If increased thermal activation is available (i.e., if the temperature is
raised) nucleation and growth of strain-free grains in the deformed matrix will take place. As
these grains grow, the dislocations in the matrix are annihilated at the boundaries of the newlyformed
grains. Strength and hardness decrease considerably and ductility increases. The
lowest temperature at which stress-free grains appear in the structure of a previously plastically
deformed metal is termed the recrystallization temperature. This depends upon the grain size,
the severity of plastic deformation, and the presence of solute atoms or second phase particles.
The recrystallization temperature is usually 1/3-1/2 the absolute melting point of the
material.