The effects of accelerators, fluorides, Mn2+, Ni2+, Zn2+, PO4; and Fe2+on the aluminum phosphating process were studied in detail using SEM, XRD, potential time curve, and film weight change methods. Research has shown that guanidine nitrate has the characteristics of good water solubility, low dosage, and rapid film formation, making it an effective promoter for aluminum phosphating. Fluoride can promote film formation, increase film weight, and refine grain size; Mn2+and Ni2+can significantly refine the grain size, make the phosphating film uniform and dense, and improve the appearance of the phosphating film; When the concentration of Zn2+is low, it cannot form a film or has poor film formation. As the concentration of Zn2+increases, the film weight increases; The content of PO4 has a significant impact on the weight of the phosphating film, so increasing PO4 is necessary. The content increases the weight of the phosphating film.

The alkaline electrolytic polishing process of aluminum was studied using an alkaline polishing solution system, and the effects of corrosion inhibitors, viscosity agents, etc. on the polishing effect were compared. A highly effective alkaline solution system was successfully obtained, and for the first time, an additive was obtained that can reduce operating temperature, extend the service life of the solution, and improve the polishing effect.

The experimental results show that adding appropriate additives to NaOH solution can produce good polishing effect. Exploratory experiments also found that under certain conditions, the surface reflectivity of aluminum can reach 90% after direct current constant voltage electrolytic polishing using a NaOH solution of glucose. However, due to unstable factors in the experiment, further research is needed. The feasibility of using DC pulse electrolytic polishing method to polish aluminum materials under alkaline conditions was explored. The results showed that the use of pulse electrolytic polishing method can achieve the leveling effect of DC constant voltage electrolytic polishing, but its leveling speed is slow.

The development of an environmentally friendly chemical polishing technology for aluminum and aluminum alloys using phosphoric acid monosulfate as the base solution has been determined. This technology aims to achieve zero NOx emissions and overcome the quality defects of similar technologies in the past. The key to the new technology is to add some compounds with special effects to the base liquid to replace nitric acid.

Firstly, it is necessary to analyze the three acid chemical polishing process of aluminum, with a particular focus on studying the effect of nitric acid. The main function of nitric acid in aluminum chemical polishing is to suppress pitting corrosion and improve polishing brightness. Based on the chemical polishing test in pure phosphoric acid monosulfate, it is believed that the special substance added to phosphoric acid monosulfate should be able to inhibit pitting corrosion, slow down overall corrosion, and must have good leveling and brightening effects.

The electrochemical surface strengthening treatment of aluminum and its alloys. The process, properties, morphology, composition, and structure of anodic oxidation deposition of aluminum and its alloys in a neutral system to form a ceramic like amorphous composite conversion film were studied, and the film formation process and mechanism were preliminarily explored.