Build Rate Optimization for Powder Bed Fusion

The authors previously proposed a geometrically based model to predict the volume fraction of lack-of-fusion porosity in parts produced by powder bed fusion. To test this model, AlSi10Mg cubes with varying hatch spacing and layer thickness were printed in this work. Bulk densities of samples were measured with the Archimedes method and agree well with model predictions. The model was also validated by results from the literature on additively manufactured PA-12 polymer parts. Quantitative prediction of conditions that lead to part porosity allows considerable improvement in the volumetric build rate, compared with the default processing parameters provided by the equipment supplier. Nearly fully dense AlSi10Mg parts (> 99.5% dense) were fabricated with a build rate double that for standard conditions. Some melt-pool variability and large changes in hatch rotation angle do not affect the overall volume fraction of residual porosity.