Role of process parameters on the effective properties of the print-bed during binder jet additive manufacturing: A discrete element method-based study
Abolfazl Malti, Christian Brandl, Tesfaye Tadesse Molla
Abstract
Analysis of the powder spreading process in additive manufacturing (AM) is often based on formation of a single layer of powders on a smooth substrate. While this approach is valid for powder-bed fusion AM techniques, it can oversimplify the printing process in binder jet (BJ-AM), where parts are built through multi-layer spreading of powders with liquid binder added in between. This study analyses the printing process based on multi-layer spreading of powders during BJ-AM process by using Discrete Element Method. The influence of printing parameters including layer thickness, roller velocity and substrate surface roughness on the bulk properties of the print-bed (e.g., density, structural homogeneity, and surface quality) are investigated. The study shows convergence of the relative density of the print-bed toward an asymptotic limit, while structural homogeneity and surface roughness vary significantly with process parameters. A process map is also suggested showing parameter-insensitive window for optimal powder spreading.