Application of a microstructure-based model for sintering and creep

A unified model for ceramic sintering and creep is presented. The model is based on the physical processes that are common to sintering and creep, i.e. grain boundary diffusion, grain boundary sliding, and grain coarsening. Additionally, the model incorporates interface reaction controlled diffusion, which is important for small grain sizes, and which leads to a nonlinear stress-strain rate relation. The model was applied to predict the sinter forming of reaction-bonded alumina. Some of the parameters required for the model were determined from sinter forging experiments, and these same experiments were used to test and validate the model predictions. Additionally, creep tests were conducted at three different temperatures, and the experimental results were compared with numerical predictions. Model predictions show good agreement with experimental sintering and creep results.