Low-voltage rapid micro-arc oxidation technique

Abstract

The invention relates to a low-voltage rapid micro-arc oxidation technique for micro-arc oxidation of valve metals such as aluminum, magnesium, titanium, zirconium and niobium by the aid of a constant-current pulse oxidation power supply and silicate system oxidation liquid. The peak current and the background current of the constant-current pulse oxidation power supply are continuously adjustable within the range of 10A-500A, the frequency of the constant-current pulse oxidation power supply is continuously adjustable within the range of 50Hz-100Hz, the duty ratio of the constant-current pulse oxidation power supply is continuously adjustable within the range of 10%-20%, and the voltage of the constant-current pulse oxidation power supply varies from 0V to 200V. The silicate system oxidation liquid comprises deionized water, sodium silicate, a regulator, a low-voltage arcing agent and a reinforcing agent. Compared with a common micro-arc oxidation technique, the low-voltage rapid micro-arc oxidation technique has the advantages that oxidation voltage is reduced to be below 200V, time for preparing ceramic films with the same thickness is shortened to be one third to one eighth of the original, micro-arc oxidation energy consumption is basically unchanged, the thickness of a loose layer of each ceramic film is obviously reduced, and the hardness is averagely improved by about HV300 and reaches more than HV1000.

Description

Technical field [0001] The invention relates to a low-pressure rapid micro-arc oxidation technology, which is suitable for in-situ growth on the surface of valve metals such as aluminum, magnesium, titanium, zirconium, niobium and the like to form a series of ceramic films with excellent properties such as corrosion resistance, wear resistance and insulation. Background technique [0002] Micro-arc oxidation technology is a new technology that can directly grow ceramic films on the surface of valve metals such as aluminum, magnesium, titanium, zirconium, and niobium. Since its discovery abroad in the 1970s, it has developed rapidly in the 1980s. my country's micro-arc oxidation technology was introduced from Russia in the early 1990s. The earliest domestic unit to systematically research and apply micro-arc oxidation technology is Harbin Huanya Micro-arc Oxidation Technology Co., Ltd., and has applied for a number of patents. Beijing Normal University carried out a series of wor...

AI Technical Summary

Problems solved by technology

Although micro-arc oxidation has been initially applied, there are still many technical problems that have not been resolved.

[0006] The main problems of micro-arc oxidation technology at present are: first, the voltage is relatively high, and the general oxidation process arc starting voltage is about 200V, and the termination voltage is about 500V; second, the oxidation time is relatively long. dm 2 It takes about 90 minutes to prepare a 50 μm micro-arc oxidation ceramic film on the surface of aluminum alloy; third, due to the high voltage of micro-arc oxidation, if the oxidation time is shortened by increasing the current density, the energy consumption of micro-arc oxidation will increase significantly