Application of System Engineering Approach as a Method to Assess the Process of Coatings Functional Properties Formation

This paper examines the basic principles of systems engineering as a methodology that makes it possible to design technological processes to obtain products with the required functional properties. A distinctive feature of systems engineering is the analysis of the functioning system in its dynamic development. According to this approach, the technological process is considered to be a system which consists of a set of interconnected operations as a sequential transformation of the source material into the finished product. This makes it possible to take into consideration the state of the system during the definite period of time, which is the key factor to select technological modes that ensure the formation of the necessary functional properties. The paper proposes the mathematical description of the technological process as a set of nonvacuous sets, which makes it possible to describe the technological process as a system of functional relationships between separate elements. The application of the basic principles of systems engineering and the developed mathematical model is shown on the example of the cold gas-dynamic spraying process. Forming of the coating by this method occurs due to the impact of a high-speed flow of powder particles with the surface. The structural and functional diagram of the cold gas-dynamic spraying process has been constructed, which allows to establish the relationship between the input and output parameters of this process. The structural and functional diagram of the formation of functional properties of the coating by cold gas-dynamic spraying has been constructed, which reflects the mechanisms of interaction of the two-phase powder flow with a surface. As a result of the theoretical investigations, the system of relationships between the control parameters of cold gas-dynamic spraying and the functional properties of the obtained coating was established. This served as the basis for constructing analytical expressions to predict the formation of coating functional properties taking into consideration the characteristics of external input and control parameters of the process applied.