TY - JOUR

T1 - Selective laser melted AlSi10Mg alloy under melting mode transition

T2 - Microstructure evolution, nanomechanical behaviors and tensile properties

AU - Wu, H.

AU - Ren, Y.

AU - Ren, J.

AU - Liang, L.

AU - Li, R.

AU - Fang, Q.

AU - Cai, A.

AU - Shan, Q.

AU - Tian, Y.

AU - Baker, I.

N1 - This is the author’s version of a work that was accepted for publication in Journal of Alloys and Compounds. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Alloys and Compounds, 873, 2021 DOI: 10.1016/j.jallcom.2021.159823

PY - 2021/8/25

Y1 - 2021/8/25

N2 - The effect of the volumetric energy density (VED) on the keyhole formation, microstructural evolution and associated mechanical properties of AlSi10Mg fabricated by selective laser melting (SLM) has been systematically investigated. The results indicated that three melting modes could be distinguished during the laser melting process, corresponding to different VED ranges, i.e. conduction mode (<50 J mm-3), transitional mode (~50–65 J mm-3), and keyhole mode (>65 J mm-3). A high VED not only produced keyhole defects and hydrogen pores, but also generated two types of molten pool, i.e. a general shallow molten pool (GSP) and a keyhole-induced deep molten pool (KDP). The GSP was mainly consisted of an α-Al matrix, with ~30 µm grains size, and enclosed by a ~500 nm eutectic Si cellular network. The grain size of the KDP was less than 15 µm, and it has both a finer Si network (~200 nm) and nano-scale Si particles. No preferential crystallographic orientation could be observed within the KDP, while a strong texture along<111>orientation was exhibited in the GSP. These were responsible for the different mechanical properties of the SLM parts under different melting modes. The related mechanisms of the GSP and the KDP formation are comprehensively discussed and a correlation between the microstructure and the mechanical properties is also outlined. 

AB - The effect of the volumetric energy density (VED) on the keyhole formation, microstructural evolution and associated mechanical properties of AlSi10Mg fabricated by selective laser melting (SLM) has been systematically investigated. The results indicated that three melting modes could be distinguished during the laser melting process, corresponding to different VED ranges, i.e. conduction mode (<50 J mm-3), transitional mode (~50–65 J mm-3), and keyhole mode (>65 J mm-3). A high VED not only produced keyhole defects and hydrogen pores, but also generated two types of molten pool, i.e. a general shallow molten pool (GSP) and a keyhole-induced deep molten pool (KDP). The GSP was mainly consisted of an α-Al matrix, with ~30 µm grains size, and enclosed by a ~500 nm eutectic Si cellular network. The grain size of the KDP was less than 15 µm, and it has both a finer Si network (~200 nm) and nano-scale Si particles. No preferential crystallographic orientation could be observed within the KDP, while a strong texture along<111>orientation was exhibited in the GSP. These were responsible for the different mechanical properties of the SLM parts under different melting modes. The related mechanisms of the GSP and the KDP formation are comprehensively discussed and a correlation between the microstructure and the mechanical properties is also outlined. 

KW - AlSi10Mg

KW - Keyhole effect

KW - Mechanical properties

KW - Melting mode

KW - Selective laser melting

U2 - 10.1016/j.jallcom.2021.159823

DO - 10.1016/j.jallcom.2021.159823

M3 - Journal article

VL - 873

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

M1 - 159823

ER -