Environment-friendly chemical conversion processing technology for aluminum alloy

Abstract

The invention relates to an environment-friendly chemical conversion processing technology for an aluminum alloy, and belongs to the technical field of aluminum alloy surface processing. The environment-friendly chemical conversion processing technology includes the chemical conversion film preparation process steps that a pre-processed aluminum alloy is obtained by conducting the oil removing working procedure, the alkali corrosion working procedure and the acid pickling working procedure on the surface of the aluminum alloy; then, the chemical conversion film forming working procedure and the hole sealing processing working procedure are conducted on the surface of the pre-processed aluminum alloy; wherein chemical conversion processing fluid required by chemical conversion film formingprocessing includes following components, namely, a H3PO4 solution with the concentration being 10 mL / L to 50 mL / L, NaF with the concentration being 3.5 g / L to 10.5 g / L, K2TiF6 with the concentrationbeing 1.0 g / L to 4.0 g / L, Na2WO4 with the concentration being 1.0 g / L to 5.0 g / L and 5-sulfosalicylic acid with the concentration being 1.5 g / L to 5.0 g / L; the pH value of the chemical conversion processing fluid is between 2.00 and 4.00, the conversion temperature is 30 DEG C to 50 DEG C, and the aluminum alloy chemical conversion processing time is 5 min to 15 min; and a solution used for hole sealing processing includes sodium molybdate with the concentration being 10 g / L to 20 g / L. The environment-friendly chemical conversion processing technology is simple in processing technology, low incost, green and environment-friendly, and a formed conversion film has good corrosion resistance.

Description

technical field [0001] The invention relates to an aluminum alloy environment-friendly chemical conversion treatment technology, which belongs to the technical field of aluminum alloy surface treatment. Background technique [0002] Aluminum has a fairly strong electronegativity and a strong affinity for oxygen. It forms a thin oxide film in the atmosphere. On the one hand, it cannot meet the needs of industrial protection, and on the other hand, it affects the stability of product quality. Therefore, its surface usually needs to be chemically treated. Conversion treatment to improve the corrosion resistance of the aluminum alloy substrate and the adhesion to the subsequent organic coating. However, the traditional treatment methods (such as chromate treatment and phosphating treatment) are currently restricted due to problems such as high toxicity and environmental pollution. However, many emerging environmentally friendly chemical conversion treatment processes are diffic...

AI Technical Summary

Problems solved by technology

However, traditional treatment methods (such as chromate treatment and phosphating treatment) have been restricted in use due to problems such as high toxicity and environmental pollution.

However, many emerging environmentally friendly chemical conversion treatment processes are difficult to meet the requirements of corrosion resistance and coating adhesion at the same time.

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