JP3746212B2 - Method of processing magnesium alloy members for press forming - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for processing a magnesium alloy member for press forming .
[0002]
[Prior art and problems to be solved by the invention]
Magnesium alloy is the lightest of all practical metals, with a specific gravity of about 2/3 that of aluminum. Furthermore, it has excellent specific strength and is easy to recycle by remelting. Used as automobile parts and household appliance parts.
[0003]
By the way, a magnesium alloy is very active (reactive) and easily rusts as it is, so that a rust prevention treatment is essential.
[0004]
In general, this rust prevention treatment is performed by subjecting a magnesium alloy member to a chemical treatment or other chemical conversion treatment as a pretreatment, followed by a coating treatment on the surface of the member.
[0005]
However, in this method, the coating is not stable due to the presence of the lubricant used in the molding of the magnesium alloy member and the segregation of impurities in the magnesium alloy, and many pretreatments are required. In addition, there is a problem that the yield is poor.
[0006]
Further, the film formed on the surface of the magnesium alloy member by the chemical conversion treatment has a drawback that it is very thin and easily peeled off, a disadvantage that the member is colored brown to gray, and the coloring is not uniform. In the end, the coating process must be performed twice or triple to form a strong and thick coating on the surface of the member, and the yield is poor in this respect as well. There is a problem.
[0007]
Furthermore, if the coating is thick, the surface of the magnesium alloy member will be determined by the coating color, and the high-class feeling due to the metal-specific luster will disappear, and the texture will be the same as that of the plastic member. There is a problem.
[0008]
The present invention solves the above-described problems, and is excellent in practicality, such as making the surface of a magnesium alloy member a glossy surface and allowing the surface to be reliably rust-proofed. A method for treating a magnesium alloy is also provided.
[0009]
[Means for Solving the Problems]
The gist of the present invention will be described with reference to the accompanying drawings.
[0010]
A processing method for a magnesium alloy member 1 for press molding, the member 1 surface by ejecting with compressed gas a first injection material liquid fine abrasive grains are mixed into the surface of the member 1 polished, subsequently, the member gloss allowed imparted to the surface of the member 1 and the second injection material liquid into fine spherical abrasive grains are mixed in the first surface by ejecting with compressed gas, subsequently, Ya etching Without performing a pretreatment such as acid cleaning, the member 1 is held in an electrolyte containing fluoride salts and phosphoric acid or the phosphoric acid salts, and subjected to electrolytic treatment to form an anode on the surface of the member 1 The present invention relates to a method for treating a magnesium alloy member for press forming, wherein an oxide film is directly formed .
[0011]
Further, the processing method according to claim 1 magnesium alloy member for press molding according to 1, as a second injection material in the fine spherical abrasive, press molding, characterized in that it has adopted as a particle size of 20 to 100μm The present invention relates to a method for processing a magnesium alloy member for use .
[0012]
Moreover, in the processing method of the magnesium alloy member 1 for press molding according to any one of claims 1 and 2, polygonal abrasive grains are employed as fine abrasive grains in the first injection material. The present invention relates to a method for processing a magnesium alloy member for press forming .
[0013]
Moreover, in the processing method of the magnesium alloy member 1 for press molding according to any one of claims 1 to 3, a fine abrasive grain in the first injection material having a particle diameter of 50 to 100 µm is adopted. The present invention relates to a method for treating a magnesium alloy member for press forming .
[0014]
Further, in the processing method of the magnesium alloy member 1 for press forming according to any one of claims 1 to 4, the concentration of fluoride salt is 0.2 to 2 mol / liter as an electrolyte, phosphoric acid Alternatively, the present invention relates to a method for treating a magnesium alloy member for press forming, wherein an electrolytic solution in which the concentration of the phosphoric acid salt is set to 0.05 to 0.5 mol / liter is employed.
[0015]
Moreover, in the processing method of the magnesium alloy member 1 for press molding according to any one of claims 1 to 5 , an electrolytic solution containing 0.05 to 0.1 mol / liter of an organic compound is used as the electrolytic solution. The present invention relates to a method of processing a magnesium alloy member for press forming, which is characterized by being adopted.
