JPS5922800B2 - Anode parts for aluminum anodizing treatment - Google Patents

Description

Detailed Description of the Invention The present invention provides a rack or clip that serves as an electrical contact for supporting and energizing an aluminum-based material to be anodized in anodizing electrolytic treatment (commonly known as alumite treatment) of aluminum or aluminum alloy. This relates to anode members such as.

In general, aluminum materials such as pure aluminum and aluminum alloys are mainly used as anode members used for anodizing treatment of 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, the portion immersed in the electrolytic solution is anodized together with the product, and an anodic oxide film is generated on the surface. In other words, since the same amount of power flows from the surface of the anode member as from the surface of the product, there is a problem of extremely large power loss. Furthermore, as mentioned above, the anodic oxide film formed on the surface of the anode member is non-conductive, so when reusing the anode member, it is necessary to dissolve and remove the anodic oxide film in order to obtain an electrical contact. be. In actual operation, the anodic oxide film is removed by dissolving it with an alkaline solution, or the anodic oxide film of the anode member is removed with these processing solutions, which also serves as alkali degreasing or chemical polishing performed as a pretreatment for the product. In this way, anode members made of aluminum are gradually worn out due to repeated formation and removal of anodized film each time a product is processed, so new ones may be replaced before they lose sufficient strength to support the product. Therefore, the cost of the anode member cannot be ignored in the operating cost. Further, as mentioned above, a considerable amount of chemicals are consumed to remove the anodic oxide film, and the cost required for this process also increases considerably. On the other hand, with anode members made of titanium material, the anodic oxide film that is generated on the surface during anodizing treatment is extremely thin, and the film is easily destroyed by the pressure caused by the product's racking. There is no need to dissolve and remove the anodic oxide film, and therefore the titanium is less consumed, so it can be used repeatedly for a long period of time. Furthermore, the amount of current flowing out from the titanium material during the anodization process is significantly smaller than that from the aluminum material, and therefore power loss is also significantly smaller. In this way, anode members using titanium materials have various advantages compared to anode members using aluminum materials, and because they have significantly higher strength and springiness than aluminum materials, they are also heavier and heavier. It is an important material as a racking member for anodizing long aluminum products such as aluminum products and aluminum sashes, and as an anode member for high current density anodizing. For example, in alumite treatment of aluminum sash, due to strength requirements, a titanium anode member is used as shown in Fig. 1, that is, a titanium clip member 1 and a titanium bolt 2.
is often used. In FIG. 1, the clip member 1 is made in a U-shape so as to sandwich the end of the product 3, and has a bolt hole 4 formed therein for attachment to an aluminum main body (not shown), and is also used to press the product 3. A female screw hole 5 is formed into which a titanium bolt 2 for holding is screwed. However, although titanium anode members as mentioned above have a small amount of wear, if they are used frequently, they often break or get damaged due to racking. This has become a problem.

For example, in a titanium anode member as shown in FIG.
Breakage accidents of titanium bolts 2 occur quite frequently,
For this reason, there is a problem that the replacement or maintenance of broken parts causes a significant decrease in work efficiency, and the collapse of the threads of the titanium bolt 2 and the threads of the female threaded hole 5 leads to electrical contact failure, and the anode of the product There are problems such as non-uniform oxide film thickness, which greatly affects the quality of the product. As a result of repeated investigations and studies by the inventors of the present invention into the causes of the breakage and damage accidents of titanium materials used as anode members as described above, it was found that environmental corrosion during a series of steps of anodizing treatment (mainly due to environmental corrosion in a reducing atmosphere caused by sulfuric acid) It became clear that the main cause was embrittlement due to hydrogen absorption associated with corrosion.

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. They also tested the corrosion resistance of zircaloy alloys, zirconium, and titanium against sulfuric acid itself. 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, hydrogen embrittlement caused by environmental corrosion is suppressed in anode members using zircaloy alloy or zirconium, especially zircaloy alloy.
It has become clear that there is almost no risk of breakage or damage occurring when titanium material is used.

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 has been found that the properties as an anode member are comparable to or better than those using titanium material, such as being able to be used repeatedly for a long period of time.

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 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. Therefore, the inventors of this invention conducted further experiments and studies, and found that depending on the usage conditions, there may be a movable part that presses and locks the product, or a movable part that movably supports and movable. Even if only the functional parts, such as the parts that make electrical contact with the parts, are made of Zircaloy alloy or zirconium, and the other structural parts are made of aluminum or aluminum alloy, it is the same as if the whole part was made of Zircaloy alloy or zirconium. We found that it is possible to achieve the following objectives. For example, in the final process of alumite finishing of aluminum sash as mentioned above, the product is often coated with resin, and in this case, the anode member is also coated with resin, and movable parts such as bolts for pressure holding and electrical contacts are coated with resin. An insulating film is formed on the removed structural parts.

