Assessing the SL Med AlSi10Mg integrity via a quantitative melt pool analysis

Abstract

This article seeks to explore how the intrinsic layer-by-layer nature of Selective Laser Melting (SLM) makes the process particularly sensitive to manufacturing parameters that govern the melt pools (MP) quality and the overall performance of printed components. The research emphasizes comprehensive characterization and analysis of the melt pools over the statistical data derived from micrographs of SLMed AlSi10Mg samples fabricated under diverse printing conditions. The main objective is to assess the impact of critical process parameters on the essential melt pool geometry, porosity distribution, and the existence of unmolten powder particles. The methodology includes a qualitative evaluation performed through optical microscopy following chemical etching with Keller’s reagent, along with the quantitative measurements obtained from the resulting images. Results inferred that all inputs factors are significant upon the MP geometric features with different influences; the materials built were also considered homogeneous and isotropic in terms of MP geometry characteristics; while the corresponding statistical distributions revealed a special character; melt pool surface areas and widths can be expected and controlled since they fit Gaussian and log-normal distributions, while the the MP width has been found to follow multimodal distribution especially for building orientation of 45°; this behavior can mislead in classical production control and can lead to a non-suitable more random variation of mechanical properties of the produced parts. The authors proposed then some advice to overtake this concern as it is discussed in the last two sections and future works.