Numerical investigation of interfacial dynamics for the melt pool of Ti-6Al-4V powders under a selective laser

Tseng, Chien-Chou; Li, Cheng Jui

doi:10.1016/j.ijheatmasstransfer.2019.01.030

Cited by 46 publications

(11 citation statements)

References 39 publications

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“…When the temperature exceeds the boiling temperature T v , the energy loss due to the ejection of metallic vapours is modelled by a volume heat sink q v [21,39,40]:…”

Section: Governing Equations 221 Energy Conservation and Heat Sourmentioning

confidence: 99%

Numerical study of the impact of vaporisation on melt pool dynamics in Laser Powder Bed Fusion - Application to IN718 and Ti–6Al–4V

Queva

Guillemot

Moriconi

et al. 2020

Additive Manufacturing

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A finite element model of Laser Powder Bed Fusion (LPBF) process applied to metallic alloys at a mesoscopic scale is presented. This Level-Set model allows to follow melt pool evolution and track development during building. A volume heat source model is used for laser/powder interaction considering the material absorption coefficients, while a surface heat source is used to consider the high laser energy absorption by dense metal alloys. An energy solver is applied considering convection and conductivity evolution in the system. Shrinkage during consolidation from powder to dense material is modelled by a compressible Newtonian constitutive law. An automatic remeshing strategy is also used to provide a good compromise between accuracy and computing time. Different cases are investigated to demonstrate the influence of the vaporisation phenomena, of material properties and of laser scan strategy on bead morphology.

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“…When the temperature exceeds the boiling temperature T v , the energy loss due to the ejection of metallic vapours is modelled by a volume heat sink q v [21,39,40]:…”

Section: Governing Equations 221 Energy Conservation and Heat Sourmentioning

confidence: 99%

Numerical study of the impact of vaporisation on melt pool dynamics in Laser Powder Bed Fusion - Application to IN718 and Ti–6Al–4V

Queva

Guillemot

Moriconi

et al. 2020

Additive Manufacturing

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“…This reaction is also an important factor in molten pool formation. The vapor recoil pressure F vap and vapor heat loss Q vap can be formulated as follows (Khairallah et al , 2016; Tseng and Li, 2019; Wang et al , 2020): where L evp , T evp , P a , R , M and K B is evaporation latent heat, evaporation temperature, ambient pressure, gas constant, molecular weight and Boltzmann constant, respectively. Assuming that only the Al element was evaporated, these parameters used in equations (17) and (18) are the properties of pure Al.…”

Section: Methodsmentioning

confidence: 99%

Section: Computational Domain and Boundary Conditionsmentioning

confidence: 99%

“…Accurate real-time three-dimensional observation is, however, still difficult since the scales of the molten pool are small. Alternatively, numerical simulations have been used to investigate the complicated mechanisms of metallurgical defects, such as voids, spattering and erosion formation in LPBF (Khairallah et al , 2016; Tseng and Li, 2019; Chen and Yan, 2020; Cook and Murphy, 2020; Wang et al , 2020; Yuan et al , 2020). Yuan et al (2020) modeled the molten pool under different laser scanning rates and found that the stability of the molten pool decreased with the increase of laser scanning rate, and the volume density could be improved by tailoring the scanning rate to obtain a moderate recoil pressure.…”

Section: Introductionmentioning

confidence: 99%

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Numerical and experimental investigation on the heat transfer and mass transport in LPBF in-situ alloying of Al/Cu alloy

Zhou,

Li,

Huang

et al. 2023

RPJ

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Purpose Laser powder bed fusion (LPBF) in-situ alloying is a recently developed technology that provides a facile approach to optimizing the microstructural and compositional characteristics of the components for high performance goals. However, the complex mass and heat transfer behavior of the molten pool results in an inhomogeneous composition distribution within the samples fabricated by LPBF in-situ alloying. The study aims to investigate the heat and mass transfer behavior of an in-situ alloyed molten pool by developing a three-dimensional transient thermal-flow model that couples the metallurgical behavior of the alloy, thereby revealing the formation mechanism of composition inhomogeneity. Design/methodology/approach A multispecies multiphase computational fluid dynamic model was developed with thermodynamic factors derived from the phase diagram of the selected alloy system. The characteristics of the Al/Cu powder bed in-situ alloying process were investigated as a benchmark. The metallurgical behaviors including powder melting, thermal-flow, element transfer and solidification were investigated. Findings The Peclet number indicates that the mass transfer in the molten pool is dominated by convection. The large variation in material properties and temperature results in the presence of partially melted Cu-powder and pre-solidified particles in the molten pool, which further hinder the convection mixing. The study of simulation and experiment indicates that optimizing the laser energy input is beneficial for element homogenization. The effective time and driving force of the convection stirring can be improved by increasing the volume energy density. Originality/value This study provides an in-depth understanding of the formation mechanism of composition inhomogeneity in alloy fabricated by LPBF in-situ alloying.

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“…For example, O’Toole et al simulated the SLM using a novel scale-bridging approach. The melt pool was described by a mesoscale effective heat capacity method, ,, while a microscale phase field model was applied to capture the chemical kinetics of the liquid–solid phase change. It was confirmed that the conventional liquid–solid phase change model without considering the solidification chemical kinetics was inaccurate.…”

Section: Phase Change For Other Purposesmentioning

confidence: 99%

Recent Advances in CFD Simulations of Multiphase Flow Processes with Phase Change

Zhu

Zhang

et al. 2023

Ind. Eng. Chem. Res.

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Phase change is a phenomenon that has been extensively utilized in chemical engineering, energy, electronics, vehicle, and space exploration. From both the science and engineering perspectives, gaining a profound understanding of the intricacies of multiphase flow processes accompanied by heat and mass transfer due to phase change is of fundamental importance. Indeed, the computational fluid dynamics (CFD) has been increasingly applied as an effective tool to give an in-depth and efficient analysis of the phase change processes, thereby enhancing our understanding and capacity to control and optimize the phase change effects in these processes. This paper seeks to provide a comprehensive review of the utilization of CFD methodologies in the simulations of phase change flows across various applications, including temperature management, drying, separation and purification, and others. First, the CFD models at various scales that are developed to elucidate the phase change processes are summarized. Second, the noteworthy advances in the recent CFD simulation work on various phase change processes are presented, respectively. Finally, the challenges and potential prospects to facilitate the application of the phase change flow are discussed. The current review aims to offer insightful guidance for the CFD modeling of phase change processes in numerous engineering application scenarios.

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Numerical investigation of interfacial dynamics for the melt pool of Ti-6Al-4V powders under a selective laser

Cited by 46 publications

References 39 publications

Numerical study of the impact of vaporisation on melt pool dynamics in Laser Powder Bed Fusion - Application to IN718 and Ti–6Al–4V

Numerical study of the impact of vaporisation on melt pool dynamics in Laser Powder Bed Fusion - Application to IN718 and Ti–6Al–4V

Numerical and experimental investigation on the heat transfer and mass transport in LPBF in-situ alloying of Al/Cu alloy

Recent Advances in CFD Simulations of Multiphase Flow Processes with Phase Change

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