Influence of Selective Laser Melting Technological Parameters on the Mechanical Properties of Additively Manufactured Elements Using 316L Austenitic Steel

Abstract

The main aim of this study was to investigate the influence of different energy density values used for the additively manufactured elements using selective laser melting (SLM).The group of process parameters considered was selected from the first-stage parameters identified in preliminary research. Samples manufactured using three different sets of parameter values were subjected to static tensile and compression tests. The samples were also subjected to dynamic Split–Hopkinson tests. To verify the microstructural changes after the dynamic tests, microstructural analyses were conducted. Additionally, the element deformation during the tensile tests was analyzed using digital image correlation (DIC). To analyze the influence of the selected parameters and verify the layered structure of the manufactured elements, sclerometer scratch hardness tests were carried out on each sample. Based on the research results, it was possible to observe the porosity growth mechanism and its influence on the material strength (including static and dynamic tests). Parameters modifications that caused 20% lower energy density, as well as elongation of the elements during tensile testing, decreased twice, which was strictly connected with porosity growth. An increase of energy density, by almost three times, caused a significant reduction of force fluctuations differences between both tested surfaces (parallel and perpendicular to the building platform) during sclerometer hardness testing. That kind of phenomenon had been taken into account in the microstructure investigations before and after dynamic testing, where it had been spotted as a positive impact on material deformations based on fused material formation after SLM processing.

Investigations on Mechanical Properties of Lattice Structures with Different Values of Relative Density Made from 316L by Selective Laser Melting (SLM)

“…Considering the possibilities offered by additive manufacturing techniques, the authors decided to use an SLM device and SS316L stainless steel metal powder to produce the lattice structure specimens. Three-dimensional printing is well known and has been characterized in detail in many scientific papers [9,[61][62][63][64][65]. Moreover, its growing importance from year to year can be observed.…”

“…This paper is a continuation of the authors' works related to additively manufactured lattice structure made from 316L stainless steel. Results associated with this work were partially published in [61][62][63]. On the basis of results of quality control and microstructure studies, certain drawbacks of the SLM technique as a method of fabrication for lattice structures were revealed.…”

Impact Behavior of Additively Manufactured Stainless Steel Auxetic Structures at Elevated and Reduced Temperatures

“…[ 7–9 ] Kluczyński et al dealt with the influence of additive manufacturing production parameters on the resulting mechanical parameters. [ 10 ] In their study, the specimens produced with different settings of laser power, exposure velocity, hatching distance, and layer thickness were subjected to microstructural analysis, hardness measurement, and a combination of quasistatic and dynamic compression. The authors concluded that the observed mechanism of material cracking during dynamic loading is affected by the energy dissipation capacity of the resulting structures.…”

The Influence of Heat Treatment on Low Cycle Fatigue Properties of Selectively Laser Melted 316L Steel

“…Based on our previous research of the AM process [ 14 , 15 , 34 ], three-parameter groups were selected, as shown in Table 2 . To be consistent with previously published papers—each sample group was named the same as before (Samples: S_01, S_17, S_30).…”

“…Based on the authors’ own previous research [ 14 , 15 , 34 ], it was a natural continuation of material analysis connected with the LCF of heat-treated and HIPped parts obtained using the selective laser melting technology (SLM). The main aim of the included research results was to determine the possibility of a void reduction in material volume and describe how it affects LCF properties.…”