Abstract:Ti-DLC coatings were deposited on Si (100) wafer and M2 tool steel using unbalanced magnetron sputtering.The microstructure and morphologies of TiDLC coatings were analyzed and observed using Xray photoelectron spectroscopy,Raman spectroscopy and scanning electron microscope (SEM).The friction properties of Ti-DLC/Si3N4 tribopairs in water at different loads were investigated using ballondisk tribometer.The results show that Ti-DLC coatings have dense surface structure and many C-Csp2 bonds.The friction coefficient is first decreased,and then increased with the increasing of normal load.When the normal load reaches to a certain value,the value of friction coefficient is almost unchanged.The wear rate of the coatings is first increased and then decreased with the increasing of normal load,while that of balls exhibit the opposite rule,which is attributed to the easy tribohydration reaction of Si3N4 balls in water,and the contact surface becomes smooth,thus the friction coefficient and wear rate are reduced.