A phenomenological sintering model of binder-jetted 316L stainless steel parts calibrated by in situ monitoring

Binder jetting is a promising metal additive manufacturing process that enables fast and cost-effective part production. However, sintering-induced shrinkage and distortions remain major challenges, particularly for complex geometries. In this study, the sintering behavior of binder jetting stainless steel 316L parts with various geometries, including cubes, bridge beams, diamonds, impellers, and lattice structures, was investigated. An in situ optical monitoring system was developed to capture shrinkage and deformation during sintering. A finite element analysis model based on continuum mechanics was implemented and calibrated using anisotropic shrinkage data obtained from experiments. The model successfully predicted the sintering response for complex geometries, with dimensional deviations within 500 µm for bridge beams and diamonds, and within 300 µm for impellers. The effects of gravity, green density, and furnace conditions were evaluated. Lattice structures showed high sensitivity to temperature gradients and radiative heat transfer. The proposed approach enables predictive modeling and compensation of sintering distortions for improved dimensional control in binder jetting.