revaporization

Revaporization, sometimes called re-evaporation, is the process in which a substance that has previously vaporized returns to the vapor phase after a period of condensation or deposition. The term is used primarily in specialized contexts such as materials science, chemical engineering, and cryogenic engineering to describe dynamic vapor‑phase behavior that follows initial vaporization.

Mechanisms of revaporization occur when conditions such as temperature, pressure, or surface interactions raise the vapor pressure of the material above the ambient pressure, or when energy input re-evaporates condensed material from surfaces. In closed systems, a vapor that heats up or experiences pressure changes can cycle between vapor and condensed phases, leading to repeated revaporization events.

In deposition and coating processes, revaporization can influence film growth. In physical vapor deposition (PVD) and chemical vapor deposition (CVD), some of the material that deposits onto substrates may re-evaporate, especially at high substrate temperatures or low ambient pressures. This reduces net deposition rate and can alter film composition and microstructure.

Other contexts include distillation and cryogenics, where evaporative losses occur when volatile components re‑vaporize and are vented, or when condensation within process equipment is reversed by temperature changes. Revaporization is an important consideration for process efficiency, material yield, and coating uniformity.

Measurement and modeling of revaporization rely on evaporation kinetics and phase‑equilibrium relations; equations such as the Hertz–Knudsen relation and Arrhenius-type models are commonly used to estimate fluxes of atoms vaporizing or re‑vaporizing at surfaces.