Deformation Processing System

 Deformation zone is concerned with the distribution of stress , strain & particle velocities . & with overall pressure required to perform the operation .  Applied force must develop yielding in the material but the stresses must not locally create fracture.  Metallurgical phenomena such as strain hardening, Recrystallisation & fracture are important but often under specialised condition of high strain rate & temperature.  Flow stress of the material will be a strong function of strain , strain rate & temperature , often at values of these variable that are difficult to simulate in the laboratory .  w/p will be in contact with non deforming (elastic ) tools or dies . The Frictions along this interface & the heat transfer from the w/p to die are important consideration & also the tool wear & the surface finish of the product . Refer : George Dieter -Mechanical Metallurgy