Modeling of recrystallization after inhomogeneous deformation

Abstract

Recrystallization in an inhomogeneously predeformed material (a cold-drawn cylindrical rod) is described by an analytical model and simulated with the Monte-Carlo technique. For this purpose, an equation for the nucleation rate during recrystallization as a function of local deformation has been derived. The analytical model considering the derived nucleation equation is capable of predicting the progress of the recrystallization front as observed in experiments with Titanium Grade 2. The Monte-Carlo model has been developed on the basis of the analytical model. Different functions for the local deformation were introduced, and recrystallization and subsequent grain growth were simulated. With the aid of simulation, the formation of both a grain size gradient and large elongated grains in the region of critical deformation can be understood. The graded microstructure is a consequence of the combined effect of inhomogeneous nucleation and anisotropic growth of the recrystallizing grains. Experimental grain size gradients were reproduced quantitatively by the present simulations. Agreement was also found for the grain elongation that forms during the recrystallization and grain growth stages.