Predictive simulation of process windows for powder bed fusion additive manufacturing: Influence of the powder size distribution

The properties of parts fabricated by powder bed fusion additive manufacturing depend on the process strategy as well as the characteristics of the powder bed. The aim of this study is to determine the influence of different powder size distributions for certain process parameters taken from a process window for Ti-6Al-4V. All results are obtained from our in-house software SAMPLE(2D). The first objective is identifying layer binding faults causing porous structures. We demonstrate the influence of surface roughness of each single layer for single- and multi-layer binding faults and the consequences for process windows. The second objective is the investigation of the final sample roughness. Generally, a minimal surface roughness is aimed to reduce the post-processing effort for surface finishing. By combining the findings regarding porosity and sample surface roughness, we conclude that powder size distributions with larger mean particle diameter generally diminish the process reliability and increase the required energy input. (C) 2018 The Authors. Published by Elsevier Ltd.