Explosive boiling or phase explosion
In thermodynamics, explosive boiling or phase explosion is a method whereby a superheated metastable liquid undergoes an explosive liquid-vapor phase transition into a stable two-phase state because of a massive homogeneous nucleation of vapor bubbles. This concept was pioneered by M. M. Martynyuk in 1976 and then later advanced by Fucke and Seydel. Mechanism Explosive boiling can be best described by a p-T phase diagram. Figure on right shows a typical p-T phase diagram of a substance. The binodal line or the coexistence curve is a thermodynamic state where at that specific temperature and pressure, liquid and vapor can coexist. The spinodal line on right is the boundary of absolute instability of a solution to decomposition into multiple phases. A typical heating process is shown using red ink. If the heating process is relatively slow, the liquid has enough time to relax to an equilibrium state and the liquid follows the binodal curve, the Clausius–Clapeyron relation is still valid. During this time heterogeneous evaporation occurs in the substance with bubbles nucleating from impurity sites, surfaces, grain boundaries etc. On the other hand, if the heating process is fast enough that the substance cannot reach binodal curve through heterogeneous boiling, the