PREDICTION OF STRESSES GENERATED DURING SINTERING OF A CONSTRAINED THIN FILM

摘要

Residual stresses generated during sintering of ceramic based fuel cell components can lead to cracking or delamination. Often the processing conditions are optimised by trial and error. An analytical plane stress model has been developed to describe the microstructural changes (e.g. density, grain size) that the individual ceramic layers undergo during constrained sintering. The model has been calibrated with sintering data for powders under free and constrained conditions. While the model accurately predicts the variation of relative density during sintering and the final average grain size, the predicted stresses are considerably higher than those measured experimentally. This discrepancy is interpreted in terms of the approximate relationships used to describe the variation of elastic properties with density and to calculate stress from curvature measurements.