JP2000263442A - Treatment method of magnesium product and treatment device of magnesium product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove the burr of a magnesium product by blowing an injection material containing abrasive grains mixed in a liquid to the magnesium product formed by a primary working means by air, and then subjecting the magnesium product to chemical conversion treatment. SOLUTION: A magnesium alloy-made magnesium product 1 formed by a primary working means such as die casting or thixo-molding is subjected to wet blast treatment of blowing an injection material 2 containing abrasive grains mixed to a liquid by air, and the resulting magnesium product 1 is then subjected to chemical conversion treatment. As the abrasive grains included in the injection material 2, resin grains, metallic grains, ceramic grains or glass grains are used, and water is used as the liquid. The liquid of the injection material 2 is neutral or alkaline with pH 12 or less. According to this, a high cutting force can be exhibited with low injection force, and the burrs can be removed in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating a magnesium product and an apparatus for treating a magnesium product.

[0002]

2. Description of the Related Art Recently,
Due to environmental problems, recyclability has been regarded as important as a material for various products, and magnesium alloy, which is easy to recycle, has been increasingly used as a lightweight material instead of plastic, which is difficult to recycle and easily becomes harmful waste. .

[0003] As this magnesium alloy, M
g-Al-Zn system, Mg-Al-Mn system, Mg-Al-
Si-based, Mg-Al-rare-earth element (RE) -based and the like have been put into practical use, and are molded by a molding means such as die casting or thixomold (melt injection molding of low melting point alloy).
Subsequently, the molded product is subjected to a chemical conversion treatment, and then the chemical conversion treated product is subjected to a coating treatment to produce a product (mobile phone, personal computer, MD)
Etc. cases and parts).

[0004] The chemical conversion treatment is a treatment for forming a chemical conversion film having an anticorrosion function on the surface of a magnesium alloy, such as a chromic acid solution containing a hexavalent chromium solution as a main component or a non-chromic acid solution containing no hexavalent chromium. By immersing the magnesium alloy in the surface of the magnesium alloy, a film of a chromium chromate complex salt (generally, xCrO ₃ .yCr ₂ O _3.
Although it is explained by 2H ₂ O or Cr (OH) ₂ HCrO ₄ .2H ₂ O, the actual identity is not clear. ). After this chemical conversion treatment, a coating treatment is performed for anticorrosion and to increase commercial value.

[0005] The following problems are encountered when a product is manufactured using this magnesium alloy as a raw material.

[0006] Molded products obtained by molding means such as die casting and thixomold have burrs. In order to remove this burr, at present, the burr is punched out with a press, removed by machining such as cutting, or removed by hand finishing, but any method is troublesome work . There is also a method of removing burrs by shot blasting, in which abrasive grains are blown to the molded product with air, but magnesium alloy and abrasive grains are easily generated and scattered, resulting in poor workability and the risk of dust explosion. There is a problem of high performance.

[0007] Pretreatment when performing a chemical conversion treatment is troublesome. FIG. 1 illustrates a conventional chemical conversion treatment step. After the molded product is degreased, it is further washed with an acid, and then the molded product is removed from the molded product in order to remove the release agent used during molding. After the etching treatment, a surface conditioning treatment is performed to polish the surface into a matte surface so that a chromium chromate complex film is easily formed on the surface of the molded product (the above treatment is a pretreatment before the chemical conversion treatment). ) Then, the formed product is immersed in the chromic acid solution or non-chromic acid solution or the like to perform a chemical conversion treatment. Subsequently, the chemical conversion-treated product is washed with water and further dried at about 70 ° C. to form a chemical conversion coating. Is to be cured. As described above, before the chemical conversion treatment, a number of steps such as degreasing treatment, cleaning treatment, etching treatment surface adjustment treatment, etc., must be performed, and the work is troublesome, the treatment equipment becomes complicated, and the treatment cost is high. There are problems, such as falling.

In addition, there is a problem that a large amount of harmful waste liquid is generated in the above pretreatment at the time of performing the chemical conversion treatment.

[0009] Further, since the chemical conversion treatment and the pre-treatment at the time of performing the chemical conversion treatment employ a chemical reaction, the treatment result immediately changes depending on temperature conditions and the like, and it is difficult to obtain a uniform chemical conversion film. There is a problem that the defect rate is as high as about 10%.

[0010] When inspecting the molding state (shrinkage, void, flow, etc.) of a molded product obtained by molding means such as die casting or thixomold, buffing is partially performed manually to make the molded product easier to see. After that, the inspection is performed visually. However, since the buffing is performed manually, there is a problem that the inspection is troublesome and a problem that dust is generated at the time of the buffing.

[0011] There is no appropriate remedy for defective molding or chemical conversion treatment, and re-forming is necessary even for fine scratches, or chemical conversion treatment must be performed again by removing the chemical film using chemicals. Disappears.

