A Physics-Based Packing Model Incorporating Cohesion Effects for Angular Micron-Sized SiC Powders in Binder Jetting

Low powder-bed packing density remains a critical challenge in binder jetting of micron-sized angular SiC powders, where strong interparticle cohesion causes packing behaviors to deviate from the geometric assumptions underlying conventional particle-packing models. This study establishes a physics-informed framework that links interparticle cohesion contrast with size-dependent packing interactions by embedding a dimensionless cohesive-stress contrast into the loosening, wall, and wedging mechanisms of angular-particle 3PM. Unlike conventional models that treat particle interactions primarily as a function of size ratio, the proposed framework captures the competition between geometric filling and cohesion-induced interference. After calibration using a single binary SiC system, the model was directly transferred without parameter refitting to an independent binary system and ternary mixtures. It successfully predicted packing trends across specific surface area size ratios from approximately 0.081 to 0.440 and reproduced the experimentally observed optimum composition. Analysis of the calibrated interaction functions revealed that cohesion alters the balance of packing mechanisms by suppressing effective wedging while maintaining loosening and wall effects. Guided by the model, an optimized bimodal feedstock increased green density from 39.87% to 50.21% and reduced surface roughness. This work provides a promising framework for understanding and designing cohesion-sensitive multimodal SiC powder feedstocks under the investigated experimental conditions.