A unified model composed of the flow function model, dislocation model and Taylor theory was used to investigate the evolution of dislocation density, cell size, and strength of tantalum during the ECAP process. From the flow function model, strain and strain rate distributions were achieved and then using a modified version of three-dimensional ETMB model, the dislocation density, cell size, and strength were predicted. The predicted dislocation density, cell size, and strength were compared with the experimental data and a remarkable agreement was obtained. In addition, the effect of dynamic recovery upon the strength of the processed tantalum was modelled and compared with other materials.

Dislocation Structure and Strength Evolution of Heavily Deformed Tantalum. E.Hosseini, M.Kazeminezhad: International Journal of Refractory Metals and Hard Materials, 2009, 27[3], 605-10