ABSTRACT
An experimental study was conducted to examine the influence of ultrafine SiC particles on grain growth in Al2O3 as a function of annealing time, particle volume fraction, and annealing temperature. The SiC particles reduced the grain growth rate of Al2O3 by over three orders of magnitude, resulting in final grain sizes which decreased with increasing particle volume fraction. It was observed that φ (fraction of particles on grain boundaries) and G (grain size) were strongly correlated, revealing a path for microstructural evolution in this system, which involved significant particle-boundary breakaway. This correlation was used to modify Zener's expression for the dependence of equilibrium grain size on particle volume fraction, and the resulting expression was used to describe the experimental data.
