5th International Conference on Advances in Solidification Processes (ICASP-5) 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5)

Laser Additive Manufacturing (LAM) can directly produce near-net-shape metallic components using commercial alloy powders. However, primary solidification during LAM is far from equilibrium due to the ultra-fast laser-powder interaction (<50 ms), mixing of solutes during melting and micro-segregation upon rapid solidification. Our understanding of these phenomena and the resultant microstructural features formed cannot be fully elucidated using traditional a posteriori characterization, necessitating in situ and operando characterization. We have developed a LAM Process Replicator (LAMPR) that allows real and reciprocal space synchrotron imaging of LAM. The X-ray diffraction study presented exploits the quasi-steady-state and layer-wise AM to enable the detection of the primary solidification of tracks under conditions distant from the near equilibrium transformations observed from conventional processing. This is complemented with in situ and operando x-ray imaging of the same process. The results can be used to help design new alloys and guide the optimisation of processing parameters to exploit the full potential of LAM.