| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Processing Effects on Microstructure and Material Performance
|
| Presentation Title |
Tailoring Microstructure Through Beam Shaping |
| Author(s) |
Saad Khairallah, Rongpei Shi, Tien Roehling, Tae Wook Heo, Joseph Mckeown, Manyalibo Matthews |
| On-Site Speaker (Planned) |
Saad Khairallah |
| Abstract Scope |
Laser powder bed additive manufacturing is promising a new process capability, that of tailoring mechanical properties by locally controlling the microstructure. The thermal history produced in a raster scan already produces heterogeneous and spatially non-uniform structures and differ from conventional manufacturing. Understanding how these thermal profiles result in AM centric microstructure is crucial to controlling AM process parameters and final mechanical properties. We present a high-fidelity powder scale simulation model that is fully-coupled with cellular automata for grain growth. The model uses full laser ray tracing to accurately capture the thermal profiles imposed by different beam shapes at varied laser scan speeds. The model accounts for nucleation and epitaxial growth and shows that beam shaping is a strategy to control the columnar to equiaxed transition.
Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory contract DE- AC52-07NA27344. Lawrence Livermore National Security, LLC. LLNL-ABS-771760. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |