There is garbage or air bubbles in the electrolyte. If there are impurities, garbage or bubbles in the electrolyte, the power loss of the electrolyte will be insufficient and the voltage will drop.
Electrolyte consumption. Electrolyte will be gradually consumed over time. There is less and less liquid medicine in the electrolyte, and the capacitance will be smaller and smaller, which will lead to the voltage drop.
Electrode aging. In the process of preparing magnesium alloy surface protective layer by micro-arc oxidation, the electrode will suffer from different degrees of loss and corrosion, which will lead to scaling or wear on the electrode surface, further increase the distance between the electrode and electrolyte, and thus lead to voltage drop.
There may be many reasons for the voltage drop of micro-arc oxidation of magnesium alloys. It is necessary to find out the specific reasons through inspection and analysis, and take corresponding measures in time to ensure the successful preparation of magnesium alloy surface protective layer.