Binder jet additive manufacturing (BJAM) is being used in many advanced applications; however, porosity control remains a key limiting factor. The purpose of this study is to examine the combined influence of roller rotation speed, roller traverse speed, binder saturation and powder layer thickness on porosity formation in stainless steel 420 green parts produced by BJAM and ranks the parameter importance across a broad design space.
Experiments quantified porosity using bulk density and microscopy analysis, while discrete element method (DEM) simulations performed a full-factorial sweep (11,000 cases) to map trends and pairwise interactions.
Experiments revealed a porosity minimum at an intermediate roller traverse speed, a monotonic increase in porosity with greater layer thickness, a modest densification benefit at mid-range roller rotation speed and a non-linear, system-dependent effect of binder saturation. Across conditions, layer thickness and roller traverse speed exerted the strongest influence on porosity. Simulations reproduced the ranking and mapped low and high porosity regions but over-predicted porosity, especially for thin layers.
This work provides a cross-validated ranking of process parameters and presents interaction maps that directly inform experiment planning. It explicitly models powder–binder interaction in DEM simulations via cohesive energy densities, treating particles as if coated with a thin binder layer to enable fast, high-coverage screening. The results pinpoint where binder infiltration and refined roller mechanics are most needed, offering a practical framework to identify operating windows and improve porosity control in BJAM.
