2015/12/31 by Saad A. Khairallah, Andrew T. Anderson, Alexander Rubenchik +2 · 2 citations
Engineering · Physics and Astronomy · #Additive Manufacturing Materials and Processes #Additive Manufacturing and 3D Printing Technologies #Composite material #Convection #Denudation #Deposition (geology) #Fusion #Geology #Laser #Laser power scaling #Marangoni effect #Materials science #Mechanics #Optics #Particle (ecology) #Recoil #Welding Techniques and Residual Stresses #physics.flu-dyn
paper · pdf · doi:10.1016/j.actamat.2016.02.014
arxiv created 2016/01/05 · openalex publication_date 2016/02/23 · arxiv updated 2016/03/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
This study demonstrates the significant effect of the recoil pressure and Marangoni convection in laser powder bed fusion (L-PBF) of 316L stainless steel. A three-dimensional high fidelity powder-scale model reveals how the strong dynamical melt flow generates pore defects, material spattering (sparking), and denudation zones. The melt track is divided into three sections: a topological depression, a transition and a tail region, each being the location of specific physical effects. The inclusion of laser ray-tracing energy deposition in the powder-scale model improves over traditional volumetric energy deposition. It enables partial particle melting, which impacts pore defects in the denudation zone. Different pore formation mechanisms are observed at the edge of a scan track, at the melt pool bottom (during collapse of the pool depression), and at the end of the melt track (during laser power ramp down). Remedies to these undesirable pores are discussed. The results are validated against the experiments and the sensitivity to laser absorptivity is discussed.