Sublimation is the correct word; both carbonization and pyrolysis deeply change the molecular structure of the substance; sublimation is a so-called phase transition, that does not alter the molecule, only its physical phase (from solid to gas). You are not talking of a chemical reaction here, like oxidation at high temperature. (the material turns into the gaseous phase, it does not 'melt' to gas)

1000 ° C is not a constant. The process in which a substance changes state (melting, evaporation, condensation, etc.) are called changes or phase transitions. Each state of matter is determined by its own pressure and temperature characteristics and requires addition or subtraction of heat to enable it to move from one state to another.

Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization. from Wikipedia. So both your answers are correct.

oh, even if you asked me in Russian I wouldn't answer )))

carbonization :)