Electric vehicle die castings are made of aluminum alloy. The alkaline electrolytic polishing process of aluminum is studied. The effects of corrosion inhibitor and viscosity agent on the polishing effect are compared. The alkaline solution system with good polishing effect is successfully obtained, which can reduce the operating temperature and prolong the service life of the solution for the first time At the same time, it can also improve the polishing effect.
The experimental results show that adding appropriate additives to NaOH solution can produce good polishing effect. The exploratory experiment also found that after DC constant voltage electrolytic polishing with NaOH solution of glucose under some conditions, the surface reflectivity of aluminum can reach 90%, but there are still unstable factors in the experiment, which needs to be further studied. The feasibility of polishing aluminum under alkaline conditions by DC pulse electropolishing method is explored. The results show that the leveling effect of DC constant voltage electropolishing can be achieved by pulse electropolishing method, but its leveling speed is slow.
Environmental friendly chemical polishing of aluminum alloy die castings is determined to develop a new environmental friendly chemical polishing technology with phosphoric acid sulfuric acid as the base solution. This technology should achieve zero NOx emission and overcome the quality defects of previous similar technologies. The key of the new technology is to add some compounds with special effects to the base solution to replace nitric acid.
Therefore, it is necessary to analyze the three acid chemical polishing process of aluminum, especially the effect of nitric acid. The main function of nitric acid in aluminum chemical polishing is to inhibit pitting corrosion and improve polishing brightness. Combined with the chemical polishing test in pure phosphoric acid sulfuric acid, it is considered that the special substances added in phosphoric acid sulfuric acid should be able to inhibit pitting corrosion and slow down overall corrosion, and must have good leveling and brightening effect.
Electrochemical surface strengthening treatment of die castings for electric vehicles the process, properties, morphology, composition and structure of ceramic like amorphous composite conversion film formed by anodic oxidation deposition of aluminum and its alloys in neutral system were discussed. The film-forming process and mechanism were discussed.