[0016]
[Action and effect of the invention]
A magnesium alloy member 1 of the surface of the press-molding, firstly, by injecting with compressed gas a first injection material liquid fine abrasive grains are mixed, and polishing the surface of the member 1, further wherein After removing surface residues such as lubricant used in molding the member 1 remaining on the surface, the surface of the member 1 is compressed with a second injection material in which fine spherical abrasive grains are mixed. When sprayed with gas, the surface of the member 1 is smoothed and textured by the contact of the fine spherical abrasive grains and the like, and emits a metallic luster.
[0017]
The member 1 without pre-treatment such as chemical etching process, it is possible to perform as anti-rust treatment, the magnesium alloy member 1 for press molding obtained by the rust-preventive treated metal gloss It can have.
[0018]
Since the present invention as described above, the surface of the magnesium alloy member for press-molding can be glossy surface, further, it is also possible to perform a reliable anticorrosive treatment on the surface of the member very the processing method for a magnesium alloy member of the press-molding Xiu was practical.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The drawings illustrate one embodiment of the present invention and are described below.
[0020]
A processing method for a magnesium alloy member 1 for press molding, the member 1 surface by ejecting with compressed gas a first injection material liquid fine abrasive grains are mixed into the surface of the member 1 Then, the surface of the member 1 is given a gloss by spraying the surface of the member 1 together with the compressed gas by spraying a second injection material in which fine spherical abrasive grains are mixed into the liquid. 1 is subjected to rust prevention treatment.
[0021]
Further, the magnesium alloy for press forming is appropriately selected from various magnesium alloys such as Mg—Al, Mg—Al—Zn, Mg—Zn, Mg—Zn—Zr, and rare earth-containing alloys. Can be used.
[0022]
Member 1 of the magnesium alloy is traditional, molding is a member is a low cost obtained by press-forming a press-molding magnesium alloys has been a end cost difficult anticorrosive treatment 1 (housing) .
[0023]
The liquid used for the first propellant can be selected from various types such as water, alcohol, chemical solution, and the like.
[0024]
As the fine abrasive grains used for the first spray material, polygonal abrasive grains having a cutting force are preferably employed so that the surface of the member 1 can be polished satisfactorily.
[0025]
For the same reason, hard ceramics such as alumina may be used as the material for the fine abrasive grains.
[0026]
The fine abrasive grains having a particle diameter of 50 to 100 μm are preferably used from the viewpoint of processing efficiency during mass production and the surface roughness of the member 1.
[0027]
Moreover, you may employ | adopt various things, such as air, an inert gas, nitrogen gas, as the compressed gas injected with a 1st injection material.
[0028]
Even if air is used as the compressed gas, the activity (reactivity) of the surface of the member 1 is suppressed by the liquid of the first propellant, and the member 1 does not react with oxygen in the air.
[0029]
The first injection material and the compressed gas are injected to the member 1 by the wide nozzle body 3 shown in FIG. In the figure, reference numeral 2 is an injection material, 4 is an injection material introduction part, and 5 is a compressed gas introduction part. According to the nozzle body 3, the first spray material is sprayed in a curtain shape, and the entire surface (one surface) of the member 1 can be treated simply by moving the member 1 below the nozzle body 3.
[0030]
According to the injection of the first injection material, a part of the surface of the member 1 is excised, the roughness of the surface of the member 1 is corrected by the excision, and the lubricating oil used at the time of molding the member 1 The surface impurities such as are also removed. That is, the surface of the member 1 is made uniform by the injection of the first injection material.
[0031]
The liquid used for the second propellant can be selected from the same liquid as the first propellant, that is, water, alcohol, chemical solution, and the like.
[0032]
As the fine spherical abrasive used for the second spray material, it is preferable to adopt a fine spherical abrasive that can crush and smooth the fine irregularities on the surface of the member 1.
[0033]
Various materials such as glass, alumina, and zirconia can be adopted as the material for the fine spherical abrasive grains.
[0034]
The fine spherical abrasive grains have a particle diameter that can satisfactorily crush fine irregularities, specifically, those having a particle diameter of 20 to 100 μm (smaller than the fine abrasive grains of the first injection material are better). Is adopted.
