JPS5922798B2 - Anode parts for aluminum anodizing treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used to support and energize an aluminum-based material to be treated in aluminum anodizing electrolytic treatment consisting of alumite treatment and secondary electrolytic coloring treatment of aluminum or aluminum alloy. The present invention relates to an anode member.

In general, pure aluminum or aluminum alloys are mainly used as anode members used for anodizing aluminum-based materials, and titanium materials are also used in some cases.

However, the aluminum material used as the anode member has various problems due to its characteristics as described below. That is, since the anode member immersed in the electrolytic solution is made of the same aluminum material as the product to be treated, it is anodized together with the product. In other words, since the same amount of current as the product flows out from the surface of the anode member, there is a problem of extremely large power loss. In addition, as mentioned above, an anodized film is produced on the surface of the product, but since this anodized film is non-conductive, when reusing this anode member, it is necessary to remove the electrical contacts. In order to obtain this, it is necessary to dissolve and remove the anodized film. In actual operation, it is dissolved and removed with an alkaline solution, or it is dissolved and removed with these processing solutions, which also serves as alkali degreasing or chemical polishing, etc., performed as a pretreatment for the product. In this way, the anode member made of aluminum gradually wears out as the anodic oxide film is repeatedly formed and removed each time the product is processed, so it is necessary to maintain sufficient strength to support the product. Therefore, the cost of the anode member cannot be ignored in the operating cost. Furthermore, as mentioned above, there is also the problem that a considerable amount of chemicals are consumed to remove the anodic oxide film. On the other hand, for anode members using titanium materials, the anodic oxide film produced during anodizing treatment is extremely thin and easily destroyed by the pressure caused by product racking. No need to dissolve and remove
Therefore, since there is little consumption of titanium, it can be used repeatedly for a long period of time. Furthermore, the amount of current flowing out from the titanium material during anodizing electrolytic treatment is extremely small, and therefore power loss is significantly lower than that of aluminum anode members. In this way, anode members using titanium materials have various advantages compared to aluminum anode members, and because they have significantly higher strength and springiness than aluminum materials, they can be used for heavy-duty aluminum. It is an important material as a racking member for long aluminum products such as products and aluminum sashes, and as an anode member in high current density anodic oxidation processing.
However, although titanium anode members have a small amount of wear and tear, when they are used frequently, they often break or get damaged due to racking, and this is a problem when using titanium materials for anode members. . Particularly in the alumite treatment of aluminum sashes, titanium racking members are sometimes used due to strength requirements. Replacement and maintenance of parts can lead to a significant drop in work efficiency, and the collapse of the threads of the titanium bolts and the threads of the female threads that these bolts are screwed into can lead to electrical contact failures, resulting in product damage. There are problems that have a major impact on product quality, such as uneven thickness of the anodic oxide film. The inventors of the present invention have repeatedly investigated and researched the causes of the above-mentioned breakage and damage accidents of titanium materials used as anode members, and have found that environmental corrosion (mainly corrosion in a reducing atmosphere caused by sulfuric acid) during a series of steps of anodizing treatment. ) was found to be the main cause of embrittlement due to hydrogen absorption.

The inventors of this invention conducted repeated research to find a new material that would solve the problems of titanium anode members as described above, and found that zirconium was made of titanium as proposed in Japanese Patent Application No. 1987-8701. It has become clear that the problem of the anode member can be solved and that the zircaloy alloy proposed in Japanese Patent Application No. 52-89637 and Japanese Patent Application No. 52-123171 is more suitable than the above-mentioned zirconium.

That is, when the corrosion resistance of titanium, zirconium, and zircaloy alloys against a sulfuric acid treatment solution (alumite treatment solution) during anodic oxidation electrolysis was tested, the results shown in Table 1 below were obtained. Note that the treatment solution here is 15% at 20°C.
The measured value is the weight after 30 minutes in 20V constant voltage electrolysis and the degree of erosion calculated from the amount of weight loss. Furthermore, when the corrosion resistance of zircaloy alloy, zirconium, and titanium to sulfuric acid itself was tested, the results shown in Table 2 below were obtained.

