The main reason for the decrease in electrical conductivity due to oxidation on the surface of graphite electrodes is the formation of an oxide film, which hinders the conduction of electric current. Here are the possible reasons for the surface oxidation of graphite electrodes and corresponding solutions:
Causes:
1.High-Temperature Oxidation: The surface of graphite electrodes is prone to react with oxygen in high-temperature environments, forming an oxide film.
2.Humidity Influence: In high-humidity environments, oxygen in water vapor can also cause oxidation reactions on the surface of graphite electrodes.
3.Presence of Oxygen: Even in environments with relatively low temperature and humidity, oxidation reactions can occur in the presence of oxygen.
Solutions:
4.Surface Protective Coating: Applying an antioxidative protective coating on the electrode surface can prevent direct reaction with oxygen. Common protective coatings include alumina and zirconia oxides.
5.Atmosphere Control: In high-temperature and high-humidity environments, using atmosphere control methods to reduce the presence of oxygen. For example, using inert gases such as nitrogen or creating a vacuum environment.
6.Protective Processes: Implementing protective measures during electrode production and usage, such as preventing exposure to harsh weather conditions, to reduce the likelihood of oxidation.
7.Selection of Antioxidant Materials: Choosing graphite materials with good antioxidative properties to slow down the oxidation rate.
8.Regular Cleaning: Periodically cleaning the electrode to remove surface oxides and maintain good conductivity.
9.Control of Working Conditions: Regulating temperature, humidity, and atmosphere during electrode usage to minimize oxidation.
10.Moisture-Proof Storage: Storing electrodes in a moisture-proof environment when not in use to reduce the impact of humidity on the electrode surface.
11.Atmosphere Heat Treatment: Subjecting electrodes to atmosphere heat treatment to eliminate or reduce the formation of surface oxides.
The choice of these solutions should be based on specific application environments and requirements. By considering these factors comprehensively, it is possible to effectively mitigate the issue of decreased electrical conductivity caused by surface oxidation of graphite electrodes.