Gure 6b shows the reduce COF values for the laser-textured surface, v= 0.085 at

April 13, 2022

Gure 6b shows the reduce COF values for the laser-textured surface, v= 0.085 at R = four.five mm and v = 0.081 (averaged over two friction laser-textured surface, av = 0.085 at R = four.five mm and av = 0.081 (averaged over two friction tests) at R = 33mm, than the friction coefficient v= 0.1 for the original film. The WLI tests) at R = mm, than the friction coefficient av = 0.1 for the original film. The WLI photos of the wear tracks and Varespladib supplier surface Trolox Reactive Oxygen Species profiles across the tracks, measured right after removal of photos of the put on tracks and surface profiles across the tracks, measured soon after removal the the filmfilm with n-heptane,shown in Figure 7, which give information about regarding the of oil oil with n-heptane, are are shown in Figure 7, which give data the wearwear character of the DLN film surface for the duration of lubricated sliding. The depth of the put on tracks around the original film (Figure 7a,d) and laser-textured surface at R = 4.five mm (Figure 7b,d) is very small–dtr = 19 nm and dtr = 28 nm, respectively. The distinction of 10 nm in the track depth may be due to (i) a thin layer of ablated material around the laser-texturedCoatings 2021, 11,9 ofcharacter in the DLN film surface throughout lubricated sliding. The depth on the put on tracks on the original film (Figure 7a,d) and laser-textured surface at R = four.5 mm (Figure 7b,d) is extremely small–dtr = 19 nm and dtr = 28 nm, respectively. The difference of ten nm within the track depth could possibly be because of (i) a thin layer of ablated material around the laser-textured surface simply removed in the track region throughout sliding [26], or (ii) slightly elevated wear due to protruding edges of microcraters. The width of both the tracks is about wtr = 48 , smaller sized than the estimated value from the speak to area diameter of 2Rcont 61 . The wear from the ball surface is also really little, which can be pronounced in the look of person scratches in the wear scars surface significantly less discernible for the ball sliding on the original surface, as shown in Figure 8a,b. Below the observed low-wear prices on the film and ball counterparts the friction reduction on the laser-textured film (shown in Figure 6b) is as a result of lubricant film stress lift inside the mixed lubrication regime of sliding, consistent with our earlier experiments together with the microcrater patterns of greater location density (20 and 40 ) and lubrication with synthetic motor oil of high viscosity [26]. Compared together with the previous final results [26], the influence from the comparatively little (ten ) dimpled region density around the lubricated friction overall performance with the fs-laser-textured DLN films appears considerable, Coatings 2021, 11, x FOR PEER Critique 10 of 16 implying that the texture optimization is required for any provided tribosystem made use of and for every specific application of laser-patterned DLC films.Figure 7. WLI photos of your wear tracks Figure 7. WLI pictures of your wear tracks formed on (a) the original film at R = 7 mm and (b) laseroriginal film at R = 7 mm and (b) lasertextured surface at R = four.five mm right after lubricated sliding at T = 23 C, and (c) right after all of the successive textured surface at R = four.5 mm right after lubricated sliding at T = 23 , and (c) soon after each of the successive lubricated sliding tests in the laser-textured film R = 3 mm and diverse temperatures; (d) surface lubricated sliding tests in the laser-textured film atat R = 3 mm and various temperatures; (d) surface profiles across the tracks measured along the marked lines inside the WLI pictures. profiles across the tracks measured along the marked line.