Simulation of additive manufacturing

   In the context of additive manufacturing the group “Numerical Simulation” focuses on beam-based technologies using a powder bed. Different materials from metals and metal alloys (Ti64, TiAl, IN718) to polymers (PA12) can be applied to the software. The scientific research focuses, in close cooperation with the experimental group “Additive Manufacturing”, on the understanding of the fundamental mechanism during powder melting and material consolidation as well as on the prediction of innovative process strategies regarding porosity, microstructure and alloy concentration.
   A predictive software relies on exact physical and numerical models. The most important aspect is the correct modelling of the thermal conditions. Almost all modifications of process parameters have a direct influence on heat conduction, the coupling of the energy source or heat sinks by e.g. heat radiation or evaporation. Furthermore, many material parameters are temperature dependent and sensitive to a correct model. During melting a melt pool evolves, which dynamics is mainly covered by capillarity, wetting, Marangoni convection and gravity. The temperature gradient and the solidification velocity mainly influence the final microstructure after solidification.
   The 2D simulation of selective electron beam melting bases on the software for modelling of foam formation. The base software is extended by certain modules comprising the electron beam absorption, phase transitions, selective evaporation or grain structure evolution. After a careful experimental validation, the aim of this software is to predict process windows and explain process phenomena. Most process phenomena during selective electron beam melting are covered by a 2D simulation. A more realistic modelling of the melt pool dynamics and the grain structure evolution is reached by 3D simulations. Therefore, two different simulation tools for these purposes are developed at WTM. The 3D hydrodynamics software requires a massively parallel implementation, which has been developed in cooperation with the Chair of System Simulation. The melt pool dynamics and the material consolidation are investigated in full spatial dimension. Using this software, process windows for dense parts as well as innovative process strategy modifications are predicted. The grain structure evolution is modelled by a separate software, which enables the grains to grow in all possible directions during processing. Here, a macroscopic approach is used, where the powder particles are approximated by a continuum. Additionally, only the thermodynamics is modelled. With these simplifications, domains on the scale of whole parts are possible to simulate.
   Besides funding from industry and DFG/EU projects, the development of the simulation software is mainly funded by the collaborative research centre SFB 814 “Additive Manufacturing” (http://www.sfb814.forschung.uni-erlangen.de/).

• Markl M., Azadi Tinat MR., Berger T., Renner J., Körner C.:
  Extracting powder bed features via electron optical images during electron beam powder bed fusion
  In: Additive Manufacturing Letters 10 (2024), Article No.: 100220
  ISSN: 2772-3690
  DOI: 10.1016/j.addlet.2024.100220
• Wahlmann B., Markl M., Körner C.:
  A thermo-mechanical model for hot cracking susceptibility in electron beam powder bed fusion of Ni-base superalloys
  In: Materials & Design 237 (2024), Article No.: 112528
  ISSN: 0264-1275
  DOI: 10.1016/j.matdes.2023.112528
• Yang Z., Markl M., Körner C.:
  Comprehensive numerical investigation of laser powder bed fusion process conditions for bulk metallic glasses
  In: Additive Manufacturing 81 (2024), Article No.: 104026
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2024.104026
• Koepf JA., Pistor J., Markl M., Körner C.:
  Numerical Microstructure Prediction for Lattice Structures Manufactured by Electron Beam Powder Bed Fusion
  In: Crystals 14 (2024), Article No.: 149
  ISSN: 2073-4352
  DOI: 10.3390/cryst14020149
• Scherr R., Liepold P., Markl M., Körner C.:
  A CALPHAD-Informed Enthalpy Method for Multicomponent Alloy Systems with Phase Transitions
