The in-flight modification of titanium carbide powders was carried out in radio-frequency (rf) inductively coupled plasmas. The powders were partially melted and evaporated, and then subjected to modifications in morphology, size, and chemical composition. Both the Ar–H2 and Ar–N2 plasma treatments induced the formation of carbon-site vacancies in titanium carbide. The mixing of NH3 to Ar–H2 plasma at the plasma tail, and the Ar–N2 plasma treatment resulted in the partial substitution of carbon by nitrogen. The variation in physical and chemical modification was discussed compared with the predictions by the thermochemical analysis, and the numerically obtained heat transfer of our preceding paper.