|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Applications of Solidification Fundamentals
||Mitigating Stray Grain Nucleation during the Laser Powder Bed Fusion of Single Crystal CMSX-4
||Runbo Jiang, Joseph Aroh, Amir Mostafaei, Benjamin Gould, Andrew Chuang, Anthony Rollett
|On-Site Speaker (Planned)
Even though the as-built microstructure of Laser Powder Bed Fusion parts is dominated by epitaxial grain growth continuing across the individual layers, stray grains frequently occur in laser melting of single crystals. The presence of these stray grains inserts grain boundaries and degrades high temperature properties. Within the current work, laser processing parameters were varied and stray grains were characterized within individual melt tracks in single crystal CMSX-4. Electron backscatter diffraction (EBSD) mapping and in-situ synchrotron x-ray diffraction studies provide complementary information on stray grain nucleation. Thermal modeling was used to provide temperature gradient fields. Combining this information with a nucleation and growth model suggests locations where nucleation has the highest probability to occur in the melt pool. It was found that, compact melt pools with nearly semi-circular cross-sections are the least likely to exhibit stray grains.
||Solidification, Additive Manufacturing, Computational Materials Science & Engineering