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.