Summarized in Figure four.four. The put on rate values will be the averaged values beneath water are summarized in Figure The put on rate values are the averaged values of of tribotests performed for each and every sliding situation. Essentially the most pronounced effect from the 22 tribotests performed for every sliding situation. The most pronouncedeffect in the aqueous environment on the put on behavior was observed Sulprostone Purity inside the sliding tests against the aqueous environment on the put on behavior was observed within the sliding tests against the Si3 N ball, as shown in Figure 3a . The wear on the DLN film below water lubrication is Si3N4 4 ball, as shown inFigure 3a . The wear from the DLN film under water lubrication is very low in comparison with the friction tests in humid air, as straight follows from comparison pretty low in comparison with the friction tests in humid air, as straight follows from comparison with the wear track profiles in Figure 3a. The wear rate of the DLN film below water lubrication amounts to W = 7.five 10-9 mm3 /(Nm), two orders of magnitude reduced than the wear rate W = 6.8 10-7 mm3 /(Nm) of the film in humid air, see Figure 4. Additionally, the wear price from the Si3 N4 ball beneath water lubrication, W = two.6 10-9 mm3 /(Nm), is considerably reduced than the wear price W = 3.eight 10-8 mm3 /(Nm) in ambient air. Having said that, the friction coefficient v = 0.14 is twice greater in water-lubricated sliding, as shown in Figure two. The observed inconsistency in between the higher friction and low wear performance below water lubrication and also the reduce friction and higher wear efficiency in humid air becomes understandable if the mechanism of friction in DLN films controlled by the transfer film formation [11,12] is taken into consideration. For hydrogenated DLC films, the presence of Zingiberene Autophagy graphitized transfer layers on the surface of counterface supplies is called a single of major factors to influence the frictional behavior on the coatings [37,38]. Below water lubrication, the formation from the graphitized transfer film (responsible for the low friction in ambient air) is difficult as a result of the incredibly low wear rate from the film surface, resulting in the elevated friction during sliding. Note, the COF values during sliding in water were reduced at higher loads [8,9], and strongly depended on the structure of Si-containing DLC films when tribochemical layers formation resulted in super low friction overall performance [39] (not observed in our experiments). In contrast to the DLN-Si3 N4 friction pair, the wear characteristics on the DLN-steel pair were not enhanced in water-lubricated sliding. The put on rates of the DLN film had been comparable in humid air and water environments: W = 5 10-7 mm3 /(Nm) and W = 4.8 10-7 mm3 /(Nm), respectively. The put on rate from the steel ball increased from the W = five.five 10-8 mm3 /(Nm) in humid air for the W = two.eight 10-7 mm3 /(Nm) below water, which was triggered by corrosion of steel referred to as a detrimental method for the DLC-steel contacts [40] in water environment. The observed friction and wear performance in the DLN films in water could be named superior in comparison with traditional a-C:H films which have been reported to become quickly removed from the substrate throughout water-lubricated tests [40]. Commonly, the obtained benefits have demonstrated theCoatings 2021, 11,wear rates of the DLN film had been comparable in humid air and water environments: W = five 10-7 mm3/(Nm) and W = four.eight 10-7 mm3/(Nm), respectively. The wear rate of the steel ball improved in the W = five.five 10-8 mm3/(Nm) in humid air towards the W = 2.8 10-7 mm3.