Combustion Synthesis of Cermets from Granular Mixtures Ti–C–NiCr for Protective Coatings.

The combustion modes of granular mixtures (100 – X)(Ti + C) + XNiCr, X = 0–30%, were studied. The experimental setup provided filtration of impurity gases released during combustion, either in the direction of propagation of the combustion front, or through the side surface of the sample. The comparison of burning velocities in different gas filtration schemes indicates the influence of convective heat transfer on the combustion patterns of mixtures with X < 30%. A method was proposed for determining the composition of the mixture in which the transition to the convective combustion mode occurs. The content of impurity gases in mixtures of different compositions was estimated quantitively. The comparison of experimental data with calculations based on the theory of filtration combustion showed that there is a conductive combustion mode for all mixtures of 0.6-mm granules and a mixture of 1.7-mm granules with X = 30%. XRD analysis of the synthesis products revealed no intermetallic phases, regardless of the size of the granules. [ABSTRACT FROM AUTHOR]