High-fidelity modeling of binder–powder interactions in binder jetting: Binder flow and powder dynamics

Binder jetting additive manufacturing has attracted rising attention in recent years. However, the interactions between binder and powder have not been fully understood, hindering the development of this technology. In this work, a high-fidelity computational model of fluid-solid interaction is developed to reproduce both binder flow and powder movement simultaneously. The model accurately reproduces the impingement of the binder droplet, the spreading and penetration of the binder, and the spattering and agglomeration of powder particles. The simulation results agree well with theoretical analysis and experimental findings from the literature. Collisions between powder particles affect the binder spreading significantly, but affect the binder penetration less. The spattering velocities of powder particles have a wide range of magnitude. Compared with jetting binder droplets sequentially, simultaneous binder jetting mode can reduce the powder spattering but lower the dimensional accuracy. This model is able to provide in-depth insights into the underlying mechanisms of binder-powder interactions, as well as a foundation to optimize the process and materials.