Electrolytic solution for aluminium alloy cast piece micro arc oxidation treatment

Abstract

The electrolyte solution is used in micro arc oxidizing treatment of aluminum alloy casting in some micro arc apparatus. By means of setting the cylinder inside electrolyte solution compounded with sodium phosphate, sodium silicate, potassium hydroxide and sodium molybdate and applying voltage to the cylinder, one alumina ceramic layer with alumina as main component may be formed on the surface of the aluminum alloy cylinder. The formed alumina ceramic layer has aluminum atom originating from the aluminum alloy and oxygen ion from the electrolyte solution, and the process produces no pollution and has high combination strength between the ceramic layer and the base. The ceramic layer has blind micropores distributed homogeneously, and under friction reducing condition, one continuous oil film is formed on the surface to raise the wear resistance of the surface of the cylinder.

Description

technical field [0001] The invention belongs to the hardening treatment technology of aluminum alloy castings, and particularly relates to an electrolytic solution suitable for micro-arc oxidation treatment of aluminum alloy cylinder bodies or aluminum alloy pistons. technical background [0002] Aluminum alloy has become one of the main consumables of gasoline (diesel) engines due to its light weight and easy forming characteristics, but its wear resistance and scratch resistance are poor, which limits its direct use as a friction pair on the engine block. application, a suitable inner surface hardening treatment or inlay wear-resistant cylinder liner must be carried out. [0003] Since the late 1960s to the present, hypereutectic aluminum-silicon alloys have been used to manufacture automotive engine blocks without gray cast iron cylinder liners in some vehicles from GM, Mereedes, Audi and Porsche. Strictly specified honing and erosion processes are used to make the granu...

AI Technical Summary

Problems solved by technology

[0006] Although the manufacturing processes of the above-mentioned engine blocks solve the problem of reducing the weight of the engine and do not cause pollution to the environment, these processes have not been applied in mass-produced vehicles due to their complexity, cost, and time.

Especially in our country, there is no precedent for using the above-mentioned manufacturing process. For large vehicles, the aluminum alloy cylinder with relatively low processing cost is still inlaid with the cylinder liner.

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