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.

arXiv commentAccepted for publication in Scripta Materialia on October 30, 2017

References in corpus (5)

• Phase-Field Formulation for Quantitative Modeling of Alloy Solidification
• Quantitative Phase Field Model of Alloy Solidification
• Application of Finite Element, Phase-field, and CALPHAD-based Methods to Additive Manufacturing of Ni-based Superalloys
• 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 (8)

• Finite Interface Dissipation Phase Field Modeling of Ni-Nb under Additive Manufacturing Conditions
• 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
• Simulation of temperature, stress and microstructure fields during laser deposition of Ti-6Al-4V
• Tusas: A fully implicit parallel approach for coupled phase-field equations
• Orientation selection in alloy dendritic evolution during melt-pool solidification
• Effects of isotherm patterns on cellular interface morphologies of melt pool origin