Titanium carbonitride fabricated by spark plasma sintering: Is it a ceramic model of carbon-induced Friedel-Fleisher strengthening effect?

Abstract This work is devoted to the analysis of the composition, microstructure and room-temperature mechanical properties of a carbonitride ceramics: the case of Ti(C,N) ceramics fabricated by spark plasma sintering (SPS). Particular attention has been given to know whether there is a possible composition change under electric field, finding all the computed lattice parameters of SPS-ed TiN1-xCx ceramics lay within tiny interval (∼TiC0.43N0.57), hence following Vegard’s law. The analysis of the strengthening effect of substitutional carbon, making use of our own results and those available in literature shows that a classical x1/2 dependence could account for experimental data. This fact reveals that a Friedel-Fleisher mode of strong localized carbon pinning points might describe the hardening effect of those impurities. However, the large scattering of experimental data and the fact that tiny deviations of stoichiometry might play a relevant role on the hardening force us to leave this as an open problem.