[T3] Modeling and Sintering

[15A-T3-09] Multiscale Sintering Simulation of 316L Produced by LMM

*O. Schenk¹, L. Vogel², A. Kaletsch¹, C. Broeckmann¹ (1.RWTH Aachen University, Institute for Materials Applications in Mechanical Engineering, Germany, 2.MetShape GmbH, Germany)

Keywords:Sinter-based additive manufacturing, multiscale simulation, anisotropic shrinkage, dilatometry

Additive manufacturing (AM) of metal components has developed rapidly throughout the last decade. Sinter-based processes hereby offer the implementation of AM within existing powder metallurgical process routes, utilizing similar powders and sintering furnaces. While processes as binder-jetting or fused-filament-fabrication have disadvantages such as limited resolution accuracy, lithography-based metal manufacturing (LMM) enables the production of filigree, complex structures with low surface roughness. However, layer-by-layer powder deposition induces anisotropic shrinkage during the subsequent sintering process. In this work, two numerical models are proposed to predict the shrinkage behaviour of 316L produced by LMM. Firstly, a kinetic Monte-Carlo model is used to simulate shrinkage and grain growth based on microstructures of green parts. Secondly, a dilatometric study is conducted to derive a constitutive model of sintering on a macroscale accounting for the effect of density, grain size, temperature and printing direction. The accuracy of both models is shown by comparison with experiments.