|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Applications of Solidification Fundamentals
||Simultaneous, In-situ Synchrotron X-ray Radiography and Thermal Imaging of Liquid-to-solid Phase Transformation during Laser Fusion Processing of Ti- and Ni-alloys
||Rakesh R. Kamath, Ryan Heldt, Logan White, David Garcia, Rongxuan Wang, Zhenyu Kong, Kamel Fezzaa, Tao Sun, Hahn Choo
|On-Site Speaker (Planned)
||Rakesh R. Kamath
Understanding the liquid-to-solid phase transformation is key in establishing process-structure correlations in fusion-based manufacturing processes such as metal additive manufacturing (MAM). The present in-situ studies used a laser-AM simulator (developed at beamline 32-ID-B, APS, Argonne National Laboratory) to mimic spot and line melt strategies used in MAM on Ti-6Al-4V and IN-625 alloy plates, along with varying relevant process parameters namely laser power, line scan speed, spot dwell time, and temporal and spatial intervals between two consecutive spot melts. In-situ dynamic synchrotron x-ray radiography was used in tandem with the laser-AM simulator to obtain the interface velocity (R) of the liquid-solid interface. Simultaneous thermal imaging was performed on the top surface of the melts during the laser melting experiments to obtain the thermal gradient (G) at the L-S interface. Post-mortem, ex-situ SEM-EBSD characterization of the melt pools were used to correlate the measured G and R evolutions to the resulting microstructure.