JPS6015719B2 - Method for forming a matte rough surface and an etched rough surface on the surface of aluminum or aluminum alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aluminum or an aluminum alloy (hereinafter referred to as
Abbreviated as aluminum.

) relates to a method of forming a rough surface on the surface. Specifically, the present invention relates to a method of electrolytically treating aluminum in a specific fin melting bath to obtain a uniform, finely grained surface and a roughened surface in the form of etching marks on the surface thereof.
Known methods for obtaining rough G surfaces include chemical or electrolytic treatments using chloride or fluoride baths, and surface texturing methods by mechanical grinding such as honing and sandblasting.

However, the shape and properties of the sludge surface obtained by these known methods are extremely limited. Aluminum with a roughened surface is expected to have a wide range of uses, not only as a building material that requires a decorative effect, but also in fields that require a roughened surface from a physical or mechanical standpoint.

In order to meet these demands, the purpose of the present invention is to provide an aluminum having a rough surface with a wide variety of properties and shapes, including a smooth surface, a fine satin finish surface, and a rough surface with an etched surface. It is to be.

That is, the present invention contains nitrate ions from 0.01 mol/min to a saturation concentration, and also contains ammonium ions, alkali metal ions, manganese group metal ions, iron group metal ions, chromium group metal ions, steel group metal ions, An aqueous solution containing at least one cation among zinc group metal ions, carbon group metal ions, titanium group metal ions, and vanadium group metal ions is used as an electrolyte, and aluminum or aluminum alloy has an alternating current or an effect equivalent to alternating current. The present invention provides a method for forming a rough surface on the surface of aluminum, which comprises performing electrolytic treatment using a current waveform.
In the method of the present invention, an aqueous solution containing nitrate ions as anions is used as an electrolytic solution, and the feature of the present invention is that the nitrate ions in the liquid are made to selectively act on aluminum by utilizing their oxidizing and dissolving effects. There is one of these.

On the other hand, the electrolyte used in the method of the present invention contains ammonium ions and cations selected from the metal ions mentioned above, along with the above-mentioned nitrate ions.

In the method of the present invention, an electrolytic treatment is performed using an aqueous solution containing the above-mentioned anions and cations as an electrolyte, using an alternating current or a waveform current having the same effect.

In this treatment method, aluminum is oxidized and dissolved by the satin-grained surface formation effect of nitrate ions in the bath when positive polarity electricity is applied during AC electrolysis, and a satin-grained surface is formed on the surface, and when negative polarity electricity is applied, ammonium ions are formed on the surface. Aluminum is subjected to dissolution, etching, or precipitation effects by aluminum and metal cations. Among metal ions, cations of alkali metals in Group IA of the periodic table are recognized to have a stronger etching action than other cations.

Furthermore, among the same alkali metal ions, ions of elements with small atomic numbers, ie, ions of strongly alkaline elements, are recognized to exhibit a strong etching effect during electrolytic treatment. On the other hand, other metal ions including alkali metals have the property of exhibiting a precipitating action when negative polarity electricity is applied. The surface of aluminum obtained by this treatment method has a mixture of a fine and uniform satin rough surface and a rough surface with etched marks, or a mixture of a fine and uniform satin rough surface and a rough surface with metal deposit marks.

The main factors for the electrolytic conditions in the method of the present invention are the ion concentration in the electrolytic bath, bath salt, and current density.

First, regarding the ion concentration in the electrolytic solution, the treatment effect of nitrate ions is observed in the range from 0.01 mol/m to the saturation concentration. As the concentration of nitrate ions increases, its effectiveness increases, making it possible to shorten the treatment time. However, from a practical point of view, 0.1 to 1
Mol/its concentration is desirable. In addition, for ammonium ions and metal cations, the saturation concentration ranges from 0.01 mol/Z to 0.1 to 1 mol/Z, preferably 0.1 to 1
Exist within the range of Mornok. Next, the substances supplying the anions and intestinal ions will be described.

For nitrate ion combined substances, HN〇3, A〆(NQ
)3・Chihichi 20, LiN〇3, NaN〇8, KN03,
Be(N03)2, Mg(N03)2・Fine 20, Ca(
N03) 2, thin 20, Ca (NQ) 2, mountain 20, Sr (
N03)2・440,Ba(NQ)2,Zn(N03)
2. Mother L0, Fe (N03) 2. Kaede 20, Fe (N03
)3・Insects are also 0,Pb(N03)2,Ni(N03)2・
Nitrates such as Hoi 20, Mn(N03)2/Hoso 20, and NH4N03 can be used. As a cation supplying substance,
In addition to ammonia and nitrates of various metals as mentioned above, inorganic acid salts and oxalates such as nitrates, phosphates, halogenates, silicates, and borates,
Organic acid salts include tartrates, citrates, formates, and acetates.