  In: Modelling 5 (2024), p. 367-391
  ISSN: 2673-3951
  DOI: 10.3390/modelling5010020
• Böhm J., Breuning C., Markl M., Körner C.:
  A new approach of preheating and powder sintering in electron beam powder bed fusion
  In: International Journal of Advanced Manufacturing Technology (2024)
  ISSN: 0268-3768
  DOI: 10.1007/s00170-024-13966-1
• Yang Z.:
  Modeling and Simulation of Bulk Metallic Glass Crystallization During Laser Powder Bed Fusion (Dissertation, 2024)
  DOI: 10.25593/open-fau-715
• Scherr R., Markl M., Körner C.:
  Volume of fluid based modeling of thermocapillary flow applied to a free surface lattice Boltzmann method
  In: Journal of Computational Physics 492 (2023), Article No.: 112441
  ISSN: 0021-9991
  DOI: 10.1016/j.jcp.2023.112441
• Wahlmann B., Markl M., Körner C.:
  A Thermo-Mechanical Model for Hot Cracking Susceptibility in Electron Beam Powder Bed Fusion of Ni-Base Superalloys
  In: Materials & Design 237 (2023), p. 112528
  ISSN: 0264-1275
  DOI: 10.1016/j.matdes.2023.112528
• Breuning C., Markl M., Körner C.:
  A return time compensation scheme for complex geometries in electron beam powder bed fusion
  In: Additive Manufacturing 76 (2023), p. 103767
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2023.103767
• Koepf JA., Gotterbarm M., Kumara C., Markl M., Körner C.:
  Alternative Approach to Modeling of Nucleation and Remelting in Powder Bed Fusion Additive Manufacturing
  In: Advanced Engineering Materials (2023)
  ISSN: 1438-1656
  DOI: 10.1002/adem.202201682
• Breuning C., Böhm J., Markl M., Körner C.:
  High-Throughput Numerical Investigation of Process Parameter-Melt Pool Relationships in Electron Beam Powder Bed Fusion
  In: Modelling 4 (2023), p. 336-350
  ISSN: 2673-3951
  DOI: 10.3390/modelling4030019
• Yang Z., Huber F., Krapf A., Merle B., Markl M., Schmidt M., Körner C.:
  Revealing bulk metallic glass crystallization kinetics during laser powder bed fusion by a combination of experimental and numerical methods
  In: Journal of Non-Crystalline Solids 619 (2023), Article No.: 122532
  ISSN: 0022-3093
  DOI: 10.1016/j.jnoncrysol.2023.122532
• Mergheim J., Breuning C., Burkhardt C., Hübner D., Köpf J., Herrnböck L., Yang Z., Körner C., Markl M., Steinmann P., Stingl M.:
  Additive manufacturing of cellular structures: Multiscale simulation and optimization
  In: Journal of Manufacturing Processes 95 (2023), p. 275-290
  ISSN: 1526-6125
  DOI: 10.1016/j.jmapro.2023.03.071
• Yang Z., Kuesters Y., Logvinov R., Markl M., Körner C.:
  SAMPLE3D: A versatile numerical tool for investigating texture and grain structure of materials processed by PBF processes
  IVth International Conference on Simulation for Additive Manufacturing (Sim-AM 2023) (München, 26. July 2023 - 28. July 2023)
  DOI: 10.23967/c.simam.2023.006
• Yang Z., Markl M., Körner C.:
  Predictive simulation of bulk metallic glass crystallization during laser powder bed fusion
  In: Additive Manufacturing 59 (2022), Article No.: 103121
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2022.103121
• Breuning C., Pistor J., Markl M., Körner C.:
  Basic Mechanism of Surface Topography Evolution in Electron Beam Based Additive Manufacturing
  In: Materials 15 (2022), Article No.: 4754
  ISSN: 1996-1944
  DOI: 10.3390/ma15144754
• Yang Z., Al-Mukadam R., Stolpe M., Markl M., Deubener J., Körner C.:
  Isothermal crystallization kinetics of an industrial-grade Zr-based bulk metallic glass
  In: Journal of Non-Crystalline Solids 573 (2021), Article No.: 121145
  ISSN: 0022-3093
  DOI: 10.1016/j.jnoncrysol.2021.121145
• Rausch A., Pistor J., Breuning C., Markl M., Körner C.:
  New grain formation mechanisms during powder bed fusion
  In: Materials 14 (2021), Article No.: 3324
  ISSN: 1996-1944
  DOI: 10.3390/ma14123324
• Wahlmann B., Leidel D., Markl M., Körner C.:
  Numerical Alloy Development for Additive Manufacturing towards Reduced Cracking Susceptibility
  In: Crystals 11 (2021)
  ISSN: 2073-4352
  DOI: 10.3390/cryst11080902
• Küng V., Scherr R., Markl M., Körner C.:
  Multi-material model for the simulation of powder bed fusion additive manufacturing
  In: Computational Materials Science 194 (2021)
  ISSN: 0927-0256