[0035]
Moreover, you may employ | adopt various things, such as air, an inert gas, nitrogen gas, as the compressed gas injected with a 2nd injection material similarly to the compression gas injected with a 1st injection material.
[0036]
This 2nd injection material and compressed gas are injected by the nozzle body 3 shown in FIG. In order to avoid confusion of the spray material, the nozzle body 3 is preferably used separately for the first spray material and the second spray material.
[0037]
According to the injection of the second injection material, the fine irregularities on the surface of the member 1 are crushed by the fine spherical abrasive grains, and thus the surface of the member 1 is smoothed and textured to exhibit a metallic luster. .
[0038]
In addition, the site | part which injects this 2nd injection material may be only the exposure site | part when the member 1 (casing) is made into a product, or it integrates into the other member 1 and makes it a product.
[0039]
According to the above treatment with the first propellant and the second propellant, the magnesium alloy member 1 having a metallic luster is obtained.
[0040]
Subsequently, the magnesium alloy member 1 is subjected to rust prevention treatment.
[0041]
As described in the prior art, in general, when a rust preventive treatment is applied to a magnesium alloy member, a plurality of pretreatments such as chemical etching treatment and acid cleaning are applied to the member. In the example, the rust prevention treatment is performed by directly forming a corrosion-resistant film on the surface of the member 1 without performing the pretreatment. This is possible because the surface of the member 1 is made uniform by the injection of the first injection material and the injection of the second injection material, and impurities and the like are removed.
[0042]
A method of forming a corrosion-resistant film on the surface of the member 1 is obtained by holding the member 1 in an electrolytic aqueous solution containing fluoride salts and phosphoric acid or salts of the phosphoric acid, and subjecting the surface of the member 1 to electrolytic treatment. A method of forming an anodic oxide film is employed.
[0043]
The concentration of fluoride salts in the electrolyte is set to 0.2 to 2 mol / liter.
[0044]
As the fluoride salts to be used, any of acidic salts and basic salts such as ammonium hydrogen fluoride, sodium hydrogen fluoride, hydrofluoric acid, sodium fluoride, and fluoride can be adopted.
[0045]
The concentration of phosphoric acid or salts of phosphoric acid in the electrolytic solution is set to 0.05 to 0.5 mol / liter.
[0046]
The phosphoric acid or salts of phosphoric acid used may be any of acidic salts and basic salts such as sodium hydrogen phosphate, ammonium hydrogen phosphate, sodium phosphate, tripotassium phosphate, etc. It is better to select the acid salt to be a pair of an acid and a base (for example, when an acid salt is employed as a fluoride salt, a basic salt is employed as a phosphate salt).
[0047]
Moreover, you may add a bath stabilizer to this electrolyte solution as needed.
[0048]
As the bath stabilizer, for example, an organic compound having a hydroxyl group, specifically, ethylene glycol, glycerin or the like is employed.
[0049]
In addition, this bath stabilizer contributes to the stability of the bath (electrolytic solution) in a relatively small amount, and if it is too much, the conductivity of the electrolytic solution may be adversely affected and the rust preventive film may be defective. The concentration is preferably set to about 0.05 to 0.1 mol / liter.
[0050]
As the power source used for the electrolytic treatment, any of direct current, alternating current, pulse current, PR, and the like can be used in the same manner as a power source used for general anodizing treatment.
[0051]
The power supply voltage can be variously selected in consideration of the thickness of the anodic oxide film produced on the member 1 and the processing time. However, rapid formation of the anodic oxide film is liable to decrease the film strength or deteriorate the appearance. Therefore, it is better to set the power supply voltage to 100 volts or less.
[0052]
In addition, after forming the anodized film, in order to further improve the rust prevention (corrosion resistance) of this anodized film, a sealing process performed after the normal anodizing process (a process of closing many holes formed on the surface of the film) ) Should be implemented.
[0053]
This sealing treatment is performed by, for example, immersing the member 1 on which the anodized film is formed in a sodium silicate aqueous solution or pure water having a liquid temperature of 90 ° C. or higher to form a hydrate layer on the surface of the anodized film. The method of forming is adopted.
