As a commonly used cathode material, although barium tungsten electrode is widely used in electron tubes and gas discharge tubes, it also has some significant disadvantages. In practical applications, it is necessary to weigh its advantages and disadvantages according to specific needs, and consider technical improvements or alternative materials to make up for these shortcomings.
1. Sensitive to Oxidation
Barium tungsten electrode is very easy to oxidize in air. When exposed to oxygen, an oxide layer will quickly form on the surface, resulting in a significant decrease in electron emission performance. Therefore, it must be used and stored in a vacuum or inert gas environment, which increases the complexity of use and maintenance.
2. Uneven Emission
Due to the unevenness of the microstructure during the preparation process, the electron emission of the barium tungsten electrode may be unevenly distributed. This unevenness can cause local overheating, affecting the performance and stability of the device, especially in high-precision applications. The problem is more obvious.
3. Limited Life Span
Barium tungsten electrodes have certain stability at high temperatures, but long-term operation under high current conditions will cause cathode surface loss and gradually reduce emission performance. Its life span is usually between 1000 and 5000 hours, depending on the working environment and load intensity, which is shorter than other cathode materials.
4. High Process Requirements
The preparation of barium tungsten electrodes requires strict control of process parameters, such as powder particle size, sintering temperature, and impregnation liquid composition. Any deviation in the process may reduce the quality of the cathode and increase production difficulty and cost.
5. Environmental Impact
Barium tungsten electrodes may release harmful substances such as barium vapor when in use, causing potential pollution to the environment. They must also be properly handled after disposal to avoid harm to the environment and human health.
6. Temperature Sensitivity
The emission performance of barium tungsten electrodes is sensitive to temperature changes. When the operating temperature deviates from the optimal range, the emission current will fluctuate significantly, affecting the stability of the equipment. Therefore, precise temperature control is required, which increases the difficulty of operation.
7. High Cost
Although the preparation process is relatively simple, the raw materials and quality control requirements are high, which makes the overall cost of barium tungsten electrodes high and lacks cost advantages in some applications.
8. Limited Adaptability
Barium tungsten electrodes are mainly suitable for vacuum or inert gas environments. Their performance will be limited in special gas or highly polluted environments, limiting their application range.
