Formation of Nb-rich droplets in laser deposited Ni-matrix microstructures

Abstract

Ni-rich $\gamma$ 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 $\gamma$ orientation influences the Laves fraction significantly.

Accepted for publication in Scripta Materialia on October 30, 2017

References in corpus (2)

• On the primary spacing and microsegregation of cellular dendrites in laser deposited Ni-Nb alloys
• Simulation and analysis of $\gamma$-Ni cellular growth during laser powder deposition of Ni-based superalloys

Cited by in corpus (3)

• Simulation and analysis of $\gamma$-Ni cellular growth during laser powder deposition of Ni-based superalloys
• Predictive modeling of solidification during laser additive manufacturing of nickel superalloys: Recent developments, future directions
• Uncertainty Analysis of Microsegregation during Laser Powder Bed Fusion