According to the present invention, the pre-treatment at the time of performing the chemical conversion treatment on the magnesium alloy is a wet blast treatment,
An object of the present invention is to provide a magnesium product processing method and a magnesium product processing apparatus which have been found to solve all of the above problems and have excellent practicality.

[0013]

The gist of the present invention will be described with reference to the accompanying drawings.

After spraying, with air, an injection material 2 in which abrasive grains are mixed into a liquid onto a magnesium product 1 formed by primary processing means such as die casting or thixomold, the magnesium product 1 is subjected to a chemical conversion treatment. The present invention relates to a method for treating a magnesium product.

The magnesium product 1 formed by primary processing means such as die casting or thixomold is
The present invention relates to a method for treating a magnesium product, comprising: after spraying an injection material 2 in which abrasive grains are mixed into a liquid with air, washing the magnesium product 1 with water, and subsequently subjecting the magnesium product 1 to a chemical conversion treatment. Things.

Further, in the method for treating a magnesium product according to any one of claims 1 and 2, the abrasive grains mixed in the blasting material 2 may be resin particles having a diameter of several μm to several hundred μm, metal particles, The present invention relates to a method for treating a magnesium product, wherein ceramic particles or glass particles are used, and water is used as a liquid.

Further, in the method for treating a magnesium product according to any one of claims 1 to 3, the invention relates to a method for treating a magnesium product, characterized in that an alkaline degreasing agent is mixed into the propellant 2. .

Further, in the method for treating a magnesium product according to any one of claims 1 to 4, wherein the liquid contained in the propellant 2 is neutral or alkaline and has a pH of 12 or less. The method according to the above.

Further, a wet blasting device 3 for spraying, with air, an blasting material 2 in which abrasive grains are mixed into a magnesium product 1 formed by primary processing means such as die casting or thixomold, and a wet blasting device 3 And a chemical conversion treatment device for performing a chemical conversion treatment on the magnesium product 1 that has been wet-blasted by the method.

Further, a wet blasting device 3 for spraying, with air, an blasting material 2 in which abrasive grains are mixed into a magnesium product 1 formed by primary processing means such as die casting or thixomolding, and the wet blasting device 3 Washing device for washing the magnesium product 1 wet-blasted by the water treatment, a chemical conversion treatment device for performing a chemical conversion treatment on the magnesium product 1 washed with the water washing treatment device, and a magnesium product chemically converted by the chemical conversion treatment device A washing treatment device for washing 1
A drying device for drying the magnesium product 1 having been washed with the water by the water washing device, wherein the magnesium product 1 moves between the respective processing devices so that the magnesium product 1 is subjected to a wet blasting process, a washing process, and a chemical conversion process. The present invention relates to an apparatus for treating a magnesium product, which is configured to be able to continuously perform a water washing process and a drying process.

[0021]

Operation and Effect of the Invention Magnesium product 1 formed by primary processing means such as die casting or thixomold
In addition, by performing a wet blasting process in which the blasting material 2 in which the abrasive grains are mixed into the liquid is blown by air, burrs of the magnesium product 1 can be easily removed. Also,
Since the generated dust is taken into the liquid of the spray material 2, there is no possibility of dust explosion.

Further, since the impurities such as the release agent adhered to the magnesium product 1 can be removed by the wet blast treatment, the degreasing treatment and the cleaning treatment with an acid which have been performed as a pretreatment of the chemical conversion treatment. And the etching process can be omitted, and the chemical conversion process can be simplified.

Further, since no acid or etchant is used, no waste liquid disposal cost is required.

Further, since the abrasive 2 is obtained by mixing abrasive grains in a liquid, it is easy to recover the same, and the cost can be further reduced by repeatedly using the abrasive 2.

Further, the surface of the magnesium product 1 is polished into a fine matte surface by a physical treatment, so that a chemical conversion film is easily formed. Become.

Further, the processing heat can be satisfactorily removed by the liquid in the propellant 2, and the surface of the magnesium product 1 can be polished into a uniform finely ground surface under a certain condition, so that the chemical conversion film is uniform and uniform. It will be formed well,
The percentage of defective chemical conversion products will be reduced. According to the experiment, the defective rate was reduced to 1% or less.

If an alkaline degreasing agent is mixed into the propellant 2, the degreasing action can be further enhanced.

Since the present invention is as described above, it is possible to very easily and safely perform a pretreatment when performing a chemical conversion treatment on a magnesium alloy, and to perform a good chemical conversion treatment with less defective products. This is an extremely practical technology.

[0029]

2 and 3 show one embodiment of the present invention, which will be described below.

In the present embodiment, a wet blasting process is performed in which a blasting material 2 in which abrasive grains are mixed with a liquid is blown by air to a magnesium product 1 made of a magnesium alloy formed by primary processing means such as die casting or thixomolding. After that, the magnesium product 1 is subjected to a chemical conversion treatment.

