Abstract

In the plastic deformation stage of metal, work hardening always goes together with softening. The nucleation, growth of small internal voids or cavities according to plastic increasing is the microscopic mechanism of softening. The voids are nucleated at the particle-matrix interface due to the agglutinate loss or the particle crack when the strain reaches critical value. The growth of voids will then occur in company with the increase of plastic deformation. The influence of void growth on material forming behaviour will be considered by softening parameter of porous material.