed under the following conditions.

 <Removal bath>

 Bath composition

Top Magster 100 (Okuno Pharmaceutical Co., Ltd.) 300mLZL Top Magster 100AD (Okuno Pharmaceutical Co., Ltd.) lOmLZL

 Aqueous solution

 pH 13.4

 Bath temperature 70 ° C

 Agitation

 Immersion time 10 minutes

 Thus, it was set as the test material shown by the sample numbers 1-13.

[0026] (Surface treatment)

 Sample No. 3 was anodized under the following conditions as a surface treatment to obtain Sample No. 14.

 <Anodizing treatment>

 Bath composition

 Ammonium dichromate 40gZL

 Ammonium sulfate 25gZL

 Ammonia water 3. OmL / L

 Bath temperature 40 ° C

 Stirring bath circulation

Current density lAZdm ²

[0027] (painting)

 A transparent polyester resin coating was applied to the sample material of sample number 3 so that the thickness after drying was 10 m and dried to obtain a sample material of sample number 15.

[0028] (Surface treatment and painting)

Sample No. ³ was anodized in the same manner as Sample No. 14 and then coated in the same manner as Sample No. 15 to give Sample No. 16 Samples were used.

[0029] (Comparative specimen)

Lubricating oil adhering to the surface of the magnesium alloy molded body of the comparative example was removed with acetone, and a sample No. 17 specimen was obtained. In addition, the magnesium alloy molded processed body of the comparative example was peeled off from the fluorocarbon resin film and used as a test material of sample number 18. [0030] (Evaluation of surface appearance of magnesium alloy molded product)

 The appearance of the magnesium alloy molded casings of sample numbers 1 to 18 obtained as described above was visually observed and evaluated according to the following criteria.

 A: No damage is observed on the sample surface.

 ◯: Damage causing practical problems is not recognized.

 Δ: Damage causing practical problems is observed.

[0031] (Evaluation of post-processing properties)

 With the magnesium alloy molded body of sample numbers 14 to 16, the state of the post-treatment (anodic acid treatment or Z and coating) performed after removing the remaining organic resin film was visually observed, and the following Evaluation based on the criteria.

 ◯: Appearance that is a problem in practical use is not recognized at all.

 These results are shown in Table 2.

[0032] [Table 2]

表 2に示すように、マグネシウム合金材に有機榭脂を被覆して成形加工を施した後 、有機榭脂除去液を用いて残存付着した有機榭脂を除去して得られる本発明のマグ ネシゥム合金成形加工体は、高加工度で成形加工可能であるとともに、これまでの潤 滑油を用いて成形カ卩ェしたマグネシウム合金成形カ卩ェ体と比較して、表面に殆ど疵 を生じることが無ぐ高価なフッ素榭脂フィルムを用いたマグネシウム合金成形加工 体と同等の美麗な表面状態が得られる。さらに、本発明のマグネシウム合金成形カロ ェ体力 残存付着した有機榭脂皮膜を除去した後、耐食性や外観を向上させるため の陽極酸ィ匕処理などの表面処理または zおよび塗装などの後処理を、問題なく適用 することができる。

As shown in Table 2, the magnesium alloy material of the present invention obtained by coating a magnesium alloy material with an organic resin and performing a forming process, and then removing the remaining organic resin using an organic resin removing solution. The alloy formed body can be formed at a high degree of workability, and almost no wrinkles are generated on the surface compared to the magnesium alloy formed case formed by using a conventional lubricating oil. A beautiful surface state equivalent to that of a magnesium alloy molded body using an expensive fluorocoating film with no wrinkles can be obtained. Furthermore, in order to improve the corrosion resistance and appearance after removing the organic resin film that has adhered to the magnesium alloy molded calorie body strength of the present invention. Surface treatments such as anodic acid treatment or post-treatments such as z and painting can be applied without problems.

Industrial applicability

 According to the present invention, the surface of the magnesium alloy material is coated with an organic resin imparting processability and formed into a predetermined shape, and then the organic resin is removed using a resin coating removing liquid. Magnesium alloy molded products that are molded using the manufacturing method of magnesium alloy molded products can be molded with a high degree of processing, and can also be molded using conventional lubricants. Compared to the magnesium alloy molded processed body, it has a beautiful surface equivalent to the magnesium alloy molded processed body formed by using an expensive fluororesin film that is difficult to be wrinkled on the surface. In addition, the organic resin can be easily removed using an inexpensive removal solution. Therefore, when manufacturing a magnesium alloy molded processed body using the manufacturing method of the present invention, the obtained magnesium alloy molded processed body has a beautiful surface free of wrinkles and can be manufactured at low cost. The exterior case material of small portable electronic devices such as mopile communication devices and laptop computers, large case materials such as suitcases for travel and attache cases for storing documents, hoods, trunk lids, doors, fenders, etc. It can apply suitably for the member for motor vehicles.

Claims

The scope of the claims  [1] The surface of the magnesium alloy material is coated with an organic resin imparting processability and formed into a predetermined shape, and then the organic resin is removed using a resin coating removal liquid. The manufacturing method of the magnesium alloy forming processed body.  [2] The magnesium alloy molded processed body according to claim 1, wherein after the organic resin is removed, a surface treatment or Z and coating are applied to the magnesium alloy material molded into a predetermined shape. Production method. [3] As the organic resin, any one of a water-soluble urethane resin, a water-soluble polyester resin, a water-soluble talyl resin, a water-soluble epoxy resin, or a resin obtained by modifying these organic resins. 3. The method for producing a magnesium alloy formed article according to claim 1 or 2, wherein one or two or more kinds of organic resin is used. [4] The organic resin comprising one or more of a silane coupling agent, colloidal silica, a lubricant, and a metal alkoxide as the organic resin. Item 4. A method for producing a magnesium alloy molded article according to Item 3. 5. The method for producing a magnesium alloy molded processed body according to claim 4, wherein an organic resin further containing a heat resistance imparting agent is used as the organic resin. [6] The magnesium alloy forming process according to any one of claims 1 to 5, wherein a liquid mainly composed of an alkaline aqueous solution having a pH of 10 or more is used as the resin coating removal liquid. Body manufacturing method.  [7] A magnesium alloy molded article produced by using the production method according to any one of claims 1 to 6.