As abrasive grains mixed in the spray material 2, resin grains, metal grains, ceramic grains or glass grains having a diameter of several μm to several hundred μm are used, and water is used as a liquid. I have.

Further, magnesium alloy has high reactivity,
If the liquid of the propellant 2 is acidic, hydrogen may be generated or an oxide film may be formed on the surface of the magnesium product 1. Therefore, the liquid of the propellant 2 is desirably neutral or alkaline. However, if the alkalinity is too high, a hydroxide film may be formed on the surface of the magnesium product 1. Therefore, it is desirable that the liquid of the propellant 2 is neutral or alkaline and has a pH of 12 or less. If the pH is 10 or more and 12 or less, the wet blast treatment can be performed more suitably.

The blasting material 2 is blasted together with air from the nozzle body 4 which blasts the blasting material 2 while keeping the abrasive grain concentration (abrasive grain / liquid) constant (see FIG. 3).

In the nozzle body 4, the injection port is provided in a slit shape. In the drawing, reference numeral 5 denotes a compressed air supply port for supplying air, 6 denotes an injection material supply port, and the injection material 2 is sucked into the nozzle body 4 by air and injected at a constant concentration (the injection material 2 / air). You. The sprayed material 2 and the shaved burrs sprayed from the nozzle body 4 fall below the nozzle body 4 and below the magnesium product 1 by free fall.

Further, the spray material 2 is made to have a constant concentration (abrasive grains / liquid) by stirring by a stirring device in the spray material collecting section. In addition, the lower part of the blast material collecting section serves as the storage section, and the blast material 2 is supplied from the storage section to the nozzle body 4 while the abrasive concentration is kept constant.

Hereinafter, the chemical conversion treatment step of the magnesium product 1 in which the wet blast treatment of this embodiment is performed as a pretreatment will be described in detail with reference to FIG.

First, wet blasting is performed on a magnesium product 1 made of a magnesium alloy formed by primary processing means such as die casting or thixomold.

Subsequently, the magnesium product 1 is washed with water to remove abrasive grains and liquid of the blast material 2 remaining in the magnesium product 1.

Subsequently, the magnesium product 1 is subjected to a chemical conversion treatment to form a chemical conversion film on the surface of the magnesium product 1.

Subsequently, the magnesium product 1 is washed with water to remove a treatment solution such as a chromic acid solution adhered to the magnesium product 1 and used during the chemical conversion treatment.

Subsequently, the magnesium product 1 is dried to harden the chemical conversion film formed on the surface of the magnesium product 1.

The following operation and effect can be obtained by performing the wet blasting as a pretreatment before the chemical conversion.

The burrs are removed from the magnesium product 1. In addition, since a liquid film is formed on the abrasive grains in the blast material 2, the surface area of the abrasive grains increases, and the liquid and the abrasive grains become particulate due to expansion of air (compressed air), thereby reducing magnesium. Since it comes into contact with the product 1, when compared with the shot blasting process, a high cutting force can be exhibited with a low injection force, and burrs can be removed in a short time.

In the shot blasting process, the cut burrs and abrasive grains are generated and scattered as dust, but in the wet blasting process, the cut burrs and abrasive grains are quickly taken into the liquid of the spray material 2. Therefore, there is no generation and scattering of dust, and there is no possibility that the dust of the magnesium alloy causes a dust explosion. In addition, since the burrs, abrasive grains, and the like are removed from the surface of the magnesium product 1 satisfactorily by the liquid in the propellant 2, the propellant 2 is always in good contact with the surface of the magnesium product 1. Thus, the wet blasting process can be favorably performed, and the occurrence of product defects can be prevented.

Since burrs, abrasive grains, and the like shaved through the liquid are handled, a simple recovery device (for example, scattered liquid particles (sharpened Such as those utilizing free fall of burrs or abrasive grains) can be used, and the work site can be made clean.

Substances that inhibit the formation of a chemical conversion film, such as oil and a release agent, attached to the magnesium product 1 during the primary processing are physically and promptly removed by the liquid, abrasive grains, or air in the injection material 2. Go. Therefore, the conventional degreasing treatment, acid cleaning treatment, and etching treatment can be performed in the same step by wet blasting. Further, if an alkaline degreasing agent is mixed into the propellant 2, the degreasing action can be further enhanced. Due to the contact of the spray material 2, a fine pear ground is formed on the surface of the magnesium product 1, so that a chemical conversion film is easily formed on the surface of the magnesium product 1. Therefore, the conventional surface conditioning can be performed in the same step by wet blasting.

The liquid in the propellant 2 satisfactorily removes the processing heat, and the surface of the magnesium product 1 is shaved by the propellant 2 under certain conditions. Therefore, the surface of the magnesium product 1 becomes uniform, and the chemical conversion film is formed uniformly in the chemical conversion treatment.

