ICME 2023: App.: AM Processing III
Program Organizers: Charles Ward, AFRL/RXM; Heather Murdoch, U.S. Army Research Laboratory

Wednesday 3:20 PM
May 24, 2023
Room: Boca I-III
Location: Caribe Royale

Session Chair: Austin Mann, ATI Materials

3:20 PM
Multiphysics Modeling of Ti-based Composite Direct Energy Deposition for Analyzing the Dynamics of Nano-sized Reinforcing Particles: Mingyu Chung¹; Kang Hyun Lee¹; Yeon Su Lee¹; Gun jin Yun¹; ¹Seoul National University
    Direct energy deposition (DED) is a promising additive manufacturing process for fabricating metal matrix composite (MMC) components. Using reinforcing particles as nucleation sites, the DED process can produce fine-grained MMC parts with enhanced tensile properties. However, coexistance of interactive phenomena (e.g., Marangoni convection, recoil pressure, and multiple reflection) with extreme short period of their presence in the melt pool hinders the control of particle dispersion, which is crucial for obtaining superior mechanical properties with equiaxed grain structure. To resolve this problem, the numerical model incorporating thermo-fluid dynamics is established to predict flows in the melt pool. Also, based on the constructed simulation results and Lagrangian discrete phase model (DPM), migration patterns of particles are investigated. The obtained results showed that recoil pressure and Marangoni convection forces had a significant role in the movement of particles. The present study better explains the dispersion mechanism of supplementary particles in the melt pool.

3:40 PM
Coupled Thermal-solidification Process Simulation of Sapphire Growth: Raluca Trasca¹; Werner Eßl¹; Georg Reiss¹; Sina Lohrasbi²; Peter Raninger¹; ¹Materials Center Leoben Forschung GmbH; ²FAMETEC GmbH
    In this work coupled thermal-solidification simulations of sapphire growth in single-boule furnaces with Heat Exchange Method (HEM) are presented. The heat transfer in the furnace is modelled via ANSYS Fluent® by considering: 1) heat conduction and radiation in furnace, 2) heat conduction, laminar convection and radiation in sapphire melt, and 3) heat conduction and internal radiation in sapphire crystal. The crystal growth is modelled by the enthalpy-porosity approach. The physical models used in simulations are validated with measurement data from a real furnace, which capture the crystal-melt interface position during the technological growth process. A simplified furnace geometry is considered to study the effect of different side and top heater powers on the crystal-melt interface during the growth process. A main focus is put on the possibilities for upscaling the sapphire crucible dimensions (height and width) to make the process more efficient and to be able to produce larger wafers.

4:00 PM
Multiscale Modeling of Metal Vaporization/Condensation in Manufacturing Processes: Scott Muller¹; Andrew Ritzmann¹; Floyd Hilty¹; W Rosenthal¹; Lance Hubbard¹; Matthew Olszta¹; ¹Pacific Northwest National Laboratory
    There are a variety of manufacturing processes where plumes of metal vapor are produced as a byproduct. The composition, size, and shape of particles condensed from metal vapor may provide information in optimizing the associated manufacturing processes and conditions. Selective laser melting is a well-defined process that we use as a surrogate for manufacturing techniques that generate particles through the condensation of metal vapor. We present the development of a multiscale model for particle formation by condensation of metal vapor generated during selective laser melting. This consists of coupling (1) thermal modeling of laser-induced metal melting and volatilization, (2) fluid dynamics modeling of the metal vapor plume, and (3) phase field modeling of metal condensation. The phase field model accounts for vapor/liquid/solid phase transitions under non-isothermal conditions. This work is informed by and validated with laser melting experiments, with investigations of plume evolution and microscopy of generated particles.

4:20 PM
Impact of Dendrite Tip Velocity Formulation on Simulated Microstructures of Powder Bed Fusion Ti-6Al-4V: Brodan Richter¹; Joshua Pribe²; Edward Glaessgen¹; ¹NASA Langley Research Center; ²National Institute of Aerospace
    The relationship between the local undercooling, dendrite tip velocity, and dendrite tip radius is a critical materials relationship that controls solidification-based manufacturing processes. That relationship impacts the final grain structure, crystallographic texture, and micro-segregation. However, collecting experimental data for empirically determining the relationship is extremely challenging due to the high temperatures and micrometer scales characteristic of engineering alloy solidification. This work compares various analytical relationships for relating undercooling to dendrite tip velocity for Ti-6Al-4V and characterizes the sensitivity of the formulations to the input material properties. The formulations are used alongside thermal and microstructure evolution models in a computational materials framework to simulate the powder bed fusion additive manufacturing process and characterize the impact of formulation selection on the resulting grain structure. The results of this work demonstrate the importance of the assumed relationship between undercooling and dendrite tip velocity by characterizing its impact on the simulated microstructure.