How to deal with surface technology of die castings

The phosphating of aluminum was studied in detail by means of SEM, XRD, potential-time curve, film weight change and other methods. The effects of accelerators, fluorides, Mn2+, Ni2+, Zn2+, PO4; Studies have shown that guanidine nitrate has the characteristics of good water solubility, low dosage and rapid film formation, and is an effective promoter for phosphating of aluminum materials; fluoride can promote film formation, increase film weight, and refine grains; Mn2+, Ni2+ can significantly Refine the grains, make the phosphating film uniform and dense, and can improve the appearance of the phosphating film; when the Zn2+ concentration is low, the film cannot be formed or the film forming is poor, with the increase of the Zn2+ concentration, the film weight increases; Heavy influence is greater, increase PO4. The content increases the weight of the phosphating film.

The alkaline electrolytic polishing process of aluminum has carried out research on the alkaline polishing solution system, and compared the effects of corrosion inhibitors and viscosity agents on the polishing effect. Additives that reduce operating temperatures and extend solution life while also improving polishing results.

The experimental results show that adding appropriate additives in NaOH solution can produce good polishing effect. The exploratory experiment also found that the reflectivity of the aluminum surface can reach 90% after DC electropolishing with NaOH solution of glucose under certain conditions, but further research is needed due to the unstable factors in the experiment. The feasibility of using DC pulse electrolytic polishing method to polish aluminum under alkaline conditions was explored. The results show 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.

Environmentally friendly chemical polishing of aluminum and aluminum alloys It is determined to develop a new environmentally friendly chemical polishing technology with phosphoric acid monosulfuric acid as the base liquid. This technology should achieve zero emission of NOx 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 fluid to replace nitric acid.

To this end, it is first necessary to analyze the triacid chemical polishing process of aluminum, especially the effect of nitric acid. The main function of nitric acid in chemical polishing of aluminum is to inhibit pitting corrosion and improve polishing brightness. Combined with the chemical polishing test in pure phosphoric acid-sulfuric acid, it is believed that the special substances added in phosphoric acid-sulfuric acid should be able to inhibit pitting corrosion, slow down overall corrosion, and must have better leveling and brightening effects.

Electrochemical surface strengthening treatment of aluminum and its alloys The process, properties, morphology, composition and structure of ceramic-like amorphous composite conversion coatings formed by anodic oxidation deposition of aluminum and its alloys in a neutral system were preliminarily discussed. Film formation process and mechanism.