In addition, even if other intestinal ions or anions are mixed in from tap water when preparing the electrolyte, a small amount (for example, 0
．． 01 mole/or less), there is no effect. The higher the current density is, the stronger the action and effect will be, and when performing matte roughening treatment, as the current density increases, it is observed that the time is shortened and the fineness, fineness, and uniformity are improved.

From a practical standpoint, 0.5 A/d or more is required, and usually it is in the range of 1 to 1 ship/d. Furthermore, when surface roughening with etching marks is carried out, an increase in the number and coarsening of the etched portions and precipitated portions is observed as the current density increases. When setting the current density in this case, it is necessary to consider the type of cation, etc., but it is usually 0.5A'd〆 or more,
Preferably, the range is 1 to 15 A/d. Next, regarding the temperature of the electrolytic grade, the lower the temperature, the slower the reaction, and the higher the temperature, the more active the dissolution of aluminum into the molten metal becomes, and the electrolytic roughening effect is also promoted. In normal processing, it is possible to apply a temperature range from room temperature to about 90°C. The time for electrolytic treatment should be determined in consideration of current density and other factors, but 3 to 60 minutes is usually appropriate. As a means of increasing the effect of forming a rough surface according to the present invention, an inorganic acid such as sulfuric acid, phosphoric acid, or boric acid, or an organic acid such as oxalic acid, citric acid, or tartaric acid may be added to the hydrant alone or in an appropriate combination. is valid.

In addition, it is also effective to use various acids or alkalis as pH regulators in order to constantly dissolve the aluminum ions that come out of the lacquer and to stabilize the bath. Furthermore, addition of a chelating agent (tartaric acid, citric acid, etc.) to aluminum ions is also effective. The Z effect exerted by these various additives indirectly improves the electrolytic phase effect through the additive's action of dissolving aluminum or forming an oxide film. A rough surface can be formed on the aluminum surface by the above electrolytic treatment, but in order to improve and emphasize the properties and shape of the dross surface, after the above treatment, aluminum is subjected to Kasei etching by a known method. It is effective to perform a treatment, acid etching treatment, or anodization treatment. 2 Furthermore, if dyeing treatment, alternating current electrolytic coloring treatment in a metal salt bath, or electrolytic natural coloring treatment using direct current or alternating current is performed by a known method, differences in the dyeing, coloring, and coloring treatment effects on the rough surface or roughness may occur. The optical difference of the surfaces makes the decoration even more effective.

According to the method of the present invention, it is possible to form a highly varied rough surface on an aluminum surface, in which a fine and uniform satin-like rough surface and a textured surface with large etching marks are mixed together.

3. The properties and shape of the finished surface obtained by the method of the present invention make it possible to apply it to various fields related to aluminum surface technology from a physical, mechanical or decorative point of view, and it is possible to expand the uses of aluminum products. For example, it is possible to give building materials such as aluminum sashes a decorative effect different from conventional products, and it is also possible to give decorative effects to products such as camera parts and tableware, as well as to improve their functionality. Furthermore, since the surface area is increased by the roughening treatment, scratch friction is increased, and optically it can be applied to fields where a diffused reflection surface is required. Furthermore, it is expected to be applied to fields such as the capacitor industry. Next, the present invention will be explained in detail by way of examples.

Example 1 Using aluminum 606 nail material as one pole and carbon as the opposite pole, a LINO325 tube with a maximum temperature of 50 qo/
Electrolytic treatment was carried out for 10 minutes at an alternating current density of 3 A/d in an aqueous solution (pH 5.8) of pH 5.8 (pH 5.8).

This treatment resulted in the formation of a rough surface with a coexistence of matte finish and corrosion holes. After that, the current density was 2A at 20oo in a 15% sulfuric acid bath.
Anodic oxidation was performed for 20 minutes at /d to obtain a product having an alumite surface with a mixture of satin finish and etched hole pattern. Example 2 Aluminum 6063 material was used as one electrode and carbon was used as the counter electrode to conduct an alternating current density of 10 A/d in an aqueous solution (bath temperature 2yo, pH 6.8) of NaN03100 1/2 (1.18 mo/2). Electrolytic treatment was carried out for 5 minutes.

As a result, a rough surface with a coexistence of matte texture and corrosion holes was formed. This was further subjected to case etching to obtain a product having a rough surface with a mixture of satin and etching marks. Example 3 Using aluminum 606 needle material as one electrode and carbon as the counter electrode, KN0330 evening/evening with bath temperature of 3500 (0.
3mo so/so) and Sun 2S0450 evening/at (0.5m
Electrolytic treatment was carried out for 10 minutes at an alternating current density of 10 A/d in an aqueous solution (pH below) containing 0.0/1.

