Synthesis and Characterization of Ti-C_x-N_1-x Coatings Prepared by Arc Ion Plating

Ternary Ti-Cx-N1-x coatings were deposited on stainless steel substrates by arc ion plating (AIP) technique using Ti target at the temperature of 300
with a negative substrate bias voltage of -25 V. The carbon content in Ti-Cx-N1-x coatings linearly increased with increasing CH4/(CH4+N2) gas flow ratio at a constant arc current of 60 A. The microstructure and mechanical properties such as micro-hardness and average friction coefficient of Ti-Cx-N1-x coatings were investigated as a function of carbon content. As the carbon content in Ti-Cx-N1-x coatings increased, the microhardness values of Ti-Cx-N1-x coatings increased from 20 GPa for TiN coatings and reached the maximum value of approximately 32 GPa at x=0.52 in Ti-Cx-N1-x coatings. The variation of microhardness of Ti-Cx-N1-x coatings had a relationship with the change of residual stress. The average friction coefficient of Ti-Cx-N1-x coatings largely decreased with increasing carbon content.