Investigation of the effect of simultaneous production on porosity in laser powder bed fusion

This study systematically investigates the effect of simultaneous multi-part fabrication on porosity formation in 10 × 10 × 5 mm³ AlSi10Mg specimens produced by laser powder bed fusion (LPBF). Four distinct parameter sets, incorporating variations in scan speed, hatch spacing, and scan angle, were examined. Initially, all specimens were fabricated as single-part builds on a common build platform to establish baseline porosity levels. Subsequently, two parameter sets were produced in close proximity to an adjacent component, while the remaining two were fabricated next to components with different geometrical characteristics. Porosity levels in single-part builds ranged from 0.02% to 0.15%, whereas simultaneous production led to a pronounced increase, with porosity values rising to 0.20–0.65%. Notably, porosity in sample 1 increased by approximately 19.8-fold, while sample 3 exhibited an increase of nearly tenfold. These increases are primarily attributed to inter-part thermal interactions and non-uniform energy redistribution induced by neighboring components. The results demonstrate that simultaneous production significantly alters heat transfer conditions and solidification behavior, thereby directly affecting microstructural integrity. Accordingly, explicit consideration of thermally induced interactions between adjacent parts is essential when optimizing LPBF process parameters to ensure consistent, repeatable, and reliable quality control in multi-part manufacturing scenarios.