Title: Fluid Dynamics Effects on Microstructure Prediction in Single-Laser Tracks for Additive Manufacturing of IN625

Abstract

Single-track laser fusion were simulated using a heat-transfer-solidification-only (HTS) model and its extension with fluid dynamics (HTS_FD) model using a parallel open-source code, which included laminar fluid dynamics, flat-free surface of the molten alloy, heat transfer, phase-change, evaporation, and surface tension phenomena. The results illustrate that the fluid dynamics affects the solidification and ensuing microstructure. For the HTS_FD simulations, thermal gradient, G was found to exhibit a maximum at the extremity of the solidified pool (i.e., at the free surface), while for HTS simulations, G exhibited a maximum around the entire edge of the solidified pool. HTS_FD simulations predicted a wider range of cooling rates than the HTS simulations, exhibited an increased spread in the solidification speed, V variation within the melt-pool with respect to the HTS model results. Primary dendrite arm spacing (PDAS) were evaluated based on power law correlations and marginal stability theory models using the (G, V) from HTS and HTS_FD simulations to quantify the effect of the fluid dynamics on the microstructure. At low-laser powers and low-scan speeds, the PDAS obtained with the fluid dynamics model (HTS_FD) was larger by more than 30 pct with respect to the PDAS calculated with the simple HTS model. Amore » new PDAS correlation, i.e., \( \lambda_{1} \left[ {\mu {\text{m}}} \right] = 832\;G\left[ {\text{K/m}} \right]^{ - 0.5} V\left[ {\text{m/s}} \right]^{ - 0.25} \), which uses the (G, V) results from the HTS_FD model was developed and validated against experimental results.« less

Authors:

Sabau, Adrian S.  ^[1];

• Search DOE PAGES for author "Sabau, Adrian S."
• Search DOE PAGES for ORCID "0000-0003-3088-6474"

Yuan, Lang ^[2]; Raghavan, Narendran  ^[1];

• Search DOE PAGES for author "Raghavan, Narendran"
• Search DOE PAGES for ORCID "0000-0002-6964-5718"

Bement, Matthew ^[1]; Simunovic, Srdjan  ^[1];

• Search DOE PAGES for author "Simunovic, Srdjan"
• Search DOE PAGES for ORCID "0000-0001-7766-8293"

Turner, John A.  ^[1];

• Search DOE PAGES for author "Turner, John A."
• Search DOE PAGES for ORCID "0000-0003-2521-4091"

Gupta, Vipul K. ^[3]

---

+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Univ. of South Carolina, Columbia, SC (United States)
3. GE Research, Niskayuna, NY (United States)

Publication Date:

Mon Mar 16 00:00:00 EDT 2020

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Advanced Manufacturing Office; USDOE Office of Science (SC); USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1617805

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science

Additional Journal Information:

Journal Volume: 51; Journal Issue: 3; Journal ID: ISSN 1073-5615

Publisher:

ASM International

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 97 MATHEMATICS AND COMPUTING