JPH08199400A - Electropolishing of aluminum parts - Google Patents

Abstract

PURPOSE: To prevent the damage to a cathode plate and the cutoff of an electrolyzing current due to a blade and to efficiently electropolishing an Al member by using a Ti or Ti-alloy blade as the cathode as a counter electrode and vertically vibrating an electropolishing soln. CONSTITUTION: An Al member 1 to be electropolished is dipped in the electropolishing soln. 2 in a tank 4 as an anode, and a Ti or Ti-alloy cathode 3 provided with a blade 7 for agitating the soln. 2 with its vertical vibration is arranged in the soln. 2 in opposition to the Al member 1 as the anode 1. A voltage is impressed on the anode 1 and cathode 3 to apply a current to electropolish the Al member 1 as the anode. In this case, the cathode 3 is vertically vibrated to fluidize the soln. 2 with the blade 7, and hence the soln. is freshly supplied on the member 1 surface. Since the Al or Al-alloy cathode is used, a corrosive current is not generated between the cathode and Al member 1 as the Al anode to be electropolished, thus excellent electropolishing is conducted, the polished surface is not pitted, and the blade of the cathode is not damaged.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrolytic polishing method applied to aluminum (and aluminum alloy) parts.

[0002]

2. Description of the Related Art In electrolytic polishing of aluminum and aluminum alloy parts, there is a problem that pits are apt to occur due to adhesion of cathode gas. In order to solve this problem, the present inventor previously proposed an electrolytic polishing method using liquid agitation by a blade plate attached to a shaft that vibrates up and down in several tens of cycles. (Japanese Patent Application No. 6-241209)

A specific example of this proposed method will be described with reference to FIG. In FIG. 2, 1 is an object to be polished made of aluminum or aluminum alloy, 2 is a polishing liquid, 4 is a liquid tank, 5 is a lead wire, 6 is an electrode, 7 is a blade plate, and 8 is a stirrer.
Here, a stirrer 8 having a vane 7 is arranged between the object to be polished 1 and the electrode 6 to stir the liquid. When electrolytic polishing is performed on an object to be polished, which is a large and large panel, the arrangement is as shown in FIG. 2 described above.

[0004]

However, the previously proposed method of disposing the stirrer 8 between the object to be polished 1 and the electrode 6 causes the following problems.

(1) The stirrer 8 made of metal is caused by the bipolar potential generated between the object to be polished 1 and the electrode 6 to cause the blade plate 7 to move.
Will melt and damage the anode.

(2) A part of the electrolytic current is blocked by the vane plate 7. That is, when the distance between the stirrer 8 and the object 1 to be polished is short, the shadowed portion of the blade 7 cannot be polished well. In order to avoid this, if the stirrer 8 and the object to be polished 1 are moved away from each other, the required space of the liquid tank increases and the liquid resistance increases.

The present invention aims to solve the above problems of the conventional method and to provide an electrolytic polishing method capable of treating a large-sized aluminum or aluminum alloy.

[0008]

The present invention is characterized in that a titanium or titanium alloy electrode having a vane plate capable of generating a liquid flow accompanied by vibration in an electrolytic solution by vibrating vertically is used. This is an electrolytic polishing method for aluminum parts.

That is, in the present invention, the electrode has an electrode structure made of titanium or a titanium alloy having a vane plate, and this electrode is vibrated up and down for several tens of cycles (20 to 55 cycles) to agitate the polishing liquid and then aluminum. Electrolytic polishing is performed by facing the object to be polished (including aluminum alloy). It is preferable to use titanium or titanium alloy as the material of the blades.

[0010]

[Action]

(1) An electrode having a vane plate vibrates up and down in several tens of cycles to stir the polishing liquid, and to guide a liquid flow having a strength suitable for electrolytic polishing and vibrating to the opposite object to be polished. it can. (Acts as an electrode and agitator)

(2) By using titanium or a titanium alloy for the electrode (cathode), it is possible to prevent corrosion current from being generated between the electrode and the aluminum or aluminum alloy polishing object, and to perform favorable electrolytic polishing. (Use of stainless steel for the cathode causes harmful corrosion current)

(3) By widening the width of the cathode corresponding to the width of the object to be polished and placing the cathode opposite to each other, it is possible to electrolytically polish a large and wide skin.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. A rectangular stainless steel container with an inner surface coated with Teflon is used as the liquid tank 4, and phosphoric acid (specific gravity 1.74) 800c
c, sulfuric acid (specific gravity 1.80) 200 cc, chromic anhydride 5
The mixed liquid prepared at a rate of 0 g was used as the polishing liquid 2.

An electrode (cathode) 3 was formed by attaching a pure titanium vane plate 7 to a vertically oscillating pure titanium shaft, and an object to be polished (anode) 1 was placed facing the electrode 3. The polishing target 1 was buffed to a surface roughness Ra = 0.1 μm, and then lightly acid-etched to obtain a satin-finished A2024 material clad plate.

Electropolishing was carried out under the processing conditions shown in Table 1 below.

[0016]

[Table 1] By the above electrolytic polishing treatment, the object to be polished 1 had a mirror finished surface and no pit was observed.

[0017]

EFFECTS OF THE INVENTION According to the present invention, (1) prevention of damage to a metallic vane plate due to bipolar potential, (2) prevention of interruption of electrolytic current by the vane plate, (3) miniaturization of liquid tank, and (4) large panel The effect of making the electrolytic polishing treatment applicable can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory view of one aspect of a proposed electrolytic electrolytic polishing method for aluminum.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naofumi Kanata 10 Oemachi, Minato-ku, Nagoya, Aichi Mitsubishi Heavy Industries, Ltd. Nagoya Aerospace Systems Works (72) Inventor Noriya Isobe, Minato-ku, Aichi 10 Oemachi Mitsubishi Heavy Industries Ltd. Nagoya Aerospace Systems Works

Claims (1)

[Claims] 1. A method for electropolishing an aluminum component, which comprises using a titanium or titanium alloy electrode having a vane plate capable of generating a liquid flow accompanied by vibration in an electrolytic solution by vertically vibrating the electrolytic solution. .