Expanding particle size distribution and morphology of aluminium-silicon powders for Laser Beam Melting by dry coating with silica nanoparticles

Journal article
(Original article)


Publication Details

Author(s): Karg M, Munk A, Ahuja B, Backer MV, Schmitt JP, Stengel C, Kuryntsev SV, Schmidt M
Journal: Journal of Materials Processing Technology
Publication year: 2018
Volume: 264
Pages range: 155-171
ISSN: 0924-0136


Abstract

Current requirements for metal powder in Additive Manufacturing via
Laser Beam Melting in powder bed (LBM) that ensure repeatably
homogeneous thin layers can be spread and LBM products with high
relative density ρrel can be built are high sphericity and
particle size distributions (PSD) with limited share of fine particles.
The most established LBM powder production method today is delicate and
costly inert gas atomization. It yields highly spherical particles with
continuous particle size distributions, but two thirds of the atomized
powder exceed established LBM size ranges. A novel process route to
improve flowability of cohesive metal powders is the coating of
micro-sized powder particles with small amounts of nanoparticles. In
this article, significant improvements in powder layer smoothness and ρrel
of LBM samples are shown by statistical analysis of physical
experiments on the example of Al-Si powders dry coated with 0.5 wt%
nanoparticular fumed silica SiOx. This setup was chosen
because Al is most prone to powder flowability issues in LBM and no new
chemical elements are added to the alloy from dry coated SiOx.
Particle shape is varied from spherical over ovoidal to irregular using
powder atomized with Ar, N and air. Effects of variations of PSD and
LBM parameters on ρrel, defect types, microstructure and hardness using powders with and without SiOx are investigated. Because ρrel
are skewed towards 100%, ANOVA on ranks is the applicable statistical
method. Since the principle of using nanoparticles as spacers between
microparticles is based on geometry, it is transferrable to other
material systems. This may help for example to increase ρrel
of LBM metal matrix composites prepared by mechanical alloying as
non-spherical particles with considerable amounts of fine particles. The
use of larger percentages of atomized powders in LBM can increase
resource efficiency.


FAU Authors / FAU Editors

Ahuja, Bhrigu
Lehrstuhl für Photonische Technologien
Karg, Michael
Lehrstuhl für Photonische Technologien
Schmidt, Michael Prof. Dr.-Ing.
Lehrstuhl für Photonische Technologien


Additional Organisation
DFG-Sonderforschungsbereiche/ Transregios/Transferbereiche
Sonderforschungsbereich 814 Additive Fertigung
Erlangen Graduate School in Advanced Optical Technologies
Zentralinstitut für Neue Materialien und Prozesstechnik


How to cite

APA:
Karg, M., Munk, A., Ahuja, B., Backer, M.V., Schmitt, J.P., Stengel, C.,... Schmidt, M. (2018). Expanding particle size distribution and morphology of aluminium-silicon powders for Laser Beam Melting by dry coating with silica nanoparticles. Journal of Materials Processing Technology, 264, 155-171. https://dx.doi.org/10.1016/j.jmatprotec.2018.08.045

MLA:
Karg, Michael, et al. "Expanding particle size distribution and morphology of aluminium-silicon powders for Laser Beam Melting by dry coating with silica nanoparticles." Journal of Materials Processing Technology 264 (2018): 155-171.

BibTeX: 

Last updated on 2019-05-01 at 21:10