Effects of LPBF process parameters on microstructure and mechanical performance of SS316L

Near net shape components can be produced through laser powder bed fusion printing, thus removing potentially weakened weld sites, which are key points of failure in nuclear reactor components. As such, additive manufacturing (AM) is currently being investigated as the a potential route for manufacturing nuclear reactor components. However, the variability of AM parameters during the printing process introduces some uncertainty to the performance of printed components, making the qualification of these components for highly regulated nuclear applications difficult. Variables such as laser energy and particle spatter lead to increased porosity and microstructural defects in printed parts, which may impact the performance of these components in service. The current study artificially introduces laser energy variation (low, standard, and high) and spatter variation to printed samples to evaluate the induced changes to microstructure and mechanical performance. This study shows that low and high laser energy, and high spatter conditions, all lead to increased porosity, which leads to reduced hardness.