Mohamed Kamal Ahmed Ali,Qiangliang Yu,Feng Zhou,Bin Li,Chaoyang Zhang
Wear is one of the most important factors limiting mechanical components' lifespan and durability. In this study, a novel, AISI 4140-Ag steel-based, self-lubricating nanocomposite was manufactured by the spark plasma sintering (SPS) technique. The high-level aim of this investigation is to obtain a deeper understanding of how silver (Ag) at the nanoscale can enhance the self-lubricating layer's replenishment, which aids in maintaining a steady supply of solid lubricant under dry conditions. Tribological experiments were conducted under various loads (30–150 N) at 5 Hz frequency and 300 °C temperature using a Rtec Universal Tribometer (ball-on-disc setup). After that, advanced surface characterization techniques were utilized to illustrate predominant wear modes, lubrication mechanisms , and the chemical identity of the self-lubrication layer. Noticeably, the AISI 4140-Ag nanocomposite reduced the friction coefficient and wear rate by 36.16–51.14 % and 93.40–97.36 %, respectively, compared to the AISI 4140 composite. The excellent self-lubricating performance is mainly attributed to the replenishment of a self-lubricating layer on the substrate material and a transfer layer on the counterbody, composed of AgO and Fe 2 O 3 . The results of our study hold considerable promise for the advancement of self-lubricating composites and the enhancement of their durability in mechanical applications.
Hybrids of fluorinated graphite/MoS2(FGr@MoS2) were prepared via a hydrothermal method and used as lubricating additives to take full advantage of the synergy between FGr and MoS2in carbon-fiber-reinforced polymer (CFRP). The results show a 21.6% reduction in the friction coefficient compared to the neat sample when the CFRP was filled with 1.2 wt.% FGr@MoS2hybrids. The addition of 1.5 wt.% FGr@MoS2resulted in a 60.9% reduction in the wear rate compared to neat CFRP. For the 1.2 wt.% FGr@MoS2-reinforced CFRP, the friction coefficient maintained a relatively steady value of approximately 0.46 at various temperatures, indicating frictional stability. However, the wear rate increased by 13.95% at 60 °C compared to that at room temperature. The interfacial bonding force between the FGr@MoS2hybrid and the matrix, as well as the adhesive force with the surface of the counterpart ball, is improved, caused by the heterostructure of FGr@MoS2, resulting in enhanced mechanical properties and formation efficiency as well as the transfer film on the surface of the counterpart ball. The results suggest that an FGr@MoS2micro-nano structure is a promising additive to be applied in polymer tribology.Keywords:CFRP;FGr@MoS2hybrid;dry sliding;self-lubricating;temperature