| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing: Microstructure, Defects, and Properties
|
| Presentation Title |
Limits of Dispersoid Size and Number Density in ODS Alloys Fabricated with Laser Powder Bed Fusion |
| Author(s) |
Nathan A. Wassermann, Yongchang Li, Alexander Myers, Christopher Kantzos, Timothy Smith, Jonathan Malen, Jack Beuth, Lin Shao, Alan McGaughey, Sneha Narra |
| On-Site Speaker (Planned) |
Sneha Narra |
| Abstract Scope |
Previous work on additively-manufactured oxide dispersion-strengthened (ODS) alloys focused on experimental approaches, resulting in larger dispersoid sizes and lower number densities than can be achieved with conventional powder metallurgy. To gain insight into the as-fabricated microstructure, this work integrates experiments with a thermodynamic and kinetic modeling framework to probe the limits of the dispersoid sizes and number densities that can be achieved with laser powder bed fusion. Bulk samples of a Ni-20Cr + 1 wt% Y2O3 alloy are fabricated using a range of laser power and scanning velocity combinations. Scanning transmission electron microscopy characterization is performed to quantify the dispersoid size distributions across the processing space. The modeling results suggest that the mechanism that limits the final number density is collision coarsening of dispersoids in the melt pool. These collisions present a significant obstacle to the use of laser powder bed fusion to fabricate ODS alloys for nuclear reactor applications. |