Pulse laser-induced cell-like texture on surface of titanium alloy for tribological properties improvement

In order to improve the surface tribological properties of TC4 titanium alloy , this paper used laser processing technology to prepare a cell-like texture on TC4 surface. The cells of cell-like texture were separated by regular cracks caused by recasting of TC4, which could be got at the parameters of 1 μm distance of adjacent laser spots and 2.5 μm patch of adjacent laser paths with a certain laser power density . The laser treatment increased the surface microhardness from 351 to 445 HV. The relationship between tribological properties of TC4 and the laser power density was studied. At 0.32 GW/cm 2 , under the lubricant of simulated body fluid (SBF), the average friction coefficient between TC4 and UHMWPE reduced significantly by 32.4%, and the wear rate of UHMWPE ball decreased by 59%, compared with the original surface. The cell-like texture could increase the transmission speed of the lubricant at the friction interface by three times with the help of capillary force , and it could also store lubricant in the texture to improve the tribological performance . The channels around cells were assumed to be rectangular groove. The width of the channel which was observed with a 3D confocal microscope was 3.2 μm, and the capillary force produced by a single rectangular groove was calculated.