In 2001, the electronic industry standard SJ/T11260-2001 of the People's Republic of China gave tolerance ranges for the diameter, flatness, and roundness of ceramic housings for vacuum switch tubes. Our factory has also formulated corresponding inspection standards based on this standard. Among the qualified suppliers of our factory, only 5% of the size and shape are generally unqualified, and some manufacturers have a failure rate of up to 30% to 40%, and the size distribution is irregular and the consistency is poor. Tolerances in size and shape will cause difficulties in assembly, especially for manufacturers using a single sealing process, and bury hidden dangers for the coaxiality and air tightness of the entire tube, thereby reducing the reliability of the product . To ensure the accuracy of the size and shape of the porcelain shell, it is necessary to strengthen the control and management of each process of porcelain production, including raw material processing, slurry preparation, molding, wax removal and firing process.
Defects on the sealing surface Because the sealing surface is the key part of the sealing of ceramic parts and metal parts, it will directly affect the intrinsic quality of metallization and sealing. Therefore, the quality requirements of the sealing surfaces of various manufacturers are very strict. Our factory requires no cracks, pores, scratches, pits, interlayers, etc. on the sealing surface. Impurities in porcelain pieces Impurities in porcelain pieces mainly come from raw materials and process. Some impurities are colored in an oxidizing atmosphere, such as Cr2O3, Fe2O3, TiO2, etc., so red, yellow or black spots can be seen under light, and some impurities are colorless.
The mixing of these impurities will affect the electrical performance of the porcelain, increase the dielectric loss, and reduce the withstand voltage level. Therefore, porcelain manufacturers should strictly control the quality of raw materials and process. The above are some problems with higher probability in production inspection. These are some problems that can be controlled or improved by porcelain manufacturers. How to control these problems needs to be taken seriously by various manufacturers.
