Tribochemical investigation of Cr-doped diamond-like carbon with a MoDTC-containing engine oil under boundary lubricated condition

Synergistic Effect of Acrylate of Dialkyl Dithiophosphoric Acid Combined with Molybdenum Dialkyl Dithiocarbamate as Additives in Gear Oil

“…As shown in Figure 9, the friction film formation on the worn surface was further studied using EDS. As can be seen from Figure 9b, there are a small amount of Mo and S elements on the worn surface of BM, which can correspond to the formation of the MoS2 lubrication film [18][19][20][21]. This layer of lubrication film can inhibit the oxidation of iron on the worn surface, leading to a significant reduction in O content, compared with Figure 9a.…”

“…BMA shows the most superior antiwear performance and WSD decreases by 29.09% compared with BO. As can be seen from Figure 4, the synthesized ADDP has a strong polar group carboxyl group at the molecular end, which will not only form a chemical reaction film to protect the surface of the friction pair, but also bring certain corrosion and wear, while the MoS 2 tribochemical film [18][19][20][21] formed by the decomposition of MoDTC on the surface of the friction pair may prevent the contact between polar groups and the metal surface of the friction pair. Thus, the corrosion of ADDP on the worn surface is alleviated, the WSD of BMA decreases by 5.00% compared with BA, and the antiwear performance of the gear oil is further slightly improved.…”

“…Molybdenum dithiocarbamate (MoDTC) is a typical friction modifier. It can decompose to form a tribochemical film containing MoS 2 on the worn surface, which can effectively reduce friction and wear between friction pairs [18][19][20][21]. However, with the development trend of low-viscosity gear oil, the range of hybrid lubrication and boundary lubrication is constantly expanding in the operation of mechanical systems [22,23], making it increasingly difficult to use MoDTC alone, to meet the needs of high-performance gear oil.…”

Tribocatalytic Reaction Enabled by TiO2 Nanoparticle for MoDTC-Derived Tribofilm Formation at ta-C/Steel Contact

“…However, with an addition amount of 2.5 wt.%, the friction increased to 0.063 and fluctuated unstably. It is known that the chemical reaction of MoDTC deteriorates the wear of DLC [9]; therefore, the wear of ta-C was measured, as shown in Figure 4b. As a result, a similar wear rate was observed even when the amount of a-TDONPs was The friction performance of TDONPs was evaluated using a ball-on-disk-type tribometer and tribotests were repeated at least 3 times to assure reliability.…”

“…Its chemical stability avoids surface damage in extreme operating environments (e.g., acid-base and high-temperature), but at the same time makes it difficult to react and form triboproducts. As a way to solve this problem, metal-doped DLCs (Me-DLCs) have been studied to increase the reactivity with additives [7][8][9]. There is a trade-off relationship between the improved lubricity due to the formation of additive-derived tribofilm at the cost of reduced hardness and worse wear resistance; therefore, we need to find a way to solve the technical limitations of these conflicting friction and wear characteristics.…”