Friction and Wear Performance of Titanium Alloys against Tungsten Carbide under Dry Sliding and Water Lubrication

The friction and wear properties of titanium alloys TC4, TC18, and TA19 against tungsten carbide under both dry sliding and water-lubricated conditions were investigated using a ball-on-flat sliding friction apparatus under a load of 3 N and at a sliding speed of 112 mm/s. These investigated titanium alloys were observed by scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The results indicated that the kinetic friction coefficients as a function of sliding time increased at the initial friction stage under dry conditions and vary within a small range under water-lubricated conditions. Furthermore, the coefficient of friction of the TA19/WC-Co tribopair was lower than that of both TC4/WC-Co and TC18/WC-Co tribopairs. However, under water-lubricated conditions, the friction coefficients and wear volume of both TC4/WC-Co and TA19/WC-Co tribopairs decreased obviously compared to that under dry conditions, and the abrasion resistance increased. On the other hand, the effect of water lubrication on the TC18/WC-Co tribopair was limited. The results showed that TC4, TC18, and TA19 alloys have different tribological behaviors and wear mechanisms when sliding against tungsten carbide under different friction conditions.