shockmelted

Shockmelted is a term used in materials science to describe a state or microstructure that forms when a material experiences rapid melting due to a propagating shock wave, followed by swift cooling. It encompasses both transient liquid phases created by the shock and the solidified products that remain after the disturbance passes.

The phenomenon arises when shock compression raises temperature and pressure along the shock front above the melting curve for the material. As the material is rapidly compressed and then released, molten regions quench quickly, often leading to amorphous or nanocrystalline structures, suppressed dendritic growth, and the formation of melt pockets. The exact outcome depends on the material, the peak pressure, the rise time of the shock, and the surrounding boundary conditions.

Observations of shockmelted regions come from high-velocity impact experiments, laser-driven shocks, and gas-gun tests. Evidence is often sought with high-resolution imaging, X-ray diffraction, and electron microscopy, which can reveal glassy layers, fine grains, melt migration, or textural features that indicate rapid solidification from a transient liquid state.

Applications and implications of shockmelted states include insights into dynamic phase transitions, the interpretation of meteoritic and planetary impact features, and the potential synthesis of novel materials with unique microstructures. However, achieving uniform control over the resulting microstructure remains a challenge, given the extreme and transient nature of shock loading.

See also: shock metamorphism, dynamic recrystallization, rapid quenching.