[0054]
According to the above rust prevention treatment, the magnesium alloy member 1 is obtained which retains the high-grade gloss peculiar to the metal surface and is subjected to the rust prevention treatment.
[0055]
By the way, the anodic oxide film formed on the surface of the member 1 by the rust-proofing treatment is not intended to exhibit strong corrosion resistance like other known rust-proof coatings, but leaves the metallic luster on the member 1. While trying to give the minimum necessary rust prevention. Therefore, it can be said that the rust prevention of the surface of the member 1 is incomplete with this anodized film alone. Therefore, in order to further enhance the rust prevention, the member 1 may be subsequently subjected to a coating treatment.
[0056]
Various known coating processes can be employed for this coating process. However, the normal coating process is performed a plurality of times, and two layers, three layers, and a coating layer are formed on the surface of the member. In this embodiment, in order to leave the metallic luster, the member 1 A method of forming a single coating layer on the surface is adopted.
[0057]
Since the present embodiment is as described above, it has a high-grade gloss peculiar to metal, further exhibits strong corrosion resistance due to the anodized film and the coating layer, and is further colored in various colors by painting. It becomes the processing method of the magnesium alloy excellent in the practicality from which the member 1 made from a magnesium alloy is obtained.
[0058]
Further, even in the case of the member 1 by press molding, which is inexpensive but has poor corrosion resistance due to the alloy component, and sufficient corrosion resistance was not obtained even by formation of an anodized film or formation of a coating layer, this example Therefore, good corrosion resistance can be exhibited, and practicality can be imparted to the inexpensive member 1 obtained by this press molding.
[0059]
In addition, it is not necessary to use special chemicals or harmful chemicals in the process of imparting gloss to the member 1, rust prevention treatment, painting treatment, etc. Therefore, each treatment is performed at a low cost and hazardous substances are discarded. Large-scale processing equipment is not required for this purpose, and in this respect also, it is excellent in practicality, productivity, and cost reduction.
[0060]
In addition, since no pretreatment for rust prevention treatment is required, the treatment process is simplified in this respect, and the utility and productivity are excellent.
[0061]
Moreover, since only one layer of the anodized film or coating layer formed on the surface of the member 1 is sufficient, the process is simplified in this respect, and the practicality and productivity are excellent. .
[0062]
The experimental results confirming the effects of this example will be described below.
[0063]
Experimental example 1
The first injection material was injected together with the compressed gas onto a magnesium rolled plate made of AZ31 (magnesium alloy for press containing about 3% aluminum and about 1% zinc) and having dimensions of 120 × 50 × 0.6 (mm).
[0064]
The conditions are as follows.
[0065]
Liquid: Water Fine abrasive: Alumina # 120 (less than about 100 μm)
Concentration of fine abrasive grains: 18% (v / v)
Compressed gas: air Compressed gas pressure: 0.2 MPa
Pump pressure for injecting the first injection material: 0.1 MPa
Movement speed of member 1: 10 mm / sec
[0066]
After the treatment, the attached fine abrasive grains were washed away and dried.
[0067]
The surface of the obtained member 1 was a uniform matte surface, and no residue or surface defects were observed visually.
[0068]
Then, the 2nd injection material was injected to the same member 1 with compressed gas.
[0069]
The conditions are as follows.
[0070]
Liquid: Water Fine spherical abrasive: Zirconia bead particle size of about 50 μm
Concentration of fine spherical abrasive grains: 18% (v / v)
Compressed gas: air Compressed gas pressure: 0.2 MPa
Pump pressure for injecting the second injection material: 0.1 MPa
Movement speed of member 1: 30 mm / sec
[0071]
After the treatment, the adhered fine spherical abrasive grains were washed away and dried.
[0072]
The surface of the obtained member 1 had a high-quality silver gloss. When this surface was enlarged and confirmed, countless dimple-like dents and light spots were observed, and it was confirmed that the gloss was due to the shape transfer of fine spherical abrasive grains.
[0073]
Subsequently, the member 1 was directly subjected to rust prevention treatment.
[0074]
The electrolytic solution used was 1 mol / liter of sodium fluoride, 0.05 mol / liter of trisodium phosphate, 0.1 mol / liter of glycerin, and an electrolytic treatment was performed for 10 minutes at a DC voltage of 50 volts.
