Skidin I. Technological bases of surface alloying of castings by obtaining functional layers from thermite melts

The dissertation is devoted to substantiation, development and realization of advanced technological receptions for surface alloying of castings by the formation of a functional layer from a thermite melt. Based on the results of thermodynamic and thermotechnical calculations, the mechanism for determining the optimal composition of the thermite charge, which provides the maximum yield of a high-quality functional layer of given chemical composition is substantiated. The mechanism of reinforcing oxide and carbide phase formation in the structure of the formed layer is substantiated based on the stochastic analysis of structural-chemical reactions. Based on the calculation of thermokinetic features of the formation of non-metallic inclusions in the functional layer, the patterns and mechanisms of its structure formation are determined. Recommendations for the organization and implementation of technological solutions for surface alloying of castings with thermite melt, as well as the restoration of their complex surfaces were developed. Experimental and industrial tests of the proposed technical and technological solutions were carried out, which confirmed the expediency of introducing the technology of surface alloying of castings due to the formation of a functional layer of thermite melt on their surface. It is stated that in comparison with traditional methods of obtaining cast parts from alloyed alloys, the proposed technology provides a higher economic effect due to significant savings on materials, electricity, time, labor, reduction of technological operations, the ability to correct complex defects.