Cermet plasma coatings with TiC and TiCrC carbides

Abstract

Four plasma cermet coatings with similar compositions based on TiC carbide and NiCrMo matrices with additional Cr3C2, WC carbides, and carbon were studied. The average oxygen content for four cermets increases from 0.51 % for powders to 0.86 % for coatings with a minimum plasma power and does not increase with its increase. The maximum average nitrogen content in the coatings, 0.34 %, is determined by the nitrogen content in the plasma. When spraying coatings, the loss of carbon, relative to the initial powder composition, is 2.79 – 3.76 %, less than in the manufacture of powders for spraying 4.3 – 6.6 %. Carbides Cr3C2, WC, matrix elements and the content of additional carbon determine the formation of the annular zone around TiC carbide, increase the total carbide content in the coating from 60 to 74 – 83% and the microhardness of the coating is 18 GPa with an indenter load of 200 gf.