## 3 Results
### PC--Tomography Scans  
After the mechanical dressing, the samples were prepared for mechanical testing. Each sample was weighed, measured, and scanned by a computed tomography method before the pressure tests. Figure 7 shows the 3D models of the samples in different views. Sampling was performed at a resolution of 33 \(\upmu\)m.  
Figure 6: (**a**) test specimens after the thermal annealing process, (**b**) removal of specimens from the platform, (**c**) untreated and treated test specimen base. Figure 7: 3D scans of the tested specimens taken by PC-tomography (**a**) trabecular with 200 \(\upmu\)m pore size, (**b**) trabecular with 400 \(\upmu\)m pore size, (**c**) trabecular with 600 \(\upmu\)m pore size, (**d**) cubic with 200 \(\upmu\)m pore size, (**e**) cubic with 400 \(\upmu\)m pore size, (**f**) cubic with 200 \(\upmu\)m pore size. The \"New defect detection\" module with a maximum pore diameter of 10 mm was used for the porosity analysis. Due to the size and shape of the pores in sample type 1, they are filled with unsintered powder. The amount of powder in the sample can be evaluated from the porosity analysis. However, in this case, the result of the analysis was inconclusive due to the interconnection of the pores. In Figure 8, the areas marked in orange are identified as pores (unconnected), the dark gray areas closed by the white line are unidentified pores (connected). The bright edge of the cross-sectional sample is caused by a beam hardening artifact. This mapping is valid for all analyzes. During the micro-CT analysis of the type 1 sample model, the software was unable to recognize individual pores. This is due to the presence of sintered powder and the low nominal porosity of the sample design. It can be seen from the cross-section of the sample model that the individual pores were not interconnected (Figure 7a). In the \(\upmu\)CT analysis of the type 2 sample model (Figure 7b), the evaluation software distinguished the pores in the material. The porosity analysis shows that the pores are interconnected, and the result is shown in Figure 8b. Unsintered titanium powder was also present but to a minimal extent. When analyzing the type 3 sample (Figure 7c), the pores were also interconnected, and the evaluation software could accurately distinguish between the sintered material and air. There were no pores detected in sample 4 (Figure 8c). The content of unbaked titanium powder is negligible compared to previous types of structures. Type 4 sample (Figure 7d) was found to contain a significant amount of sintered titanium powder. For this reason, the software could not distinguish the material from the air and thus did not evaluate the individual pores. Pore size determinations were approximate (the software did not detect the pores) and therefore this value is also only approximate. In sample type 4 (Figure 7d) was found a significant amount of sintered titanium powder. Unlike the trabecular structure, in the case of a cubic structure, all pores should be interconnected, so the porosity analysis is irrelevant. With a pore size of 200 \(\upmu\)m, it is clear in the cross-sectional view that there are areas in the sample where the pores did not form at all or were clogged with sintered material (there is no difference in density)--an orange bounded area (Figure 9). Figure 8: Sample 1 with a porosity of 200 \(\upmu\)m with marked pores (**a**), 400 \(\upmu\)m (**b**), 600 \(\upmu\)m (**c**). Figure 9: Pore layout and shape: 200 \(\upmu\)m (**a**), 400 \(\upmu\)m (**b**), 600 \(\upmu\)m (**c**). Type 5 sample (Figure 7e) also contained unsintered titanium powder which affected the evaluation of the sample properties. The shape of the pores was mostly circular, not square. The average pore size was 270 \(\upmu\)m which means that the pore size decreased by 32.5% compared to the solid sample (type 7). For type 6, the pores were not clogged with unbaked titanium powder which means that the pores were large enough to be optimally cleaned from this powder.