## 3 Results and Discussion
### Development of the Basic Techniques of Additive Manufacturing  
The development of additive manufacturing techniques was conducted in the case of manufacturing a \"hollow cylinder\" spatial primitive. Such a cylinder from the HYF-103 powder of the Fe-Cr-Ni-B-Si system should have the dimensions of \(\mathcal{O}\)40 \(\times\) 32.5 mm with a wall thickness of 3.5 mm and should be deposited in 20 passes. The dimensions of the substrate from the AISI 304 stainless steel for primitive deposition were equal to 200 \(\times\) 100 \(\times\) 10 mm. After several iterations of calculations of the mode with minimal residual strains and stresses, the following mode parameters were derived: values of the main (microplasma) arc current \(\mathrm{I_{MA}}\) = 25 A, voltage U = 30 V, and deposition rate V = 550 mm/min. Here,  
Figure 11: Modeled (**a**) and measured (**b**) radial displacements of the wall of the cylinder deposited via the additive microplasma method with the HYF–103 powder. Figure 10: Results of modeling the distributions of temperature (**a**) and residual deformations (**b**). the following geometrical parameters of the pool were obtained: depth--0.7-1.0 mm; width--3.5 m; and length--8 mm. In order to more precisely determine the flow rates of filler powder Q\({}_{\text{f}}\) and working gases (plasma-forming Q\({}_{\text{PL}}\), shielding Q\({}_{\text{SH}}\), and transporting Q\({}_{\text{TR}}\)), several technological experiments were conducted, the results of which are given in Table 8. For each mode, input energy E (J/mm) was determined, allowing for the efficiency factor of the microplasma deposition process (of the order of 0.8 according to ref. [33]). The performed technological investigations allowed the establishment of the optimal mode at which the pre-determined product is formed (a cylinder in this case)--mode \(N\)5, Table 8. It was established that, to achieve a positive result, it is necessary to minimize the power consumption and somewhat increase the energy input. Here, in order to begin the deposition process, 35 A current was used at the start, and after achieving a stable process (within 2-3 s), the main arc current was reduced to 25 A. In addition to the case of the cylinder, deposition modes were also selected for a range of basic spatial prototypes and arbitrary objects (Figure 12). This allowed for the creation of a database of optimal parameters of the modes of additive microplasma powder deposition, which can be applied for process automation by developing a control program and an automatic monitoring system. A reduction in deviations from the specified dimensions within up to 1 mm was the optimization criterion. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Mode \(\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{\mathbf{ }}}}}}}}}}}}}}}\) ** ** **** **MoTechnological investigations were performed using a microplasmatron with transporting nozzle channel diameters \(d_{\text{T}}\) of 2.5 mm, 3.5 mm, and 4.5 mm, respectively. At these dimensions, its stable operation is ensured at the main arc current of 20-40 A. The width of the deposited metal pool (or the deposited bead) varied with an increase in deposition current from 25 to 35 A at a constant speed of microplasma arc movement in the range from 2.5 mm up to \(\sim\)5.0 mm (Table 9). The HYF-103 filler powder with a particle size of 40-60 \(\upmu\)m used in the experiments was fed at a rate of up to \(G_{0}\) = 6.5 g/min. The specific weight of the deposited bead \(M_{\text{d}}\) was determined experimentally by weighing the grown plate-like samples with an accuracy of 0.02 g before and after 1 min of deposition. The powder utilization coefficient (PUC) was defined as the ratio of \(M_{\text{d}}\) to powder feed rate \(G_{0}\).