Relationship of strain hardening and damage in ductile fracture

The majority of theories of ductile fracture consider the values of the imposed strains needed to initiate and grow voids. However, in describing the microstructural damage resulting from the production and growth of voids, it is important to consider the spatial distribution of the damage in relation to the microstructure. It is shown that the process of void initiation is dominated by the location and size of second-phase particles rather than the average imposed strain level. In the growth stage the use of recovery anneal cycles indicates that the accumulation of microstructural damage depends not only on the local level of the flow stress and the imposed strain rate, but on the work-hardening rate of the matrix. If the work-hardening capacity can be restored it is possible to coax the material to much larger strains prior to failure.