Muffle furnace vacuum extraction

Muffle furnaces can be evacuated, especially vacuum Muffle furnaces and vacuum atmosphere Muffle furnaces, which are specifically designed for high-temperature heating treatment in a vacuum environment. Let’s take a detailed look below!

Commonly used vacuum sintering furnaces (click on the image to view product details)

1. The purpose of vacuuming
Preventing oxidation: In a vacuum environment, the material does not react with oxygen in the air when heated, thus avoiding oxidation.
Improving purity: For experiments that require a high-purity environment, such as semiconductor material preparation, a vacuum environment can reduce impurity contamination.
Promote specific reactions: Some chemical reactions are easier to carry out under vacuum conditions, such as degassing, purification, etc.

2. The operation process of vacuuming
preparation:
Ensure good ventilation and no flammable materials around the equipment.
Check if the power and grounding wires are intact and if the voltage matches the equipment requirements.
The sample needs to be clean, dry, and avoid containing volatile or corrosive substances.
Use alumina or quartz crucibles to hold samples and avoid direct contact with the furnace.

Vacuum extraction steps:
Open the furnace door: After placing the sample, close the furnace door.
Pre vacuuming: Close the vacuum valve, turn on the mechanical pump, and start vacuuming. When the vacuum degree reaches a certain value (such as below 7.6Pa), the next step can be carried out.
High vacuum extraction: For experiments that require higher vacuum levels, the diffusion pump can be turned on, the switch of the vacuum unit can be pushed in, and the cooling water can be turned on at the same time. When the vacuum degree reaches the required level, heating begins.
Heating and insulation: Heating treatment is carried out in a vacuum environment, and the temperature, heating rate, and insulation time are set according to the process requirements.

Cooling and Sampling:
Cooling: After the program ends, the device will automatically cool down or manually start air/water cooling. When the temperature drops to a safe range (such as ≤ 100 ℃), prepare to take samples.
Sampling: Turn off the diffusion pump (if used), pull out the vacuum unit switch, and turn off the cooling water and mechanical pump after the diffusion pump cools down. After venting, open the furnace door and take out the sample.

3. Precautions for Vacuum Extraction
Safe operation:
Wear insulated gloves and goggles during operation to avoid burns.
Flammable gases such as H ₂ must be strictly controlled in flow to avoid leakage.
Vacuum furnaces need to be equipped with explosion-proof devices and regularly checked for air tightness.
Overloading operation is strictly prohibited to avoid short circuits or fires.

Equipment maintenance:
Regularly check whether the thermocouple and heating element connections are loose.
Clean the residue in the furnace after each use to prevent contamination.
Regularly replace the sealing ring to ensure the airtightness of the furnace door.
Calibrate the temperature sensor every 6 months with an error of ≤± 1 ℃.
Check if the heating element is aging (such as the silicon molybdenum rod turning white or breaking).

Process optimization:
Adjust the heating curve and atmosphere type according to the characteristics of the sample to improve the experimental effect.
When using a silicon molybdenum rod for heating, the heating rate should be ≤ 10 ℃/min, and the holding time should be set according to the process requirements.
Atmosphere selection: Vacuum or inert gas (N ₂, Ar) can prevent sample oxidation; The reducing atmosphere (H ₂, CO) is suitable for metal reduction treatment.

Industrial vacuum furnace (click on the image to view product details)

In general, vacuum muffle furnace or atmosphere muffle furnace, as commonly used electric heating equipment in the heat treatment industry, are highly favored by major enterprises. Before choosing, you can communicate with relevant technical personnel about the parameters you want, so as to customize a vacuum muffle furnace that is more suitable for your production needs!Click to learn more Vacuum Furnaces! Or click on online customer service to learn more about product information!