Microstructure and mechanical property of graphene oxide/AlSi10Mg composites fabricated by laser additive manufacturing

The low laser absorptivity and high thermal conductivity of Al are the foremost concerns when developing Al matrix composites (AMCs) through laser powder bed fusion (L-PBF) process. In this study, we demonstrated an example of improving the 3D-printability of AMCs by means of powder surface modifica...

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Bibliographic Details
Published in:Materials characterization 2020-12, Vol.170, p.110678, Article 110678
Main Authors: Dong, Mingqi, Zhou, Weiwei, Kamata, Kohei, Nomura, Naoyuki
Format: Article
Language:English
Subjects:
Graphene
Laser powder bed fusion (L-PBF)
Metal matrix composites (MMCs)
Microstructural evolution
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Summary:The low laser absorptivity and high thermal conductivity of Al are the foremost concerns when developing Al matrix composites (AMCs) through laser powder bed fusion (L-PBF) process. In this study, we demonstrated an example of improving the 3D-printability of AMCs by means of powder surface modification. Flexible graphene oxide (GO) sheets were carefully coated onto the surface of AlSi10Mg powders under electrostatic self-assembly via a hetero-agglomeration process. In addition to maintaining a shape and particle size similar to the initial metallic powders, the GO-coated AlSi10Mg powders exhibited enhanced laser absorptivity and decreased thermal conductivity, beneficial to their fusion. Under high-energy irradiation, the GO sheets were partially transformed to Al4C3 nanorods individually distributed in the matrix, while the un-reacted parts floated within molten pools under buoyancy, forming an in-situ carbon layer tightly deposited on the surface of the composite build. This work may provide significant guidance for the design and production of high-performance AMCs with advanced architectures for practical applications. •Graphene oxide (GO) sheets were uniformly coated onto the surface of AlSi10Mg powders via electrostatic self-assembly.•The mixed powders exhibited enhanced laser absorptivity and lower thermal conductivity, beneficial to the 3D-printability.•The microstructure evolution of GO was investigated systematically during laser additive manufacturing.•A carbon layer was in-situ deposited on the surface of composite builds.
ISSN:1044-5803
1873-4189
DOI:10.1016/j.matchar.2020.110678