In my country's traditional aluminum alloy chemical polishing solution, the more widely used is phosphate-sulfate-nitrate chemical polishing solution. Depending on the relative content of its phosphate, it can be divided into class A (low relative content of phosphate) and class B (high content of phosphate). The composition and polishing temperature of the three -acid polishing fluid are as follows.
Long -term industrial production has found that trigly acid can basically meet product requirements, but there are also fatal defects, such as yellow smoke (toxic gas, pollution environment), and no environmental requirements. Therefore, I summarized some defects.
1. Severe oxidation, and the quality is greatly reduced. Three -acid polishing can generally form a mirror surface. Once anode oxidation, the gloss is greatly reduced.
2. The decomposition of nitric acid is too fast, a large amount of yellow smoke pollution is severe, and the treatment costs are expensive. Nitric acid is a strong oxidant. Under high temperature conditions, when encountering aluminum, a very restored metal, the fast decomposition speed is unimaginable: a large amount of yellow smoke overflows like a fire, it is difficult to pull the wind, it is more difficult to absorb it! In addition, it is more difficult! In addition, it is even more difficult! In addition, The upper and lower fluctuations of the concentration of nitric acid will inevitably cause the surface of the polished aluminum alloy to be alternately alternate and the finished product rate is low.
3. Do not set up sand and go to mechanical patterns. During the molding process of aluminum alloy, there are many mechanical patterns on the surface. After tribne polishing, the lines are more obvious, which seriously affects the appearance quality of the aluminum alloy. In addition to the pre -processing of mechanical methods with low efficiency (such as sand spray, machine throw), in recent decades, mature technologies that have not developed chemical methods for removal and sand supporting processing, and then polishing. It restricts the promotion of polishing technology.
4. The drip time is too short, the medicament consumption is too large, and the yield rate is too low. Therefore, although the polishing process is so simple, the cost is the highest in all pre-oxidation treatment technology! Up to 6000-8000 yuan/ton material. After the aluminum alloy leaves the polishing fluid, the dripping time in the air generally must not exceed 30 seconds, otherwise the flow marks will occur and waste products. The flow of polishing materials is a world problem that plagues the aluminum processing industry. Such a short time dripping time will inevitably cause two major serious consequences: one is that the medicament consumption is too large, and it is as high as 400-600kg/ton material. The finished product rate is too low, generally less than 70%. Most waste products are caused by flow marks or flower materials, which further increases production costs. At present, the generally used method is to use chemical polishing to remove pony additives for polishing raw solution to solve the problem of flow marks.
With the deepening of research, many manufacturers on the market have used nicotin -free dual -acid chemical polishing high -gloss highlights, mainly composed of phosphate and sulfuric acid, which will not produce yellow smoke and can meet environmental protection requirements.
