INFLUENCE OF STRUCTURAL-PHASE CONDITION ON THE MECHANICAL-TRI BOLOGICAL PROPERTIES OF Ti3SiC2 COATINGS OBTAINED BY THE DETONATION METHOD

Abstract

The article provides the results of the research of the structure and properties of powder coatings based on titanium carbosilicide Ti3SiC2 obtained by detonation spraying on the surface of tool steel U9/У9 (equivalent to N9). Micro-indentation methods and abrasive wear tests for mechanical and tribological properties of Ti3SiC2 based coatings were conducted. The microstructure of the coating has a layered structure. The border between the coating and the base has a characteristic crinkled appearance. It was determined that the phase composition of the coatings changes during detonation spraying is a result of the decomposition of Ti3SiC2 powder into titanium carbide and titanium carbosilicide (secondary phases). Selected consolidation conditions ensure the formation of a Ti3SiC2/TiC composite material. The influence of the second phase content (TiC, TiO2) on the properties of coatings was studied. Studies of the microhardness of samples with coatings showed that, in the entire range of annealing temperatures, the microhardness of the Ti3SiC2/TiC composite material increases compared to the coating before annealing. It was found that the maximum microhardness of the Ti3SiC2/TiC composite material after annealing at a temperature of 800 ○C is explained by an increase in the content of the Ti3SiC2 phase. It was established that, during detonation spraying of Ti3SiC2 powders, a coating with a higher microhardness and wear resistance is formed.