Heat treatment external processing manufacturers: Vacuum brazing furnaces are used for brazing in furnaces or brazing chambers that extract air for a long time. They are particularly suitable for joints with large and continuous brazing areas, as well as for network connections and certain metals with special properties, including titanium, zirconium, niobium, molybdenum, and tantalum. The application research scope is relatively wide. However, there are also issues with vacuum brazing, and here are some of our main drawbacks:
① Metals are prone to volatilization under vacuum conditions, therefore vacuum brazing and soldering of volatile components are not suitable. If necessary, corresponding complex process measures should be taken.
② The vacuum brazing furnace is sensitive to the surface roughness, assembly quality, and fit tolerance of brazed parts, and requires the theoretical level of the working environment and operators.
③ Vacuum equipment is complex, requires a large one-time investment, and incurs high maintenance costs. So how to implement brazing technology in a vacuum furnace? When performing brazing operations in a vacuum furnace, place the added welded parts into the furnace (or brazing container), close the furnace door (or close the brazing container cover), and perform vacuum pre pumping before heating. Start the mechanical pump first, and when the vacuum reaches 1.35Pa, turn the steering valve to close the direct channel between the mechanical pump and the brazing furnace. Connect it to the brazing furnace through a diffusion pump, and the mechanical pump will enter the required vacuum. Then start the power heating.
During the entire heating process, the vacuum device should continuously operate to maintain the vacuum inside the furnace, counteract air leaks at the joints of the vacuum system and brazing furnace, release adsorbed gases and water vapor at the furnace walls, fixtures, and welds, as well as evaporate metals and oxides, and reduce the vacuum degree. There are two types of vacuum brazing: high vacuum brazing and partial vacuum (intermediate vacuum) brazing. High vacuum brazing is highly suitable for brazing difficult to decompose base metals, such as nickel based high-temperature alloys. Partial vacuum brazing is used when the base metal or filler metal evaporates under brazing temperature and high vacuum conditions.
When special precautions need to be taken to ensure high purity, vacuum purification should be used before dry hydrogen brazing. Similarly, using dry hydrogen or inert gas purification before vacuuming will help achieve better results in high vacuum brazing.
The above heat treatment introduces the welding effect of vacuum brazing furnace to external processing manufacturers. If you need to learn more, feel free to contact us anytime! I have many years of experience in heat treatment for external processing companies and look forward to your joining at any time.

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