What gases can be passed through a heat treatment tube furnace?

The types of gases that can be introduced into the heat treatment tube furnace are diverse, mainly including inert gases, reducing gases, oxidizing gases, mixed gases, and other special gases, as follows:

1. Inert gases: such as argon, nitrogen, helium, etc., these gases have stable chemical properties and will not react with the materials being processed. They are mainly used to protect materials from oxidation or other chemical reactions, such as preventing surface oxidation in metal heat treatment or protecting material surfaces from contamination in semiconductor manufacturing.
2. Reductive gases: such as hydrogen, carbon monoxide, etc., these gases have reducibility and can react with certain materials to remove surface oxides and improve the surface properties of the materials. For example, in the metal annealing process, passing hydrogen gas can reduce metal oxides and improve material purity; In the preparation of carbon materials, hydrogen can promote carbonization reactions and optimize material structures.
3. Oxidative gases: such as oxygen, mainly used to promote the oxidation process of materials, change the surface properties or internal structure of materials. For example, in metal oxidation treatment, oxygen can form a specific oxide layer to enhance the corrosion resistance of the material; In ceramic sintering, oxygen can promote grain boundary oxidation and optimize material properties.
4. Mixed gases: Different gases can be mixed in specific proportions according to process requirements. For example:
5. Nitrogen based mixture: Nitrogen is mixed with hydrogen (N ₂+H ₂) to protect heating and prevent material oxidation; Nitrogen mixed with hydrocarbons (N ₂+CH ₄) is used for carburizing treatment to enhance the surface hardness of materials.
6. Ammonia decomposition gas: Ammonia gas decomposes into nitrogen and hydrogen, which are used in processes such as brazing and sintering to provide a reducing environment.
7. Heat absorbing atmosphere: By controlling the ratio of air to fuel, a mixed gas containing hydrogen, carbon monoxide, and nitrogen is generated for processes such as bright quenching and carburizing.
8. Other special gases: Depending on specific experimental or production needs, special gases such as ammonia, methane, hydrocarbons, etc. can also be introduced. For example, introducing hydrogen gas during catalyst activation can promote reduction reactions; Methane can be used as a carbon source in the synthesis of nanomaterials to prepare materials such as carbon nanotubes.