Structural materials of vacuum materials

    Structural materials are the materials that constitute the main body of the vacuum system, including shell materials and materials used in various structures and mechanisms inside the vacuum system. The main body of the vacuum system includes: vacuum chambers, vacuum pumps, vacuum components, vacuum gauges, etc., among which the shell will The vacuum is separated from the atmosphere and is subjected to atmospheric pressure.

    Commonly used structural materials are mainly metal and glass, and some pipelines use vacuum rubber tubes or metal-reinforced plastic tubes. The metal has good mechanical strength and the glass is transparent, which is convenient for observing the internal conditions of the equipment; electrical insulation can be used from the outside to the internal metal The parts are heated by high frequency; the high frequency spark gun can be used for leak detection, which is convenient for processing. However, the glass material is brittle and fragile, and it is not easy to make a large-volume container. Most vacuum systems currently use metal materials. The use of bellows, metal coils, vacuum rubber tubes or metal-reinforced plastic tubes can realize the soft connection between the two parts, which is convenient to install, isolates vibration, and is cheap.

    The structural materials should meet the following requirements:

    1) Sufficient mechanical strength and rigidity, the shell should be able to withstand atmospheric pressure, and the internal components should have the required strength;

    2) has machinability, and is easy to seal and weld;

    3) It has sufficient air tightness, and requires that the material has no porous structure, no cracks, bubbles and other defects that may cause air leakage;

    4) Sufficiently low saturated vapor pressure;

    5) The amount of dissolved gas inside the material and the amount of gas adsorbed on the surface is small enough;

    6) sufficiently small gas permeability;

    7) Good chemical stability, does not decompose under working conditions, and does not cause unwanted chemical reactions with other materials;

    8) Good thermal stability, with required mechanical properties and vacuum performance at the operating temperature of the system;

    9) For the ultra-high vacuum system, it should be able to withstand the necessary baking and be easy to degas;

    10) Compatible with the working requirements of the system, and does not affect other performance of the system.

(huiputech)