Eur. Phys. J. Special Topics 229, 205-216 (2020)
https://doi.org/10.1140/epjst/e2019-900100-6

Regular Article

Numerical simulation of selective laser melting with local powder shrinkage using FEM with the refined mesh

¹ Udmurt State University, Institute of Matematics, Informatics and Physics, Universitetskaya str. 1 426034 Izhevsk, Russia
² Vereshchagin Institute for High Pressure Physics, Russian Academy of Sciences, 108840 Moscow, Troitsk, Russia
³ Udmurt Federal Research Center, Ural Branch, Russian Academy of Science, Baramzinoy str. 34, 426067 Izhevsk, Russia

^a e-mail: gordeevgeorgii@gmail.com

Received: 8 June 2019
Received in final form: 10 July 2019
Published online: 11 February 2020

Abstract

A mathematical model of selective laser melting (SLM) of fine-grained metallic powders under the pulse laser annealing conditions has been developed. The processed powder bed is considered in the approximation of continuous medium where its effective thermophysical properties depend on local porosity. The model allows simulation of unsteady distributions of temperature, specific enthalpy, local porosity, morphology and thickness of the processed track. In the paper, all stages of problem analysis are described including its mathematical formulation and numerical implementation. To take into account shrinkage of the powder layer during sintering and remelting, the numerical model utilizes the arbitrary Lagrangian–Eulerian (ALE) method. Thus the finite element mesh provides robust control of quality and dynamic remeshing through adaptive mesh refinement. Using the proposed numerical model the unsteady thermal fields and local porosity of a Fe-based powder layer processed with a pulsed laser has been investigated.