Bake-out
Bake-out turns up in 2 fields: thermal spray, vacuum. Here is what it means to the people in each one.
Bake-out in thermal spray
Heating oily or porous parts before blasting to drive out absorbed oil that would ruin the bond.
Oven heating of used or porous parts, such as cast iron pump housings, sintered parts and shafts that ran in oil, typically at a few hundred degrees Celsius until no more oil weeps out. Solvent cleaning removes surface oil but not oil soaked into pores and graphite flakes, which otherwise bleeds out under the heat of spraying and lifts the coating. Bake-out comes before the final degrease and grit blast.
"That housing ran in gear oil for ten years, bake-out first or it'll sweat right through the bond coat."
Bake-out in vacuum
Heating a vacuum system while pumping to drive off water and other adsorbed gas and lower the base pressure.
Heating the chamber walls and internal parts while pumping, typically to 120 to 250 °C for 24 to 48 hours in UHV work, so adsorbed water and other gases leave in a day instead of over weeks. A good bake lowers the base pressure by one to three decades once the system cools. Every part has to take the heat: Viton seals are usually limited to about 150 °C, while CF copper seals handle far more.
"Wrap the chamber in heater tape and foil, we'll bake out at 150 C for 48 hours, then activate the NEG."