Science & Technology Thrust (STT) 2
Material Design, Processing, and Characterization for Laser-Based Metal 3-D Printing
An incomplete understanding of:
- Laser interaction with the powder feedstock.
- Dynamics of laser-induced melting and melt coalescence.
- Microstructure evolution during re-solidification including grain growth.
- Possible segregation of impurities and alloying elements to grain boundaries and boundaries between successively melted and re-solidified regions.
- Residual stresses and post-printing heat treatment.
Three Focus Areas
1. Powder Synthesis
2. Selective Laser Melting (SLM) 3D Printing
3. Hierarchical Modeling
- Goal: Understand the influence of relevant thermophysical properties of metallic liquids on custom powder synthesis and SLM printing processes.
- Acquire powder synthesis capabilities.
- Study the powder synthesis process.
- Investigate thermophysical properties of metallic liquids.
- Investigate the influence of powder and liquid characteristics on 3D printing parameters.
Thermophysical Property Measurements (Electrostatic Levitation: ESL)
Selective Laser Melting (SLM) 3D Printing
Setup and Commissioning of SLM Instrumentation
Dross Formation Mechanisms and Impact for Selective Laser Melting
Porosity Imaging with Spatially Resolved Small Angle Neutron Scattering
Defect Analysis of Selective Laser Melted Parts by Positron Annihilation Spectroscopy
Radiation Heat Transfer in Powder Bed
High Entropy Alloy Development: Experimental Testing and CALPHAD Simulation
Dr. Yang's Group at Southern Univeristy
In particular, the bulk modulus is calculated along with the Bader charge of each composing element, and charge density contours were calculated to show electron density surrounding certain atoms within the HEA, to investigate the nature of the bonding taking place during the alloy’s formation.
Besides major metallic bonding in the bulk alloy, weak partial covalence bonding are found at Mo-Nb, Nb-Ta, Nb-V, Ta-V and Mo-Nb interatomic bonding.
Louisiana State University Senior Design Project: A Novel Powder Feeder for Selective Laser Melting Based 3D Printers
Dr. Shengmin Guo's Group (Louisiana State University) and Dr. Zhao's Group (Southern University): Electromagnetic Interference Shielding Effectiveness of HEAs