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ARTICLE
Prediction of Melt Pool Dimension and Residual Stress Evolution with Thermodynamically-Consistent Phase Field and Consolidation Models during Re-Melting Process of SLM
Kang-Hyun Lee1, Gun Jin Yun1,2,*
1 Department of Aerospace Engineering, Seoul National University, Seoul, 08826, South Korea
2 Institute of Advanced Aerospace Technology, Seoul National University, Seoul, 08826, South Korea
* Corresponding Author: Gun Jin Yun. Email:
Computers, Materials & Continua 2021, 66(1), 87-112. https://doi.org/10.32604/cmc.2020.012688
Received 09 July 2020; Accepted 17 August 2020; Issue published 30 October 2020
Abstract
Re-melting process has been utilized to mitigate the residual stress level
in the selective laser melting (SLM) process in recent years. However, the complex consolidation mechanism of powder and the different material behavior after
the first laser melting hinder the direct implementation of the re-melting process.
In this work, the effects of re-melting on the temperature and residual stress evolution in the SLM process are investigated using a thermo-mechanically coupled
finite element model. The degree of consolidation is incorporated in the energy
balance equation based on the thermodynamically-consistent phase-field
approach. The drastic change of material properties due to the variation of temperature and material state is also considered. Using the proposed simulation framework, the single-track scanning is simulated first to predict the melt pool
dimension and validate the proposed model with the existing experimental data.
The obtained thermal histories reveal that the highest cooling rate is observed
at the end of the local solidification time which acts as an important indicator
for the alleviation of temperature gradient. Then, the scanning of a whole single
layer that consists of multiple tracks is simulated to observe the stress evolution
with several re-melting processes. After the full melting of powder material in the
first scanning process, the increase of residual stress level is observed with one remelting cycle. Moreover, the predicted stress level with the re-melting process
shows the variation trend attributable to the accumulated heat in the tracks. The
numerical issues and the detailed implementation process are also introduced
in this paper.
Keywords
Cite This Article
K. Lee and G. Jin Yun, "Prediction of melt pool dimension and residual stress evolution with thermodynamically-consistent phase field and consolidation models during re-melting process of slm,"
Computers, Materials & Continua, vol. 66, no.1, pp. 87–112, 2021.
Citations