Metals spontaneously transform toward lower free energy

Transformation processes that occur at lower temperatures or in early stages

The strength and hardness are reduced, the plasticity and toughness are improved, and the microstructure remains unchanged.

Low temperature recovery

medium temperature reply

High temperature recovery

The degree of lattice distortion of the entire metal is greatly reduced, and its properties also change accordingly.

stress relief annealing

When the cold deformed metal is heated to a higher temperature, new distortion-free equiaxed crystals will be re-formed in the original deformed metal until the cold deformed metal structure is completely replaced.

Transformation processes that occur at higher temperatures or at later stages

The strength and hardness of the metal are significantly reduced, the plasticity is greatly improved, work hardening and internal stress are completely eliminated, and the physical properties are restored.

Large degree of deformation

Less deformation

It is a process of complete reorganization of the microstructure, resulting in fundamental changes in performance.

Realized through dislocation climbing and cross-slip

Dynamic recovery is the only softening mechanism during thermal deformation of high-rise dislocation metals

micro deformation stage

True stress increases due to work hardening, but the work hardening rate gradually decreases

Stable deformation stage

Recrystallization that occurs during thermoplastic deformation

Completed by nucleation and growth

The level of stacking fault energy of metal

The difficulty of grain boundary migration

Grains have greater strength and hardness than static recrystallized grains of the same size

static reply

static recrystallization

subdynamic recrystallization

Deformation temperature during thermal deformation

strain rate

Degree of deformation

Material composition

The level of stacking fault energy