The interrelated effect of activation energy and grain boundary energy on grain growth in nanocrystalline materials

The interrelated effect of activation energy and grain boundary energy on grain growth and thermal stabilization in nanocrystalline materials was investigated. Departing from Borisov's equation and Kirchheim's grain boundary energy model, an activation energy model was derived incorporating solute segregation and grain growth. An integrated thermokinetic model for nanoscale grain growth was then developed by incorporating the coupled effects of activation energy and grain boundary energy. By application of the model to nanoscale grain growth of dense nanocrystalline gadolinia-doped ceria, a good agreement between the model predictions and the experimental results was obtained. It is shown that the interrelated effect of increased activation energy and decreased grain boundary energy induced thermal stability in the nanocrystalline materials.