Numerical simulation of grain size distributions in liquid phase sintered materials

Abstract

Many technologically important ceramics such as silicon nitride ceramics, alumina substrates and barium titanate electrical capacitors are liquid phase sintered. It is important to understand evolution of microstructural features generated by processes such as grain growth so that these materials may be engineered for their respective applications. Grain growth in liquid phase sintered materials by Ostwald ripening has been modeled extensively by both analytical and numerical techniques. However, all models make simplifying approximations to make the problem tractable and the approximations used in these models make them most accurate at very low solid fractions. A two-dimensional, Monte Carlo simulation technique based on the Potts model that makes no assumptions about solid fraction, grain shapes or diffusion fields around grains has been used to study grain growth in fully wetting, liquid phase sintered systems. The grain size distribution, GSD, was found to vary with solid fraction, becoming broader and more peaked with increasing solid fraction. The skewness was near zero at solid fraction of 0.41 and shifted to larger grain sizes with increasing solid fraction.