boilingfreezing

Boilingfreezing is a coinage used to describe a phenomenological situation in which a substance exhibits boiling and freezing within a short interval or even in overlapping time frames under non-equilibrium conditions. It is not a standard phase in the phase diagram, but a descriptive label for complex transient behavior involving vaporization and solidification.

The mechanism arises from rapid changes in temperature and pressure, strong heat fluxes, and heterogeneous nucleation dynamics. Boiling is driven by local heating or depressurization that reduces the liquid’s saturation temperature, causing vapor bubbles to form. Freezing is driven by rapid cooling or pressure changes that promote solidification. In some cases, heat removal or addition through latent heat exchange can sustain a regime where liquid, solid, and vapor phases coexist or alternate.

Practical contexts include cryogenic systems and spray cooling, where flash boiling of a liquid can occur near surfaces that are simultaneously cooling; in such cases, local subcooling can lead to simultaneous or subsequent freezing of deposited liquid. In materials processing, rapid quenching of molten droplets can produce a mixture of solidified material and vaporized portions, particularly when volatile components are present.

Because boilingfreezing is not standard terminology, researchers emphasize precise language: separate phase transitions, metastable states, or non-equilibrium phase mixtures are typically described using established terms such as boiling, freezing, superheating, supercooling, and cavitation. Diagnostic methods include synchronized temperature, pressure, imaging, and spectroscopy.

See also: phase transitions, phase diagram, boiling point, freezing point, latent heat, metastability, cavitation.