Before operating a vacuum sintering furnace, the following safety checks should be completed:
- Power and Frequency Check – After all preparations, connect the power, close the mid-frequency power switch, follow mid-frequency startup procedures, test-start the variable frequency drive, then stop it. Only after this can the furnace be opened.
- Inspection Holes – Clean the observation and temperature measurement holes on the furnace cover before each operation to ensure clear observation and accurate temperature readings.
- Loading Method – Load the furnace according to the type of sintering product. Follow relevant material loading rules; do not change them arbitrarily.
- Thermal Insulation – To maintain constant temperature and prevent heat radiation, place two layers of carbon fiber over the heating crucible and cover with a thermal shield.
- Vacuum Sealing – Place vacuum sealing tape properly.
- Avoid Volatile Materials – Do not put into the furnace any workpieces or containers that easily volatilize under vacuum, as they may contaminate the vacuum system or block pipes.
- Remove Binders – Any products containing binders (such as oil or wax) must be completely removed before sintering to avoid negative effects.
- Vacuum Pump Check – Check the pump’s power system, belt tension, and oil level (oil should be at the midpoint of the sight glass). Manually rotate the pump pulley; if normal, start the pump with the butterfly valve closed.
- Furnace Interior Inspection – Ensure the furnace interior is clean, induction coil insulation is intact, vacuum sealing tape is elastic and of correct dimensions.
- Lever Operation – Check that the furnace’s lever handles operate smoothly.
- Vacuum Gauge Check – Ensure the rotary McLeod vacuum gauge meets specifications.
- Crucible and Accessories – Inspect the graphite crucible and ensure all loading accessories are complete.