Vacuum pump shell material knowledge
In order to meet all kinds of performance requirements, there are also many requirements in the selection of vacuum pump shell materials, especially in some cases where the working medium environment is relatively poor. What are the specific shell materials and what are the requirements?
There are many kinds of vacuum pump materials, such as metal alloy, ceramic, rubber plastic, glass quartz, carbon fiber and so on. The vacuum pump shell material is mainly two categories: metal and glass.
Metal as a vacuum shell material mainly includes iron, copper, aluminum based metals and various alloys, such as low carbon steel, stainless steel, oxygen-free copper, copper, aluminum and aluminum clad steel or iron. They have good mechanical strength and machinability. Various metal materials have different performance and outgassing rate according to different vacuum application characteristics. The physical and mechanical properties of various metal alloys can be inquired.
Glass is mainly used in some glass vacuum systems (such as glass diffusion pump, valve), observation window, some gauge shell, high-voltage electrode insulator, etc., with the advantages of transparency, low price, easy processing, insulation, etc., the disadvantage is low strength and fragile. There are many kinds of glass, according to the different softening temperature and expansion coefficient, there are different properties of soft glass, hard glass and quartz glass.
Whether it’s metal or glass, the shell material of vacuum pump needs to have certain mechanical strength and rigidity, which can ensure that it can bear atmospheric pressure under normal temperature and baking temperature without deformation; good air tightness, without defects such as porous structure, cracks and other leakage; low air outlet rate and penetration rate; low saturated vapor pressure under working temperature and baking temperature It has good chemical stability, is not easy to oxidize and corrode, and will not react with the working medium in the system; it has good temperature stability, can maintain its vacuum performance and mechanical performance within a certain temperature range; it is easy to process, has good welding performance and good economy.