Grain growth and thermal stability in nanocrystalline Fe-B alloys prepared by melt spinning

Using the melt spinning technique, a nanocrystalline (NC) Fe-B single-phase solid solution was prepared at a disk speed of 7 000 rpm. After treatment by isothermal annealing at 700 °C for the NC solid solution, the grain growth behavior was investigated using the dimensionless parabolic growth model, the dimensionless purely kinetic model, and a recently proposed dimensionless thermo-kinetic model. Neither the parabolic growth model nor the purely kinetic growth model with solute drag was in agreement with the experimental results, although the grain growth rate was partially inhibited. However, the thermo-kinetic model was consistent with the experimental results, which confirmed that the main stabilizing mechanism is a reduction in the grain boundary energy and an increase in the interface activation energy.