Selective laser melting (SLM) additive manufacturing (AM) exhibits uncertainties, where variations in build quality are present despite utilizing the same optimized processing parameters. In this work, we identify the sources of uncertainty in SLM process by in-situ characterization of SLM dynamics induced by small variations in processing parameters. We show that variations in the laser beam size, laser power, laser scan speed, and powder layer thickness result in significant variations in the depression zone, melt pool, and spatter behavior. On average, a small deviation of only ~5% from the optimized/reference laser processing parameter resulted in a ~10% or greater change in the depression zone and melt pool geometries. For spatter dynamics, small variation (10 µm, 11%) of the laser beam size could lead to over 40% change in the overall volume of the spatter generated. The responses of the SLM dynamics to small variations of processing parameters revealed in this work are useful for understanding the process uncertainties in the SLM process.


Mechanical and Aerospace Engineering


This work is funded by the Boeing Company through the Center for Aerospace Manufacturing Technology (CAMT) at Missouri University of Science and Technology, and the US National Science Foundation.

Keywords and Phrases

Additive Manufacturing; Laser Powder Bed Fusion; Melt Pool Dynamics; Quality Uncertainty; Selective Laser Melting; Spatter

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Article - Journal

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Final Version

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Publication Date

11 Jan 2022