[0075]
After the treatment, it was washed with water and dried, and the cross section of the anodized film was observed, and it was confirmed that a uniform anodized film having a thickness of 2 to 3 μm was formed.
[0076]
Subsequently, an epoxy paint was applied to the member 1 to a thickness of 15 μm without a primer.
[0077]
The obtained member 1 was finished with a very high-quality surface compared with the surface of the member on which the conventional two-layer or three-layer coating layer was formed, leaving a slight roughness of the substrate.
[0078]
When this member 1 was subjected to a 100 square gobang test (JIS-K5600, a method for evaluating the adhesion of a coating film), 100/100 and no peeling of the coating occurred. Further, a salt spray test was carried out on this member 1 for 2 hours by spraying for 8 hours and stopping for 16 hours, but no corrosion was observed (see FIG. 2).
[0079]
Comparative Example 1
The AZ31 test plate was sprayed with the first spray material and the second spray material in the same manner as in Experimental Example 1 and further subjected to the salt spray test. Was crumbled.
[0080]
Comparative Example 2
In the same manner as in Experimental Example 1 on a test plate made of AZ31, the first spray material and the second spray material were sprayed, followed by the chrome oxidation treatment, and the salt spray test was performed. Innumerable through-holes were observed, and the corrosion area ratio reached 25%.
[0081]
Comparative Example 3
In the same manner as in Experimental Example 1 on the AZ31 test plate, injection of the first injection material and injection of the second injection material was performed, and a salt spray test was performed on the same anodized film as in Experimental Example 1. As a result, the corrosion area ratio was 8%.
[0082]
Comparative Example 4
In the same manner as in Experimental Example 1 on a test plate made of AZ31, the first injection material and the second injection material were injected, and only the voltage was set to 100 volts to form the same anodized film as in Experimental Example 1. When the salt spray test was carried out, the corrosion area ratio was 2%.
[0083]
The above experimental results, according to this embodiment, while having a metallic luster, it was confirmed that the very magnesium alloy member 1 of high corrosion resistance press molding can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a nozzle body 3 of the present embodiment.
FIG. 2 is a table showing corrosion areas after a salt spray test in an experimental example.
[Explanation of symbols]
1 member

Claims (6)

A method for processing magnesium for press forming alloy member, by polishing the surface of the member by injecting with compressed gas a first injection material liquid fine abrasive grains are mixed into the surface of the member, Subsequently, the surface of the member is given a gloss by injecting a second injection material, in which fine spherical abrasive grains are mixed into the liquid, together with the compressed gas , and then, before etching, acid cleaning, etc. Without performing the treatment, the member was held in an electrolyte containing fluoride salts and phosphoric acid or the phosphoric acid salts, and an anodized film was directly formed on the surface of the member by electrolytic treatment. A method for treating a magnesium alloy member for press forming . In the processing method of the magnesium alloy member for press molding according to claim 1 wherein magnesium for press molding as fine spherical abrasive grains in a second injection material, characterized by being adopted as the particle size 20 to 100μm A method for processing an alloy member . In the processing method of the magnesium alloy member for press molding according to any one of claims 1, 2, press forming as fine abrasive grains in the first injection material, characterized in that employing a polygonal abrasive grains Of processing magnesium alloy members for use in a process. In the processing method of the magnesium alloy member for press molding of any one of Claims 1-3, The thing with a particle size of 50 thru | or 100 micrometers was employ | adopted as a fine abrasive grain in a 1st injection material, A method for processing a magnesium alloy member for press forming . 5. The method for treating a magnesium alloy member for press molding according to claim 1, wherein the electrolyte has a concentration of fluoride salt of 0.2 to 2 mol / liter, phosphoric acid or the phosphorous. A method for treating a magnesium alloy member for press forming , characterized in that an electrolytic solution having an acid salt concentration of 0.05 to 0.5 mol / liter is employed. In the processing method of the magnesium alloy member for press molding of any one of Claims 1-5 , the electrolyte solution containing 0.05 thru | or 0.1 mol / l of organic compounds was employ | adopted as electrolyte solution A method for treating a magnesium alloy member for press forming .

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