Dynamic recrystallisation in a copper/stainless steel pseudo-two-phase material

The initiation and development of dynamic recrystallisation in a pseudo-two-phase material have been investigated to study the effect of area fraction and distribution of the pseudo-second phase. Hot compression tests have been conducted at 400°C on specially fabricated pseudo-two-phase copper test specimens and single-phase copper test specimens. A material model has been implemented into finite element software coupled with the recently proposed criterion for initiation of dynamic recrystallisation in single-phase materials. Micro-mechanical models have been employed to predict deformation, the initiation of dynamic recrystallisation and microstructural change in the pseudo-two-phase specimens. Good agreement is observed between the experimental results and the model predictions. It is found that an increase in area fraction of pseudo-second phase accelerates the initiation of dynamic recrystallisation but reduces the spatial development of recrystallisation. Furthermore, the intensity of localised deformation and the constraint imposed by different configurations of rigid pseudo-second phase influence the initiation of dynamic recrystallisation and its spatial development. A distribution with lower intensity of localised deformation and less constraint has a later initiation of dynamic recrystallisation and a larger spatial development of recrystallisation. The bonding condition between matrix/fibre interfaces influences the nominal strain to initiation, locations where dynamic recrystallisation first occurs and the spatial development of recrystallisation.