| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Phase Transformations in Additively Manufactured Materials
|
| Presentation Title |
In-situ Characterization of Rapid Phase Evolution of AM Metals with High Energy Synchrotron X-ray Diffraction |
| Author(s) |
Seunghee Oh, Rachel Lim, Joseph Aroh, Joseph Pauza, Runbo Jiang, Venkata Satya Surya Amaranth Karra, Sidi Feng, Andrew Chihpin Chuang, Joel Bernier, Benjamin J Gould, Robert M. Suter, Anthony D. Rollett |
| On-Site Speaker (Planned) |
Seunghee Oh |
| Abstract Scope |
Laser-based processing in additive manufacturing (AM) is accompanied by rapid heating and cooling, resulting in abrupt changes in phase and microstructure. Using an in-situ high-speed high-energy synchrotron X-ray dynamic diffraction technique built with a 520W fiber laser system coupled with a scan head at 1-ID-E at the Advanced Photon Source provides key insights about AM processing. The fast acquisition rate, 250Hz, allows us to observe transient phenomena in phase formation, which were not previously accessible. A Pilatus area detector, which can capture whole diffraction rings, provides intuitive and quantitative information for quantifying the evolution of the phases during the AM process. Data processing was utilized to quantify several aspects, including phase fractions and microstrain. Thermal history was inferred from thermal expansion. Material in the fusion zone develops tensile residual strain, as expected. Unexpected precipitation behavior is observed, however. Time-resolved descriptions were used to represent the various trends. |