Here, 10% H2SO4 at 70°C was used as the sulfuric acid.
Each material was immersed in this for 5.5 hours, and the weight loss, degree of corrosion, and degree of erosion were determined. From the results in Table 1, it can be seen that titanium suffers a weight loss due to corrosion during anodic oxidation. This means that hydrogen absorption easily occurs in the atmosphere, and from the results in Table 2, titanium actually undergoes significant environmental corrosion in the sulfuric acid treatment solution after anodic oxidation electrolysis. It is expected that hydrogen absorption will occur.

On the other hand, zircaloy alloys or zirconium, especially zircaloy alloys, undergo almost no corrosion weight loss during anodic oxidation, resulting in a complete anodic oxide film and extremely good corrosion resistance against sulfuric acid itself. It is clear that environmental corrosion is less likely to occur. Therefore, in an anode member using a zircaloy alloy or zirconium, especially a zircaloy alloy, hydrogen embrittlement due to environmental corrosion is suppressed, and there is almost no risk of breakage or damage occurring when titanium material is used. It became clear.

In addition, zircaloy alloys and zirconium are available in previously filed Japanese Patent Application No. 53-8701 and Japanese Patent Application No. 52-896.
As disclosed in No. 37 and Japanese Patent Application No. 52-123171, the anodic oxide film produced during the anodizing electrolytic treatment is extremely thin (usually about several hundred amps), and is therefore similar to that when titanium material is used. Since there is no need to dissolve and remove the anodic oxide film, it can be used repeatedly for a long period of time, and it has high strength compared to titanium, and the current flowing out from the surface of the material is extremely small, especially for Zircaloy alloys. It has become clear that the properties as an anode member are about the same as or better than when titanium is used, such as about 1/30 of titanium.

For example, regarding the current flowing out from the surface of the anode member, the test results for Zircaloy alloy, zirconium, and titanium members used in anodizing electrolytic treatment are shown in Table 3 below. Here, the electrolytic treatment test is 20
Performed potentiostatically in a 15% H2SO4 bath at 20 °C,
The current density on the surface of the member was measured immediately after the start of electrolysis and after 30 minutes had passed. Thus, zircaloy alloy or zirconium is the most suitable material for the anode member.

However, all of these materials have extremely high material costs, and therefore, if the entire anode member is made of a zircaloy alloy or zirconium, there is a risk that the material costs will become significantly high. This invention was made against the background of the above-mentioned circumstances, and it is possible to combine a zirconium alloy such as zircaloy or metallic zirconium with copper or a copper alloy, thereby making the entire structure made of a zirconium alloy or metallic zirconium. The same effect can be obtained as
Moreover, it is an object of the present invention to provide an anode member whose material cost is significantly reduced.

That is, the anode member of the present invention is characterized by being constructed by integrating a zirconium alloy material such as Zircaloy or a zirconium material with a copper material or a copper alloy material, and in particular, the anode member is composed of a zirconium alloy material such as Zircaloy or a zirconium material and a copper material or a copper alloy material. The non-immersed part, which is not immersed in the electrolytic treatment solution, is made of copper or copper alloy material, thereby achieving the same characteristics as an anode member when the entire body is made of zirconium alloy or zirconium. It was designed to obtain

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of an anode member of the present invention.

In FIG. 1, a concave-shaped frame 1 is formed by bending a bar or tube made of zirconium alloy or zirconium, and between both ends of the upper part of this frame 1, copper, cypronickel, aluminum bronze, An upper connecting piece 2 made of a rod or rectangular piece of copper alloy such as aluminum brass or brass is horizontally suspended, and both ends of this upper connecting piece 2 are made of copper or a similar copper alloy as mentioned above at both ends of the upper part of the frame 1. It is fixed by a fixing member 3 such as a rivet or bolt. Further, in the center of the upper connecting piece 2, there is a locking part 4 for hooking onto a bus bar (not shown), that is, a conductor rod on the electrolytic treatment tank to energize it, and attaching it to a fixing member 5 such as a rivet or bolt similar to the above. It is twisted and fixed. The locking portion 4 is also made of copper or a copper alloy similar to the above, and is made by bending a rectangular material made of copper or a copper alloy, for example. However, when performing anodizing treatment etc. using the anode member of the above embodiment, one or more products to be treated such as aluminum are placed between the upper connecting piece 2 and the lower side of the frame 1. 6 are hung in a bead shape by aluminum wire rods 7, the locking part 4 is hooked to the busbar, and the holder is immersed in the electrolytic bath.

Here, the concave-shaped frame 1 is immersed in the electrolytic treatment solution up to a position near its upper end, while the upper connecting piece 2 and the locking part 4 are not immersed in the electrolytic treatment solution but are immersed in the electrolytic treatment solution. To position. Therefore, the frame 1 is the above-mentioned immersed part, and the upper connecting piece 2 and the locking part 4 constitute the non-immersed part. The immersed portion is made of a zircaloy alloy or zirconium, and the non-immersed portion is made of copper or a copper alloy. In the above configuration, the frame body 1 is a immersed part that is immersed in the electrolytic treatment solution, so it has high corrosion resistance and hydrogen absorption embrittlement resistance, has a small amount of current flowing out from the surface, and has low consumption, or the anode The oxide film is required to be thin and easily destroyed, and as mentioned above, zirconium alloys and zirconium are extremely superior in these respects.

On the other hand, since the upper connecting piece 2 and the locking part 4 are non-immersed parts that are not immersed in the electrolytic treatment solution, there is no problem even if the material is a material that is subject to significant current flow and wear in the treatment solution, and the corrosion resistance of the immersion part is also improved. It's not as demanding. That is, the non-immersed portion only needs to have good electrical conductivity as a member for feeding power from the bus bar to the frame and a certain degree of corrosion resistance. However, copper or a copper alloy has high conductivity and relatively good corrosion resistance, and thus satisfies the above-mentioned conditions for a non-immersed part. In addition, using the anode member of the above-mentioned example (length: 550 m x width: 40,011 cm), in which the immersed part was made of Zircaloy alloy and the non-dipped part was made of copper, the series of alumite treatment steps were repeated 250 times in actual operation. However, no change in appearance or weight due to corrosion was observed in both the immersed and non-immersed areas, and the alumite treatment was successfully performed each time.

In addition, the immersion part was changed to zirconium and actual operation was carried out in the same manner, but the results were the same as described above. Furthermore, in the anode member of the present invention, the first Zircaloy alloy is
Any of the types from seeds to types 4 can be used.

In addition, even if it is a zirconium alloy other than Zircaloy,
Any material containing zirconium as a main component can be similarly used. As is clear from the above description, the anode member of the present invention is composed of a zirconium alloy represented by zircaloy, or a composite of zirconium and copper or a copper alloy, so that the anode member of the present invention is composed entirely of zirconium alloy or zirconium. The material cost is much lower than that of the anode member, and especially in the embodiment where the immersed part is made of zirconium alloy or zirconium and the non-immersed part is made of copper or copper alloy, the whole is made of zirconium alloy or zirconium. This has a remarkable effect in that almost the same good properties as those made of zirconium can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the anode member of the present invention. 1... Frame body (immersed part), 2... Upper connecting piece (non-immersed part), 4... Locking part (non-immersed part)
.

Claims (1)

[Claims] 1 A concave-shaped frame body that is immersed in the electrolytic treatment solution is made of a zirconium alloy material or a zirconium material, and each has an upper connecting piece that is not immersed in the electrolytic treatment liquid, and an upper connecting piece that is integrally attached to this upper connecting piece and that is immersed in the electrolytic treatment liquid. Aluminum anodization, characterized in that a locking part that is locked and connected to a conductor rod on the processing tank is made of steel or a copper alloy, and the upper connecting piece is integrally attached to both ends of the upper part of the frame. Anode parts for electrolytic treatment.