  DOI: 10.1016/j.commatsci.2021.110415
• Breuning C., Arnold C., Markl M., Körner C.:
  A multivariate meltpool stability criterion for fabrication of complex geometries in electron beam powder bed fusion
  In: Additive Manufacturing 45 (2021), Article No.: 102051
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2021.102051
• Kergaßner A., Köpf J., Markl M., Körner C., Mergheim J., Steinmann P.:
  A Novel Approach to Predict the Process-Induced Mechanical Behavior of Additively Manufactured Materials
  In: Journal of Materials Engineering and Performance (2021)
  ISSN: 1059-9495
  DOI: 10.1007/s11665-021-05725-0
• Yang Z., Bauereiß A., Markl M., Körner C.:
  Modeling laser beam absorption of metal alloys at high temperatures for selective laser melting
  In: Advanced Engineering Materials 23 (2021), Article No.: 2100137
  ISSN: 1438-1656
  DOI: 10.1002/adem.202100137
• Rausch A., Gotterbarm M., Pistor J., Markl M., Körner C.:
  New grain formation by constitutional undercooling due to remelting of segregated microstructures during powder bed fusion
  In: Materials 13 (2020), p. 1-14
  ISSN: 1996-1944
  DOI: 10.3390/ma13235517
• Körner C., Markl M., Koepf JA.:
  Modeling and Simulation of Microstructure Evolution for Additive Manufacturing of Metals: A Critical Review
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science (2020)
  ISSN: 1073-5623
  DOI: 10.1007/s11661-020-05946-3
• Gotterbarm M., Rausch A., Körner C.:
  Fabrication of Single Crystals through a µ-Helix Grain Selection Process during Electron Beam Metal Additive Manufacturing
  In: Metals (2020)
  ISSN: 2075-4701
  DOI: 10.3390/met10030313
• Köpf J., Soldner D., Ramsperger M., Mergheim J., Markl M., Körner C.:
  Numerical microstructure prediction by a coupled finite element cellular automaton model for selective electron beam melting
  In: Computational Materials Science 162 (2019), p. 148-155
  ISSN: 0927-0256
  DOI: 10.1016/j.commatsci.2019.03.004
• Köpf J., Gotterbarm M., Markl M., Körner C.:
  3D multi-layer grain structure simulation of powder bed fusion additive manufacturing
  In: Acta Materialia 152 (2018), p. 119-126
  ISSN: 1359-6454
  DOI: 10.1016/j.actamat.2018.04.030
• Rausch A., Markl M., Körner C.:
  Predictive simulation of process windows for powder bed fusion additive manufacturing: Influence of the powder size distribution
  In: Computers & Mathematics with Applications (2018)
  ISSN: 0898-1221
  DOI: 10.1016/j.camwa.2018.06.029
• Hübner D., Gotterbarm M., Kergaßner A., Köpf J., Pobel C., Markl M., Mergheim J., Steinmann P., Körner C., Stingl M.:
  Topology Optimization in Additive Manufacturing Considering the Grain Structure of Inconel 718 using Numerical Homogenization
  iCAT 2018 (Maribor, 10. October 2018 - 11. October 2018)
  In: Proceedings of 7th International Conference on Additive Technologies 2018
• Köpf J., Rasch M., Meyer A., Markl M., Schmidt M., Körner C.:
  3D grain growth simulation and experimental verification in laser beam melting of IN718
  10th CIRP Conference on Photonic Technologies (LANE 2018) (Fürth, 4. September 2018 - 6. September 2018)
  In: Procedia CIRP 74 (2018) 2018
  DOI: 10.1016/j.procir.2018.08.034
  URL: https://www.sciencedirect.com/science/article/pii/S2212827118308187/pdf?md5=ea85f15a94f75d82fce787e5b0a20225πd=1-s2.0-S2212827118308187-main.pdf
• Bauereiß A.:
  Mesoskopische Simulation des selektiven Strahlschmelzens mittels einer Lattice Boltzmann Methode mit dynamischer Gitteranpassung (Dissertation, 2018)
• Klassen A., Forster V., Jüchter V., Körner C.:
  Numerical simulation of multi-component evaporation during selective electron beam melting of TiAl
  In: Journal of Materials Processing Technology 247 (2017), p. 280-288
  ISSN: 0924-0136
  DOI: 10.1016/j.jmatprotec.2017.04.016
• Markl M., Lodes M., Franke M., Körner C.:
  Additive Fertigung durch selektives Elektronenstrahlschmelzen
  In: Schweissen und Schneiden (2017), p. 30-39
  ISSN: 0036-7184
• Rai A., Helmer H., Körner C.:
  Simulation of grain structure evolution during powder bed based additive manufacturing
  In: Additive Manufacturing 13 (2017), p. 124-134
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2016.10.007
