Online Lecture by dr. Greta Lindwall

Advanced experimental characterization and computational modelling for additive manufacturing of steels

Department of Materials Science and Engineering,
KTH Royal Institute of Technology,
Sweden

Title:
Advanced experimental characterization and computational modelling for additive manufacturing of steels.

Abstract:
Understanding microstructure evolution during additive manufacturing (AM) of metallic materials requires insight into transient thermal and phase transformation phenomena.
While post-process characterization provides valuable data, it cannot fully capture the dynamic mechanisms at play during solidification and subsequent phase transformations.

In this work, we perform in situ observations using synchrotron X-rays combined with computational thermodynamics and kinetics to study real-time microstructure evolution during laser- and electron-beam based AM. To replicate conditions typical for AM while enabling in situ X-ray studies, dedicated AM sample environments are required. Here, the construction of an electron beam-powder bed fusion (PBF-EB) sample environment is described [1]. Both high-speed X-ray radiography and diffraction are applied to image process dynamics and to follow microstructure evolution during PBF-EB, respectively.

The emphasis is on how in situ X-ray diffraction can reveal solidification behavior and solid-state phase transformations in steels during AM, and how these experimental data contribute to the validation and development of modeling approaches.

[1] H-H. König, N. Semjatov et al., MiniMelt: An instrument for real-time tracking of electron beam additive manufacturing using synchrotron x-ray techniques, Rev. Sci. Instrum. 94, 125103 (2023)

This session was chaired by Joakim Odqvist (KTH Royal Institute of Technology)