Ni-rich γ cells and Nb-rich eutectic droplets that form during laser power bed fusion solidification of Ni-Nb alloys are studied using experiments and simulations. Finite element simulations estimate the cooling rates in the melt pool and phase-field simulations predict the resulting cellular microstructures. The cell and droplet spacings are determined as a function of cooling rate and fit to a power law. The formation of Laves phase is predicted for a critical composition of Nb in the liquid droplets. Finally, our simulations demonstrate that anisotropy in the γ orientation influences the Laves fraction significantly.
@article{arxiv.1710.11525,
title = {Formation of Nb-rich droplets in laser deposited Ni-matrix microstructures},
author = {Supriyo Ghosh and Mark R. Stoudt and Lyle E. Levine and Jonathan E. Guyer},
journal= {arXiv preprint arXiv:1710.11525},
year = {2017}
}
Comments
Accepted for publication in Scripta Materialia on October 30, 2017