(104d) Multi-Scale Computational Modeling of Selective Laser Melting

Selective Laser Melting (SLM) is an additive manufacturing technique used to rapidly create parts by selectively fusing successive layers of powder with a laser. Defects can arise in SLM parts due to poor selection of processing parameters. Accurate models of the SLM process have the potential to reduce the testing and experimentation required when using SLM. However, simulating the complete build of an SLM part is challenging due to the difference in scale between the size of the part being built and the size of the particles and laser being used. Bed-scale continuum models, in which the powder bed is represented as a continuous medium, are typically used to reduce computational cost. Continuum models require as inputs volume-averaged effective properties of the powder which are often unknown and difficult to obtain by experimental means. In this work, we describe a multi-scale modeling approach in which particle-scale models, where individual particles are resolved in a small, representative, domain, are used to predict effective properties of a powder with uncertainty. These properties are then used in a part-scale continuum model to predict temperature history, melt percentage, and thermal stresses with uncertainty in an SLM build.