| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Additive Manufacturing of Metals: Complex Microstructures and Architecture Design
|
| Presentation Title |
Mitigating Stray Grain Nucleation during the Laser Powder Bed Fusion of Single Crystal CMSX-4 |
| Author(s) |
Joseph W. Aroh, Amir Mostafaei, Joseph Pauza, Runbo Jiang, Jerard Gordon, Anthony Rollett |
| On-Site Speaker (Planned) |
Joseph W. Aroh |
| Abstract Scope |
Despite the rapid, nonequilibrium solidification conditions in Laser Powder Bed Fusion processing, the as-built microstructure is typically dominated by epitaxial grain growth which continues across many successive build layers/melt pool boundaries. In this work, we investigated the effects that laser processing parameters have on maintaining epitaxial growth and mitigating stray grains within a melt track on single crystal CMSX-4. Observations from electron backscatter diffraction, scanning electron microscopy, and synchrotron high energy diffraction microscopy experiments inform how the degree of epitaxy is affected in each condition. Each experiment was performed on both bare plate and with various Ni-alloy powder layers to see how powder might further promote nucleation sites. Further validation of this work included using classical nucleation theory coupled with thermal modeling to predict where nucleation has the highest probability to occur as a function of melt pool position. |