In materials science, quenching is the rapid cooling of a workpiece in water,
oil or air to obtain certain material properties. A type of heat treating,
quenching prevents undesired low-temperature
processes, such as phase transformations, from occurring. It does this by
reducing the window of time during which these undesired reactions are both
thermodynamically favorable, and kinetically accessible; for instance, quenching
can reduce the crystal grain size of both metallic and plastic materials,
increasing their hardness.