Effect of reactive gas composition on the microstructure, growth mechanism and friction coefficient of TiC overlayers

Titanium carbide overlayers were synthesized by gas phase carburization of titanium at 1150 degrees C with varying reactive gas compositions and durations. These layers were investigated by X-ray diffraction, tribometry, Raman spectroscopy and scanning electron microscopy. Titanium carbide layers exhibited very low coefficient of friction due to the presence of amorphous carbon on the surface. The growth mechanism and the surface microstructure of the layers showed a critical dependence on methane content in the reactive gas mixture. (C) 2011 Elsevier Ltd. All rights reserved.