During the laser powder bed fusion (L-PBF) process, the built part undergoes multiple rapid heating-cooling cycles, leading to complex microstructures with nonuniform properties. In the present work, a computational framework, which weakly couples a finite element thermal model to a non-equilibrium PF model was developed to investigate the rapid solidification microstructure of a Ni-Nb alloy during L-PBF. The framework is utilized to predict the spatial variation of the morphology and size of cellular segregation structure as well as the microsegregation in single-track melt pool microstructures obtained under different process conditions. A solidification map demonstrating the variation of microstructural features as a function of the temperature gradient and growth rate is presented. A planar to cellular transition is predicted in the majority of keyhole mode melt pools, while a planar interface is predominant in conduction mode melt pools. The predicted morphology and size of the cellular segregation structure agrees well with experimental measurements.
@article{arxiv.1906.10200,
title = {Finite Interface Dissipation Phase Field Modeling of Ni-Nb under Additive Manufacturing Conditions},
author = {Kubra Karayagiz and Luke Johnson and Raiyan Seede and Vahid Attari and Bing Zhang and Xueqin Huang and Supriyo Ghosh and Thien Duong and Ibrahim Karaman and Alaa Elwany and Raymundo Arroyave},
journal= {arXiv preprint arXiv:1906.10200},
year = {2020}
}