Gure 6b shows the lower COF values for the laser-textured surface, v= 0.085 at R = four.five mm and v = 0.081 (averaged more than two friction laser-textured surface, av = 0.085 at R = four.5 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 pictures from the wear Deoxycorticosterone Protocol tracks and surface 3-Methyl-2-oxovaleric acid Epigenetics profiles across the tracks, measured soon after removal of photos of the wear tracks and surface profiles across the tracks, measured after removal the the filmfilm with n-heptane,shown in Figure 7, which give information regarding concerning the of oil oil with n-heptane, are are shown in Figure 7, which give information and facts the wearwear character with the DLN film surface throughout lubricated sliding. The depth of the wear tracks on 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 difference of 10 nm within the track depth could possibly be as a consequence of (i) a thin layer of ablated material on the laser-texturedCoatings 2021, 11,9 ofcharacter of your DLN film surface for the duration of lubricated sliding. The depth on the put on tracks on the original film (Figure 7a,d) and laser-textured surface at R = 4.five mm (Figure 7b,d) is extremely small–dtr = 19 nm and dtr = 28 nm, respectively. The distinction of 10 nm in the track depth may be resulting from (i) a thin layer of ablated material on the laser-textured surface quickly removed in the track area through sliding [26], or (ii) slightly elevated put on due to protruding edges of microcraters. The width of each the tracks is about wtr = 48 , smaller sized than the estimated value from the get in touch with area diameter of 2Rcont 61 . The wear from the ball surface can also be quite smaller, that is pronounced in the appearance of individual scratches inside the put on scars surface much less discernible for the ball sliding around the original surface, as shown in Figure 8a,b. Below the observed low-wear prices of your film and ball counterparts the friction reduction around the laser-textured film (shown in Figure 6b) is as a result of lubricant film stress lift in the mixed lubrication regime of sliding, consistent with our earlier experiments together with the microcrater patterns of higher location density (20 and 40 ) and lubrication with synthetic motor oil of high viscosity [26]. Compared with all the previous outcomes [26], the influence of your comparatively smaller (ten ) dimpled location density around the lubricated friction performance with the fs-laser-textured DLN films appears significant, 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 each distinct application of laser-patterned DLC films.Figure 7. WLI pictures of the wear tracks Figure 7. WLI photos 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 = 4.5 mm immediately after lubricated sliding at T = 23 C, and (c) immediately after each of the successive textured surface at R = four.five mm right after lubricated sliding at T = 23 , and (c) soon after each of the successive lubricated sliding tests of the laser-textured film R = three mm and diverse temperatures; (d) surface lubricated sliding tests of your laser-textured film atat R = three mm and unique temperatures; (d) surface profiles across the tracks measured along the marked lines within the WLI images. profiles across the tracks measured along the marked line.