Structural and phase composition of Ni—Ti system coatings formed on gray cast iron by electric spark alloying and self-propagating high-temperature synthesis methods

The results of a study of the structural-phase composition of the alloy layer on the surface of samples of gray cast iron SCh15, obtained by methods of electric spark processing and self-propagating high-temperature synthesis, are presented. The result of the synthesis by volumetric heating of a pressed powder mixture of nickel—ferrotitanium FT70 (70 % Ti) is the production of a compact nickel-based material strengthened by intermetallic compounds Ni4Ti3 and Ni3Ti. Electric spark processing of gray cast iron SCh15 using this material as a strengthening electrode leads to the production of Ti2C carbide in the surface layer and an increase in the nickel content in the metal matrix of SCh15. The nickel-ferrotitanium mixture as an alloying facing composition, due to the occurrence of synthesis between the components, ensures the formation of intermetallic compounds of the Ni—Ti system in the surface layer of composite castings made of gray cast iron, obtained by casting using gasified models.