Effects of fused filament fabrication parameters on the manufacturing of 316L stainless-steel components: geometric and mechanical properties

Abstract

Purpose The extrusion-based additive manufacturing method followed by debinding and sintering steps can produce metal parts efficiently at a relatively low cost and material wastage. In this study, 316L stainless-steel metal filled filaments were used to print metal parts using the extrusion-based fused filament fabrication (FFF) approach. The purpose of this study is to assess the effects of common FFF printing parameters on the geometric and mechanical performance of FFF manufactured 316L stainless-steel components. Design/methodology/approach The microstructural characteristics of the metal filled filament, three-dimensional (3D) printed green parts and final sintered parts were analysed. In addition, the dimensional accuracy of the green parts was evaluated, as well as the hardness, tensile properties, relative density, part shrinkage and the porosity of the sintered samples. Moreover, surface quality in terms of surface roughness after sintering was assessed. Predictive models based on artificial neural networks (ANNs) were used for characterizing dimensional accuracy, shrinkage, surface roughness and density. Additionally, the response surface method based on ANNs was applied to represent the behaviour of these parameters and to identify the optimum 3D printing conditions. Findings The effects of the FFF process parameters such as build orientation and nozzle diameter were significant. The pore distribution was strongly linked to the build orientation and printing strategy. Furthermore, porosity decreased with increased nozzle diameter, which increased mechanical performance. In contrast, lower nozzle diameters achieved lower roughness values and average deviations. Thus, it should be noted that the modification of process parameters to achieve greater geometrical accuracy weakened mechanical performance. Originality/value Near-dense 316L austenitic stainless-steel components using FFF technology were successfully manufactured. This study provides print guidelines and further information regarding the impact of FFF process parameters on the mechanical, microstructural and geometric performance of 3D printed 316L components.

Shrinkage behaviour of material extrusion steel 316L: influence of primary 3D printing parameters

“…Whereas, PS showed little or no influence on shrinkage rate within this experimental design (which corresponds to a subset of the broader range of acceptable set of parameters). While it is evident from the results presented above that MEX process parameters indeed influence the shrinkage properties of Steel 316L parts, interestingly, Caminero et al (2022) found that build orientation, LH and PS had no significant effect on shrinkage rate, although, they found nozzle diameter to influence shrinkage behaviour. Quarto et al (2021), on the other hand, found manufacturing parameters to influence each axis differently, with PS topping the list, followed by LH and nozzle temperature.…”

“…From the ANOVA statistical results, LH and RA were found to be the most statistically significant manufacturing parameters influencing the shrinkage behaviour of the MEX Ultrafuse Steel 316L specimens, while PS was found to have little or no influence on the shrinkage behaviour (within the experimental design). Quarto et al (2021) similarly established the influence of MEX parameters on subsequent shrinkage behaviour of Steel 316L specimens, while Caminero et al (2022) found varying manufacturing parameters to have a negligible influence on shrinkage rate.…”

“…Wei et al (2022) identified that primary manufacturing parameters, including build orientation, affect the shrinkage behaviour of MEX metal parts following their investigations on MEX bronze metal specimens. In this regard, to the authors’ best knowledge, in-depth investigations into the influence of varying MEX manufacturing processes and subsequent shrinkage behaviour of MEX Steel 316L parts are currently limited to the works of Quarto et al (2021) and Caminero et al (2022).…”

“…The authors used the ANOVA statistical tool to study the relationship between the parameters and shrinkage behaviour, recommending the combination of 20 mm/s PS, 0.1 mm LH and line infill pattern. Caminero et al (2022) similarly studied the relationship between manufacturing parameters and subsequent shrinkage of Ultrafuse 316L samples, varying PS (30, 40 and 50 mm/s), LH (0.20 and 0.25 mm), build orientations (upright, on-edge and flat) and nozzle diameter (0.4 and 0.6 mm), whilst keeping infill density and pattern, nozzle temperature and print bed temperature constant. The authors used the artificial neural networks (ANNs) model to characterise and develop predictive models to estimate the shrinkage behaviour of the specimens.…”

Filament Extrusion-Based Additive Manufacturing of 316l Stainless Steel: Effects of Sintering Conditions on the Microstructure and Mechanical Properties

“…For this reason, 316L is one of the most researched materials in the field of FFFm. Numerous studies on filament-based fabrication of steel have investigated the print-porosity and its influence on the mechanical anisotropy [4,[11][12][13][14][15], surface roughness [16,17], or fatigue [18]. The sintering process has fundamental effect on the final microstructure and the mechanical properties.…”