1. Factors Affecting Heat Transfer in a Vacuum Sintering Furnace

Several factors influence how temperature from the furnace core transfers outward:

  1. Intensity of internal heat sources
    • Vacuum sintering furnaces primarily use internal heat sources. Heat is generated inside the furnace and transfers outward.
    • The intensity of these internal heat sources directly affects the temperature distribution inside the furnace.
    • The higher the intensity, the higher the temperature at a given point, and the larger the temperature difference (ΔT) over a certain radius (r).
    • In practice, operators can control the furnace core surface load (i.e., core power) to manage the internal temperature distribution.
  2. Distance of the material from the furnace core (Δr)
    • With constant core power, the farther the material is from the core, the lower its temperature, which may not reach the desired reaction temperature.
    • Conversely, the closer the material to the core, the higher its temperature, which favors the reaction.
  3. Heat dissipation of the material
    • Materials with high heat dissipation lose internal heat quickly, which can lower the temperature at certain points and reduce sintering efficiency.

2. Operational Practices to Minimize Risks in a Vacuum Furnace

  1. Starting the furnace
    • Switch on the vacuum furnace power.
    • Set the control cabinet switch to automatic control.
    • Enter all process parameters into the computer according to the sintering procedure.
  2. Loading the furnace
    • Use a loading cart to gently and steadily transport the workpieces into the furnace.
    • Close and lock the furnace door to ensure a proper seal.
  3. Selecting cooling conditions
    • Choose the appropriate cooling medium, method, and pressure according to the process.
  4. Running the sintering cycle
    • Press the start button for the cycle. The furnace will automatically execute vacuum pumping → heating → cooling.
    • Continuously monitor all systems; report any abnormalities to the supervisor.
  5. Unloading
    • Restore normal furnace pressure before opening the door.
    • Only open the furnace door once indicator lights show normal status.
    • Handle workpieces and fixtures carefully to avoid collisions at the furnace mouth.