## 4 Discussion of the Research Results
Figure 14: An example of microplasma additive deposition of a cylinder–type product: (**a**)—application of the modeled stress–strain state; (**b**)—a combination of the modeled stress–strain state with additional analysis of the accumulated statistical data. Figure 13: An example of modeling the residual stress–strain state at layer–by–layer microplasma deposition of a cylinder–type object in the optimal model: (**a**)—stresses normal to X; (**b**)—stresses normal to Y; (**c**)—equivalent stresses; (**d**)—residual deformations along Z. Thus, it can be considered proven that the application of prediction of the stress-strain state in combination with the acquisition of statistical data on the actual deposited parts and development of software for their analysis and selection of the parameters of additive microplasma deposition of 3D metal products further enhances their manufacturing efficiency. Furthermore, the proposed approaches to adjustment of the stress-strain state of the products made by additive microplasma deposition will be the basis for designing the respective hardware and software complex. The hardware and software complex for microplasma deposition developed on the base of program analysis and selection of process parameters can significantly expand the capabilities of the regular deposition process and bring this process to a fundamentally new level with the capability of predicted detection of deviations from printing accuracy. It will allow optimizing the parameters of the technological process of manufacturing spatial objects using an analysis of the model-accumulated data by the criterion of minimizing the residual stresses and deformations (movements). Thus, we proposed the basic principles for the creation of the hardware-software complex for microplasma deposition, which has the capability of analysis of data accumulated through modeling to provide automatic 3D printing of spatial metal products with a predictable structure and stressed state. Future application of such a complex will ensure industrial 3D printing of metal product billets for mass production. For instance, this method enables the manufacturing of complex-shaped parts for aviation, automotive, railway, and sea transport, such as complex pipe adapters, etc. Note that because of the considerable roughness of the produced billet walls (of the order of Rz 60-120 \(\upmu\)m), their machining is required, for instance, finish milling. Despite the need for finish machining, the speed of producing finished parts by the proposed 3D printing method is higher than that of SLM printing, which is associated with a larger volume of the liquid metal pool at similar printing speeds. So, the efficiency of the SLM method of producing the finished part is of the order of 10-100 cm\({}^{3}\)/h [39], whereas the efficiency of producing the billet by the proposed method is equal to 200-3000 cm\({}^{3}\)/h which, allowing for finished machining, is approximately 10-20 times higher than the speed of producing a finished part by SLM printing. The efficiency of producing the part billets via the WAAM method using the MIG/MAG process is equal to 500-6000 cm\({}^{3}\)/h on average [39], which is 2-3 times higher than the speed of producing the billet by the proposed method. It should be taken into account, however, that the proposed method  
Figure 15: The S-shaped wall manufactured via additive microplasma deposition with the application of the HYF–103 powder. allows producing the minimal thickness of the deposited wall of the order of 3.0-3.5 mm, whereas for the WAAM method, it is not less than 5-6 mm. This determines certain limits of the proposed process applicability, compared to SLM and WAAM processes. The proposed process envisages finish machining, and it is rational to apply it to produce finished metal parts with a wall thickness of the order of 2-4 mm.