On the limitations of Volumetric Energy Density as a design parameter for Selective Laser Melting

Energy density is often used as a metric to compare components manufactured with Selective Laser Melting (SLM) under different sets of deposition parameters (e.g., laser power, scan speed, layer thickness, etc.). We present a brief review of the current literature on additive manufacturing of 316L stainless steel (SS) related to input parameter scaling relations. From previously published work we identified a range of Volumetric Energy Density (VED) values that should lead to deposition of fully dense parts. In order to corroborate these data, we designed a series of experiments to investigate the reliability of VED as a design parameter by comparing single tracks of 316L SS deposited with variable deposition parameters. Our results show the suitability of VED as a design parameter to describe SLM to be limited to a narrow band of applicability, which is attributed to the inability of this parameter to capture the complex physics of the melt pool. Caution should be exercised when using VED as a design parameter for SLM. (C) 2016 Elsevier Ltd. All rights reserved.