Shape distortion and delamination during constrained sintering of ceramic stripes: Discrete element simulations and experiments

Particle-based simulations using the discrete element method are applied for the sintering of thin ceramic stripes that are constrained by a rigid substrate. The inhibition of lateral particle movement in vicinity of the substrate leads to a preferred shrinkage direction perpendicular to the substrate, which causes shape distortion as well as delamination of the stripe at the interface edges. Multiple processing parameters are varied in simulations to analyze their influence on the mentioned effects. The amount of particle rearrangement and the height to width aspect ratio of the cross-section are identified to be factors that determine the level of shape distortion and edge delamination. The simulation results are compared with measurements of stripes produced by soft micromolding in capillaries. Good accordance is observed regarding parameters like axial and lateral shrinkage or delamination angle.