Can a heat treatment tube furnace be filled with atmosphere?

The heat treatment tube furnace can pass through the atmosphere, and its atmosphere control ability is one of the core advantages of this equipment, which can meet the heat treatment needs of materials in specific gas environments. The following is a specific analysis:

1. The core role of promoting atmosphere
Protect the surface of the material
Preventing oxidation/corrosion: In metal heat treatment (such as annealing and quenching), introducing inert gases such as nitrogen and argon can isolate oxygen and prevent surface oxidation of the material. For example, titanium alloys are prone to react with oxygen at high temperatures to form brittle oxide layers, and passing argon gas can maintain surface smoothness and improve material toughness.
Reduction reaction support: In semiconductor manufacturing, hydrogen gas can be used to reduce metal oxides (such as copper oxide) and prepare high-purity metal thin films. Hydrogen can also eliminate internal stress in materials and improve crystal structure.
Promote specific chemical reactions
Carbonization/Nitriding Treatment: In the heat treatment of tool steel, passing methane (CH ₄) or ammonia gas (NH ∝) can achieve carbonization or nitriding and improve the surface hardness of the material. For example, after nitriding treatment, high-speed steel has higher surface hardness and significantly improved wear resistance.
Chemical Vapor Deposition (CVD): In the synthesis of nanomaterials, gases such as silane (SiH ₄) and methane are introduced to deposit thin films of silicon, carbon nanotubes, and other materials on the substrate surface. The uniform temperature field of the tube furnace ensures the uniformity of the film thickness.
Control the microstructure of materials
Carburizing/nitriding process: In the manufacturing of automotive gears, the introduction of carburizing gas (such as CO+CH ₄) can allow carbon atoms to penetrate the surface of steel parts, forming a high hardness carburizing layer; The nitriding process enhances fatigue resistance by generating nitrides on the surface through the passage of ammonia gas.
Grain boundary engineering: In the preparation of functional ceramics (such as piezoelectric ceramics), oxygen can be introduced to regulate the concentration of oxygen vacancies and optimize the piezoelectric properties of the material. For example, annealing barium titanate ceramics in an oxygen rich atmosphere can increase the piezoelectric coefficient.

2. Technical Implementation of Atmosphere Control
gas supply system
Multi channel gas access: Tube furnaces are usually equipped with 2-4 gas inlets, which can simultaneously introduce different gases (such as inert gas and reactive gas), and the flow rate is precisely controlled by a mass flow meter (MFC). For example, in CVD synthesis of graphene, methane (carbon source) and hydrogen (carrier gas) can be simultaneously introduced with high flow accuracy.
Gas mixing device: Some high-end tube furnaces are equipped with static mixers or dynamic mixing systems to ensure that the gas is uniformly mixed before entering the furnace chamber, avoiding local concentration differences from affecting experimental results.
Sealing and flow channel design
Furnace tube material selection: Select the furnace tube material according to the gas type. Quartz furnace tubes are resistant to high temperatures and corrosion, suitable for most inert/reducing gases; Stainless steel furnace tubes are more suitable for high-pressure or reactive gas environments.
Optimization of airflow distribution: Porous flow equalization plates or spiral airflow channels are designed inside the furnace cavity to allow gas to flow uniformly over the surface of the sample. For example, a certain tubular furnace improves the temperature uniformity and gas flow velocity uniformity inside the furnace by optimizing the airflow design.
Security protection mechanism
Gas leakage detection: equipped with combustible gas sensors such as hydrogen and methane, real-time monitoring of furnace chamber and pipeline leakage, automatic alarm and cut-off of gas source when exceeding the limit.
Exhaust gas treatment system: For toxic gases (such as Cl ₂, NH ∝) or flammable gases (such as H ₂), they are discharged through combustion, absorption, or catalytic treatment to ensure experimental safety. For example, hydrogen exhaust gas needs to be ignited to generate water, avoiding the risk of explosion.