The Recrystallization Kinetics and Electron Microscopy of Magnesium and Chromium

摘要

The effect if grain size and degree of deformation on the recrystallization temperature of pure magnesium was determined. The effects of the alloying elements Mn, Fe, Co, Ni, Zn and Cd in amounts ranging from .005 to .02 atomic per cent recrystallization temperature and kinetics were determined. It was found that the effect on recrystallization temperature of solute additions was not a function of their atomic size or electronic structure but seemed to be related to the distribution coefficient of the solute. The recrystallization kinetics were determined for pure chromium and electron microscopic studies made of dislocation structures during various stages of recovery and recrystallization. The activation energy for recrystallization was found to be the same as the activation energy for self-diffusion in chromium. Finally grain growth measurements have been made for pure magnesium which indicates that secondary recrystallization invariably follows primary recrystallization. The activation energy for grain growth was found to be about one-half the activation energy for magnesium self-diffusion which indicates that the growth process is controlled by atomic migration across the boundary. Equations are given which fit the kinetic process observed in recrystallization and grain growth.