| About this Abstract |
| Meeting |
10th International Symposium on Superalloy 718 and Derivatives (2023)
|
| Symposium
|
Superalloy 718 and Derivatives
|
| Presentation Title |
Correlating Alloy 718 and Haynes 282 Solidification Microstructures to Local Thermal History using Laser Powder Bed Fusion Process Monitoring |
| Author(s) |
Andrew E. Wessman, Timothy Smith, Yi Zhang, Fan Zhang, Thomas Spears, John Middendorf, Mohammed Shafae, Nazmul Hasan |
| On-Site Speaker (Planned) |
Andrew E. Wessman |
| Abstract Scope |
Additive manufacturing processes such as laser powder bed fusion produce material by localized melting of a powder feedstock layer by layer. The small meltpools and high energy density generate very different microstructures in nickel superalloys when compared to more traditional cast or wrought processing, including features such as cellular structures and epitaxial grain growth. The features of these microstructures vary depending on local thermal history, alloy chemistry and processing parameters. In this work in-situ monitoring of a laser powder bed fusion process is used to characterize the local thermal conditions throughout an AM build for alloys IN718 and Haynes 282, and this information is correlated to observations on the microstructural features of these alloys in the as-built condition. In IN718, segregation of niobium and molybdenum are found in interdendritic regions of the 200nm wide cellular precipitate structures, while in Haynes 282 segregation of gamma prime forming elements such as titanium and aluminum segregate to the interdendtritic cell walls. In-process monitoring using thermal tomography is utilized to observe the local thermal conditions during the solidification of the AM material and correlate those conditions to the microstructures formed through computational modeling of the segregation and dendrite formation. Results for both IN718 and Haynes are compared. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |