The Effect of Laser Focus Shift on the Morphology of Melt Pool and Microstructure in Selective Laser Melting AlSi10Mg

Abstract:

Selective Laser Melting (SLM) enables to fabricate complex freeform geometries parts from computer models. In this paper, the effect of laser focus shift on the morphology, surface quality, grain size and texture of the SLMed AlSi10Mg was studied. Deep melt pool was found in 0 mm laser focus shift, while shallow and wide melt pool were found in-1.5 mm and +1.5 mm laser focus shift. The proportion of high angle grain boundaries in 0mm laser focus shift sample is the biggest han that in-1.5mm and +1.5mm. Height has a maximum value of 338 μm in +1.5 mm laser focus shift. The maximum Arithmetic average height is 33.5 μm in +1.5 mm laser focus shift. When the laser focus shift is 0 mm, the average grain diameter has a minimum grain diameter of 4.9 μm. {001}<100> cubic texture was found in sample fabricated by +1.5 mm laser focus shift rather than 0 mm and-1.5 mm laser focus shift.

• Periodical: Materials Science Forum (Volume 1054)
• Pages: 9-14
• DOI: https://doi.org/10.4028/p-o6v3wj
• Online since: February 2022
• Authors: Ting Ting Wang, Zhi Heng Hu, Shi Wen Liu, Hai Hong Zhu*
• Keywords: AlSi10Mg, Laser Focus Shift, Melt Pool, Selective Laser Melting

References

[1] Beyer C, Figueroa D. Design and Analysis of Lattice Structures for Additive Manufacturing[J]. Journal of Manufacturing Science and Engineering, 2016, 138(12): 121014.

DOI: 10.1115/1.4033957

[2] Xiong Z H, Liu S L, Li S F, et al. Role of melt pool boundary condition in determining the mechanical properties of selective laser melting AlSi10Mg alloy[J]. Materials Science and Engineering: A, 2019, 740-741: 148-156.

DOI: 10.1016/j.msea.2018.10.083

[3] Cunningham R Z, Cang; Parab, Niranjan. Keyhole threshold and morphology in laser melting revealed by ultrahigh-speed x-ray imaging[J]. Science, 2019, 363(6429): 849-852.

DOI: 10.1126/science.aav4687

[4] Galy C, Le Guen E, Lacoste E, et al. Main defects observed in aluminum alloy parts produced by SLM: From causes to consequences[J]. Additive Manufacturing, 2018, 22: 165-175.

DOI: 10.1016/j.addma.2018.05.005

[5] Kouraytem N, Chiang P-J, Jiang R, et al. Solidification crack propagation and morphology dependence on processing parameters in AA6061 from ultra-high-speed x-ray visualization[J]. Additive Manufacturing, 2021, 42: 101959.

DOI: 10.1016/j.addma.2021.101959

[6] Wang J, Liu Z, Bai S, et al. Microstructure evolution and mechanical properties of the electron-beam welded joints of cast Al–Cu–Mg–Ag alloy[J]. Materials Science and Engineering: A, 2021, 801: 140363.

DOI: 10.1016/j.msea.2020.140363

[7] Babu A P, Huang A, Birbilis N. On the heat treatment and mechanical properties of a high solute Al–Zn–Mg alloy processed through laser powder bed fusion process[J]. Materials Science and Engineering: A, 2021, 807: 140857.

DOI: 10.1016/j.msea.2021.140857

[8] Martin J H, Yahata B D, Hundley J M, et al. 3D printing of high-strength aluminium alloys[J]. Nature, 2017, 549(7672): 365-369.

DOI: 10.1038/nature23894

[9] Andreau O, Koutiri I, Peyre P, et al. Texture control of 316L parts by modulation of the melt pool morphology in selective laser melting[J]. J Mater Process Technol, 2019, 264: 21-31.

DOI: 10.1016/j.jmatprotec.2018.08.049

[10] Scime L, Beuth J. Melt pool geometry and morphology variability for the Inconel 718 alloy in a laser powder bed fusion additive manufacturing process[J]. Additive Manufacturing, 2019, 29: 100830.

DOI: 10.1016/j.addma.2019.100830

[11] Abolhasani, Seyedkashi, Kang, et al. Analysis of Melt-Pool Behaviors during Selective Laser Melting of AISI 304 Stainless-Steel Composites[J]. Metals, 2019, 9(8): 876.

DOI: 10.3390/met9080876

[12] Wu Y-C, San C-H, Chang C-H, et al. Numerical modeling of melt-pool behavior in selective laser melting with random powder distribution and experimental validation[J]. J Mater Process Technol, 2018, 254: 72-78.

DOI: 10.1016/j.jmatprotec.2017.11.032

[13] Hooper P A. Melt pool temperature and cooling rates in laser powder bed fusion[J]. Additive Manufacturing, 2018, 22: 548-559.

DOI: 10.1016/j.addma.2018.05.032

[14] Furumoto T, Egashira K, Munekage K, et al. Experimental investigation of melt pool behaviour during selective laser melting by high speed imaging[J]. CIRP Annals, 2018, 67(1): 253-256.

DOI: 10.1016/j.cirp.2018.04.097

[15] Wang T, Wang Y, Chen C, Zhu H, Relationships between the characteristics of porosity, melt pool and process parameters in laser powder bed fusion Al-Zn alloy, Journal of Manufacturing Processes 68 (2021) 1236-1244.

DOI: 10.1016/j.jmapro.2021.06.027