| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Solid-State Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Assessing Compositional Gradients in DED Inconel 718 Builds via Directional Reflectance Microscopy |
| Author(s) |
Ekta Jain, Yeoh Yong Chen, Bernard Gaskey, Guido Macchi, Antonio Mattia Grande, Matteo Seita |
| On-Site Speaker (Planned) |
Ekta Jain |
| Abstract Scope |
Directed-energy-deposition (DED) is an additive manufacturing technology that enables rapid production and repair of metallic parts. The inherent multi-directional solidification and non-uniform cooling rate throughout the process, however, may yield parts with heterogeneous microstructures, which exhibit large scatter in mechanical properties. Assessing this heterogeneity in additively manufactured metals is challenging using conventional characterization techniques due to their low-throughput and limited field-of-view. Here, we employ an optical technique, directional reflectance microscopy (DRM), to rapidly assess large-scale microstructure heterogeneity information from Inconel 718 builds produced by DED. DRM relies on acquiring a series of optical micrographs of the chemically etched sample surface under different illumination angles. Using DRM, we successfully map the spatial distribution of niobium across the builds by quantifying local changes in surface reflectance, which stem from differences in δ-precipitates (Ni3Nb) size and distribution. These results demonstrate the capability of inferring compositional information using a low-cost and high-throughput optical technique. |
| Proceedings Inclusion? |
Planned: |