Synthesis, characterization and evaluation of titanium carbonitride surface layers with varying concentrations of carbon and nitrogen

Titanium carbonitride (TiCN) surface layers were grown by direct exposure of Ti to a gas mixture of ammonia and methane at 1050 degrees C. TiCxN1-x coatings with varying C/N ratio were synthesized by appropriately changing the content of methane and ammonia in the reactive gas mixture. The resultant layers were subjected to various characterization and evaluation techniques to study the variation of properties with respect to change in C/N ratio. A systematic change in lattice parameter and microstructure was observed as a function of the composition of active gas mixture. Friction coefficient of TiC was found to be extremely low (0.078). Reaction mechanisms for the growth of TiN and TiC were found to be entirely different. The effect of composition of the gas mixture on growth kinetics of TiCN is elucidated. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.