Plastic deformation performed on a material, usually at room temperature, so as to increase its yield strength and tensile strength (See "strain hardening ")
Plastic deformation at such temperatures and rates that substantial increases occur in the strength and hardness of the metal visible structural changes include changes in grain shape and, in some instances, mechanical twinning or banding
Deforming metal plastically at a temperature lower than the recrystallization temperature Mechanical or hydraulic expansion employed to achieve higher mechanical properties