In a chemical treatment such as a degreasing treatment, an acid cleaning treatment, an etching treatment, or a shot blasting treatment, the treatment state changes due to a change in processing conditions in which it is difficult to control the temperature, humidity, and the like. Since it is hardly affected by temperature and humidity, the reproducibility can be improved by setting the injection time of the injection material 2, the type of abrasive particles contained in the injection material 2, the abrasive concentration, the air pressure, the material of the magnesium product 1, and the like. Wet blasting can be performed.

In the present embodiment, the chemical conversion treatment is simplified as a whole, and furthermore, since no chemical treatment is performed in the pretreatment, it is possible to easily obtain an apparatus for continuously performing the pretreatment and the chemical conversion treatment. it can.

That is, a wet blasting apparatus 3 for spraying, with air, an blasting material 2 in which abrasive grains are mixed into a magnesium product 1 formed by primary processing means such as die casting or thixomold, and a wet blasting apparatus 3 Washing device for washing the magnesium product 1 wet-blasted by the water treatment, a chemical conversion treatment device for performing a chemical conversion treatment on the magnesium product 1 washed with the water washing treatment device, and a magnesium product chemically converted by the chemical conversion treatment device A washing treatment device for washing 1
A drying device for drying the magnesium product 1 having been washed with water by the water washing device, wherein the magnesium product 1 moves between the respective processing devices to wet-blast, wash, and form a chemical treatment on the magnesium product 1; If the washing process and the drying process can be performed continuously, the pretreatment and the chemical conversion process of the present embodiment can be continuously performed to increase the productivity.

In this embodiment, as described above, the pretreatment of the chemical conversion treatment of the magnesium product 1 can be easily and reliably performed, and the chemical conversion film can be uniformly and favorably formed on the magnesium product 1. Practicality, workability,
This is a low cost magnesium treatment method.

Further, since no harmful chemicals such as acid and etching agent are used, the burden of waste liquid treatment is reduced, and the method for treating magnesium is more excellent in practical use.

The wet blasting process of this embodiment is performed as follows.
Conventionally, it can be performed instead of the buffing that has been performed at the time of inspection of the formed magnesium product 1. Further, in the wet blast treatment of the present embodiment, by appropriately setting the treatment conditions, the magnesium product 1 with poor molding is obtained.
Of the magnesium product 1 having a poor conversion treatment can be removed, and the defective product can be relieved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a conventional chemical conversion process.

FIG. 2 is a flowchart showing a chemical conversion process of the present embodiment.

FIG. 3 is an explanatory perspective view of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnesium product 2 Injection material 3 Wet blast processing equipment

Claims (7)

[Claims] 1. A magnesium product formed by a primary processing means such as die casting or thixomold is sprayed with air with an blasting material in which abrasive particles are mixed with a liquid, and then the magnesium product is subjected to a chemical conversion treatment. Method of treating magnesium products. 2. A spraying method in which abrasives mixed with a liquid are sprayed on a magnesium product formed by primary processing means such as die casting or thixomold with air, and then the magnesium product is washed with water. A method for treating a magnesium product, comprising subjecting the magnesium product to a chemical conversion treatment. 3. The method for treating a magnesium product according to claim 1, wherein the abrasive particles mixed into the blasting material are resin particles, metal particles, ceramics having a diameter of several μm to several hundred μm. Using grains or glass grains,
A method for treating a magnesium product, wherein water is used as a liquid. 4. The method for treating a magnesium product according to claim 1, wherein an alkaline degreaser is mixed into the propellant. 5. The method for treating a magnesium product according to claim 1, wherein the liquid contained in the propellant is neutral or alkaline and has a pH of 12 or less. Processing method. 6. A wet blasting apparatus for spraying, with air, an blasting material in which abrasive grains are mixed into a liquid on a magnesium product formed by primary processing means such as die casting or thixomold, and a wet blasting treatment by the wet blasting processing apparatus. A chemical conversion treatment device for performing a chemical conversion treatment on the treated magnesium product. 7. A wet blasting device for spraying, by air, an blast material in which abrasive grains are mixed into a liquid on a magnesium product formed by primary processing means such as die casting or thixomold, and a wet blasting process by the wet blasting device. Rinsing treatment device for rinsing the treated magnesium product with water, chemical conversion treatment device for performing a chemical conversion treatment on the magnesium product rinsed by the rinsing treatment device, and rinsing treatment device for rinsing the magnesium product chemically converted by the chemical treatment treatment device And a drying device for drying the magnesium product washed with the water by the washing device, wherein the magnesium product moves between the respective processing devices to wet-blast, wash, convert, and wash the magnesium product. Processing and drying can be performed continuously An apparatus for treating a magnesium product, wherein the apparatus is configured as follows.