Investigation of porosity behavior in SLS polyamide-12 samples using ex-situ X-ray computed tomography

Ziółkowski, Grzegorz; Grochowska, Emilia; Kęszycki, Dawid; Gruber, Piotr; Hoppe, Viktoria; Szymczyk-Ziółkowska, Patrycja; Kurzynowski, Tomasz

doi:10.2478/msp-2021-0035

Abstract

The paper presents a detailed description of the method of carrying out static tensile tests in ex-situ X-ray computed tomography (XCT) conditions. The study compares samples manufactured with the use of additive technology in two orientations, horizontally and vertically, which correspond to the in-layer and between-layer sintering mechanisms. Both the fracture mechanism and porosity behavior differed significantly for the two manufacturing directions. The conducted analysis made it possible to compare the changes in porosity, the number of pores, and also their diameters and shape before and after the tensile test. This allows for in-depth identification and better understanding of the phenomena occurring during the static tensile test of polyamide-12 samples manufactured using selective laser sintering (SLS) technology.

References

Ziółkowski G, Chlebus E, Szymczyk P, Kurzac J. Application of X-ray CT method for discontinuity and porosity detection in 316L stainless steel parts produced with SLM technology. Arch Civ Mech Eng. 2014;14(4). https://doi.org/10.1016/j.acme.2014.02.003.
Search in Google Scholar Back to article
Thompson A, Maskery I, Leach RK. X-ray computed tomography for additive manufacturing: a review. Meas Sci Technol. 2016;27(7). https://doi.org/10.1088/0957-0233/27/7/072001.
Search in Google Scholar Back to article
Gapinski B, Janicki P, Marciniak-Podsadna L, Jakubowicz M. Application of the computed tomography to control parts made on additive manufacturing process. Procedia Eng. 2016;149(June):105–21. https://doi.org/10.1016/j.proeng.2016.06.645.
Search in Google Scholar Back to article
Chatham CA, Long TE, Williams CB. A review of the process physics and material screening methods for polymer powder bed fusion additive manufacturing. Prog Polym Sci. 2019;93:68–95. https://doi.org/10.1016/j.progpolymsci.2019.03.003.
Search in Google Scholar Back to article
Stansbury JW, Idacavage MJ. 3D printing with polymers: challenges among expanding options and opportunities. Dent Mater. 2016;32(1): 54–64. https://doi.org/10.1016/j.dental.2015.09.018.
Search in Google Scholar Back to article
Yaagoubi H, Abouchadi H, Taha Janan M. Review on the modeling of the laser sintering process for Polyamide 12. E3S Web Conf. 2021;234:1–5. https://doi.org/10.1051/e3sconf/202123400006.
Search in Google Scholar Back to article
Wohlers Associates. Wohlers Report 2020: 3D printing and additive manufacturing global state of the industry. Wohlers Associates Inc.; 2020. p. 2020.
Search in Google Scholar Back to article
Schmid M, Wegener K. Additive manufacturing: polymers applicable for laser sintering (LS). Procedia Eng. 149(June):457–64. https://doi.org/10.1016/j.proeng.2016.06.692.
Search in Google Scholar Back to article
Xu Z, Wang Y, Wu D, Ananth KP, Bai J. The process and performance comparison of polyamide 12 manufactured by multi jet fusion and selective laser sintering. J Manuf Process. 2019;47(July): 419–26. https://doi.org/10.1016/j.jmapro.2019.07.014.
Search in Google Scholar Back to article
Yusheng S, Zhichong L, Haixiao S, Shuhuai H, Fandi Z. Development of a polymer alloy of polystyrene (PS) and polyamide (PA) for building functional part based on selective laser sintering (SLS). Proc Inst Mech Eng Part L J Mater Des Appl. 2004;218(4):299–306. https://doi.org/10.1177/146442070421800404.
Search in Google Scholar Back to article
Olejarczyk M, Gruber P, Ziólkowski G. Capabilities and limitations of using Desktop 3-D printers in the laser sintering process. Appl Sci. 2020;10(18). https://doi.org/10.3390/APP10186184.
Search in Google Scholar Back to article
Mertens JCE, Henderson K, Cordes NL, Pacheco R, Xiao X, Williams JJ, et al. Analysis of thermal history effects on mechanical anisotropy of 3D-printed polymer matrix composites via in situ X-ray tomography. J Mater Sci. 52(20):12185–206. https://doi.org/10.1007/s10853-017-1339-4.
Search in Google Scholar Back to article
Al-Maharma AY, Patil SP, Markert B. Effects of porosity on the mechanical properties of additively manufactured components: a critical review. Mater Res Express. 2020;7(12). https://doi.org/10.1088/2053-1591/abcc5d.
Search in Google Scholar Back to article
Zhu Z, Majewski C. Understanding pore formation and the effect on mechanical properties of High Speed Sintered polyamide-12 parts: a focus on energy input. Mater Des. 2020;194:108937. https://doi.org/10.1016/j.matdes.2020.108937.
Search in Google Scholar Back to article
Ziółkowski G, Treter G, Tokarczyk E, Szymczyk-Ziółkowska P. New possibilities for in situ CT analysis of additive manufactured samples. Tech Trans. 2020;1–9. https://doi.org/10.37705/techtrans/e2020028.
Search in Google Scholar Back to article
Ziółkowski G, Gruber K, Tokarczyk E, Roszak R, Ziegenhorn M. X-ray computed tomography for the ex-situ mechanical testing and simulation of additively manufactured IN718 samples. Addit Manuf. 2021;45(January). https://doi.org/10.1016/j.addma.2021.102070.
Search in Google Scholar Back to article
Schob D, Sagradov I, Roszak R, Sparr H, Franke R, Ziegenhorn M, et al. Experimental determination and numerical simulation of material and damage behaviour of 3D printed polyamide 12 under cyclic loading. Eng Fract Mech. 2019;229(November):106841. https://doi.org/10.1016/j.engfracmech.2019.106841.
Search in Google Scholar Back to article
Roszak R, Schob D, Sagradov I, Kotecki K, Sparr H, Maasch Ph, et al. Experimental determination and numerical simulation of temperature dependent material and damage behaviour of additively manufactured polyamide 12. Mech Mater. 2021;159(April): 103893. https://doi.org/10.1016/j.mechmat.2021.103893.
Search in Google Scholar Back to article
Kok Y, Tan XP, Wang P, Nai MLS, Loh NH, Liu E, et al. Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: a critical review. Mater Des. 2018;139:565–86. https://doi.org/10.1016/j.matdes.2017.11.021.
Search in Google Scholar Back to article
Hou G, Zhu H, Xie D. The influence of SLS process parameters on the tensile strength of PA2200 powder. IOP Conf Ser Earth Environ Sci. 2020;571(1). https://doi.org/10.1088/1755-1315/571/1/012111.
Search in Google Scholar Back to article
Craft G, Nussbaum J, Crane N, Harmon JP. Impact of extended sintering times on mechanical properties in PA-12 parts produced by powderbed fusion processes. Addit Manuf. 2018;22(June):800–6. https://doi.org/10.1016/j.addma.2018.06.028.
Search in Google Scholar Back to article

Investigation of porosity behavior in SLS polyamide-12 samples using ex-situ X-ray computed tomography

Abstract

Paradigm

My account