OBSERVATION OF A NEW DYNAMIC RECOVERY MECHANISM IN THE HIGH STRAIN REGIME

摘要

Plastic deformation of metals refines the microstructure and increases the strength through work hardening, but this effect of deformation is counterbalanced by dynamic recovery. After deformation to large strains, the microstructure typically shows a lamellar morphology, with finely spaced lamellar boundaries connected by triple junctions. Here we report that mechanically assisted triple junction motion is an important mechanism of dynamic recovery, and it replaces two boundaries by one, while maintaining the structural morphology. The observation rationalizes many features of the evolution of microstructure and strength in metals deformed to large strains, including an approach to a steady state.