• Riedlbauer DR., Scharowsky T., Singer R., Steinmann P., Körner C., Mergheim J.:
  Macroscopic simulation and experimental measurement of melt pool characteristics in selective electron beam melting of Ti-6Al-4V
  In: International Journal of Advanced Manufacturing Technology (2017)
  ISSN: 0268-3768
  DOI: 10.1007/s00170-016-8819-6
  URL: http://link.springer.com/article/10.1007/s00170-016-8819-6
• Rausch A., Küng V., Pobel C., Markl M., Körner C.:
  Predictive Simulation of Process Windows for Powder Bed Fusion Additive Manufacturing: Influence of the Powder Bulk Density
  In: Materials 10 (2017)
  ISSN: 1996-1944
  DOI: 10.3390/ma10101117
• Markl M., Lodes M., Franke M., Körner C.:
  Additive manufacturing using selective electron beam melting
  In: Welding and Cutting (2017), p. 177-184
  ISSN: 1612-3433
• Klassen A., Forster V., Körner C.:
  A multi-component evaporation model for beam melting processes
  In: Modelling and Simulation in Materials Science and Engineering 25 (2017), Article No.: 025003
  ISSN: 1361-651X
  DOI: 10.1088/1361-651X/aa5289
• Markl M., Rausch A., Forster V., Pobel C., Körner C.:
  Predictive numerical simulations of processing windows for powder bed based additive manufacturing
  2017 Simulation for Additive Manufacturing, Sinam 2017 (Munich, 11. October 2017 - 13. October 2017)
  In: Simulation for Additive Manufacturing 2017, Sinam 2017 2017
• Köpf J., Markl M., Körner C.:
  3D multilayer grain structure simulation for beam-based additive manufacturing
  2017 Simulation for Additive Manufacturing, Sinam 2017 (Munich, DEU, 11. October 2017 - 13. October 2017)
  In: Simulation for Additive Manufacturing 2017, Sinam 2017 2017
• Markl M., Körner C.:
  Multiscale Modeling of Powder Bed-Based Additive Manufacturing
  In: Annual Review of Materials Research 46 (2016), p. 93-123
  ISSN: 1531-7331
  DOI: 10.1146/annurev-matsci-070115-032158
• Rai A., Markl M., Körner C.:
  A coupled Cellular Automaton–Lattice Boltzmann model for grain structure simulation during additive manufacturing
  In: Computational Materials Science 124 (2016), p. 37-48
  ISSN: 0927-0256
  DOI: 10.1016/j.commatsci.2016.07.005
• Markl M., Bauereiß A., Rai A., Körner C.:
  Numerical Investigations of Selective Electron Beam Melting on the Powder Scale
  Fraunhofer Direct Digital Manufacturing Conference 2016 (Berlin, 16. March 2016 - 17. March 2016)
  In: Proceedings of the Fraunhofer Direct Digital Manufacturing Conference 2016 2016
• Köpf J., Rai A., Markl M., Körner C.:
  3D Grain Structure Simulation for Beam-Based Additive Manufacturing
  6th International Conference on Additive Technologies iCAT (Nürnberg, 29. November 2017 - 30. November 2016)
  In: Proceedings of the 6th International Conference on Additive Technologies iCAT 2016 2016
• Markl M., Ammer R., Rüde U., Körner C.:
  Numerical investigations on hatching process strategies for powder-bed-based additive manufacturing using an electron beam
  In: International Journal of Advanced Manufacturing Technology 78 (2015), p. 239-247
  ISSN: 0268-3768
  DOI: 10.1007/s00170-014-6594-9
  URL: http://link.springer.com/article/10.1007/s00170-014-6594-9
• Markl M., Körner C.:
  Free surface Neumann boundary condition for the advection-diffusion lattice Boltzmann method
  In: Journal of Computational Physics 301 (2015), p. 230-246
  ISSN: 0021-9991
  DOI: 10.1016/j.jcp.2015.08.033
• Markl M.:
  Numerische Modellierung und Simulation des selektiven Elektronenstrahlschmelzens basierend auf einer gekoppelten Gitter Boltzmann und Diskrete Element Methode (Dissertation, 2015)
• Ammer R., Markl M., Jüchter V., Körner C., Rüde U.:
  Validation Experiments for LBM Simulations of Electron Beam Melting
  In: International Journal of Modern Physics C (2014), p. 1-9
  ISSN: 0129-1831
  DOI: 10.1142/S0129183114410095
  URL: http://arxiv.org/pdf/1402.2440.pdf
• Bauereiß A., Scharowsky T., Körner C.:
  Defect generation and propagation mechanism during additive manufacturing by selective beam melting
  In: Journal of Materials Processing Technology 214 (2014), p. 2522-2528
  ISSN: 0924-0136
  DOI: 10.1016/j.jmatprotec.2014.05.002
• Klassen A., Scharowsky T., Körner C.:
  Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods
  In: Journal of Physics D: Applied Physics 47 (2014), Article No.: 275303
  ISSN: 0022-3727
  DOI: 10.1088/0022-3727/47/27/275303
• Ammer R., Ljungblad U., Markl M., Körner C., Rüde U.:
  Simulating fast electron beam melting with a parallel thermal free surface lattice Boltzmann method
  In: Computers & Mathematics with Applications 67 (2014), p. 318-330
  ISSN: 0898-1221
  DOI: 10.1016/j.camwa.2013.10.001
  URL: http://www.sciencedirect.com/science/article/pii/S0898122113005944
• Klassen A., Bauereiß A., Körner C.:
  Modelling of electron beam absorption in complex geometries
  In: Journal of Physics D-Applied Physics 47 (2014), Article No.: 065307
  ISSN: 0022-3727
  DOI: 10.1088/0022-3727/47/6/065307
• Bauer M., Schornbaum F., Godenschwager C., Markl M., Anderl D., Köstler H., Rüde U.:
  A Python extension for the massively parallel framework waLBerla
  4th Workshop on Python for High Performance and Scientific Computing (New Orleans, 17. November 2014 - 17. November 2014)
  In: online 2014
  URL: http://www.dlr.de/sc/Portaldata/15/Resources/dokumente/pyhpc2014/submissions/pyhpc2014_submission_5.pdf
• Körner C., Bauereiß A., Attar E.:
  Fundamental consolidation mechanisms during selective beam melting of powders
  In: Modelling and Simulation in Materials Science and Engineering 21 (2013), Article No.: 085011
  ISSN: 0965-0393
  DOI: 10.1088/0965-0393/21/8/085011
• Markl M., Ammer R., Ljungblad U., Rüde U., Körner C.:
  Electron beam absorption algorithms for electron beam melting processes simulated by a three-dimensional thermal free surface lattice Boltzmann method in a distributed and parallel environment
  In: Procedia Computer Science 18 (2013), p. 2127-2136
  ISSN: 1877-0509
  DOI: 10.1016/j.procs.2013.05.383
  URL: http://www.sciencedirect.com/science/article/pii/S1877050913005267
• Scharowsky T., Bauereiß A., Singer R., Körner C.:
  Observation and numerical simulation of melt pool dynamic and beam powder interaction during selective electron beam melting
  23rd Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2012 (Austin, TX)
  URL: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84889688177&origin=inward
• Körner C., Attar E., Heinl P.:
  Mesoscopic simulation of selective beam melting processes
  In: Journal of Materials Processing Technology 211 (2011), p. 978-987
  ISSN: 0924-0136
  DOI: 10.1016/j.jmatprotec.2010.12.016
• Attar E., Körner C.:
  Lattice Boltzmann model for thermal free surface flows with liquid-solid phase transition
  In: International Journal of Heat and Fluid Flow 32 (2011), p. 156-163
  ISSN: 0142-727X
  DOI: 10.1016/j.ijheatfluidflow.2010.09.006
• Attar E.:
  Simulation of Selective Electron Beam Melting Process (Dissertation, 2011)
• Attar E., Körner C.:
  Lattice Boltzmann method for dynamic wetting problems
  In: Journal of Colloid and Interface Science 335 (2009), p. 84-93
  ISSN: 0021-9797
  DOI: 10.1016/j.jcis.2009.02.055
• Markl M., Colosimo BM., Körner C.:
  Progress in electron beam additive manufacturing
  In: Progress in Additive Manufacturing (2024)
  ISSN: 2363-9512
  DOI: 10.1007/s40964-024-00679-w
• Yang Z., Koepf JA., Markl M., Körner C.:
  Effect of scanning strategies on grain structure and texture of additively manufactured lattice struts: A numerical exploration
  In: Advanced Engineering Materials (2024)
  ISSN: 1438-1656
  DOI: 10.1002/adem.202400661
• Kupfer T., Breuning C., Markl M.:
  Graph-based spot melting sequence for electron beam powder bed fusion
  In: Additive Manufacturing 91 (2024), Article No.: 104321
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2024.104321
• Semjatov N., Wahlmann B., Körner C.:
  Multiple interaction electron beam powder bed fusion for controlling melt pool dynamics and improving surface quality
  In: Additive Manufacturing 90 (2024), Article No.: 104316
  ISSN: 2214-7810
  DOI: 10.1016/j.addma.2024.104316
• Breuning C., Markl M., Körner C.:
  A Scan Strategy Based Compensation of Cumulative Heating Effects in Electron Beam Powder Bed Fusion
  In: Progress in Additive Manufacturing (2024)
  ISSN: 2363-9512
  DOI: 10.1007/s40964-024-00807-6