Titanium carbonitride coating by pulsed electrical discharge in an aqueous solution of ethanolamine

Titanium carbonitride (TiCN) coating is prepared by electrical discharge machining using a titanium tool electrode and a carbon and nitrogen containing dielectric media of ethanolamine. The composition, morphology and microstructure of the TiCN coating are characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, electron probe micro-analyzer and X-ray photoelectron spectroscopy. Its microhardness and interfacial adhesion strength against 45# carbon steel substrate are also investigated. The results reveal that a 15 μm thick layer mainly composing of TiC0.3N0.7 phase with fine-grain structure is created and it metallurgically bonds with the steel substrate. Such unique microstructure results in an improved hardness of 1780 HV and bonding strength of TiCN coating is 4 times higher than TiN coating obtained by magnetron sputtering.