(1) In the manufacture of electronic tubes, other substances, such as cathode, anode and mica sheet, are often coated on the material or on the other parts after processing. The purpose of the coating is:
1. Changing the Radiation Performance of the Surface of Another Part
2. Changing the Electron Emission Capability of Another Surface
3. Changing the Conductivity of Another Surface
4. Prevent metal parts from being corroded
5. Changing the Thermal Conductivity of Materials
6. Other
In addition to the above, in order to improve the vacuum degree of the tube, many other materials are coated on the other parts to achieve the purpose of absorbing the gas released by the tube in operation.
(2) Types and methods of covering
1. Mechanical coating method: a spraying method, B spraying method, C impregnation method, D melting spraying method, e melting spraying method (hot spraying method), f melting impregnation method and G rolling method
2. Physical coating method: a cathode sputtering method B vacuum evaporation method
3. Chemical coating method: a chemical solvent method, B oxidation method and C carbonization method
4. Electrochemical coating method: a electroplating method B electrophoresis method
