Effect of Matrix on Properties of Cermet Plasma Coatings Based on Titanium Carbide

摘要

Comparative studies of cermet coatings with titanium carbide and matrices from high-speed steel grade 10P6M5 and self-fluxing alloy based on nickel H77X15C3P2 were carried out. The powders were obtained by self-propagating high temperature synthesis (SHS). The coatings were formed by plasma spraying with local protection. The introduction of additional carbon into cermet TiC-10P6M5 + 2.38 C made it possible to compensate for carbon losses during plasma spraying and to form a coating with an additional carbon content of 1.35%. The content of the titanium carbide phase in the coating is retained; however, the period of the carbide lattice is reduced, the more so for the coating with a nickel-based matrix. The content of oxygen and nitrogen in the coatings with respect to the initial powders increases mainly in the cermet containing the steel matrix. The presence of silicon and boron in the cermet grade obtained with the matrix from the alloy H77X15C3P2 did not reduce the loss of carbon in the coating. The microhardness of the obtained coatings, measured with a load on the indenter of 20 g, is 19-65% higher than the microhardness of the particles of the sprayed powders. The highest values of microhardness, 16.34 GPa, were obtained in a cermet coating sprayed from a powder with an additional carbon content of 45.23 TiC-52.39 10P6M5-2.39 C.