Aluminum alloy polishing solution and preparing method thereof

Abstract

The invention relates to an aluminum alloy polishing solution, which includes the following components according to mass percent: 50 to 80wt% of phosphoric acid, 10 to 30wt% of sulfuric acid, 0.7 to 5wt% of glycerin, 0.05 to 3wt% of corrosion inhibitor, and 1 to 12wt% of surfactant. The aluminum alloy polishing solution has low corrosivity, excellent polishing effect and good market prospect, and produces no toxic nitrogen dioxide.

Description

technical field [0001] The invention relates to polishing technology, in particular to an aluminum alloy polishing liquid and a preparation method thereof. Background technique [0002] Due to their special properties, aluminum and aluminum alloy products are widely used and occupy an extremely important position in the hardware market. Aluminum products must be polished in surface treatment, which not only makes the appearance of aluminum products bright, but also uniform and smooth The surface can be dispersed to reduce the adsorption of corrosive media and improve the anti-corrosion performance. [0003] Polishing refers to the use of mechanical, chemical or electrochemical action to reduce the surface roughness of the workpiece to obtain a bright and smooth surface. At present, the main polishing technology is tri-acid polishing. [0004] Aluminum alloy tri-acid polishing technology has the following four defects that limit the application of polishing technology: [...

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Problems solved by technology

[0004] Aluminum alloy tri-acid polishing technology has the following four major defects that limit the application of polishing technology:

[0005] 1. No sanding, no mechanical lines

During the forming process of aluminum alloy, there are many mechanical lines on the surface. After three-acid polishing, the lines are more obvious, which seriously affects the appearance quality of aluminum alloy.

In addition to pretreatment with low-efficiency mechanical methods (such as sandblasting, machine polishing), etc., in recent decades, no mature technology has been developed for chemical methods for grain removal and sanding, and then polishing. Restricted the promotion of polishing technology

[0006] 2. The trickle time is too short, the medicament consumption is too large, and the yield is too low

Such a short drip time will inevitably cause two serious consequences: one is that the chemical consumption is too large, as high as 400-600kg / ton of material, and about 800Kg of caustic soda must be added for such a high waste acid treatment to treat wastewater

The second is that the finished product rate is too low, generally less than 70%. Most of the waste products are caused by flow marks or flower materials, which further increases the production cost

Therefore, although the polishing process is so simple, the cost is the highest among all oxidation pretreatment technologies, as high as 6000-8000 yuan / ton of material.

[0007] 3. The decomposition of nitric acid is too fast, a large amount of yellow smoke is seriously polluted, and the treatment cost is expensive

Nitric acid is a strong oxidizing agent. Under high temperature conditions, when encountering a highly reducing metal such as aluminum, the decomposition speed is unimaginable: a large amount of yellow smoke overflows instantly like a fire, and it is difficult to ventilate, and it is even more difficult to completely absorb it.

In addition, the fluctuation of nitric acid concentration will inevitably cause the surface of polished aluminum alloy to alternate between bright and dark, resulting in low yield

[0008] 4. Oxidation seriously loses light and the quality is greatly reduced

[0011] On the other hand, those skilled in the art have also developed corresponding diacid (phosphoric acid-sulfuric acid) type aluminum alloy polishing liquid, but the polishing effect is not satisfactory, far from the polishing effect of the nitric acid type polishing liquid

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