The State of Grain Boundaries and Grain-Boundary Diffusion in Ultrafine-Grained Mo Obtained by Severe Plastic Deformation
The grain-boundary diffusion of Co in ultra-fine grained Mo processed by high-pressure torsion has been studied by emission Mössbauer spectroscopy and radio-tracer analysis. It is demonstrated that under the severe plastic deformation by high-pressure torsion the non-equilibrium grain boundaries are formed which are the ultra-fast diffusion paths. At annealing in the temperature range of 623-823 K the relaxation of the non-equilibrium boundaries proceeds and their properties approach to those of equilibrium boundaries of recrystallization origin.
Prof. Andreas Öchsner, Prof. Irina V. Belova and Prof. Graeme E. Murch
V. V. Popov and A.V. Sergeev, "The State of Grain Boundaries and Grain-Boundary Diffusion in Ultrafine-Grained Mo Obtained by Severe Plastic Deformation", Defect and Diffusion Forum, Vol. 367, pp. 130-139, 2016