## 4 Discussion
Due to the relatively smaller solidification structures, the light microscopic images of the same magnification displayed in Figure 15a-c for the specimen geometry manufactured utilizing the cross support (Figure 15a) did not disclose any darker regions. Further qualitative and quantitative assessment of the performance quality of the different support removal strategies is depicted in Figure 16a-f using the surface roughness profile comparisons between the as-built state and after different post-processing routes. The surface roughness values in terms of Sz (maximum height) and Sa (arithmetical mean height) are plotted in Figure 16e-f. The surface roughness indicated by the Sz values is relatively high for the as-built state, with the maximum roughness reaching 120 \(\upmu\)m. SB reduced the maximum Sz value to ~60 \(\upmu\)m, albeit with non-uniform roughness throughout  
Figure 15: **(a,b)** Struts of the specimen geometry manufactured using the cross support after GB; (**c,d**) line support after SB; (**e,f**) line support after ECP. the measured locations within the sample. Maximum Sz values observed for the GB were comparable to those obtained after SB. However, the maximum Sz value was observed only close to one edge within the measurement area. This could be due to the presence of a single large particle or an agglomerated region that was not able to be eliminated completely using the GB. Minimum values of Sz and Sa were observed for GB and ECP, with Sa values less than 1 \(\upmu\)m indicating the high efficiency of these two post-processing methods in realizing the final shape of the component. The obtained roughness values are closer to that required for the biomedical application of stents [22]. Numerous research studies have proven that the successful manufacturing of stents/lattice structures using L-PBF is possible if the relevant design rules are obeyed [21; 22; 23; 39; 40]. The specific advantage of L-PBF systems is that they allow the variation of a number of laser parameters in coalition, making it possible to achieve the near-net-shape manufacturing of stents [21]. Traditional manufacturing of the stents, involving micro-tubing followed by laser cutting, can lead to non-uniform surface properties [41]. However, further post-processing treatments are needed because of the stringent requirements regarding the final product specifications in a highly regulated field such as medical technology. Typical post-processing methods include heat treatment and chemical or electrochemical polishing. Thus, the relevance of an integrative approach combining the support optimization and support removal as followed in the present study is essential to achieve the successful near-net-shape manufacturing of stents using L-PBF. Excluding the time required for post-processing treatments, lower manufacturing times up to one third of that required for laser cutting for a single coronary stent have been reported [22]. Signifi  
Figure 16: Surface roughness profiles of the L-PBF-manufactured specimen geometries in different conditions with the intensity profile in \(\upmu\)m: (**a**) as-built, (**b**) sand-blasted, (**c**) glass-bead-blasted, (**d**) electrochemically polished. Measured roughness values plotted and compared in terms of (**e**) Sz value and (**f**) Sa value. cant improvements in the time required for support removal using the ECP method for the representative aortic stent geometry using a line support was observed in the present study. Similar time requirements are therefore expected during the removal of support structures from the whole stent geometry. Therefore, the successful support removal within eighteen minutes for the heaviest sample having a strut thickness of 1 mm for the representative aortic stent geometry manufactured using a line support confirms the efficacy of the holistic approach followed here.