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. 2021 Oct 29;14(21):6504.
doi: 10.3390/ma14216504.

Comparison of Different Additive Manufacturing Methods for 316L Stainless Steel

Javier Bedmar  1 , Ainhoa Riquelme  1 , Pilar Rodrigo  1 , Belen Torres  1 , Joaquin Rams  1
Affiliations

Comparison of Different Additive Manufacturing Methods for 316L Stainless Steel

Javier Bedmar et al. Materials (Basel). .

Abstract

In additive manufacturing (AM), the technology and processing parameters are key elements that determine the characteristics of samples for a given material. To distinguish the effects of these variables, we used the same AISI 316L stainless steel powder with different AM techniques. The techniques used are the most relevant ones in the AM of metals, i.e., direct laser deposition (DLD) with a high-power diode laser and selective laser melting (SLM) using a fiber laser and a novel CO2 laser, a novel technique that has not yet been reported with this material. The microstructure of all samples showed austenitic and ferritic phases, which were coarser with the DLD technique than for the two SLM ones. The hardness of the fiber laser SLM samples was the greatest, but its bending strength was lower. In SLM with CO2 laser pieces, the porosity and lack of melting reduced the fracture strain, but the strength was greater than in the fiber laser SLM samples under certain build-up strategies. Specimens manufactured using DLD showed a higher fracture strain than the rest, while maintaining high strength values. In all the cases, crack surfaces were observed and the fracture mechanisms were determined. The processing conditions were compared using a normalized parameters methodology, which has also been used to explain the observed microstructures.

Keywords: 316L; additive manufacturing; direct laser deposition; mechanical properties; selective laser melting.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
(a) SEM image of the 316L powder used; (b) histogram of particles size.
Figure 2
Figure 2
Sample orientations used.
Figure 3
Figure 3
Processing diagram of several AM alloys with the materials studied in this work, based on [25]. The x axis is the E*min.
Figure 4
Figure 4
(a) Three-point bending test configuration; (b) bending sample used.
Figure 5
Figure 5
Macrostructure of the manufactured samples. Rows correspond to a manufacturing technique and orientation, and columns show the different cross sections of the specimens.
Figure 6
Figure 6
SEM micrograph of samples: (a) DLD; (b) FL–SLM; and (c) grain sizes measured in the samples.
Figure 7
Figure 7
Optical micrograph: (a) FL–SLM sample; and (b) CO2–SLM sample.
Figure 8
Figure 8
XRD of the samples made using different processes.
Figure 9
Figure 9
Schaeffler diagram with the 316L point marked [40].
Figure 10
Figure 10
(a) Porosity of the samples manufactured. Pores (black arrow) and lack of fusion (white arrow) in (b) DLD; (c) FL–SLM; (d) CO2 laser XZ90 sample; (e) XY67 sample.
Figure 11
Figure 11
Microhardness (HV0.1) of the AM samples.
Figure 12
Figure 12
(a) Flexural tests of the different samples manufactured and (b) scheme of the flexural tests of the parts with their layers marked.
Figure 13
Figure 13
Bending test results of the AM samples: (a) yield strength, (b) maximum flexural strength, and (c) maximum flexural strain.
Figure 14
Figure 14
Fracture surfaces: (a) DLD; (b) zone of DLD with brittle fractures; (c) FL–SLM and (d) detail of FL–SLM; (e) and (f) YZ0 CO2 laser SLM.
Figure 15
Figure 15
Fracture surfaces of CO2 laser SLM samples: (a) XZ0; (b) XZ90; (c) YZ0; (d) YZ90; and (e) XY67.
See this image and copyright information in PMC

References

    1. Milewski J.O. Additive Manufacturing of Metals. Spinger; Basingstoke, UK: 2017.
    1. Yang L., Hsu K., Baughman B., Godfrey D., Medina F., Menon M., Wiener S. Additive Manufacturing of Metals: The Technology, Materials, Design and Production. Palgrave Macmillan; London, UK: 2017.
    1. DebRoy T., Wei H.L., Zuback J.S., Mukherjee T., Elmer J.W., Milewski J.O., Beese A.M., Wilson-Heid A., De A., Zhang W. Additive manufacturing of metallic components—Process, structure and properties. Prog. Mater. Sci. 2018;92:112–224. doi: 10.1016/j.pmatsci.2017.10.001. - DOI
    1. Malekipour E., El-Mounayri H. Common defects and contributing parameters in powder bed fusion AM process and their classification for online monitoring and control: A review. Int. J. Adv. Manuf. Technol. 2018;95:527–550. doi: 10.1007/s00170-017-1172-6. - DOI
    1. du Plessis A., Yadroitsava I., Yadroitsev I. Effects of defects on mechanical properties in metal additive manufacturing: A review focusing on X-ray tomography insights. Mater. Des. 2020;187:108385. doi: 10.1016/j.matdes.2019.108385. - DOI

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