Nano Serpentine Powders as Lubricant Additive: Tribological Behaviors and Self-Repairing Performance on Worn Surface

Abstract

Natural serpentine powders are applicable as additives for various lubricating oils. However, no uniform theories explain their tribological performance, lubrication, and wear mechanism, especially their self-repairing mechanism. Herein, the influence of different nano serpentine powders (NSPs) contents in liquid paraffin on the friction and wear characteristics of steel balls and the self-repairing process of NSPs on the worn surface were studied. Results show that the optimal amount of NSPs was 0.5 wt %. Relative to those of the base oil, the friction coefficients and wear spot diameters were reduced by 22.8% and 34.2%, respectively. Moreover, the long-term tribological test shows that the wear scar diameter decreased slightly after 3 h, reaching the state of dynamic balance between wear and repair. The outstanding tribological performance should be attributed to the formed bilayer tribofilm, the first layer of which contains nanoparticles surrounded by lubricants and the second layer of which contains nanoparticles compacted onto the surface of the steel ball.

Nano-Particles Additives as a Promising Trend in Tribology: A Review on their Fundamentals and Mechanisms on Friction and Wear Reduction

“…15 and 16. Also, material with rough surface sliding due observe nanoparticles deposit in troughs on the rubbing surface, thereby serve as medium of treating the surface 27,116) . Graphite nanomaterial was prepared and applied as additive in oil lubricating system, the result was so significant, but its preparation process was so challenging 13,112) .…”

“…However, mending operation and selfrepairing mechanism is not limited to accumulation of NPs on material element surfaces but also size of NPs, melting points attributes. Explaining this, at severe temperature beyond the added materials, the NPs melts or sintered in the wounded contact area, symotheniously turn to filler and repair the element working surface 27,69) . Carbon nanotubes (CNTs) and Carbon nanofibers (CNFs) observed infiltrate of small gaps between rough surfaces in contact 132) thus, forming self-lubricating thin films as shown in Fig.…”

Materials of biological origin and biofuels: Small environmental footprint and epigenetic impact (Review)

“…Additives provide lubricating oils with new useful properties, enhance their existing properties and improve product lifetime (41). Traditional additives include sulfonate, sulfide alkylphenols and dialkyl dithiophosphate, which cause detrimental environmental effects (42). Lubricants were also used to contain polychlorinated biphenyls (PCBs) up until the 1970s when they were banned; they functioned as endocrine disruptors which altered gene methylation and were shown to exert carcinogenic effects (43).…”

Water‐based Cu nanofluid as lubricant for steel hot rolling: Experimental investigation and molecular dynamics simulation

“…In addition to the formation of tribofilm, several other lubrication mechanisms of nanoparticles have been proposed by relevant scholars including rolling effect, 2,12 polishing effect, 5,13 self‐repairing effect 14 and interlayer sliding effect 15 . However, these mechanisms are mainly extrapolated from experimental results, which are lack direct evidence and theoretical support.…”