Solution heat treatment
A type of heat treatment in which the metal is heated in a furnace until it has a uniform temperature throughout. It is then removed and quenched in cold water. When the metal is hot, the alloying elements enter into a solid solution with the base metal to become part of its basic structure. When the metal is quenched, these elements are locked into place.
Aviation Maintenance Technician Handbook — Airframe, p. G-32
Taught in AF-A Quick reference.