Comparisons of Tribological Properties of Ti(C,N)/SiC in Water and Seawater

Ti(C,N)-based cermets offer good high temperature strength, perfect chemical stability, excellent wear resistance, and relatively better machinability. In the present work, the tribological behaviors of Ti(C,N)/SiC sliding pairs lubricated in water and seawater were evaluated using a ball-on-disk tribometer. The experimental results show that a relatively low friction coefficient (about 0.025) can be obtained when lubricated with artificial seawater at the sliding speed of 200 mm/s, while the friction coefficient is about 0.2 in purified water. The wear surface profiles and the lubricants collected after running-in process for the high and low friction conditions were compared. In addition, the effects of salt molar concentration of the lubricant on the Ti(C,N)/SiC friction properties were investigated. It was found that the smooth and flat surface is the premise to gain the low friction. At the same time, the proper concentration of silica colloid, which is affected by the salt ions, is also an essential one. Moreover, the high sliding speed (200 mm/s) is beneficial to achieve low friction.