## 3 Results and Discussion
### Technological Studies of the Formation of Spatial Primitives Using Additive Deposition Processes
This resulted in the slow cooling of metal in the sample's upper part, and, hence, it led to significant grain growth. Figure 4: Structures of a primitive “thin wall” type printed via additive microplasma deposition with the HYF–103 powder. In the longitudinal direction, the dendrites form extended crystal branches, oriented predominantly in the direction of heat removal and united into colonies. Analysis of the microstructure of a sample cut out in the lower part showed that the crystal growth took place in one direction (Figure 5a). The dendrites consisted of grain blocks of a similar crystalline orientation, the boundaries of which were revealed by etching. Comparison of the structure of metal of specimens cut out in the longitudinal direction in the sample upper and lower parts pointed to a different nature of crystallization during the part upward formation (Figure 5). Microanalysis of individual regions of the structure showed that the deposited metal composition was close to that of the deposited powder. Therefore, and also due to the presence of boron in the composition of the initial powder, the resulting structure, with a high probability, should be austenitic [25]. The dimensions of the resulting structure were as follows: h \(\times\) 1 = (40-100) \(\times\) (400-600) \(\upmu\)m in the deposited metal lower part (Figure 5a, \(\times\)200), h \(\times\) 1 = (40-100) \(\times\) (200-400) \(\upmu\)m in the middle layer (Figure 5b, \(\times\)200), and h \(\times\) 1 = (20-80) \(\times\) (140-360) \(\upmu\)m in the deposited metal upper layer (Figure 5c, \(\times\)200). At  
Figure 5: The microstructure of metal produced via layer–by–layer deposition of the HYF–103 powder using additive technology: (**a**)—deposited sample bottom; (**b**)—deposited sample middle; (**c**)—deposited sample top. the transition from the deposited metal lower section into the middle layer, the crystallite width was the same, but the length became smaller after a decrease in grain shape factor \(\mathbf{\alpha}\) from \(\mathbf{\alpha}\) = 6-10 (deposit bottom) to \(\mathbf{\alpha}\) = 4-5 (middle). In the upper layer of the deposited metal, the crystallite size decreased by 1.1-1.4 times relative to the middle part at \(\mathbf{\alpha}\) = 4.5-7. The inner structure of the crystallites has a cellular substructure of the following dimensions: d\({}_{\text{c}}\) = 20-30 \(\upmu\)m in the deposited metal lower part (Figure 5a, \(\times\)1000), d\({}_{\text{c}}\) = 15-25 \(\upmu\)m in the middle layer (Figure 5b, \(\times\)1000) and d\({}_{\text{c}}\) = 10-20 \(\upmu\)m in the deposited metal upper layer (Figure 5c, \(\times\)1000). In the deposited metal upper part, the metal substructure was refined compared with the lower and middle layers, on average, by 1.7 and 1.25 times, respectively. A slight coarsening of the grain and subgrain structure in the deposited metal lower and middle parts is associated with slowing down of the heat removal process and lowering of the metal cooling rate. In the deposited metal upper part, a finer structure formed, ensuring both the strength and toughness of the deposited material. Conducted investigations of mechanical properties (Table 5) led to the conclusion that metal deposited by the additive method ensures high strength, reaching more than 600 MPa.