Thermal de-oiling

Powder metal (PM) components must be freed from auxiliary substances before they can be heat treated in vacuum. These auxiliary substances are typically calibration oils which remain in the open porosity of the components after calibration or after mechanical surface densification.

These oils would evaporate or crack in the vacuum process, which may have a negative effect on heat treatment results.

During thermal de-oiling, the sintered PM components are heated to a temperature higher than the decomposition temperature of the oil, so that the oil expels from the pores.