| About this Abstract | 
   
    | Meeting | 2021 TMS Annual Meeting & Exhibition | 
   
    | Symposium | Additive Manufacturing: Solid-State Phase Transformations and Microstructural Evolution | 
   
    | Presentation Title | In Situ Synchrotron Observation of Directed Energy Deposition Additive Manufacturing Process | 
   
    | Author(s) | Yunhui  Chen, Samuel  Clark, David M Collins, Sebastian  Marussi, Thomas  Connolley, Robert  Atwood, Oxana V. Magdysyuk, Gavin  Baxter, Martyn  Jones, Chu Lun Alex  Leung, Peter David Lee | 
   
    | On-Site Speaker (Planned) | Yunhui  Chen | 
   
    | Abstract Scope | The mechanical performance of Directed Energy Deposition Additive Manufactured (DED-AM) components are highly process condition dependent due to rapid laser induced heating and cooling rates. However, the fast non-equilibrium solidification process during DED-AM is not easily measured with conventional methods. Through combined in situ synchrotron imaging and diffraction using a unique DED-AM process replicator implemented at a synchrotron beamline, we experimentally reveal the underlying mechanical and phase transformation behaviour which controls the build quality in IN718, a nickel based super-alloy widely used for safety critical components. Quantification of the solidification sequence was performed to reveal the residual stress development in a high temperature region is thermal dominant. The observed transformation behaviour during DED-AM newly relates the AM processing conditions to the eventual microstructures and properties. The results presented in this work provide an enhanced fundamental understanding of the DED-AM process with relevance to microstructure control in AM fabricated components. | 
   
    | Proceedings Inclusion? | Planned: |