Denudation of metal powder layers in laser powder bed fusion processes
By Manyalibo Matthews, Gabe Guss, S. Khairallah, A. Rubenchik, P. Depond, Wayne E. King. 2016
765 citations recorded by the source corpus.
Abstract Understanding laser interaction with metal powder beds is critical in predicting optimum processing regimes in laser powder bed fusion additive manufacturing of metals. In this work, we study the denudation of metal powders that is observed near the laser scan path as a function of laser parameters and ambient gas pressure. We show that the observed depletion of metal powder particles in the zone immediately surrounding the solidified track is due to a competition between outward metal vapor flux directed away from the laser spot and entrainment of powder particles in a shear flow of gas driven by a metal vapor jet at the melt track. Between atmospheric pressure and ∼10 Torr of Ar gas, the denuded zone width increases with decreasing ambient gas pressure and is dominated by entrainment from inward gas flow. The denuded zone then decreases from 10 to 2.2 Torr reaching a minimum before increasing again from 2.2 to 0.5 Torr where metal vapor flux and expansion from the melt pool dominates. The dynamics of the denudation process were captured using high-speed imaging, revealing that the particle movement is a complex interplay among melt pool geometry, metal vapor flow, and ambient gas pressure. The experimental results are rationalized through finite element simulations of the melt track formation and resulting vapor flow patterns. The results presented here represent new insights to denudation and melt track formation that can be important for the prediction and minimization of void defects and surface roughness in additively manufactured metal components.
Subfields: Computational Mechanics, Mechanical Engineering
View Paper: https://www.semanticscholar.org/paper/5f40bccb72e84f22ef27a1d02b7d067f30b3948c
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In Computational Mechanics
In Mechanical Engineering
Citations in the corpus
- Process defects and in situ monitoring methods in metal powder bed fusion: a review (2017, neutral): “…2015; Kleszczynski et al., 2012 Foster et al., 2015 Baseplate Prabhakar et al., 2015 Prabhakar et al., 2015 Process Parameters and scan strategy Matthews et al., 2016; Yasa et al., 2009; Attar, 2011; Gong, 2013; Read et al., 2015; Kruth et al., 2004; Weingarten et al., 2015; Thijs et al.,…”
- Influence of energy density on metallurgy and properties in metal additive manufacturing (2017, background): “These conflicting observations may be caused by a number of factors including energy density, gas pressure in the build chamber as well as feedstock material properties [122,128].”
- Keyhole-induced porosities in Laser-based Powder Bed Fusion (L-PBF) of Ti6Al4V: High-fidelity modelling and experimental validation (2019, methodology): “also developed an FEM-based model of L-PBF to study the effect of different process conditions on the denudation of powder [24] during the process.”