On thermal properties of metallic powder in laser powder bed fusion additive manufacturing

Zhang, Shanshan; Lane, Brandon; Whiting, Justin G.; Chou, Kevin

doi:10.1016/j.jmapro.2019.09.012

Cited by 48 publications

(18 citation statements)

References 27 publications

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“…In contrast with welding, these solidified regions can have very different material properties compared to the initial powder phase. Two key materials properties of interest here are the electrical conductivity and thermal diffusivity, where the powder phase diffusivity can be 5-10% lower than the solid [42]. A similar drop is taken for the electrical conductivity by assuming the Wiedemann-Franz law holds true.…”

Section: Methodsmentioning

confidence: 99%

Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing

Kao

Gan

Tonry

et al. 2020

Phil. Trans. R. Soc. A.

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Large thermal gradients in the melt pool from rapid heating followed by rapid cooling in metal additive manufacturing generate large thermoelectric currents. Applying an external magnetic field to the process introduces fluid flow through thermoelectric magnetohydrodynamics. Convective transport of heat and mass can then modify the melt pool dynamics and alter microstructural evolution. As a novel technique, this shows great promise in controlling the process to improve quality and mitigate defect formation. However, there is very little knowledge within the scientific community on the fundamental principles of this physical phenomenon to support practical implementation. To address this multi-physics problem that couples the key phenomena of melting/solidification, electromagnetism, hydrodynamics, heat and mass transport, the lattice Boltzmann method for fluid dynamics was combined with a purpose-built code addressing solidification modelling and electromagnetics. The theoretical study presented here investigates the hydrodynamic mechanisms introduced by the magnetic field. The resulting steady-state solutions of modified melt pool shapes and thermal fields are then used to predict the microstructure evolution using a cellular automata-based grain growth model. The results clearly demonstrate that the hydrodynamic mechanisms and, therefore, microstructure characteristics are strongly dependent on magnetic field orientation. This article is part of the theme issue ‘Patterns in soft and biological matters'.

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Section: Methodsmentioning

confidence: 99%

Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing

Kao

Gan

Tonry

et al. 2020

Phil. Trans. R. Soc. A.

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“…Although the current study does not deal with the mechanisms of spatter formation, it is suspected that the overhang features exacerbate spattering by one of the two following mechanisms or a combination of both. On one hand, since the powder surrounding the melt pools has higher absorptivity [39] and has lower thermoconductivity [40] compared to its bulk metal counterpart, the heat input by the laser is locally intensified and accumulated at overhanging structures. This overheating effect (intensification and accumulation of laser heat) is captured by the OT images as the L7D3 container shows higher GVs in the laser-irradiated region of OT images (e.g., Fig.…”

Section: Influence Of Part Geometry On Powder Degradationmentioning

confidence: 99%

Influence of part geometry on spatter formation in laser powder bed fusion of Inconel 718 alloy revealed by optical tomography

Chen

Raza

Hryha

2022

Journal of Manufacturing Processes

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“…Existe una gran diversidad de técnicas de fabricación basadas en la manufactura mediante la adición capa a capa de material, conocidas como Additive Manufacturing (AM) (Zhang et al, 2019). Entre esta variedad de técnicas se encuentra el método de fabricación cuya fuente de energía es un plasma, denominado Plasma Metal Deposition (PMD) (Perez-Soriano et al, 2020).…”

Section: Introductionunclassified

Sinergias en la investigación en STEM

Arias¹,

Vázquez²,

Parejo³

2021

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En este trabajo, se evalúa la impedancia eléctrica de distintas muestras de titanio poroso modificadas superficialmente con un láser de femtosegundo; como método experimental para caracterizar la macroporosidad inherente al proceso de fabricación y el efecto del tratamiento superficial de los discos. El estudio se realiza sobre discos con distinto contenido en volumen y rango de tamaño de poros. Las medidas de impedancia eléctrica se realizaron usando el Hewkett-Packard 4395A de Agilent. Los resultados revelan la potencialidad de esta técnica de medida en términos de ventajas frente a técnicas más engorrosas y costosas, permitiendo de forma semi-cuantitativa relacionar las medidas de impedancia con el contenido y tamaño de los poros, así como detectar el efecto de la modificación superficial generada con el láser de femtosegundo (microporosidad adicional y capa de óxido de titanio).

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On thermal properties of metallic powder in laser powder bed fusion additive manufacturing

Cited by 48 publications

References 27 publications

Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing

Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing

Influence of part geometry on spatter formation in laser powder bed fusion of Inconel 718 alloy revealed by optical tomography

Sinergias en la investigación en STEM

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