That is, since the structural portion of the anode member is insulated from the electrolyte, that portion will not wear out even if it is made of aluminum or aluminum alloy. On the other hand, breakage or damage is likely to occur in movable parts such as pressure holding bolts that directly receive the load of the product, and threaded parts that support them movably, and even these parts are made of Zircaloy alloy. If it is made of zirconium, there is less risk of breakage or damage. Therefore, in anode materials used for alumite treatment of aluminum sash,
Even if only the functional parts such as moving parts are made of Zircaloy alloy or zirconium, and the other structural parts are made of aluminum or aluminum alloy, it will not only cause no problems, but it will also be better than if the entire structure was made of Zircaloy alloy, etc. Raw material costs are significantly lower. Furthermore, if the entire anode member 1 is made of Zircaloy alloy or the like as shown in FIG. As mentioned above, if the structural parts of the anode member 1, especially the parts to be attached to the aluminum main body, are made of aluminum or aluminum alloy, it becomes possible to fix the anode member 1 to the aluminum main body by welding. ,
It is possible to prevent contact failures that tend to occur due to bolt attachment. Therefore, the anode member of the present invention is characterized by being constructed by integrating a zirconium alloy material represented by Zircaloy or a zirconium material and an aluminum material or an aluminum alloy material, and is particularly suitable for treating products. Functional parts such as a movable part for pressing and holding and a movable support part that movably supports the movable part and makes electrical contact with the movable part are made of zirconium alloy or zirconium, and other structural parts are made of aluminum or aluminum. It is made of alloy. Embodiments of the present invention will be described in detail below with reference to the drawings. Figures 2 and 3 are diagrams showing an embodiment in which the present invention is applied to a so-called clip-shaped anode member for holding and supporting a product to be processed, such as an aluminum sash, and is generally U-shaped as a whole. The member body 10 is made of aluminum or aluminum alloy, and one of the left and right projecting pieces 10A, 10A' of the member main body 10 has a groove parallel to the longitudinal direction of the bottom side 10B. A through hole 11 is formed.

A hollow cylinder 12 made of Zircaloy alloy or zirconium is fitted into this through hole 11 . This cylindrical body 12 has a female thread 13 formed on its inner peripheral surface, and is fixed to the member main body 10 by caulking both ends of the cylindrical body 12 to both end edges of the through hole 11. Note that the female thread 13 of this cylindrical body 12 is carved after the cylindrical body 12 is fixed to the member main body 10 by caulking. Furthermore, a bolt 14 made of Zircaloy alloy or zirconium is screwed into the female thread 13 of the cylindrical body 12. This bolt 14
This is for pressing the processed product 15 such as aluminum sash and holding the processed product 15 between the projecting piece 10A' of the member body 10. In the configuration of the above-described embodiment, the bolt 14 corresponds to the above-mentioned movable part, and the cylindrical body 12
corresponds to the above-mentioned movable support section, and furthermore, the member main body 10 corresponds to the above-mentioned structural section.

Since the member main body 10 is made of aluminum or an aluminum alloy, it can be fixed by welding to a power supply main body (not shown) which is usually made of aluminum or an aluminum alloy. The anode member of the above-mentioned example was used for anodizing an aluminum sash for 6 months, but there was no accident of breakage of the bolt 14 or collapse of the thread of the female screw 13.

Furthermore, under the same conditions, the conventional titanium anode member shown in FIG. 1 was used for anodizing an aluminum sash, but in this case, bolt breakage and thread collapse occurred within 1 to 3 months. In addition, in this invention, the first Zircaloy alloy
Any of the species from species to type 4 can be used.

Furthermore, zirconium alloys other than zircaloy alloys can be used as long as they are mainly composed of zirconium. Furthermore, as the zirconium alloy or zirconium material used for the mechanical parts, it is of course possible to use not only ordinary processed materials (rolled materials, extruded materials, etc.) but also high-density powder molded materials. As is clear from the above description, the anode member of the present invention is constructed by integrating a zirconium alloy or zirconium material with aluminum or an aluminum alloy material. The material cost is much lower than other components, and like anode components made entirely of zirconium alloy or zirconium, it can prevent breakage and damage accidents that occur with titanium anode components, and can be used in various ways. Compared to an anode member made entirely of aluminum, it has various advantages, such as much less wear and tear and less power loss.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a conventional anode member made of titanium, Fig. 2 is a partially cutaway front view showing an embodiment of the anode member of the present invention, and Fig. 3 is a perspective view taken along the - line in Fig. 2. FIG. 10... Member body (structural part), 12...
- Cylindrical body (moving support part), 14... Bolt (movable part).

Claims (1)

[Claims] 1 An integral unit consisting of a movable part for pressing the product to be processed, a movable support part that movably supports this movable part and makes electrical contact with this movable part, and a structural part to which this movable support part is fixed. An anode member for aluminum anodizing treatment, characterized in that at least the movable part is made of a zirconium alloy material or a zirconium material, and the structural part is made of an aluminum alloy or aluminum.