Effects of electrolyte composition and electrical parameter on titanium carbonitride films by plasma electrolytic carbonitriding of Ti₆Al₄V alloy

Porous nanocrystalline Ti(C_xN_1-x) films on a Ti₆Al₄V alloy surface were prepared in an electrolytic solution by plasma electrolytic carbonitriding (PECN) with a pulse power supply. The effects of electrolyte composition and electrical parameter on the morphologies and phase compositions of the modified layers were investigated. The results show that the increase of the formamide concentration in the electrolyte can favor the growth of the Ti(C_xN_1-x) films. The increase of potassium chloride can affect the permeation of hydrogen, leading to the formation of TiH₂. The applied voltage is a dominant effect on the electrical parameters. The decrease of the applied voltage and duty cycle or the increase of the pulse frequency could have a negative effect on the development of Ti(C_xN_1-x) films. The applied voltage of 600 V, the duty cycle of 40% and the pulse frequency of 100 Hz were determined as the optimal electrical parameters according to the experimental results.