As a result, a product with a uniform, fine, pit-like finished surface was obtained. After that, a product with an even more emphasized aspect was obtained by performing case etching. Example 4 Aluminum 6063 material was used for one electrode and aluminum 1100 material was used for the opposite electrode.
03) 2.' Sun 2030 evening/so (0.13 mo so'so)
1 at an alternating current density of 3 A/d in an aqueous solution (pH 6) of
Electrolytic treatment was performed for 0 minutes to form a phase surface containing a matte surface and precipitation traces.

Next, by performing an etching process, the lees surface was further emphasized. 0 Example 5 Using aluminum 6063 material as one electrode and carbon as the counter electrode, Zn(N03)2/mother L0 50 at a bath temperature of 60°C
Each powder is electrolytically treated in an aqueous solution (pH 5.8) of 0.17 molar powder at an alternating current density of 1 M'd to form a lees surface with a coexistence of a satin rough surface and a rough surface with precipitation marks. I forced it.

Thereafter, this was etched to obtain a rough surface with complex properties. Example 6 Using aluminum 6063 material as one electrode and carbon as the opposite electrode, Fe(N03)3・field L0 5 with a maximum temperature of 30 oo
Aqueous solution (below pHI) containing 0 y/c (0.12 mo y/y) and H 0410 ta'zo (0.1 mo y/s)
By electrolytically treating the sample for 10 minutes at an alternating current density IM/d force, a rough surface containing a satin finish and precipitates was obtained.

Next, this was subjected to case etching and anodized in a sulfuric acid bath to obtain a product with an alumite surface roughened into a complex shape. Example 7 Using aluminum 606q material for one electrode and aluminum 110 material for the counter electrode, Ni(N03)2 was heated at a nominal temperature of 25°C.
・Mother L0 50 min/so (0.17 mo so'so) in an aqueous solution (pH 6.4) at an alternating current density of 10 A/d for 10
Electrolytic treatment was carried out for a few minutes, and then caustic etching was performed to obtain a rough surface in which a white-like satin grain surface and a rough surface with etched marks were mixed together.

Example 8 One pole was aluminum having a rough alumite surface with a combination of satin finish and etched hole pattern obtained in Example 1,
Using stainless steel SUS as the counter electrode, the electrolyte composition was adjusted to pH 7.5 with stannous sulfate 7 t/t, tartaric acid 30 t/t, and boric acid 10 t/t, and the electrolysis temperature in this solution was 25 t/t.
o, AC current was applied for 2 minutes at a voltage of 10V.

As a result, a gold-colored film was formed on the aluminum surface. Example 9 The same operation as in Example 8 was performed except that the voltage was 13 V and the electrolysis time was 10 minutes.

As a result, a bronze-colored film was formed on the aluminum surface. Example 10 The aluminum having the complex-shaped and roughened alumite surface obtained in Example 6 was treated with 50% iron ammonium oxalate.
Evening/ Soaked in the solution at 50q0 for 10 minutes.

Claims (1)

[Claims] 1 Contains nitrate ions from 0.01 mol/l to saturation concentration, and contains ammonium ions, alkali metal ions, alkaline earth metal ions, manganese group metal ions, iron group metal ions, and chromium group metal ions. , copper group metal ions, zinc group metal ions, carbon group metal ions, titanium group metal ions and vanadium group metal ions. A method for forming a rough surface on the surface of aluminum or an aluminum alloy, characterized by electrolytic treatment using a current waveform having an effect. 2. The method according to claim 1, wherein the aqueous solution containing nitrate ions and cations is an aqueous solution containing nitrate ions at a concentration of 0.1 to 1 mol/l. 3. Claim 1, characterized in that at least one substance among an inorganic acid, an organic acid, a pH adjuster, and a chelating agent is added to an aqueous solution containing nitrate ions and cations.
or the method described in Section 2. 4. The method according to any one of claims 1 to 3, characterized in that an etching treatment or an anodizing treatment is performed after the electrolytic treatment. 5. The method according to any one of claims 1 to 3, wherein after the electrolytic treatment, a dyeing treatment, an alternating current electrolytic coloring treatment, a direct current natural coloring treatment, or an alternating current natural coloring treatment is performed. 6. The method according to claim 4, wherein after the etching treatment or the anodizing treatment, a dyeing treatment, an AC electrolytic coloring treatment, a DC natural coloring treatment, or an AC natural coloring treatment is performed.