R and distilled water had been performed using the DLN films (on Si substrate) of 2.4 thickness and higher hardness H = 28 GPa and elastic modulus E = 182 GPa, Amylmetacresol Purity sliding against 100Cr6-steel (H = eight GPa, E = 210 GPa) and Si3 N4 (H = 15 GPa, E = 310 GPa) balls of 6 mm-diameter. The usage of the steel and ceramic balls was aimed at investigating the SB 204741 site friction pair-dependent tribological behavior with the Coatings 2021, 11, x FOR PEER Evaluation six of 16 difficult DLN films beneath water lubrication and specifics of the corrosive impact for DLN-steel tribological contacts which was not discussed in the early studies [8,9] of DLN films in water environment. The friction behavior on the DLN films throughout sliding in humid air and beneath water The friction behavior in the DLN films in the course of sliding in humid air and beneath water is shown in Figure two. For the load F = 0.five N and ball radius Rb = 3 mm, the mean make contact with is shown in Figure two. For the load = 0.five b = 3 mm, the mean make contact with stress (P), estimated from Hertz theory relationships [36], amounts to P = 0.35 GPa and pressure (P), estimated = 0.35 GPa and 0.37 GPa for the DLN-steel 0.37 GPa for the DLN-steel and DLN-Si3N44contacts in the starting of sliding. As follows 3 N contacts in the beginning of sliding. As follows from Figure 2, the average values of coefficient ( v in humid air are almost from Figure 2, the average values from the friction coefficient (av)) in humid air are almost precisely the same for the two friction pairs: = 0.065 for for the DLN-steel and 0.07 for the DLNthe exact same for the two friction pairs: av v = 0.065 the DLN-steel and av = v = 0.07 for the DLN-Si3 N4 . water water lubrication the friction coefficient increases to 0.14 0.14 for fricSi3N4. Under Below lubrication the friction coefficient increases to av = v =for both both friction pairs. Some friction instabilities throughout sliding water look to be triggered by water tion pairs. Some friction instabilities through sliding inin water appear to becaused by water evaporation and varying thickness from the water layer. The comparative information in the wear evaporation and varying thickness on the water layer. The comparative information in the wear tracks profiles and wear scars images are tracks profiles and put on scars photos are shown in Figure 3.Figure two. Friction performance on the DLN films during sliding against 100Cr6 steel and Si N4 balls Figure 2. Friction efficiency in the DLN films throughout sliding against 100Cr6 steel and Si3N4 balls in ambient air (RH = 50 ) and distilled water; the load 0.5 N, the sliding speed five cm/s. in ambient air (RH = 50 ) and distilled water; the load 0.five N, the sliding speed 5 cm/s.Coatings 2021, 11,six ofFigure two. Friction performance of your DLN films during sliding against 100Cr6 steel and Si3N4 balls in ambient air (RH = 50 ) and distilled water; the load 0.5 N, the sliding speed five cm/s.Figure three. WLI surface profiles across the put on tracks (a,d) and OM images on the wear scars (b,c,e,f) around the ball surface Figure 3. WLI surface profiles across the put on tracks (a,d) and OM photos from the wear scars (b,c,e,f) on the ball surface formed immediately after two 10cycles of Si3N4 ball (a ) and steel ball (d ) sliding around the DLN films in humid air and in water. formed soon after two 104 4 cycles of Si3 N4 ball (a ) and steel ball (d ) sliding on the DLN films in humid air and in water.Traits of the put on rates on the DLN film and ball surfaces in humid air and Qualities with the put on rates on the DLN film and ball surfaces in humid air and underwater are.
