INITIATION AND GROWTH OF VOIDS AT SECOND PHASE PARTICLES.
Abstract
Recent work on the plastic behavior of dispersion-hardened systems has emphasized the central role played by the plastic strain. The forest hardening and the local stress at a particle depend on the strain applied to the material, whereas the overall stress on the system depends strongly on the volume fraction of particles. It seems reasonable then to try to formulate a theory of fracture toughness in terms of the local strain history which assumes that there exist local critical strains for the various stages of the fracture process. Although there exist in the literature alternative and more exact approaches to the description of the plastic strain at the notch tip, the objective of the present work is to provide a simple physical guide to delineating the structural parameters such as size, shape, and volume fraction of particles and their effect on the strain history at the crack tip.