Revealing mechanisms underlying powder reusability of Ti-48Al-2Cr-2Nb intermetallic in electron beam powder bed fusion process

Wang, Pan; Nai, Mui Ling Sharon; Ng, Fern Lan; Tan, A.L.K.; Sin, Wai Jack; Goh, Min Hao; Maruno, Yusaku

doi:10.1016/j.addma.2022.103155

Cited by 5 publications

(2 citation statements)

References 53 publications

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“…[10] Therefore, printing pure ceramics or oxides is seen as almost impossible with EB-PBF if the powder is not altered somehow to increase the conductivity by, e.g., intermixing with a powder with higher conductivity or alloying. [13][14][15][16][17] Spattering of particles can be caused by localized pressure changes in the melt pool or repulsive electrostatic forces between powder particles leading to localized ejection of powder particles, which can lead to defects such as lack-of-fusion. [18,19] There are few applications today where printing ceramics using EB-PBF has been utilized.…”

Section: Introductionmentioning

confidence: 99%

Feasibility of Melting NbC Using Electron Beam Powder Bed Fusion

Wennersten,

Xu,

Armakavicius

et al. 2024

Adv Eng Mater

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High melting point materials such as ceramics and metal carbides are in general difficult to manufacture due to their physical properties, which imposes the need for new manufacturing methods where electron beam powder bed fusion (EB‐PBF) seems promising. Most materials that have been successfully printed with EB‐PBF are metals and metal alloys with good electrical conductivity, whereas dielectric materials such as ceramics are generally difficult to print. Catastrophic problems such as smoking and spattering can occur during the EB‐PBF processing owing to inappropriate physical properties such as lack of electrical, and thermal conductivity and high melting point, which are challenging to overcome by process optimization. Due to these difficulties, a limited level of understanding has been achieved regarding melting ceramics and refractory alloys. In this work, three different substrates of niobium carbide (NbC) were melted using EB‐PBF. The established process parameter window showed a good correlation between EB‐PBF process parameters, surface and melt characteristics, which could be used as a baseline for a printing process. Melting NbC was proven feasible using EB‐PBF, the work also pointed out challenges related to arc trips and spattering, as well as future investigations necessary to create a stable printing process.This article is protected by copyright. All rights reserved.

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Section: Introductionmentioning

confidence: 99%

Feasibility of Melting NbC Using Electron Beam Powder Bed Fusion

Wennersten,

Xu,

Armakavicius

et al. 2024

Adv Eng Mater

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“…1013) L-PBF has offered a novel approach of processing intermetallics with complex structures. 14,15) As is known that the quality of L-PBF parts is largely influenced by building parameters and powder characteristics. The effects of building parameters on the porosity, microstructures, and mechanical properties of L-PBF parts have been extensively studied.…”

Section: Introductionmentioning

confidence: 99%

Effects of Plasma Spheroidization Treatment on the Characteristics of MoSiBTiC Powders Fabricated by Freeze-Dry Pulsated Orifice Ejection Method

et al. 2023

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Freeze-dry pulsated orifice ejection method (FD-POEM) is a promising approach of fabricating spherical refractory alloy or composite powders for laser powder bed fusion (L-PBF). However, due to the weak particle strength induced by their intrinsic pore characters, the FD-POEM powders were likely crushed during the powder recoating process. Taking MoSiBTiC alloys as an example, in this work, plasma spheroidization (PS) treatment was utilized to strengthen the FD-POEM powders. The MoSiBTiC powders were completely melted and rapidly solidified during PS, leading to the evolution of mesh-pore to a fully dense structure. Correspondingly, the PS powders displayed an increased sphericity of 0.98, while showing a significantly decreased particle size of 53.1 µm. Moreover, the laser absorptivity of PS powder was reduced because of the decreased multiple reflections via the smooth powder surface. Microstructure evaluations illustrated that the PS MoSiBTiC powders mainly consisted of the elemental (Ti, B, and C)-supersaturated Mo phase, as well as small amounts of Mo 5 SiB 2 , TiC, and Mo 2 B, indicating the occurrence of in-situ alloying during PS. Furthermore, the internal and inter-particle microstructures of PS powders were highly homogeneous, attributing to the uniformly dispersed elemental powders of FD-POEM powders. The results of this work suggest that the combination of FD-POEM and PS is an effective approach of fabricating refractory powders for L-PBF.

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